CN102562639A - Anti-surge control method of blast furnace blower - Google Patents

Abstract

The invention relates to the anti-surge control of a blower and aims at providing an anti-surge control method of a blast furnace blower. The anti-surge control method comprises the steps of: 1) conducting dimensionless treatment to an anti-surge curve to obtain the anti-surge curve which is not changed with an inlet condition and a structure; 2) obtaining real-time operating parameters, making a comparison with the dimensionless value of an anti-surge point after the dimensionless treatment and determining whether a current operating point is in a safe area or not; 3) determining the distance between the current operating point and the anti-surge curve and change speed in the current dimensionless flow direction and determining proportional-integral-derivative (PID) control parameters by taking the change speed as an input valve; and 4) transmitting the PID control parameters to the controller of an anti-surge valve to realize the control over the anti-surge valve. The anti-surge control method of the blast furnace blower has the advantages that the anti-surge curve offset caused by the change of the inlet condition and the structure is eliminated and the safe operating area can be accurately judged during operation; and the problems of pressure fluctuation and energy wastage caused by a reason that the anti-surge valve is opened too large or too small because the control parameters are fixed can be eliminated.

Description

A kind of method of blast furnace blower Anti-surge Control

Technical field

The present invention relates to a kind of blast furnace blower anti-surge method.In particular, be to carry out Anti-surge Control to the blast furnace blower in the blast furnace.

Background technique

Blast furnace blower is the core drive equipment in the ironmaking processes, and blast furnace blower is the heart of blast furnace equipment.The high pressure that blower is carried is distinguished and admirable, is heated to 1100～1200 ℃ through hot blast stove, by being located at the underbelly air loop duct of blast furnace, is blown in the blast furnace through being installed in blast furnace air port all around, holds the furnace charge that is added by furnace roof portion fuel spreader place on the one hand; Form molten iron and slag through chemical reduction reaction at furnace bottom on the other hand.If air-supply is cut off, blast furnace can not continue to produce molten iron, because of the power that supports furnace charge in the stove disappears, certainly will stay by furnace charge simultaneously, and molten iron, slag will splash, and cause the major accident in the stifled air port of blast furnace.Therefore require blower unit can realize along with the smelting operating mode of blast furnace regulating automatically and control; For blast furnace provides high-quality; An amount of wind regime is self-evident for the significance of whole iron and steel process, the running state of blower and the output of enterprise, benefit, closely bound up safely.

Suppress reason regular meetings such as wind owing to blast furnace and cause the blower fan surging phenomenon." surge " of so-called blower fan is exactly the low frequency oscillation of generating period property in the blower fan whole system, the phenomenon that compressor flow and outlet pressure fluctuate widely.The consequence that surge causes is very serious; It not only can make blower rotor and stator stand alternating stress and rupture; Make interstage pressure not normal and cause judder; Cause sealing and thrust-bearing to damage, motor element and stationary element collided, have in addition destroyed the accidents such as blast, fire that caused that seal.Except that serious accident, surge also can make the ironmaking invisible waste increase, and ton iron cost raises.

The blower of fields such as metallurgy operation nearly all is provided with antisurge control system.Control measure mainly are anti-asthma emptying.Main controlling method is when occurring operating point near the anti-surge curve at present, promptly opens the anti-surge valve at once, prevents that operating point from getting into the anti-surge curve left side, is in the safety zone again.

The setting of anti-surge curve has very important significance.In general; The anti-surge curve that blower manufacturer provides is that test is given when dispatching from the factory; But owing to temperature, molecular weight change the influence of surge limit is not taken into account, practical application is when often having the performance of certain deviation, particularly old unit to change; Cause the unreasonable of antisurge control system setting, thereby cause unnecessary loss.The aperture of same anti-surge valve has important effect.Aperture is excessive too fast, not only can produce bigger flow and pressure surge, and this fluctuation is unacceptable in the blast furnace ordinary production, and the waste energy.If to cross small offence slow for aperture, can not guarantee again to rise at operating point guarantees that blower fan does not get into surge area under the situation faster.

Anti-surge Control is as a most important ring in the blast furnace blower control; Whether its control effect is improved; Determined to give full play to the potential of blower to a great extent,, guaranteed that blast furnace reaches desirable utilization factor for blast furnace provides a safety, stable, wind regime efficiently.

Summary of the invention

The technical problem that the present invention will solve is, overcomes deficiency of the prior art, and a kind of method of blast furnace blower Anti-surge Control is provided.

Solution of the present invention is:

A kind of method of blast furnace blower Anti-surge Control is provided, may further comprise the steps:

The anti-surge curve of confirming during (1) to the blower delivery test carries out dimensionless to be handled, and obtains the dimensionless anti-surge curve that does not change with blower inlet condition and blower fan structure;

(2) obtain the real-time Operational Limits of blower by temperature transducer, pressure transducer and flow transducer; And after carrying out the nondimensionalization processing; Compare with the dimensionless numerical value of anti-surge point in the anti-surge curve, confirm whether present operating point present position is in the safety zone;

(3) confirm distance and the pace of change on the current dimensionless direction of the traffic between present operating point and the anti-surge curve, and be input value, confirm the parameter of PID control through the BP neural network algorithm with it;

(4) controller to the anti-surge valve transmits pid control parameter, realizes the control to the anti-surge valve.

Among the present invention, the distance between said operating point and the anti-surge curve obtains according to following formula:

$\mathrm{DS}=\frac{q_s}{q_1/\sqrt{R{T}_1}}$ (formula 1)

In the formula, DS is the distance between operating point and the anti-surge curve, q _sBe the dimensionless flow of anti-surge point,

Dimensionless flow for operating point.

Among the present invention, the pace of change on the said dimensionless direction of the traffic obtains according to following formula:

$v=\frac{d(q_1/\sqrt{R{T}_1})}{\mathrm{Dt}}$ (formula 2)

In the formula; V is the pace of change on the current dimensionless direction of the traffic, and

is the dimensionless flow of operating point.

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

1, handles through the anti-surge curve being carried out nondimensionalization, eliminated inlet condition and structural change and the anti-surge curve offset that causes, can accurately judge the safe operation zone when guaranteeing operation.

2, the speed with safe distance and blower operating point is input, confirms the parameter of PID control.This adaptive PID controlling method can eliminate because the excessive or too small pressure surge that brings of opening of the anti-surge valve that Control Parameter is fixedly brought and the problem of energy dissipation.

Description of drawings

Fig. 1 is blast furnace blower operation schematic representation;

Fig. 2 is a dimensionless anti-surge curve;

Fig. 3 be operating point and anti-surge point apart from schematic representation;

Fig. 4 is a BP neural network algorithm schematic representation;

Fig. 5 is an Anti-surge Control algorithm schematic representation.

Embodiment

Fig. 1 representes blast furnace blower operation schematic representation.Blower is driven by motor or steam turbine.When normal operation, blower is in the safety zone, and anti-surge valve complete shut-down, air all get into hot blast stove and heat.When blower during near the anti-surge curve, the anti-surge valve is opened, and air is entered atmosphere, thereby makes the flow of blower increase, away from the anti-surge curve.

Fig. 2 is the blast furnace blower anti-surge curve of nondimensionalization.Wherein p2/p1 is the blast furnace blower compression ratio;

is similar rotating speed, and is the flow of nondimensionalization.As can be seen from the figure, after the calculating of adopting nondimensionalization, the anti-surge curve does not change with inlet air conditions.

Fig. 3 representes that the dimensionless flow of operating point does The time, this moment, the dimensionless flow of anti-surge point was q _s, so actual motion point from the distance of anti-asthma point is:

$\mathrm{DS}=\frac{q_s}{q_1/\sqrt{R{T}_1}}$ (formula 1)

When DS less than 1 the time and operating point on guide line the right, therefore be in the safe operation zone.When DS equals 1, on the operating point anti-surge curve, be in threshold state.In order to guarantee the safety of blower, should avoid this type of situation as far as possible.Therefore as DS less than 1 time but when being in the guide line left side, should open that the anti-surge valve is moved operating point on the guide line to or on the right of.

Fig. 4 adopts BP neural network algorithm calculating PID Operational Limits schematic representation for as DS less than 1 time but when being in the guide line left side.BP (Back Propagation) neural network model topological structure comprises input layer (input), latent layer (hide layer) and output layer (output layer).When reality output is not inconsistent with desired output, get into the back-propagation phase of error.Error is through output layer, by each layer of mode correction weights of error gradient decline, to latent layer, input layer anti-pass successively.Information forward-propagating that goes round and begins again and error back propagation process; Be the constantly processes of adjustment of each layer weights; Also be the process of neural network learning training, the error that this process is performed until network output reduces to the acceptable degree, till the perhaps predefined study number of times.

Here chosen distance DS and the operating point pace of change on the dimensionless direction of the traffic is as input layer, and the ratio of PID control and integral parameter are as output.Wherein the pace of change on the dimensionless direction of the traffic is:

$v=\frac{d(q_1/\sqrt{{\mathrm{RT}}_1})}{\mathrm{Dt}}$ (formula 2)

Rule of thumb parameter is trained the BP neuron network, obtains neural network model.

Fig. 5 representes the schematic representation of Anti-surge Control algorithm.At first import and export nondimensional compression ratio of calculation of parameter and flow according to the blower of gathering.Obtain the flow on the corresponding dimensionless anti-surge curve through compression ratio from the anti-surge curve.Utilize formula (1) and formula (2) computed range DS and pace of change v.Obtain pid control parameter Kp and Ki according to the BP neuron network then.

Claims (3)

1. the method for a blast furnace blower Anti-surge Control is characterized in that, may further comprise the steps:

The anti-surge curve of confirming during (1) to the blower delivery test carries out dimensionless to be handled, and obtains the dimensionless anti-surge curve that does not change with blower inlet condition and blower fan structure;

(2) obtain the real-time Operational Limits of blower by temperature transducer, pressure transducer and flow transducer; And after carrying out the nondimensionalization processing; Compare with the dimensionless numerical value of anti-surge point in the anti-surge curve, confirm whether present operating point present position is in the safety zone;

(3) confirm distance and the pace of change on the current dimensionless direction of the traffic between present operating point and the anti-surge curve, and be input value, confirm the parameter of PID control through the BP neural network algorithm with it;

(4) controller to the anti-surge valve transmits pid control parameter, realizes the control to the anti-surge valve.

2. method according to claim 1 is characterized in that, the distance between said operating point and the anti-surge line obtains according to following formula:

$\mathrm{DS}=\frac{q_s}{q_1/\sqrt{R{T}_1}}$

In the formula, DS is the distance between operating point and the anti-surge line, q _sBe the dimensionless flow of anti-surge point, Dimensionless flow for operating point.

3. method according to claim 1 is characterized in that, the pace of change on the said dimensionless direction of the traffic obtains according to following formula:

$v=\frac{d(q_1/\sqrt{R{T}_1})}{\mathrm{dt}}$

In the formula; V is the pace of change on the current dimensionless direction of the traffic, and

is the dimensionless flow of operating point.

Images