JPH02157051A - Monitoring and predicting system for mill ball wear state - Google Patents

Abstract

PURPOSE:To permit a systimatic control of mill balls with a high degree of efficiency by monitoring and analyzing the operation state of a mill on the view point of the quantities of the state of current power plant to quantitatively grasp the abrasion loss of the mill balls, monitoring the wear state thereof and grasping and predicting the wear tendency. CONSTITUTION:An input means 6 inputs various quantities of state in a power plant 2, a mill operation state collecting means 7 collects the mill operation state from the quantities of state in the aforesaid plant, a mill ball wear calculating means 8 calculates the abrasion loss of the mill balls using the data obtained from the means 7 and the inherent coefficient of the wear of the coal in current use inputted by the operator. A mill ball state memory means 9 grasps the current state of the mill balls and stores the transitional state thereof from the supplementary quantity of the mill balls, the initial information of the power plant or each information required to be indicated in a display means and the results obtained by the means 8, a wear prediction means 1 estimates the future state of the mill balls from the information on the transitional state thereof obtained by the means 9 and a display means 11 displays such prediction on a CRT display device 4.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention monitors and predicts the wear amount of mill balls of a tube mill that crushes and pulverizes fuel coal for thermal power generation plan 1. Regarding a mill ball wear condition monitoring and prediction system.

(Prior Art) Coal is finely pulverized in a mill by the pulverizing action of mill balls. These mill balls wear out as the mill operates over time, which reduces the grinding efficiency of the mill, and it becomes necessary to replenish worn mill balls with new ones. In conventional mills, the efficiency of the mill is monitored to determine when this replenishment is required, and if the efficiency drops below a certain level.

An appropriate amount of new mill balls was replenished based on the operator's judgment. Furthermore, the amount of new mill balls to be replenished at this time is determined by internal verification by disassembling the mill and measuring the mass of the mill balls, or by the operator's empirical judgment.

(Problem to be Solved by the Invention) In the conventional method of determining the amount of mill ball replenishment, internal verification by disassembling and inspecting the mill not only takes a great deal of time and effort, but also requires stopping the operation of the mill during this time. There was a problem that it had to be done.

In addition, when the operator makes an empirical judgment, the basis for the judgment is inaccurate, so there is a problem that the judgment made is often inaccurate.

Therefore, the present invention quantitatively grasps the amount of wear of the mill balls by monitoring and analyzing the operating state of the mill from the current plant state quantities, and thereby monitors the condition of the mill balls and determines the tendency of wear of the mill balls. A mill ball wear state monitoring and prediction system 11 that can grasp and predict the wear tendency of mill balls in the future.
The purpose is to provide

[Structure of the Invention] (Means for Solving the Problems) The mill ball wear state monitoring and prediction system of the present invention is applied to thermal power generation plans 1 to 1 which use pulverized fuel coal. The means inputs various state quantities of the power generation plant, the mill operation state analysis means aggregates the mill operation state from the state quantities for the plan 1, and the mill ball wear amount calculation means calculates the mill operation state The wear amount of the mill ball is calculated using the yearly data obtained by the means and the unique wear coefficient of the coal used inputted by the operator, and the mill ball state storage means calculates the amount of mill ball replenishment inputted by the operator, The current state of the mill ball is grasped from the power generation plant initialization information or each information requested to be displayed on the display device and the calculation result by the mill ball wear amount calculation means, and the transition of this mill ball state is stored, and the mill ball wear prediction means is used. Then, the future state of the mill ball is predicted from the stored information of the shift of the mill ball state obtained by the mill ball state storage means,
The display means combines the stored information on the transition of the mill ball state with the predicted information on the future state and displays this on a CRT display device.

(Function) The mill ball wear amount can be calculated based on the type of coal used in the mill, or the condition based on the difference in mills can be memorized, so the condition of the mill balls and the predicted wear amount state of the mill balls can be displayed on the display device. be able to.

(Example) First, before describing specific examples of the present invention, the wear coefficient of mill balls will be described.

We will collect data on mill operation from the current state of the plant, extract and analyze the factors that are directly involved in mill ball wear, and quantitatively understand the amount of mill ball wear.

The following three terms are determined as factors for this mill ball wear, and the amount of wear of the mill balls is quantitatively determined.

(a) Abrasion due to coal feeding amount This is the amount of wear of the mill ball with respect to the mass of coal pulverized by the mill, and since there is a proportional relationship between these, the following formula holds true.

Dl-αX... (1) Dl・Wear amount α due to coal feed amount α... Wear coefficient X depending on coal feed amount X... Coal feed amount Here, wear coefficient α due to coal feed amount is the This value varies depending on the type of coal and is determined by the pulverization properties specific to the type of coal. The better the pulverizability of coal is, the smaller the value of the abrasion coefficient α becomes, and the worse the pulverizability of coal is, the larger the value of the abrasion coefficient α becomes. Regarding the exact relationship between these wear coefficients α,
Determined by experimental method.

(b) Wear due to mill operating time Wear of the mill balls occurs constantly when the mill is operated regardless of the presence or absence of coal feeding, and since the mill operating time and the amount of wear of the mill balls are proportional, the following equation is It works.

D2=βT (2) D2...Amount of wear due to operating time β...Abrasion coefficient due to operating time T...Operating time Here, the wear coefficient β due to mill operating time is a value determined by the model of the mill. , which is determined by an experimental method.

(c) Wear caused by the number of times the mill starts and stops Warming up and cooling down of the mill causes wear that is unique to when the mill starts and stops. Since this amount of wear is proportional to the number of times of starting and stopping, the following formula holds true.

D3-γZ... (3) D3... Wear γ due to starting and stopping... Wear coefficient due to the number of starting and stopping 2... Number of starting and stopping Here, the wear coefficient γ due to the number of starting and stopping is a value determined by the model of the mill. and is determined by the experimental r-method.

The wear fiD of the mill balls associated with the operation of the mill is the sum of the wear amounts due to the above factors, so it can be calculated using the following formula % Formula % D Mill ball wear amount Next, referring to FIGS. 1 to 3, the present invention An example of this will be described in detail.

FIG. 1 is a block diagram of a mill ball wear state monitoring and prediction system 1 according to the present invention. The mill ball wear state monitoring and prediction system of the present invention calculates the amount of mill ball wear based on the signal input from the power generation plant 2,
Based on the calculation results, the wear state of the mill balls is monitored and the future state is predicted. Using the operator console 3 that can interact with the mill ball wear state monitoring and prediction system 1, the operator can calculate the wear coefficient of the mill balls, ■, and the mill ball replenishment amount K.
, requests display, and inputs initialization information M.

The CRT display device 4 displays the mill ball wear condition monitoring and prediction system 1 according to instructions from the operator via the operator console 3.
Displays information generated by mill ball wear conditions, future predictions, etc.

Mill ball wear status can be monitored using operator console 3.
The process is started by initialization information M input via the operator input means 5 from . After starting monitoring of the wear state of the mill balls, a plant signal A indicating the operating state of each mill and the amount of coal fed is constantly inputted from the power generation plant 2 to the input means 6. The operation status signal is ON when the mill is in operation and OFF when the mill is stopped, and the coal feeding amount signal indicates the amount of coal feeding by the magnitude of current or voltage. Input means 6 receiving these plant signals A converts these signals into plant state quantities B which are engineering unit values that can be understood by mill operation state aggregation means 7 , and converts these signals into mill operation state aggregation means 7 . Always outputs to.

Here, the details of how the mill operation state totaling means 7 totalizes the mill operation state from the plan 1-state quantity B will be explained with reference to the block diagram shown in FIG. 2.

In FIG. 2, there are two types of plant status jfLB that are input to the mill operation status aggregation means 7: coal feeding IB1 and mill start/stop signal B2.

First, the coal feeding amount integration means 71 into which the coal feeding amount B1 is inputted,
The amount of coal fed within a certain period of time is integrated to generate the total amount of coal fed within a certain period of time C1.

On the other hand, the mill start/stop signal B2 is input to both the mill start/stop count integrating means 72 and the mill operating time integrating means 73. The mill start/stop signal B2 is a signal that is generated every time a mill starts and stops in the plant, and the mill start/stop frequency accumulating means 72 calculates the number of times this signal is generated within a certain period of time, that is, the start and stop of the mill. The number of times C2 of starting and stopping the mill within a certain period of time is generated. Further, the mill operation time accumulating means 73 has a clock for accumulating the elapsed amount of time. The mill operation time accumulating means C3 generates the mill operation time C3 as the total operation time of the mill within a fixed time.

Here, the constant time in each of the integration means 71 to 73 is the same, and in this embodiment is one day (ie, 24 hours).

In each of the integrating means 71 to 73, the total coal feeding IC1, the number of mill start/stop times 02, and the mill operating time C3, which are accumulated within a certain period of time and generated at the same time, are used as mill operating state data C at the same time as they are generated. The state aggregation means 7 outputs the information to the mill ball wear amount calculation means 8.

Moreover, at the same time as the output, in each integration means 7] to 73,
The generated data is completely lost in each of the integrating means 71 to 73, and the generation of the next integrated data is restarted from zero. The mill operation state aggregating means 7 repeats these series of operations for a fixed period of time, that is, in this embodiment, every 24 hours.

On the other hand, in FIG. 1, the operator input means 5 sorts the operator input information (2) from the operator console 3 according to its type, and outputs the information in an appropriate format for each destination. There are four types of information to be output as described below.

The wear coefficient J is required for calculating the mill ball wear amount and is output to the mill ball wear amount calculation means 8.

The wear coefficient J is a value determined depending on the type of coal used, and is input from the operator console 3 every time the type of coal used in the plan is changed.

The mill ball replenishment amount is output to the mill ball state storage means 9. The mill ball replenishment amount is the weight of mill balls actually replenished during mill maintenance.
This information is input from the operator console 3 every time mill balls are replenished.

The display request is output to the mill ball state storage means 9. The display request is a command for causing the CRT display device 4 to display various types of information generated and stored in this system.

The initialization information M is output to the mill ball state storage means 9. The initialization information M is a command to erase all information generated and stored in this system, initialize the system, and restart the system from its initial state.

Next, the mill ball wear amount calculation means 8 calculates the mill ball wear ID based on the mill operation state data C output from the mill operation state aggregation means 7. The calculation of the mill ball wear amount will be explained in detail with reference to FIG. 2 again.

First, the wear coefficient J is input into the wear coefficient storage means 81.

The wear coefficient storage means 81 stores this and outputs this stored content to the wear amount calculation 82 based on the amount of coal fed at the time of lit. Further, the wear coefficient storage means 81 updates its memory every time a new wear coefficient J is input.

Next, the mill operating state summary data C input into the mill ball wear amount calculating means 8 includes the coal feed amount integrated value C1, the number of mill start/stop times C2, and the mill operating time C3.

The coal feed amount integrated value C1 is calculated by the wear amount R4 calculation means 8 based on the coal feed amount.
2 is input. The wear amount calculation means 82 based on the coal feeding amount is
Together with the wear coefficient J, the amount of wear D1 based on the amount of coal fed is calculated, and this is output to the summation means 83.

The number of mill start-stops C2 is input to the wear amount calculation means 84 based on the number of starts and stops, and the wear amount calculation means 84 based on the number of starts and stops calculates the wear amount D2 depending on the number of starts and stops.
This is output to the summation means 83.

The mill operating time C3 is determined by the wear amount calculation means 8 based on operating time.
5, and the wear amount calculation means 85 based on operating time is
This calculates the amount of wear D3 depending on the operating time, and outputs this to the summation means 83.

The summation means 83 receives the three calculated values DI to D3, sums them all up, and outputs the sum as a mill ball wear measurement.

Next, in FIG. 1, the mill ball wear amount D indicated by the mill ball state storage means 9 and the mill ball replenishment amount inputted from the operator console 3 via the operator input means 5, and the initialization information M Integrate, organize, and memorize information obtained from The details of these operations will be explained according to FIG.

First, the mill ball replenishment iK is input into the mill ball replenishment amount accumulation storage means 91. The mill ball replenishment amount integration storage means 91 stores this information and integrates it every time a new input is made. and.

A positive sign is added to the currently stored value and this is outputted to the summation a1 means 92 as the mill ball replenishment amount integrated value N.

Of the initialization information M, the mill ball initial mass M1 is input to the mill ball initial mass storage means 93, and the mill ball initial mass storage means 93 stores this. Further, the mill ball initial mass storage means 93 updates the stored mass content every time there is a new input, and always outputs the stored value with a positive sign added to the mill ball initial mass 0 to the summing means 92. .

The mill ball wear amount is input into the wear amount accumulation storage means 94. The wear amount accumulation storage means 94 stores this, and
This is accumulated each time a new input is made. Then, a negative sign is added to this integrated value, and this is outputted to the summation means 92 as the wear amount integrated value P.

When a display request is input, the wear amount accumulation storage means 94 adds a positive sign to the accumulated value at that time and outputs it as the wear amount accumulation value F1 of the mill ball wear prediction data F.

The data of each output so far, the mill ball replenishment amount integrated value N, the mill ball initial mass ○, and the wear amount integrated value P are all summed up and outputted as the mill ball mass Q to the mill ball mass history storage means 95. Here, each data is given a code, so the total subtraction is as follows.

Q= (10N) +(+O) +(-P)... (5
) Q... Mill ball mass N... Mill ball replenishment amount integrated value 0 - Mill ball initial mass P... Wear amount integrated value Mill ball quality iQ Mill ball mass history storage means 9
5 memorizes this in chronological order.

This stored data is output as mill ball mass layer data E when a display request is input. At the same time, the latest stored value at that time is output as the mill ball mass current value F3 of the mill ball wear prediction data F.

The elapsed days accumulating means 96 is a clock that accumulates the number of days required for wear of the mill ball, and upon input of the display request L, the accumulated value is calculated as the elapsed number of days in the mill ball wear prediction data F. Output as code 2.

Finally, the initialization information M consists of a mill ball initial mass M1 and a memory erasing command M2, where the mill ball initial mass M1 is the total mass of the mill balls actually measured at the time of disassembly and inspection of the mill, and a memory erasing command M2 is a signal generated along with the input of M1. Therefore, the initialization information M is input to this system when the mill is disassembled and inspected, and the mill ball initial mass M1 is input to the mill ball initial mass storage means 93 to update the stored contents. Further, the memory erasing command M2 is inputted to the mill ball replenishment amount accumulation storage means 91, the wear amount accumulation storage means 94, the elapsed opening number accumulation means 96, and the mill ball mass calendar storage means 95, and erases all the memories in each means.

In FIG. 1, mill ball wear prediction data F from mill ball state storage means 9 is input to mill ball wear prediction means 10. As shown in FIG. In the mill ball wear prediction means 10,
The wear of the mill ball is predicted by the following calculation.

fc=F3-Fb ・ ・ ・ (7) fa fa However, Fl...Cumulative wear value F2/Number of days elapsed F3...Current mill ball mass fa...--Average daily wear amount fb...Mill ball Usable minimum mass fc-
・Remaining usable mass fd ・Remaining days Here, the minimum usable mass fb of the mill ball is:
This is the minimum mass of the mill ball required for operation of the mill, and is set and stored in advance in the mill ball wear prediction means 10.

From the above calculation results, the usable remaining mass and remaining days are outputted to the display means 11 as mill ball wear prediction data G.

In FIG. 1, millpole mass history data E is obtained from each of the millball state storage means 9 and the millball wear prediction means 10.
and display means 1 into which mill ball wear prediction data G is input.
1 converts these data and display information H into display information H, and displays the graph on the CRT display device 4.

An example of a graph display is shown in FIG. In FIG. 4, the vertical axis of the graph represents the mass of the mill balls, and the horizontal axis represents the date.

In the figure, point a is the initial mass of the mill ball, point b is the current value at 3°, which is the starting point for monitoring the condition of the mill ball in this system, and d represents the change due to replenishment of the mill ball. The graph from the starting point a through the intermediate transition d to the current point is based on the mill ball mass layer data from the mill ball state storage means 9.

Next, the 0 point is the predicted point C calculated by the mill ball wear prediction means, which is based on the graph Q from the current value to the predicted point C, and the mill ball wear prediction data G from the mill ball wear prediction means 10. It is.

[Effects of the Invention] According to the present invention, the wear state of the mill balls can be quantitatively grasped at all times, so when it is necessary to replenish the mill balls, the amount of replenishment can be determined more easily than in the conventional method.
It becomes possible to obtain a more accurate replenishment amount. moreover,
Since disassembling and inspecting the mill is not required when determining the replenishment amount, it is possible to suspend mill operation and, in turn, plan 1-
There is no need to interrupt operation.

In addition, according to the present invention, it is possible to understand the tendency of wear of mill balls and predict the future, so it is possible to know when maintenance such as replenishment of mill balls is required, and thereby to prevent low efficiency of the mill. Since it is possible to take measures in advance, it is possible to perform more planned and highly efficient management of mill operations, such as keeping the efficiency of the mill always above a certain level.
Becomes M-noh.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2 and 3 are detailed explanatory diagrams of the block diagram in FIG.
The figure shows an explanatory diagram of a graphical display output obtained by an embodiment of the present invention. 1. Mill ball wear condition monitoring and prediction system, 2...
Power generation plant, 6... Input means, 7... Mill operation status aggregation means, 8... Mill ball wear amount calculation means, 9...
Mill ball state storage means, 10. Mill ball wear prediction means, 11. Display means, 4. CRT display device, 3.
・Operator console, 5... Operator input means (7317) Agent Patent attorney Noriyuki Chika (
8869) Ken Daishimaru

Claims (1)

[Claims] In a thermal power plant that uses finely pulverized fuel coal, an input means for inputting a state quantity of the plant, a mill operation state aggregation means for aggregating a mill operation state from the state quantity of the plant, and a mill operation state aggregation means. a mill ball wear amount calculation means for calculating the amount of wear of the mill balls using the aggregated data obtained by the means; grasping the current state of the mill balls from various information input by the operator and calculation results by the mill ball wear amount calculation means; Further, a mill ball state storage means for storing the transition of the mill ball state, a mill ball wear prediction means for predicting the future state of the mill ball from the stored information of the transition of the mill ball state obtained by the mill ball state storage means; A mill ball wear state monitoring and prediction system comprising display means for displaying a combination of stored information on the transition of the mill ball state and predicted information on the future state on a display device.