CN102766730B - Method for on-line prediction of total decarbonization amount of molten steel in circulating vacuum degassing method - Google Patents

Abstract

The invention provides a method for on-line prediction of total decarbonization amount of molten steel in a circulating vacuum degassing method. The method comprises steps of: dividing a decarbonization process in a circulating vacuum degassing device into a high-speed reaction stage, a forced decarbonization stage and low-concentration reaction stage; segmenting the decarbonization positions in the circulating vacuum degassing device; and calculating a sum of the respective decarburization amount of the decarbonization positions corresponding to the high-speed reaction stage, the forced decarbonization stage and the low-concentration reaction stage, so as to obtain the total decarbonization amount of the molten steel. The method provided by the invention has the advantages of capability to carry out real-time detection on the total decarbonization amount of the molten steel in an RH process, flexible operation, high precision and low cost.

Description

A kind of method of the total decarburized amount of molten steel in on-line prediction recirculation degassing

Technical field

The present invention relates to the production control technical field of metallurgical refining, more particularly, relate to the method for the molten steel decarburized amount in a kind of on-line prediction circulating vacuum degasification process.

Background technology

The vacuum decarburization of recirculation degassing (that is, RH method) for produce ultra low-carbon steel play a part crucial, but the on-line Control technology of RH decarburization is but due to cannot Real-Time Monitoring carbon oxygen content and cannot improve precision; Existing RH Decarburization Control model mostly is static model, cannot accurately simulate the virtual condition of carbon rejection process in RH vacuum unit, document " Effect of Refining Conditions for Ultra Low Carbon Steel on Decarburization Reaction in RH Degasser " (ISIJ International for example, 1992,32 (1): 126～135.Yamaguchi K.et al), ignored the decarburizating of bubble and the decarburizating of vacuum chamber drop in upcast; Document " Dynamic Modeling and Control of Vacuum Circulation Process " (Iron and Making, 1993,20 (5): the decarburizating of 390.Kleimt B.et al) not considering the interior bubble of upcast and vacuum chamber droplet position; And document " RH-MFB carbon rejection process model and process optimization " (Tangshan: Institutes Of Technology Of Hebei's Master's thesis, Liu Bosong, 2005) although considered the decarburization on molten steel body, splash droplet and lift gas Argon Bubble surface, also detailed not for the description of decarburization mechanism.Up to the present finding document is not all discussed the impact for decarbonization rate in the different decarburization stages of decarburization position from patent.Existing RH Decarburization Control model mostly is static model, the processing parameters such as vacuum tightness, pressure drop pattern can only be set by rule of thumb data, once operation just cannot be revised parameter, the carbon oxygen content in vacuum chamber cannot be accurately detected, corrected Calculation result, causes precision to guarantee in time.

Document " Application of Off-gas Analysis for RH Decarburization Process " (SEAISI Quarterly, 1997,26 (2): 27-30.Ming.SiangChiang, et al.) be presented in RH exhaust system mass spectrograph is installed, by mass spectrograph on-line continuous, detect CO, CO in exhaust ₂deng variation, simultaneously since the correlation parameters such as vacuum tightness, pressure drop pattern, lift gas flow of steel bar part and carbon rejection process calculate the variation of carbon content in steel, thereby take optimized processing parameter, the object that reaches automatic control and accurately control.But this dynamic decarburization model need to be installed mass spectrograph in RH exhaust system, by mass spectrograph on-line continuous, detect CO, CO in exhaust ₂deng variation, and want Real-Time Monitoring vacuum tightness to change and lift gas fluctuations in discharge, calculate, process is sample examination carbon content repeatedly, cost is very high, domestic a lot of steel mills cannot reach condition like this.

For these reasons, of the present invention, both solved static model dumb, precision is difficult to the problem improving, and has improved again the high situation of dynamic decarburization model cost.

Summary of the invention

The deficiency existing for prior art, one of object of the present invention is to provide a kind of method of molten steel decarburized amount that can on-line prediction recirculation degassing.

To achieve these goals, the invention provides the method for the total decarburized amount of molten steel in a kind of on-line prediction recirculation degassing.Described recirculation degassing is realized by comprising the circulating vacuum de-gassing vessel of vacuum chamber and upcast, said method comprising the steps of: the carbon rejection process in circulating vacuum de-gassing vessel is divided into: high speed step of reaction, pressure decarburization stage and lower concentration step of reaction; Decarburization position in circulating vacuum de-gassing vessel is divided into: the inner CO bubble of molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p}; By calculating high speed step of reaction, forcing decarburization stage and lower concentration step of reaction to distinguish the inner CO bubble of corresponding molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p}summation, draw the total decarburized amount of molten steel.

In one exemplary embodiment of the present invention, described total decarburized amount draws according to formula (a), and described formula (a) is: ∑ Q ^c=α _cO* Q _co+ α _sur* Q _sur+ α _ar* Q _ar+ α _dro* Q _dro+ α _{ar, p}* Q _{ar, p},

Wherein, at high speed step of reaction, α _cOget 0.78～1.22, α _droget 0.78～1.22, α _ar, α _sur, α _{ar, p}get 0.30～0.52; Forcing the decarburization stage, α _cO, α _sur, α _ar, α _dro, α _{ar, p}get 0.47～0.52; At lower concentration step of reaction, α _arget 0.37～0.43, α _cO, α _sur, α _dro, α _{ar, p}get 0.

The beneficial effect of method of the present invention comprises: can detect in real time by total decarburized amount the molten steel in RH process; Compare with the static model of prior art more flexibly and precision high, and to compare cost low with the dynamic decarburization model of prior art.

Accompanying drawing explanation

By the description of carrying out below in conjunction with accompanying drawing, above and other object of the present invention and feature will become apparent, wherein:

Fig. 1 shows according to the Organization Chart of exemplary embodiment of the present invention model system;

Fig. 2 shows the decarburization position detailed map according to exemplary embodiment of the present invention;

Fig. 3 shows the decarburization mechanism schema according to exemplary embodiment of the present invention.

Embodiment

Hereinafter, describe with reference to the accompanying drawings embodiments of the invention in detail.

Technical conceive of the present invention is: according to coming steel bar part and target call, feature in conjunction with RH top rifle, from metallurgy carbon and oxygen balance principle, according to information such as molten steel initial carbon content, oxygen level and liquid steel temperature, vacuum tightnesss, carry out the online of the total decarburized amount of molten steel and calculate in real time, reach the desired effect of user.In carbon rejection process, the position of playing principal reaction effect in the different steps of vacuum decarburization process is different, and each response location is different to the contribution rate of total decarbonization rate.According to practical situation, adjust the primary and secondary of response location, can simulate each response location of conforming to RH vacuum refining device in the contribution rate of different steps, show as in the method for the invention the difference that parameter arranges, thus the carbon rejection process to greatest extent in real simulation RH.

The invention provides the method for the total decarburized amount of molten steel in a kind of on-line prediction recirculation degassing.Described recirculation degassing is realized by comprising the circulating vacuum de-gassing vessel of vacuum chamber and upcast, said method comprising the steps of: the carbon rejection process in circulating vacuum de-gassing vessel is divided into: high speed step of reaction, pressure decarburization stage and lower concentration step of reaction; Decarburization position in circulating vacuum de-gassing vessel is divided into: the inner CO bubble of molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p}; By calculating high speed step of reaction, forcing decarburization stage and lower concentration step of reaction to distinguish the inner CO bubble of corresponding molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p}summation, draw the total decarburized amount of molten steel.

Fig. 1 shows according to the Organization Chart of exemplary embodiment of the present invention model system.Fig. 2 shows the decarburization position detailed map according to exemplary embodiment of the present invention.Fig. 3 shows the decarburization mechanism schema according to exemplary embodiment of the present invention, and wherein, A represents data management and tracking module, B represents nature decarburization module, C represents to force decarburization module, and D represents deoxidation module (for MFB/ top rifle), and E represents to show output module.

In one exemplary embodiment, method of the present invention can adopt programmodule to realize.The system structure that system adopts: C/S structure.By client terminal, complete data processing, data representation and user interface function; Client-requested server, is completed its main operational function of model by server end.As shown in Figure 1, model and steelworks L2 carry out information interaction by database.Model calls dynamic base and calculates, interactive flexibly with each intermodule, and by calculation result deposit in database altogether L2 obtain.L2 by L1 information acquisition in interface table, for model system.

The realization of whole model function can be described by different functional modules.Modules, by connecting shown in Fig. 1 and coordinating, is realized function separately.

(1) data management and tracking module

This module records is come steel information and smelting requirements, as steel grade, heat (batch) number, Metal Weight, processing target etc.; The thermometric analysis of the initial sampling of record simultaneously result, composition information, for other technology controlling and process module provides corresponding information.This module is carried out data interaction by database and L1 and L2;

(2) dynamic parameter is calculated and adjusting module

(i) in this model, the variation of the parameter of equipment and manufacturing parameter is carried out in calculating that real-time data gathering is input to parameters, parameters such as molten steel weight, circulation flow of hot metal, agitation of molten steel energy in the molten steel degree of depth, vacuum chamber in vacuum chamber is all according to the real time data variation of vacuum indoor pressure and lift gas flow, by one-level key-course, to collect level two to calculate for model, so more can guarantee that the situation of the vacuum chamber that model calculates is consistent with actual state.

(ii) model segments decarburization position, the inner CO bubble of molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _dro, Ar bubble surface decarburization Q in upcast _{ar, p}.And these decarburization positions are set by the form of parameter for the contribution of total decarburized amount

∑Q ^C＝α _CO×Q _co+α _sur×Q _sur+α _Ar×Q _Ar+α _dro×Q _dro+α _Ar，p×Q _Ar，p。

(iii) model is divided into three decarburization stages, high speed step of reaction, pressure decarburization stage and lower concentration step of reaction, have nothing in common with each other in the decarburization position that play a major role each period, by scene, move and set and Model Self-Learning can be adjusted parameter alpha, with determine distinct device in the different decarburization stage contribution rate to decarbonization rate.Here, described high speed step of reaction, force decarburization stage and lower concentration step of reaction can distinguish corresponding decarburization early stage, decarburization mid-term and decarburization later stage.

(iv) according to the detected result of the actual carbon content of each time point in the mathematical simulation of RH carbon rejection process and production process (carbon content detects and can operate with reference to each manufacturing enterprise's actual process), determine initial parameter, model parameter is setting range and initial value before operation, deposit the result of each heat in database, require model inverse to go out each parameter, revise gradually, until meet the requirements of precision.Through modelling verification, parameter is chosen suggestion: decarburization reaction between carbon and oxygen in early stage is violent, and splash drop and the decarburization of CO bubble play a major role, α _cOget 0.78～1.22, α _droget 0.78～1.22, α _ar, α _sur, α _{ar, p}get 0.30～0.52; Decarburization reaction between carbon and oxygen in mid-term is tending towards gentle, and each parameter can be chosen in 0.47～0.52 scope, and preferably, each parameter all gets 0.5; The decarburization later stage is mainly Argon Bubble surface decarburization, α _arcan in 0.37～0.43 scope, choose, preferably, α _arget 0.4, other parameters get 0.

(3) mechanism model computing module

In order to make model be easier to express with mathematical formula, now decarburization model is done to following hypothesis:

(i) molten steel in ladle and vacuum chamber all fully mixes;

(ii) decarburizing reaction is mainly carried out in vacuum chamber, and in upcast, also there is certain contribution rate on Argon Bubble surface to decarburization;

(iii) C of liquid-vapo(u)r interface, O concentration and CO gaseous phase partial pressure keep balance;

(iv) decarbonization rate is by C, O mass transport limitation.

According to above hypothesis, use for reference forefathers' work, the analysis in conjunction with the author to decarburization mechanism, can obtain following model equation.Formula (5), (6) have represented the relation between decarburized amount and carbon oxygen transfer.

$W\frac{{\mathrm{dC}}_L}{\mathrm{dt}}=Q(C_V-C_L)---\left(1\right)$

$W\frac{{\mathrm{dO}}_L}{\mathrm{dt}}=Q(O_v-O_L)---\left(2\right)$

$w\frac{{\mathrm{dC}}_V}{\mathrm{dt}}=Q(C_L-C_V)-\mathrm{\Σ}{Q}^C---\left(3\right)$

$w\frac{{\mathrm{dO}}_V}{\mathrm{dt}}=Q(O_L-O_V)-\frac{M_O}{M_C}\mathrm{\Σ}{Q}^C---\left(4\right)$

∑Q ^C＝α _CO×Q _co+α _sur×Q _sur+α _Ar×Q _Ar+α _dro×Q _dro+α _Ar，p×Q _Ar，p

(5)

∑Q ^C＝αk _Cρ(C _V-C _s) (6)

$\frac{{\mathrm{ak}}_C\mathrm{\ρ}(C_V-C_S)}{M_C}=\frac{{\mathrm{ak}}_O\mathrm{\ρ}(O_V-O_S)}{M_O}---\left(7\right)$

$\log \frac{C_S{C}_O}{P_{\mathrm{CO}}}=-(\frac{1160}{T}+2.003)---\left(8\right)$

In formula: Metal Weight in W-ladle, t; Metal Weight in W-vacuum chamber, t; Q-circulation flow of hot metal, C _vcarbon content of molten steel in-vacuum chamber, ppm; C _lcarbon content of molten steel in-ladle, ppm; O _voxygen Content in Liquid Steel in-vacuum chamber, ppm; O _loxygen Content in Liquid Steel in-ladle, ppm; M _othe molar mass of-oxygen; M _cthe molar mass of-carbon; C _s-reaction interface place carbon content of molten steel, ppm; O _s-reaction interface place Oxygen Content in Liquid Steel, ppm; In formula (5)-Q _cofor the CO bubble decarburization of molten steel inside, Q _surfor the decarburization of molten steel free surface, Q in vacuum chamber _arfor the decarburization of Ar bubble surface, Q in vacuum chamber _drofor splash droplet decarburization, Q in vacuum chamber _{ar, p}for Ar bubble surface decarburization in upcast; Parameter alpha represents respectively their contribution rate to decarbonization rate; CO dividing potential drop in Pco-gas phase, Pa; ρ-molten steel density, t/m ³; Ak-volumetric coefficient, represents the speed of reaction m of vacuum indoor carbon or oxygen ³/ min; (a-effective interface is long-pending, m ²; K-coefficient of mass transfer)

What formula (1)～(8) represented is the core formula of model nature decarburization, and wherein, formula in (5) is segmented decarburization place, and has introduced the decarburized amount of Argon Bubble in upcast.Each decarburization place is different for the contribution rate of decarburized amount, and also there is different contribution rates in same place in the different steps of RH decarburization.So this contribution rate need to be processed as adjustable parameter in sequencing below.

Force the oxygen blast of decarburization module to operate drawing-in system (9).

$w\frac{{\mathrm{dO}}_V}{\mathrm{dt}}=Q(O_L-O_V)-\frac{M_O}{M_C}\mathrm{\Σ}{Q}^C+1.429\×{10}^2{\∂F}_{O_2}---\left(9\right)$

In formula: F _o2the flow velocity of oxygen lance oxygen in-vacuum chamber, Nm ³/ min;

-be blown into the rate of the oxygen absorption of molten steel.

Formula (5)～(9) are brought in formula (1)～(4) and adopted Runge-Kutta algorithm to solve, can try to achieve each and set the C under step-length _v, C _l, O _v, O _l.

The amount of removing of its Chinese style (5) carbon, is the core formula of this model, and what this formula was expressed is that the decarburization position in model is segmented, the inner CO bubble of molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _dro, Ar bubble surface decarburization Q in upcast _{ar, p}.

The decarburization of the inner CO bubble of molten steel is $Q_{\mathrm{co}}=-\frac{{\mathrm{dC}}_V}{\mathrm{dt}}=K_V(K_{\mathrm{CO}}{C}_i{O}_{\mathrm{CO}}-P_{\mathrm{CO}})---\left(10\right)$

In molten steel, CO dividing potential drop is P _co=P ₀+ ρ gh+ (2 σ/r)

(11)

Wherein, K _cOthe equilibrium constant for [C] on interface+[O]=CO reaction between carbon and oxygen; K _vfor model parameter; C _i, O _cOcarbon oxygen concn for molten steel and gas phase interface place; ; H is that molten steel surface is to the degree of depth of bubble position, m; P ₀vacuum tank internal gas pressure, Pa; R is CO bubble diameter, m.

This reactive moieties accounts for certain proportion when the decarburization initial stage, reaction between carbon and oxygen was stronger, but to the later stage, along with the reduction of carbon oxygen concn, the CO number of bubbles of generation is also reducing gradually, and this part will progressively reduce for the contribution of whole decarburization.

In steel, the constrain equation of the rate of mass transfer of carbon and free surface chemical reaction rate constrain equation are suc as formula shown in (11) formula (12).

$\frac{-{\mathrm{dC}}_V}{\mathrm{dt}}=\frac{k_L{\mathrm{\ρA}}_V(C_V-C_i)}{w}---\left(12\right)$

In formula: A _veffective free area in-vacuum chamber, m ²; k _lcarbon mass transfer coefficient in-molten steel, m/s; C _v, C _ithe carbon content of molten steel and free surface in-vacuum chamber, ppm.

$\frac{-{\mathrm{dC}}_V}{\mathrm{dt}}=\frac{1000M_C{k}_C{A}_V(C_i{O}_i{K}_{\mathrm{CO}}-P_{\mathrm{CO}})}{\mathrm{wRT}}---\left(13\right)$

In formula: R thinks gas law constant, 8.314J * (molK) ^-1; P _cOcO dividing potential drop in-vacuum chamber, Pa; k _cchemical reaction rate constant on-interface, m/s.

Decarbonization rate has mass transfer and the surface chemical reaction mixture control of molten steel, equals formula (13) can obtain free carbon contents C by formula (12) _i, by this C _isubstitution formula (12), can obtain speed of reaction and be:

$Q_{\mathrm{sur}}=\frac{-{\mathrm{dC}}_V}{\mathrm{dt}}=\frac{1000M_C{k}_C{k}_L{\mathrm{\ρA}}_V(C_V{O}_i{K}_{\mathrm{CO}}-P_{\mathrm{CO}})}{w(100M_C{k}_C{O}_i{K}_{\mathrm{CO}}+k_L\mathrm{\ρRT}}---\left(14\right)$

In vacuum chamber, the decarburization of Ar bubble surface thinks that Ar bubble is all spherical, along with the circulation of molten steel, floats, and there is decarburizing reaction on its surface.Because oxygen is enough with respect to the content of carbon in molten steel, so do not think that the mass transfer of oxygen is restricted link here.Restricted link comprises the rate limiting of carbon mass transfer and the restriction of bubble surface chemical reaction.

The rate limiting equation of mass transfer is:

$\frac{{\mathrm{dn}}_{\mathrm{CO}}}{\mathrm{dt}}=\frac{k_L\mathrm{Aw}(C_V-C_{\mathrm{Ar}})}{100M_C\×V}=\frac{k_L\mathrm{\ρA}(C_V-C_{\mathrm{Ar}})}{100M_C}---\left(15\right)$

In formula: n _cOcO mole number in-bubble, mol; V-molten steel volume, m ³; C _v, C _armolten steel and Ar bubble surface carbon content in-vacuum chamber, ppm;

Bubble surface chemical reaction rate constrain equation is:

$\frac{{\mathrm{dn}}_{\mathrm{CO}}}{\mathrm{dt}}=\frac{k_{C}A(C_{\mathrm{Ar}}{O}_{\mathrm{Ar}}{K}_{\mathrm{CO}}-P_{\mathrm{CO},i})}{\mathrm{RT}}---\left(16\right)$

In formula: P _{cO, t}cO dividing potential drop on-bubble surface, Pa.

Rate limiting equation in gas phase is:

$\frac{{\mathrm{dn}}_{\mathrm{CO}}}{\mathrm{dt}}=\frac{k_{G}A(P_{\mathrm{CO},i}-P_{\mathrm{CO}})}{\mathrm{RT}}---\left(17\right)$

In formula: k _g-gas phase inner transmission matter coefficient, m/s; P _cOcO dividing potential drop in-bubble, Pa.

The speed of reaction of bubble surface can be thought gas, liquid mass transfer and the common restriction of surface chemical reaction.By formula (15), equated with formula (16) (17), the carbon content that can obtain bubble surface is:

$C_{\mathrm{Ar}}=\frac{C_V+\frac{100M_C{k}_C{k}_G{P}_{\mathrm{CO}}}{{\mathrm{\ρRTk}}_L(k_C+k_G)}}{1+\frac{100M_C{k}_C}{{\mathrm{\ρRTk}}_L}{O}_{\mathrm{Ar}}{K}_{\mathrm{CO}}\frac{1-k_C}{k_C+k_G}}---\left(18\right)$

Formula (18) substitution formula (15) can be obtained

$Q_{\mathrm{Ar}}=\frac{-{\mathrm{dC}}_V}{\mathrm{dt}}=\frac{-\frac{G_s}{0.024}{C}_V{O}_V{K}_{\mathrm{CO}}f}{\frac{w}{100M_C}(C_V{O}_V{K}_{\mathrm{CO}}f-P)}---\left(19\right)$

Wherein: Gs-is argon gas cycle rate, L/min; F-decarburization efficiency,

In vacuum chamber, due to the boiling of violent reaction between carbon and oxygen and vacuum chamber molten steel, have a lot of liquid and leave molten steel surface, form splash droplet.The dynamic conditions that these drops have larger specific surface area and applicable decarburizing reaction to occur, so its decarburized amount also can not be ignored.

But the decarburized amount of splash droplet is subject to number of drops quantitative limitation, in decarburization in earlier stage, decarburizing reaction is more violent, in vacuum chamber, can form a large amount of splash droplets, carrying out along with reaction, the severe degree of reaction between carbon and oxygen reduces gradually, and the quantity of drop is corresponding minimizing also, and its contribution rate for decarburization is with regard to corresponding decline.

Q _dro＝N×q (20)

In formula: the decarburized amount of the single drop of quantity q-of N-current time drop.

The decarburized amount of single drop is:

$q=C_V-C_e=\{1-\frac{6}{{\mathrm{\π}}^2}\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}\frac{1}{n^2}\exp (-\frac{n^2{\mathrm{\π}}^2{D}_C\mathrm{\θ}}{R^2})\}(C_V-C_S)---\left(21\right)$

In formula: D _cthe mass transfer coefficient of-carbon, cm/s; The residence time of θ-drop in vacuum chamber, s.θ approximates 3～4s.

In upcast, under the effect of molten steel and Argon Bubble two phase flow, the speed of reaction of reaction between carbon and oxygen also progressively increases, and in upcast, the decarburization of Ar bubble surface can have formula (22) to represent.

$Q_{\mathrm{Ar},p}=\frac{-{\mathrm{dC}}_V}{\mathrm{dt}}=\frac{P_V}{P}\frac{-\frac{G_s}{0.024}{C}_V{O}_V{K}_{\mathrm{CO}}f}{\frac{w}{100M_C}(C_V{O}_V{K}_{\mathrm{CO}}f-P)}---\left(22\right)$

Wherein, P and P _vbe respectively atmosphere and vacuum indoor pressure, Pa.

This invention core point is for to have carried out setting ∑ Q for the contribution of total decarburized amount by the form of parameter by these decarburization positions ^c=α _cO* Q _co+ α _sur* Q _sur+ α _ar* Q _ar+ α _dro* Q _dro+ α _{ar, p}* Q _{ar, p}.By revising the status of equipment that can determine model running of Model Parameter α, and then simulate the decarburization state that is suitable for this equipment.

(4) errot analysis module

The predicted value in the sampling moment and the carbon content of sample examination are compared, error ± (x) ppm thinks in limit of error (x can need to set according to different progresses), if surpass this scope, actual measurement carbon content is invested to model, with this, be worth calculating from this moment.

(5) show output module

After calculating finishes, by this module, carry out data output, and data calculated is passed to L1 by L2 operate and pass to L3 and database and carry out data and retain the reference when next time calling.

To sum up, the invention provides a kind of method that can realize the decarburized amount of the molten steel in on-line prediction RH device.In addition, the on-line control system of the RH equipment for vacuum refining decarburization of the method according to this invention, can realize on-line Control to RH vacuum decarburization production process.For researchist and production technique personnel provide the platform of research and production control, thereby improve RH decarburization efficiency, improve decarburization accuracy at target, reduce production costs.

Although described exemplary embodiment of the present invention with exemplary embodiment by reference to the accompanying drawings above, those of ordinary skills should be clear, in the situation that do not depart from the spirit and scope of claim, can carry out various modifications to above-described embodiment.

Claims (1)

1. a method for the total decarburized amount of molten steel in on-line prediction recirculation degassing, described recirculation degassing is realized by comprising the circulating vacuum de-gassing vessel of vacuum chamber and upcast, it is characterized in that, said method comprising the steps of:

Carbon rejection process in circulating vacuum de-gassing vessel is divided into: high speed step of reaction, pressure decarburization stage and lower concentration step of reaction;

Decarburization position in circulating vacuum de-gassing vessel is divided into: the inner CO bubble of molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p};

By calculating high speed step of reaction, forcing decarburization stage and lower concentration step of reaction to distinguish the inner CO bubble of corresponding molten steel decarburization Q _cO, molten steel free surface decarburization Q in vacuum chamber _sur, Ar bubble surface decarburization Q in vacuum chamber _ar, splash droplet decarburization Q in vacuum chamber _drowith Ar bubble surface decarburization Q in upcast _{ar, p}summation, draw the total decarburized amount of molten steel, wherein,

Described total decarburized amount draws according to formula (a), and described formula (a) is:

∑Q ^C＝α _CO×Q _co+α _sur×Q _sur+α _Ar×Q _Ar+α _dro×Q _dro+α _Ar，p×Q _Ar，p，

Wherein, at high speed step of reaction, α _cOget 0.78～1.22, α _droget 0.78～1.22, α _ar, α _sur, α _{ar, p}get 0.30～0.52; Forcing the decarburization stage, α _cO, α _sur, α _ar, α _dro, α _{ar, p}get 0.47～0.52; At lower concentration step of reaction, α _arget 0.37～0.43, α _cO, α _sur, α _dro, α _{ar, p}get 0.

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