CN115712284A - High-online-rate open type cement mill control system and method - Google Patents

Abstract

The invention discloses a high online rate open type cement mill control system and a method, comprising the following steps: a roll squeezer side loop data acquisition unit; a grinding side loop data acquisition unit; the prediction unit is used for inputting the operation data of the rolling machine side grinding side loop and the operation data of the grinding side loop into a trained prediction model to obtain the quality trend of the cement product a period of time after the current time point; the optimization unit is used for responding to the result output by the prediction unit and is out of a preset threshold range, and determining the equipment control mode of the roller press side loop and the grinding side loop; a roller press side loop control unit; the grinding side loop control unit. By adopting the scheme, the automatic and stable control of the cement grinding system can be realized, so that the stability of the quality of cement products is ensured.

Description

High-online-rate open type cement mill control system and method

Technical Field

The invention belongs to the technical field of cement grinding operation systems, and particularly relates to a high-online-rate open type cement grinding control system and method.

Background

The cement grinding system is supplied by a cement grinding and allocating station, and the allocating station has four storehouses which are respectively used for storing clinker, limestone, gypsum and shale. The mixture from the cement grinding and blending station is discharged from the warehouse by a constant feeder according to the set proportion and the total feeding amount, and is conveyed to the cement grinding system by a mixture rubber belt conveyor. The top of the blending warehouse is provided with a bag dust collector, and the dust-containing gas in the warehouse and at each discharge point at the bottom of the warehouse is purified. An electromagnetic iron remover is arranged on the mixture rubber belt conveyor to remove iron pieces in the mixture, so that the roller press equipment in the grinding system is protected. The method is characterized in that a fly ash warehouse is arranged to store and measure fly ash, a Coriolis force scale is used for measuring the fly ash, and the measured fly ash is conveyed to a cement mill by an air conveying chute, a lifter and the like.

The cement grinding system is a typical process system with large hysteresis and coupling among multiple variables. During operation of a cement mill, the effect of any variable on other process variables must be considered when adjusting it. This also reflects the coupling between system variables from the side. For such a process system, conventional single-in single-out based PID loop control is insufficient. However, the adjustment depending on the experience of the operator often cannot ensure the smooth operation of the device due to the limitation of human factors, such as different experiences of the operator and different operation methods of the operator, and even the optimal operation of the cement mill system is not mentioned.

Disclosure of Invention

In order to solve the problem that the control of a process system has extremely high requirements on the experience of personnel due to the coupling among multiple variables in the existing cement grinding system process in the existing method, the invention provides the open type cement grinding mill control system and the open type cement grinding mill control method with high online rate, which can realize the automatic and stable control of the cement grinding system, thereby ensuring the stability of the quality of cement products.

The purpose of the invention is realized by the following technical scheme:

the invention provides a high online rate open type cement mill control system, comprising:

the system comprises a data acquisition unit of a side loop of the roller press, a data acquisition unit of the side loop of the roller press, a data acquisition unit of a side loop of the roller press and a data acquisition unit of a side loop of the roller press, wherein the data acquisition unit of the side loop of the roller press is used for acquiring the operation data of the side loop of the roller press;

the grinding side loop data acquisition unit is used for acquiring the operation data of the grinding side loop;

the prediction unit is used for inputting the operation data of the grinding side loop and the operation data of the grinding side loop of the rolling machine into a trained prediction model to obtain the quality trend of the cement product a period of time after the current time point;

an optimization unit for determining the equipment control mode of the roller press side loop and the grinding side loop in response to the result output by the prediction unit being outside a preset threshold range, so that the quality of the cement product a period of time after the current time point is within the preset threshold range;

the roll squeezer side loop control unit is used for controlling equipment of the roll squeezer side loop according to the equipment control mode output by the optimization unit;

and the grinding side loop control unit is used for controlling the equipment of the grinding side loop according to the equipment control mode output by the optimization unit.

This scheme passes through the data acquisition unit and gathers the operational data of roll squeezer side return circuit side and mill side return circuit side respectively, adopts the prediction model with training completion to predict the quality trend of cement product to realize the control of roll squeezer side return circuit side and mill side return circuit side equipment according to the prediction result, it need not rely on experienced technical staff to accomplish, and through feedback control technique, realizes the steady operation of equipment, guarantees the quality stability of cement product.

In one possible design, the prediction unit includes at least one of a state space model, a finite impulse response model, FIR, a transfer function model, and a convolutional neural network model.

In one possible design, the optimization unit determines the plant control of the roller press side and mill side circuits using a linear or non-linear program with constraints.

In one possible design, the roller press side loop data acquisition unit comprises roller press data acquisition equipment, V-shaped powder concentrator data acquisition equipment and cold air valve data acquisition equipment.

In one possible embodiment, the roller press data acquisition device comprises a roller press roll gap data acquisition unit.

In one possible design, the grinding side loop data acquisition unit comprises dynamic powder concentrator data acquisition equipment, a system fan data acquisition unit and tail grinding exhaust fan data acquisition equipment.

The second aspect of the invention provides a control method for a high online rate open type cement mill, which comprises the following steps:

adopting the operation data of a side grinding side loop of the roller press and the operation data of the side grinding loop;

inputting the running data of the side grinding side loop and the running data of the side grinding side loop of the roller press into the trained prediction model to obtain the quality trend of the cement product a period of time after the current time point;

in response to the result output by the prediction unit being outside a preset threshold range, determining a device control mode for the roller press side loop and the mill side loop, the control mode being such that the quality of the cement product a period of time after the current point in time is within the preset threshold range;

and respectively controlling equipment of the side loop and the grinding side loop of the roller press according to the control mode.

Compared with the prior art, the invention at least has the following advantages and beneficial effects:

the running data of the side loop side and the grinding side loop side of the roller press are respectively collected through the data collecting unit, the quality trend of a cement product is predicted by adopting a prediction model completed through training, the control of equipment on the side loop side and the grinding side loop side of the roller press is realized according to a prediction result, the control is completed without depending on experienced technicians, the stable running of the equipment is realized through a feedback control technology, and the quality stability of the cement product is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a raw material block diagram of the system of the present invention;

FIG. 2 is a flow chart of the method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In addition, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or orientations or positional relationships that the present invention is used to usually place, or orientations or positional relationships that are usually understood by those skilled in the art, which are merely for convenience of description and simplification of the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

As shown in fig. 1, a first aspect of the present invention provides a high on-line rate open type cement mill control system, comprising: the device comprises a roll squeezer side loop data acquisition unit, a grinding side loop data acquisition unit, a prediction unit, an optimization unit, a roll squeezer side loop control unit and a grinding side loop control unit.

The rolling machine side loop data acquisition unit is used for acquiring the operation data of a rolling machine side grinding side loop. The grinding side loop data acquisition unit is used for acquiring the operation data of the grinding side loop.

The cement mill system adopts a combined grinding system of a roller press and a ball mill. The system consists of two parts: one part is a roller press side closed loop, and the other part is a grinding side closed loop. On the return path side of the roller press, fine materials are sent to the side of the mill through a V-shaped powder concentrator, and coarse materials return to the roller press to be continuously extruded; and on the side of the grinding side loop, materials meeting the fineness requirement are sent into a finished product for dust collection through a powder concentrator (the rotating speed is adjustable), one part of the coarse materials is returned to the grinding machine, and the other part of the coarse materials is returned to the side of the roller press through a cold air valve. The roller press loop and the grinding loop are both closed-loop systems, namely self-balancing systems, only materials meeting the fineness requirement can enter a downstream flow through the powder concentrator, and coarse materials can circulate in the loops all the time. And the cold air valve can coordinate the load distribution conditions of the roller press loop and the grinding loop.

Based on this, roll squeezer side return circuit data acquisition unit includes roll squeezer data acquisition equipment, V type selection powder machine data acquisition equipment and cold blast valve data acquisition equipment. The data acquisition equipment of the roller press comprises a roller gap data acquisition unit of the roller press. The adjustment of the roll gap not only determines the working size of the roll squeezer, but also determines the load distribution between a roll squeezer loop and a grinding loop. The roll gap is reduced, the roll squeezer bears more load, and the mill bears less load; on the contrary, the wear side load increases. And the expert system optimizes roll gap control of the roll squeezer according to the load conditions of the roll squeezer and the mill, thereby optimizing the working efficiency of the system and reducing energy consumption. The fineness of the finished product materials is maintained by adjusting the rotating speed of the V-shaped powder selecting machine, the fineness control quality is improved, the quality fluctuation is reduced, and the fineness fine control of the cement finished product is realized. The cold air valve can coordinate the load distribution conditions of the roller press loop and the grinding loop to realize power cooperation.

The grinding side loop data acquisition unit comprises dynamic powder concentrator data acquisition equipment, a system fan data acquisition unit and grinding tail exhaust fan data acquisition equipment. The mill tail exhaust fan is mainly responsible for ventilation in the mill and maintaining the pressure difference in the mill. In the current operation, the adjustment of the baffle opening of the exhaust fan at the tail end of the mill is not related to the outlet pressure of the tail end of the mill (and the pressure measurement of the grinding head is not installed on the site, so that the pressure difference of the mill cannot be obtained). The expert system maintains the relative pressure of the mill system by using the mill tail exhaust fan, thereby ensuring the normal work of the mill. The system fan is mainly responsible for maintaining the pressure of the whole system and meets the technological requirements. In current operation, the rotational speed of the system fan is not associated with any process pressure. The expert system maintains the related pressure (such as the negative pressure at the outlet of the powder concentrator) by adjusting the rotating speed of the fan of the system, thereby ensuring the normal production of the system.

And the prediction unit is used for inputting the operation data of the grinding side loop and the operation data of the grinding side loop of the rolling machine into a trained prediction model to obtain the quality trend of the cement product after a period of time from the current time point. And the data acquired by the rolling machine side loop data acquisition unit and the rolling machine data acquisition unit are the equipment operation data at the same moment, and when the equipment operation data at the same moment are input into the trained prediction model, the prediction model outputs the quality trend of the finished cement of the cement grinding system for a period of time after the time point. Model predictive control is a multivariable advanced control technique that generates a mathematical model based on the behavior of previous program dynamics to predict the future behavior of the controlled program. Model prediction allows the calculation of optimal behavior under practical constraints, minimizing the error between actual and desired program behavior. In addition, a model can be used to calculate the optimum point for the operating point of the program and optimize process control. Model predictive control is particularly useful for complex dynamic process control with large hysteresis, and process control where several variables interact in the process. For the above-mentioned process, it is difficult to achieve precise control by using the conventional control method. The prediction model prediction unit comprises at least one of a state space model, a Finite Impulse Response (FIR) model, a transfer function model and a convolutional neural network model. The training data set of the prediction model based on the convolutional neural network needs to be consistent with the data of the rolling machine side loop data acquisition unit and the rolling machine data acquisition unit, and the more data of the data set, the more accurate the data prediction.

The optimization unit is used for responding the result output by the prediction unit to be out of a preset threshold range, and determining the equipment control mode of the roller press side loop and the grinding side loop so as to enable the quality of the cement product in a period of time after the current time point to be within the preset threshold range. The optimization unit adopts constrained linear programming or nonlinear programming by formulating an economic objective function to solve the operating condition for maximizing the economic benefit of the device and determine the equipment control modes of the roll squeezer side loop and the grinding side loop. To ensure that the device is propelled toward the optimal operating point for each control cycle.

Operators generally prefer to operate the plant over a large operating area, away from various constraints/constraints, so that smooth operation of the plant can be ensured. The optimal point for the device to operate is on various constraint boundaries, such as the area circled in red in the figure below. The optimization module finds the optimal operating point of the device through an optimization technology (linear programming with constraints or non-linear programming), and the device is stably operated at the optimal point through the model predictive control module, so that the economic benefit of an enterprise is maximized. The optimization operation is realized based on the improvement of control quality. Only if the fluctuation of the variable is reduced, the device can be operated on the boundary of the constraint condition (card edge operation), and the device operation can not be caused to fly out of the normal operation area due to large fluctuation, thereby threatening the safe production. Thus, the operation of the stabilization device is a prerequisite for optimal production.

And the roller press side loop control unit is used for controlling the equipment of the roller press side loop according to the equipment control mode output by the optimization unit. And the grinding side loop control unit is used for controlling the equipment of the grinding side loop according to the equipment control mode output by the optimization unit. The roll squeezer side loop control unit and the grinding side loop control unit are connected with the valve opening, the frequency converter rotating speed, the pressure point of the grinding head grinding tail, the temperature control, the pressure control, the roll gap control and other units in the loop, so as to realize the control of the valve opening, the frequency converter rotating speed, the pressure, the temperature, the pressure, the roll gap and the like of the grinding head grinding tail.

A second aspect of the present invention provides a method for controlling a high on-line rate open type cement mill, as shown in fig. 2, including the following steps S01 to S04.

S01, adopting operation data of a side grinding side loop of the roller press and operation data of the side grinding loop;

s02, inputting the operation data of the side grinding side loop and the operation data of the side grinding side loop of the roller press into a trained prediction model to obtain the quality trend of the cement product a period of time after the current time point;

s03, responding to the result output by the prediction unit out of a preset threshold range, determining equipment control modes of a roller press side loop and a grinding side loop, wherein the control modes can enable the quality of a cement product a period of time after the current time point to be within the preset threshold range;

and S04, respectively controlling equipment of the side loop and the grinding side loop of the roller press according to the control mode.

The specific implementation manner of each step in the method is described in detail in the first aspect, and is not described herein again.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof.

Claims (7)

1. The utility model provides a high online rate open type cement mill control system which characterized in that: the method comprises the following steps:

a data acquisition unit of a side loop of the rolling machine, the roll squeezer side loop data acquisition unit is used for acquiring the operation data of a roll squeezer side grinding side loop;

the grinding side loop data acquisition unit is used for acquiring the operation data of the grinding side loop;

the prediction unit is used for inputting the operation data of the grinding side loop and the operation data of the grinding side loop of the rolling machine into a trained prediction model to obtain the quality trend of the cement product a period of time after the current time point;

an optimization unit for determining the equipment control mode of the roller press side loop and the grinding side loop in response to the result output by the prediction unit being outside a preset threshold range, so that the quality of the cement product a period of time after the current time point is within the preset threshold range;

the roll squeezer side loop control unit is used for controlling equipment of the roll squeezer side loop according to the equipment control mode output by the optimization unit;

and the grinding side loop control unit is used for controlling the equipment of the grinding side loop according to the equipment control mode output by the optimization unit.

2. The high on-line rate open cement mill control system as claimed in claim 1, wherein: the prediction unit comprises at least one of a state space model, a Finite Impulse Response (FIR) model, a transfer function model and a convolutional neural network model.

3. The high on-line rate open cement mill control system according to claim 1, wherein: the optimization unit determines the equipment control mode of the roller press side loop and the grinding side loop by adopting a linear program with constraint or a nonlinear program.

4. The high on-line rate open cement mill control system as claimed in claim 1, wherein: the roller press side loop data acquisition unit comprises a roller press data acquisition device, a V-shaped powder concentrator data acquisition device and a cold air valve data acquisition device.

5. The high on-line rate open cement mill control system as claimed in claim 4, wherein: the data acquisition equipment of the roller press comprises a roller gap data acquisition unit of the roller press.

6. The open cement mill control system with high on-line rate according to claim 1, characterized in that: the grinding side loop data acquisition unit comprises dynamic powder concentrator data acquisition equipment, a system fan data acquisition unit and grinding tail exhaust fan data acquisition equipment.

7. A high online rate open type cement mill control method is characterized in that: the method comprises the following steps:

running data of a side grinding loop of the roller press and running data of the side grinding loop are acquired;

inputting the running data of the side grinding side loop and the running data of the side grinding side loop of the roller press into the trained prediction model to obtain the quality trend of the cement product a period of time after the current time point;

in response to the result output by the prediction unit being outside a preset threshold range, determining a device control mode for the roller press side loop and the mill side loop, the control mode being such that the quality of the cement product a period of time after the current point in time is within the preset threshold range;

and respectively controlling equipment of the side loop and the grinding side loop of the roller press according to the control mode.

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