CN103019090B - A kind of intelligent sintering, mixing and water adding control method with forecast function - Google Patents

Abstract

The present invention relates to a kind of intelligent sintering, mixing and water adding control method with forecast function, the method adopts different control modes to mixed once with secondary mixing, mixed once adopts the feed-forward control manner with identification and forecast function, and secondary mixing adopts feedforward feedback complex controll mode; Advantage of the present invention is: the features CONTROLLER DESIGN respectively mixed according to sintering mixed once and secondary.By reducing system disturbance to the identification of mixed front water percentage during mixed once, increasing control accuracy, adopting feedforward feedback complex controll to make to add water management during secondary mixing more stable.Applicability of the present invention, portability are strong, can be widely used in sintered production line.<!--1-->

Description

A kind of intelligent sintering, mixing and water adding control method with forecast function

Technical field

The present invention relates to a kind of intelligent sintering, mixing and water adding control method with forecast function, mixer automatic watering for sintered production line controls, make mixer granulate evenly and ensure good gas penetration potential, the method be specially adapted to one mixed time have the mixing and water adding of hot returning ore to control.

Background technology

The effect of mixing and water adding plays great role to SINTERING PRODUCTION.It not only affects vertical sintering speed, also affects the yield rate of sintering deposit, production efficiency and sintering finished tumbler index etc.If mixture moisture is little, sintering velocity is fast, but yield rate is low, and quantity of return mines is large, and tumbler index declines; If mixture moisture is large, sintering velocity is slow, and throughput rate is low, and various consumption all increases.If sintering humid control is unstable, the frequent adjustment of the follow-up post parameters such as sintering machine can be caused again, cause the instability of production line.

In order to make the process stabilization that adds water, current mixing and water adding generally adopts the process program of twice mixing, but nonetheless, mixture moisture is stablized, accurately still there is certain difficulty.Main cause has: the delayed FEEDBACK CONTROL that causes of system of three to five minutes of all existing of general mixer cannot be timely, the fluctuation of hot returning ore temperature and doses brings larger disturbance to control system, one mixed before water percentage do not mix due to sintered material, even if there have measuring instrument also to measure to be inaccurate etc.

Due to above Railway Project, the mixing and water adding of current most domestic sintering plant controls all to adopt Non-follow control, both increased workload, and accuracy also cannot be guaranteed.

Summary of the invention

The object of this invention is to provide a kind of intelligent sintering, mixing and water adding control method with forecast function, the method adopts different control modes to mixed once with secondary mixing, mixed once due to water percentage before mixed cannot Measurement accuracy, and the simple amount of water that controls in feedback fashion cannot realize promptly and accurately, therefore mixed once of the present invention adopts the feed-forward control manner with identification and forecast function; Because water percentage before mixed can be recorded by water percentage after mixed once during secondary mixing, adopt the mode of feedforward feedback complex controll, this complex controll mode has taken into full account the perturbed problem that the factors such as moisture loss in mixed process cause.

For achieving the above object, the present invention is achieved through the following technical solutions:

A kind of intelligent sintering, mixing and water adding control method with forecast function, the method adopts different control modes to mixed once with secondary mixing, mixed once adopts the feed-forward control manner with identification and forecast function, and secondary mixing adopts feedforward feedback complex controll mode; Mixed once control device comprises mixed front water yield identifier, feedforward controller, flow controller, and secondary mixed control apparatus comprises feedforward controller, feedback controller, flow controller; Described mixed once control procedure is:

1) mixed front water yield identifier is by water percentage after yield, actual amount of water and mixed once, calculate according to water percentage identification formula, and the mixed front water percentage of the result of calculating and several computation of Period front is adopted least square method linear regression, the mixed front water percentage c that can obtain next control cycle is predicted by fit line; Described water percentage identification formula is:

$c=\frac{\mathrm{Mo}*\mathrm{pe}-\mathrm{Wact}}{\mathrm{Mo}}+b---\left(1\right)$

In formula, Mo is mixer yield, and pe is water percentage after mixing, and Wact is actual amount of water, and b is that compensating approach amount can adjust according to field condition, and initial value gets 0

2) feedforward controller according to water yield identifier before mixed send mixed before water percentage, enter ore deposit amount, hot returning ore amount and temperature, and Target moisture rate set-point to be gone out to add water target flow set-point by the amount of water formulae discovery that feedovers; Described feedforward amount of water formula is:

$W1=\frac{M1*\mathrm{per}1+\mathrm{Mr}*\mathrm{per}1-\mathrm{Wb}1-a*k*\mathrm{Mr}}{1-\mathrm{per}1}---\left(2\right)$

Water cut Wb1=M1*c(3 before mixed once)

In formula: W1 is feedforward amount of water, M1 infiltrates ore deposit to measure, and per1 is a mixed Target moisture rate, and Mr is hot returning ore amount, and Wb1 is the water cut recorded by instrument before mixed once, and a is hot returning ore absorption coerfficient, and k is hot returning ore temperature, and c is mixed front water percentage

3) flow controller according to add water target flow and flowmeter that feedforward controller transmits transmit current add discharge before deviation, then adopt pid algorithm to transmit control signal regulating and controlling valve opening to variable valve by deviate; Finally, the required water yield is added in mixer;

Secondary Hybrid mode process is:

1) feedforward controller is according to a mixed rear water cut, two mixed advance ore deposits amounts and two mixed Target moisture rate set-points by the mixed amount of water that feedovers of following formulae discovery two, and this amount of water calculated value is the flow set-point of secondary mixed traffic controller;

Two mixed feedforward amount of water computing formula are:

$W2=\frac{M2*\mathrm{per}2-\mathrm{Wb}2}{1-\mathrm{per}2}---\left(4\right)$

In formula: W2 is two mixed feedforward amount of water, M2 two infiltrates ore deposit amount, and per2 is two mixed Target moisture rates, Wb2 be one mixed after the water cut that recorded by instrument

2) feedback controller compares with water percentage after the actual mixing detected of moisture detector according to system input i.e. two mixed moisture rate set-points, if difference is less than 2%, feedback controller does not adjust, if difference is greater than 2%, feedback controller calculates feedback rate of water make-up by pid algorithm, using feeding back rate of water make-up with feedforward amount of water sum as flow controller input value;

3) the current deviation added between discharge that transmits of the flow input value that transmits according to feedback controller of flow controller and flowmeter, adopts pid algorithm to transmit control signal to variable valve, regulating and controlling valve opening; Finally, the required water yield is added in mixer.

Compared with prior art, the invention has the beneficial effects as follows:

1) the overall control mode of sintering, mixing and water adding adopts the cascade control system of two close cycles composition, and outer shroud is water percentage ring, and inner ring is flow ring, and the outer shroud cycle is long, and the inner ring cycle is short.In flow ring, PID is adopted to control to the control of flow control valve.

2) system to hot returning ore amount, hot returning ore temperature, enter ore deposit amount, yield, amount of water and mixing after water percentage carry out filtering process, after filtering irrational interference value, input control device, accurately can show the overall variation trend of field parameters.

3) mixed once control by hot returning ore amount, hot returning ore temperature, enter ore deposit amount, amount of water and mixing after the assay value of moisture rate carry out to water percentage before mixed prediction; And use least square method to carry out linear regression to the once mixed front water percentage predicted to go out straight line, dope the mixed front water cut value of next control cycle thus.

4) the discharge set-point that calculated according to moisture content meter before mixed by feedforward controller of mixed once, this value compares with the instrument measured value before mixed once, is realized the control of control valve opening by pid algorithm.

5) secondary mix moisture rate ring adopts feedforward and feedback complex control mode, and after being mixed according to one by feedforward controller, water percentage, two mixed advance ore deposits are measured and the mixed feedforward amount of water of two mixed Target moisture rate set-points calculating two; Feedback controller inputs i.e. two mixed moisture rate set-points according to system and compares with water percentage after the actual mixing detected of moisture detector, calculates feedback rate of water make-up by pid algorithm, using feeding back rate of water make-up with feedforward amount of water sum as flow controller input value.

6) the current deviation added between discharge that transmits of the flow input value that transmits according to feedback controller of flow controller and flowmeter, adopts pid algorithm to transmit control signal to variable valve, regulating and controlling valve opening.

Advantage of the present invention is: the features CONTROLLER DESIGN respectively mixed according to sintering mixed once and secondary.By reducing system disturbance to the identification of mixed front water percentage during mixed once, increasing control accuracy, adopting feedforward feedback complex controll to make to add water management during secondary mixing more stable.Applicability of the present invention, portability are strong, can be widely used in sintered production line.

Accompanying drawing explanation

Fig. 1 is that the present invention sinters mixed once control structure figure.

Fig. 2 is that the present invention sinters secondary hybrid control architecture figure.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

A kind of intelligent sintering, mixing and water adding control method with forecast function, the method adopts different control modes to mixed once with secondary mixing, mixed once adopts the feed-forward control manner with identification and forecast function, and secondary mixing adopts feedforward feedback complex controll mode.

See Fig. 1, mixed once control device comprises mixed front water yield identifier, feedforward controller, flow controller.Mixed once control procedure is:

1) mixed front water yield identifier is according to water percentage pe after yield Mo, actual amount of water Wact and mixed once, calculated by water percentage identification formula, and the result and front four computation of Period that calculate mixed before water percentage adopts least square method linear regression (the present embodiment is selected 5 to mix front water percentage and simulated straight line, this value number does not limit, value is rationally), the mixed front water percentage c that can obtain next control cycle is predicted by fit line; Described water percentage identification formula is:

$c=\frac{\mathrm{Mo}*\mathrm{pe}-\mathrm{Wact}}{\mathrm{Mo}}+b---\left(1\right)$

In formula, Mo is mixer yield, and pe is water percentage after mixing, and Wact is actual amount of water, and b is that compensating approach amount can adjust according to field condition, and initial value gets 0.

2) feedforward controller according to water yield identifier before mixed send mixed before water percentage c, enter ore deposit amount M1, hot returning ore amount Mr and hot returning ore temperature k, and Target moisture rate set-point per1 to be gone out to add water target flow set-point W1 by the amount of water formulae discovery that feedovers; Described feedforward amount of water formula is:

$W1=\frac{M1*\mathrm{per}1+\mathrm{Mr}*\mathrm{per}1-\mathrm{Wb}1-a*k*\mathrm{Mr}}{1-\mathrm{per}1}---\left(2\right)$

Water cut Wb1=M1*c(3 before mixed once)

In formula: W1 is feedforward amount of water, M1 infiltrates ore deposit to measure, and per1 is a mixed Target moisture rate, and Mr is hot returning ore amount, and Wb1 is the water cut recorded by instrument before mixed once, and a is hot returning ore absorption coerfficient, and k is hot returning ore temperature, and c is mixed front water percentage.

3) flow controller according to add water target flow and flowmeter that feedforward controller transmits transmit current add discharge before deviation, then adopt pid algorithm to transmit control signal regulating and controlling valve opening to variable valve by deviate; Finally, the required water yield is added in mixer.

See Fig. 2, secondary mixed control apparatus comprises feedforward controller, feedback controller, flow controller.Secondary Hybrid mode process is:

1) feedforward controller mixes feedforward amount of water W2 according to water cut Wb2, the mixed Target moisture rate set-point per2 of two mixed advance ore deposits amount M2 and two of a mixed rear actual measurement by following formulae discovery two, and this amount of water calculated value is the flow set-point of secondary mixed traffic controller;

Two mixed feedforward amount of water computing formula are:

$W2=\frac{M2*\mathrm{per}2-\mathrm{Wb}2}{1-\mathrm{per}2}---\left(4\right)$

In formula: W2 is two mixed feedforward amount of water, M2 two infiltrates ore deposit amount, and per2 is two mixed Target moisture rates, Wb2 be one mixed after the water cut that recorded by instrument.

2) after the feedback controller mixing of surveying according to system input i.e. two mixed moisture rate set-points and moisture detector, water percentage compares, if difference is less than 2%, feedback controller does not adjust, if difference is greater than 2%, feedback controller calculates feedback rate of water make-up by pid algorithm, using feeding back rate of water make-up with feedforward amount of water sum as flow controller input value.

3) the current deviation added between discharge that transmits of the flow input value that transmits according to feedback controller of flow controller and flowmeter, adopts pid algorithm to transmit control signal to variable valve, regulating and controlling valve opening; Finally, the required water yield is added in mixer.

Control principle of the present invention is:

By sintering, mixing and water adding process characteristic, the principal element of mixing and water adding flow has into the water cut before and after ore deposit amount, yield, mixing, hot returning ore amount, hot returning ore temperature and target water content etc.In sintering mixed once process, consider hot returning ore amount and temperature to the impact of moisture, feedforward amount of water formula (2) draws according to mass conservation principle in mixed process, hot returning ore plays two effects, and an ore deposit of entering being the increase in material is measured, and needs to increase a part of amount of water in proportion, another is because hot returning ore itself is not moisture, and also can evaporate a part of water yield because temperature is higher, therefore, the water yield of evaporation is relevant with temperature with hot returning ore amount.

Before mixed, the service condition of the computing formula (1) of water percentage is: after the mixing and water adding of execution a period of time, according to the mixed front water percentage in water percentage analysis during this period of time after mixer yield, actual amount of water and mixing in a period of time.

The system complex that may exist for solving this kind of identification control method causes identification to be forbidden and the hysteresis quality problem of System Discrimination, avoiding system to there is disturbance to a certain degree, realizing by increasing the identification cycle.The delayed mixed front water percentage of mixed front water percentage to next cycle gone out by front some computation of Period of system carries out prediction and can obtain, and Forecasting Methodology adopts least square method, predicts next cycle by simulating straight line.

The present invention adopts cascade control system, and adopt two cover moisture detectors and two cover controllers, the output of previous controller is as the setting of a rear controller, and variable valve is sent in the output of a rear controller.

Previous controller is called master selector, and the variable of its institute's detection and control claims master variable (main controlled parameter), established technology Con trolling index; A rear controller is called secondary controller, and the variable of its institute's detection and control claims secondary variable (sub-quilt control parameter), is the auxiliary variable introduced in order to stable master variable.Whole system comprises two control loops, major loop and subloops.

The feature of cascade control system is:

1) dynamic perfromance of process is improved

Cascade control system is structurally more than a single loop control system subloop, reduces the time constant of link in this loop, adds its bandwidth, thus the response of system is accelerated, control more timely.

2) there is stronger Ability of Resisting Disturbance

In cascade control system, the product of major and minor regulator amplification coefficient is larger, then the Ability of Resisting Disturbance of system is stronger, and Mass Control better.Owing to there is subloop in cascade control system, as long as disturbance enters subloop, it is not waited to have influence on the change of principal parameter, by the timely adjustment of subloop, this disturbance will weaken the impact of principal parameter widely or eliminate completely, thus improves the Mass Control of principal parameter.

3) there is certain adaptive ability

Cascade control system is a fixed set point control system with regard to its major loop, and subloop is then a servomechanism.The output of master selector can change according to the change of load and operating conditions, thus constantly changes the set-point of secondary controller, makes the set-point of subloop regulator adapt to load and change with operating conditions, namely has certain adaptive ability.

Sintering, mixing and water adding control system master controller is that moisture rate controls (i.e. outer shroud), submaster controller is flow controller (i.e. inner ring), the moisture rate controller of mixed once is the feedforward controller with discriminating function, and the moisture rate controller of secondary mixing is feedforward feedback composite controller composition.

Feedforward control is also known as disturbance compensation, and it is completely different from feedback regulation principle, is to carry out regulating according to the interference size causing controlled variable to change.In this regulating system, want the change of direct sensing lead interference volume, when interference has just occurred and energy is measured, controller just can send conditioning signal has made regulated quantity do corresponding change, makes both offset before regulated variable generation deviation.Therefore, feed-forward regulation is more timely than feedback regulation to overcoming of interference.But feedforward control is opened loop control, its control effects needs to be checked by feedback.Feedforward controller, after measuring disturbance, calculates corrected value by certain material of process or energy equilibrium condition.If disturbance appears in feedforward branch circuit, after flowmeter survey, measure the size obtaining disturbing, then pass through adjustment control valve opening at feedback branch, directly compensate.

Claims (1)

1. one kind has the intelligent sintering, mixing and water adding control method of forecast function, it is characterized in that, the method adopts different control modes to mixed once with secondary mixing, mixed once adopts the feed-forward control manner with identification and forecast function, and secondary mixing adopts feedforward feedback complex controll mode; Mixed once control device comprises mixed front water yield identifier, feedforward controller, flow controller, and secondary mixed control apparatus comprises feedforward controller, feedback controller, flow controller; Described mixed once control procedure is:

1) mixed front water yield identifier is by water percentage after yield, actual amount of water and mixed once, calculate according to water percentage identification formula, and the mixed front water percentage of the result of calculating and several computation of Period front is adopted least square method linear regression, the mixed front water percentage c that can obtain next control cycle is predicted by fit line; Described water percentage identification formula is:

$c=\frac{Mo*pe-Wact}{Mo}+b---\left(1\right)$

In formula, Mo is mixer yield, and pe is water percentage after mixing, and Wact is actual amount of water, and b is that compensating approach amount can adjust according to field condition, and initial value gets 0

2) feedforward controller according to water yield identifier before mixed send mixed before water percentage, enter ore deposit amount, hot returning ore amount and temperature, and Target moisture rate set-point to be gone out to add water target flow set-point by the amount of water formulae discovery that feedovers; Described feedforward amount of water formula is:

$W1=\frac{M1*per1+Mr*per1-Wb1-a*k*Mr}{1-per1}---\left(2\right)$

Water cut Wb1=M1*c (3) before mixed once

In formula: W1 is the amount of water that feedovers, M1 infiltrates ore deposit amount, and per1 is a mixed Target moisture rate, and Mr is hot returning ore amount, and a is hot returning ore absorption coerfficient, and k is hot returning ore temperature, and c is mixed front water percentage

3) flow controller according to add water target flow and flowmeter that feedforward controller transmits transmit current add discharge before deviation, then adopt pid algorithm to transmit control signal regulating and controlling valve opening to variable valve by deviate; Finally, the required water yield is added in mixer;

Secondary Hybrid mode process is:

1) feedforward controller is according to a mixed rear water cut, two mixed advance ore deposits amounts and two mixed Target moisture rate set-points by the mixed amount of water that feedovers of following formulae discovery two, and this amount of water calculated value is the flow set-point of secondary mixed traffic controller;

Two mixed feedforward amount of water computing formula are:

$W2=\frac{M2*per2-Wb2}{1-per2}---\left(4\right)$

In formula: W2 is two mixed feedforward amount of water, M2 two infiltrates ore deposit amount, and per2 is two mixed Target moisture rates, Wb2 be one mixed after the water cut that recorded by instrument

2) feedback controller compares with water percentage after the actual mixing detected of moisture detector according to system input i.e. two mixed moisture rate set-points, if difference is less than 2%, feedback controller does not adjust, if difference is greater than 2%, feedback controller calculates feedback rate of water make-up by pid algorithm, using feeding back rate of water make-up with feedforward amount of water sum as flow controller input value;

3) the current deviation added between discharge that transmits of the flow input value that transmits according to feedback controller of flow controller and flowmeter, adopts pid algorithm to transmit control signal to variable valve, regulating and controlling valve opening; Finally, the required water yield is added in mixer.