CN102994731A - System and method for calculating optimal heating curve of blank in heating furnace - Google Patents

Abstract

The invention relates to a method for calculating an optimal heating curve of a blank in a heating furnace and stepping and heating of the blank in the heating furnace can be realized mainly by position tracking and temperature tracking. The original furnace temperature schedule is revised by comprehensive considering of a difference between the tapping temperature and the target temperature of the blank and a heating rate of the blank, and the blank is reheated by the revised furnace temperature schedule; for the blank satisfying the tapping temperature, the fuel consumption used for the heating in the time is represented by an integral-replaced objective function; and after the optimizing calculation can be carried out for specified number of times, one integral-replaced objective function having the least value is selected out, and a heating curve corresponding to the integral-replaced objective function having the least value is taken as the optimal heating curve of the blank with the size. According to the method for calculating the optimal heating curve of the blank in the heating furnace, the calculations of the optimal heating curves of a plurality of blanks before the blanks are sent into the furnace can be finished, and the calculating efficiencies are high; and a heating schedule is beneficially revised by the calculated optimal heating curve of the blank by a heating furnace mathematical model, the heating quality of metal and the production efficiency of the heating furnace are improved, and the optimal control of the heating furnace is beneficially realized.

Description

Blank is optimized heating curve computing system and method in the heating-furnace

Technical field

The present invention relates to the process furnace thermal treatment process of blank in the hot rolling technical field, relate in particular to the method for calculation of blank optimization heating curve in process furnace optimum control field and the process furnace.

Background technology

The hot state mathematical model of blank progressively is applied in process furnace optimum design and the optimal control technique in process furnace thermal process and the stove., under the condition that satisfies the target tapping temperature, adopt rational heating cycle, reduce the production efficiency that stove thermal losses and fuel consumption could improve process furnace to greatest extent for blank in the process furnace.The heating cycle of blank mainly is rule of thumb to come to determine in the process furnace at present, is determined target tapping temperature, time inside furnace and the furnace temperature system of blank by the characteristic of heating blank.Can adopt mathematical model to generate heating cycle according to heating blank property calculation for the higher process furnace of level of automation, its core is the deviation between the given target temperature of the Current Temperatures by the calculated with mathematical model blank and blank heating technique under the current furnace temperature system state of process furnace, and by this deviation current furnace temperature system is constantly revised, simultaneously with the Heating temperature set(ting)value of revised furnace temperature system as heating furnace foundation instrument automation system, thereby make blank in the stove finish thermal treatment in process furnace according to heating process.And the heating process of blank, be called again blank and optimize heating curve, it is given to enter the stokehold at this blank, mainly on original heating process basis, manually intervened according to production and operating experience by the technician at present, labour intensity is large, and be difficult to adapt to heating process demand, precision and the very flexible of different blanks.To directly affect the formulation that blank enters stove post-heating system like this, thereby affect the production efficiency of heating quality and the process furnace of metal, be difficult to realize the process furnace optimum control.

Summary of the invention

Technical problem solved by the invention is to provide a kind of method of calculating blank optimization heating curve in the process furnace for the problems referred to above.The method is not subjected to restriction, computational accuracy and the counting yield of billet size specification high, can enter the stokehold at blank and finish the calculating that the polylith blank is optimized heating curve.Be beneficial to the process furnace mathematical model and utilize described blank to optimize heating curve correction heating cycle, improve the heating quality of metal and the production efficiency of process furnace, be beneficial to and realize the process furnace optimum control.

The present invention solve the technical problem and mainly takes following technical scheme:

Blank is optimized the heating curve computing system in the heating-furnace, comprising:

Blank stepping and location tracking module are carried out step-by-step operation and are returned current position blank;

The blank temperature tracking module is followed the tracks of the internal temperature field of blank in the process furnace;

Furnace temperature of heating furnace system amendment module according to temperature parameter, is revised furnace temperature system;

The fuel consumption computing module, for the blank that satisfies the target tapping temperature with integration substitute objective function characterize its from enter stove to the fuel consumption of the whole heat-processed of coming out of the stove what;

Above-mentioned each module links to each other successively.

Described system also comprises blank parameter initialization module, initialize stove blank to be entered geometric parameter transitivity parameter; Furnace temperature of heating furnace system enactment module is carried out initialize to the correlation parameter of process furnace; Timing register, timing also judges whether to reach stepping or the temperature tracking cycle.

The method of calculation of described system comprise:

S1) call blank parameter initialization module, initialize stove blank to be entered geometric parameter transitivity parameter; Simultaneously, given blank enters the stokehold temperature;

S2) call furnace temperature of heating furnace system enactment module, initialize process furnace correlation parameter;

S3) whether timing register timing and the time of judging reach the process furnace stepping period, if do not reach the process furnace stepping period, then timing register continues timing; If reach the process furnace stepping period, then carry out blank stepping module, according to the stepwise operation of stepping period emulation blank in process furnace of process furnace, and realization is to the real-time prediction of blank position in the stove;

S4) whether timing register continuation timing and the time of judging reach the blank temperature tracking cycle, if do not reach the blank temperature tracking cycle, then timing register continues timing; If reach the blank temperature tracking cycle, then carry out the blank temperature tracking module, to the blank of different size specification in process furnace in different time inside furnaces, the different stove internal temperature field of position follow the tracks of;

S5) the blank current location data that returns according to blank location tracking module judges whether blank steps to the position of coming out of the stove, if blank not yet steps to the position of coming out of the stove, then gets back to step S3; If blank has stepped to the position of coming out of the stove, then enter next step;

S6) temperature parameter of calculating blank, comprise the blank tapping temperature and the blank section temperature difference when coming out of the stove, compare with blank target value tapping temperature, if not in target tapping temperature allowed band, then call furnace temperature of heating furnace system amendment module, former furnace temperature is revised, then turned back to step S2; If in the target value allowed band, then blank is carried out match formation blank optimization heating curve from entering stove to the temperature rise of coming out of the stove, then call the fuel consumption computing module, for the blank that satisfies the target tapping temperature with integration substitute objective function characterize its from enter stove to the fuel consumption of the whole heat-processed of coming out of the stove what;

S7) judge whether blank optimization heating curve calculation times reaches the calculation times of setting, if do not reach, then blank optimization heating curve calculation times adds 1, then calls furnace temperature of heating furnace system amendment module, furnace temperature is revised, then turned back to step S2; If reach the calculation times of setting, then export blank and optimize heating curve.

Described method, among the step S1, the blank geometric parameter comprises charge length and thickness; The blank physical parameter comprises blank density, specific heat capacity, thermal conductivity and blackness.

Described method, among the step S2, the process furnace correlation parameter comprises that process furnace tapping cycle, process furnace stepping rhythm, each stove segment length of process furnace, the total furnace superintendent of process furnace, each stove section thermopair of process furnace distribute and the initial furnace temperature set(ting)value of the upper and lower burner hearth of each stove section of process furnace.

Described method, among the step S3, control the blank stepping by following formula:

L＝L-d

In the formula, L be blank apart from the distance of furnace outlet fire door, d is the step distance of a stepping period of process furnace walking beam.

Described method, the concrete grammar that step S4 carries out the blank temperature tracking module comprises:

At first, according to current furnace temperature system, adopt blanket thermal absorptivity method to determine the upper and lower surface heat flow of blank, its calculating formula is:

In the formula, q _u, q _bBe respectively the heat flow density on the upper and lower surface of blank; T _{Fur_u}, T _{Fur_b}Be respectively the upper and lower burner hearth furnace temperature of process furnace of blank place stove section; T _{Surf_u}, T _{Surf_b}Be respectively the current upper and lower surface temperature of blank; σ is this fence-Boltzmann of making a mistake; φ _{CF_u}, φ _{CF_b}Be respectively the blanket thermal absorptivity coefficient of the upper and lower burner hearth of the corresponding process furnace of blank current position;

Then, by following heat conduction governing equation solution blank internal temperature field T (y, τ):

$\mathrm{\ρ}\left(T\right)c\left(T\right)\frac{\∂T(y,\mathrm{\τ})}{\∂\mathrm{\τ}}=\frac{\∂}{\∂y}\left[\mathrm{\λ}\left(T\right)\frac{\∂T(y,\mathrm{\τ})}{\∂y}\right]$

The starting condition of heat conduction governing equation is:

(1) for the cold charge blank,

T(y,τ)| _τ＝0＝T ₀ (0≤y≤h)

(2) for the hot charging blank,

T(y,τ)| _τ＝0＝T(y) (0≤y≤h)

The final condition of heat conduction governing equation is:

$q_u\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=h}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

$q_b\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=0}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

In the formula, ρ (T) is blank density, and c (T) is the blank specific heat capacity, and λ (T) is the blank thermal conductivity, T ₀Be envrionment temperature, T (y) is the temperature distribution function of hot charging sotck thinkness direction, τ _TimeInFurBe the heat-up time of blank in process furnace, h is sotck thinkness, and T=T (y, τ) is blank temperature field distribution function, and y is the coordinate of sotck thinkness direction, and τ is the time.

Described method, the temperature distribution function T (y) of hot charging sotck thinkness direction determines by the following method:

The blank through-thickness is divided, and T (y) value that then begins i node from the blank lower surface is:

（1）i＝0

T _CharNode(i)＝T _Surf

（2）i＝1～(N-1)/2

T _CharNode(i)＝-4.621+0.01762·h+1.014·T _Surf+0.01387·Δh·i(0°C≤T _Surf≤350°C)

T _CharNode(i)＝-89.8+0.1979·h+1.122·T _Surf+0.157·Δh·i(350°C＜T _Surf≤700°C)

T _CharNode(i)＝-387.5+0.7166·h+1.345·T _Surf+0.6436·Δh·i(700°C＜T _Surf≤1050°C)

T _CharNode(i)＝-526.6+0.5363·h+0.5191·T _Surf+0.5004·Δh·i (1050°C＜T _Surf≤1400°C)

（3）i＝(N-1)/2+1～N-1

T _CharNode(i)＝T _CharNode(j) (j＝N-1-i)

In the formula, N is the interstitial content of equidistantly dividing along the sotck thinkness direction, and N is odd number, T _CharNodeThe temperature of inner i node when (i) entering stove for blank, T _SurfThe surface temperature that detects when entering stove for blank, Δ h is blank adjacent two internodal thickness, and i=0 represents the node of blank lower surface, and i=N-1 represents the node of blank upper surface.

Described method, the method that step S6 revises furnace temperature system comprises:

Revise as follows:

$T_{\mathrm{fur}\_u,i}^{n+1}=c_u\&CenterDot;T_{\mathrm{fur}\_u,i}^n\&CenterDot;(1-c_{1\_u,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002502567800011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{2\_u,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

$T_{\mathrm{fur}\_b,i}^{n+1}=c_b\&CenterDot;T_{\mathrm{fur}\_b,i}^n\&CenterDot;(1-c_{1\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002502567800011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{2\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

In the formula,

Be respectively the furnace temperature of the upper and lower burner hearth of process furnace i stove section when carrying out the n time furnace temperature system correction,

Be respectively the furnace temperature to the n time upper and lower burner hearth of the revised process furnace of furnace temperature system i stove section, and as the initial value of the n+2 time furnace temperature system correction, c _u, c _bFor effectively revising the relevant coefficient of number of times, c with furnace temperature system _{1_u, i}, c _{1_b, i}Be respectively the furnace temperature system modifying factor of i stove section, c _{2_u, i}, c _{2_b, i}Be respectively i stove section blank temperature rise rate modifying factor, Δ T is the deviation of blank tapping temperature and target tapping temperature, T _DischargeBe the target tapping temperature of blank, Be the relative deviation of blank at i stove section temperature rise rate.

Described method, the method that step S6 calls the fuel consumption computing module is: calculate the area that blank heating curve and blank time inside furnace surround, be designated as Area (n-1), the area that the blank heating curve that calculates for the first time and time inside furnace surround, be designated as Area (0), the area that the last blank heating curve that calculates and time inside furnace surround is designated as Area (N-1), from Area (i), select the numerical value minimum one, and with the blank heating curve of this calculating optimization heating curve as this blank, wherein, i=0,1, ..., N-1.

The present invention has following main beneficial effect:

1, to propose first by Theoretical Calculation be the method for calculation that process furnace thermal treatment blank generate to be optimized heating curve in the present invention.Stepping and the heat-processed in process furnace by stepping module and blank temperature tracking module emulation blank.Substitute objective function with integration and characterize the fuel consumption size, algorithm is simple, is easy to realize.

2, the method for the interior blank optimization of calculating process furnace provided by the present invention heating curve is not subjected to the restriction of billet size specification, and computational flexibility is large.And, entering the stokehold at blank and can finish the generation that the polylith blank is optimized heating curve, counting yield is high, effectively reduces the labour intensity that technology and operator set heating process by hand.

3, with the deviation of comprehensive blank tapping temperature and target temperature and blank the temperature rise rate of each stove section on both side the corrected parameter of factor furnace temperature system is revised, effectively guaranteed the heating quality of blank, simultaneously revised furnace temperature system can be used as again the initial furnace temperature set(ting)value that blank enters stove post-heating stove, if avoided the initial furnace temperature of manual setting depart from actual required furnace temperature excessive cause can not control.

Description of drawings

Fig. 1 is a kind of schema that calculates blank optimization heating curve method in the process furnace provided by the present invention.

Among the figure, 1 is that blank parameter initialization module, 2 is that furnace temperature of heating furnace system enactment module, 3 is that blank stepping module in the process furnace, 4 is that blank temperature tracking module in the process furnace, 5 is that furnace temperature of heating furnace system amendment module, 6 is the alternative objective function computing module of blank integration in the process furnace.

Embodiment

A kind of method of calculating blank optimization heating curve in the process furnace provided by the present invention, it mainly comprises: the blank position tracking function, according to the stepwise operation of stepping period emulation blank in process furnace of process furnace, and realization is to the real-time prediction of blank position in the stove; Blank temperature following function in the process furnace can realize its internal temperature field of position tracking in different time inside furnaces, the different stove in process furnace to the blank of different size specification; The furnace temperature system debugging functions, take the deviation of blank tapping temperature and target temperature and blank at the temperature rise rate of each stove section as corrected parameter, furnace temperature system is revised; The fuel consumption computing function substitutes objective function for the blank that satisfies the target tapping temperature with integration and characterizes fuel consumption.

Described optimization heating curve is characterized in that, it comprises blank position array and the blank internal node temperature array corresponding with the position array.Described temperature array can be blank internal node temperature array, also can be its variation, such as part medial temperature array on the blank, or blank lower part medial temperature array.

Described blank position tracking function is characterized in that, simulates the forward motion of walking beam according to stepping period and the tapping rhythm of process furnace, realizes the dynamic tracking of blank in the process furnace along furnace superintendent direction position.

Described blank temperature following function, it is characterized in that, find the solution the hot-fluid on the upper and lower surface of steel billet according to the blanket thermal absorptivity method of the furnace temperature state utilization of the current position of blank, as the final condition of finding the solution the inner heat conduction difference equation of blank, calculate the temperature distribution of each node of sotck thinkness direction, realize the tracking to blank temperature field in the process furnace.The blanket thermal absorptivity coefficient of using when utilizing blanket thermal absorptivity method to find the solution the hot-fluid on the upper and lower surface of steel billet can obtain by black box experiment.

Described furnace temperature system debugging functions, it is characterized in that, at first call the blank position tracking function and judge whether blank steps to the position of coming out of the stove in the process furnace, then call the blank temperature following function the come out of the stove blank internal temperature field of position of arrival is followed the tracks of to judge whether blank satisfies the target tapping temperature, and calculate the deviation of itself and target tapping temperature.Simultaneously, calculate blank from entering stove temperature rise rate in each stove section to the process of coming out of the stove.Furnace temperature system is revised as corrected parameter at the temperature rise rate of each stove section take the deviation of blank tapping temperature and target temperature and blank.

Described fuel consumption computing function is characterized in that, the fuel consumption size when the present invention adopts integration to substitute objective function to characterize blank be heated to the target tapping temperature in process furnace.Namely adopt the blank surface temperature rise that the act as a fuel integration of consumption of blank integration of heat-up time in process furnace is substituted objective function, if the temperature of blank surface is minimum to the integrated value of time, the fuel consumption when then being equivalent to heating is minimum.

At first, finish stepping and the heating of blank in process furnace under the current furnace temperature state by blank position tracking function and blank temperature following function; Then, initial furnace temperature system is revised according to deviation and the temperature rise rate of blank in each stove section of process furnace of blank tapping temperature and target tapping temperature by the furnace temperature system debugging functions; Repeat above-mentioned steps with revised furnace temperature system and again blank is heated, when the deviation of blank tapping temperature and target tapping temperature and the section temperature difference all satisfied target value, counter increased by 1, until counter reaches the appointment calculation times, calculated and finished.

According to technique scheme, finish the furnace temperature system correction of predetermined number of times and the calculating that integration substitutes objective function for the blank that satisfies the target tapping temperature, therefrom select the optimization heating curve as this dimensions blank that integration substitutes objective function calculated value minimum, and the initial furnace temperature set(ting)value will optimize furnace temperature system corresponding to heating curve and heat in process furnace as this blank the time.

Be described in further detail the present invention below in conjunction with accompanying drawing.

The invention provides a kind of method of calculating blank optimization heating curve in the process furnace, its calculation process mainly comprises following module: blank stepping module 3, the interior blank temperature tracking module 4 of process furnace, furnace temperature of heating furnace system amendment module 5, the interior blank integration of process furnace substitute objective function computing module 6 in blank parameter initialization module 1, furnace temperature of heating furnace system enactment module 2, the process furnace.Describe embodiments of the present invention in detail below in conjunction with accompanying drawing 1.

The first step is called blank parameter initialization module 1, initialize stove blank to be entered geometric parameter transitivity parameter.The blank geometric parameter mainly comprises blank width, thickness; The blank physical parameter mainly comprises blank density, blackness; Simultaneously, given blank enters the stokehold temperature.For the cold charge blank, the initial temperature field is generally envrionment temperature; For the hot charging blank, its initial temperature field determines that the method back can describe in detail.

Second step calls furnace temperature of heating furnace system enactment module 2, initialize process furnace correlation parameter.Main given process furnace tapping cycle, process furnace stepping rhythm, each stove segment length of process furnace, the total furnace superintendent of process furnace, each stove section thermopair of process furnace distribute and the initial furnace temperature set(ting)value of the upper and lower burner hearth of each stove section of process furnace.

Whether the 3rd step timing register timing and the time of judging reach the process furnace stepping period.

If reach the process furnace stepping period, then carry out blank stepping module 3.Control the blank stepping by following formula:

L＝L-d

In the formula, L be blank apart from the distance of furnace outlet fire door, unit is m; D is the step distance of a stepping period of process furnace walking beam, and unit is m.

The 4th step timing register continues timing and whether the time of judging reaches the blank temperature tracking cycle.

If reach the blank temperature tracking cycle, then carry out blank temperature tracking module 4.

At first, according to current furnace temperature system, adopt blanket thermal absorptivity method to determine the upper and lower surface heat flow of blank, its calculating formula is as follows:

q _u＝σ·φ _{CF_u}·(T _{fur_u} ⁴-T _{surf_u} ⁴)

q _b＝σ·φ _{CF_b}·(T _{fur_b} ⁴-T _{surf_b} ⁴)

In the formula, q _u, q _bBe respectively the heat flow density on the upper and lower surface of blank, unit is W/m ²T _{Fur_u}, T _{Fur_b}Be respectively the upper and lower burner hearth furnace temperature of process furnace of blank place stove section, unit is K; T _{Surf_u}, T _{Surf_b}Be respectively the current upper and lower surface temperature of blank, unit is K; σ is this fence-Boltzmann of making a mistake (Stefan-Boltzmann) constant, and its value is 5.67 * 10 ^-8W/ (m ²K ⁴); φ _{CF_u}, φ _{CF_b}Be respectively the blanket thermal absorptivity coefficient of the upper and lower burner hearth of the corresponding process furnace of blank current position, can determine by black box experiment.

Then, by following heat conduction governing equation solution blank internal temperature field:

$\mathrm{\&rho;}\left(T\right)c\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;\mathrm{\&tau;}}=\frac{\&PartialD;}{\&PartialD;y}\left[\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}\right]$

The starting condition of heat conduction governing equation is:

(1) for the cold charge blank,

T(y,τ)| _τ＝0＝T ₀ (0≤y≤h)

(2) for the hot charging blank,

T(y,τ)| _τ＝0＝T(y) (0≤y≤h)

The final condition of heat conduction governing equation is:

$q_u\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=h}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

$q_b\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=0}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

In the formula, ρ is blank density, and unit is kg/m ³C is the blank specific heat capacity, and unit is J/ (kgK); λ is the blank thermal conductivity, and unit is wm ^-1K ^-1T ₀Be envrionment temperature, unit is K; T (y) is the temperature distribution function of hot charging sotck thinkness direction, and unit is K; τ _TimeInFurBe the heat-up time of blank in process furnace, unit is h; H is sotck thinkness, and unit is m.

For the hot charging blank, when finding the solution blank heat conduction governing equation, determine by following formula by blank initial internal node temperature discrete for the temperature distribution function T (y) of described thickness direction:

i＝0

T _CharNode(i)＝T _Surf i=1~(N-1)/2

T _CharNode(i)＝-4.621+0.01762·h+1.014·T _Surf+0.01387·Δh·i(0°C≤T _Surf≤350°C)

T _CharNode(i)＝-89.8+0.1979·h+1.122·T _Surf+0.157·Δh·i(350°C＜T _Surf≤700°C)

T _CharNode(i)＝-387.5+0.7166·h+1.345·T _Surf+0.6436·Δh ·i(700°C＜T _Surf≤1050°C)

T _CharNode(i)＝-526.6+0.5363·h+0.5191·T _Surf+0.5004·Δh·i(1050°C＜T _Surf≤1400°C)

i=(N-1)/2+1~N-1

T _CharNode(i)＝T _CharNode(j) (j＝N-1-i)

In the formula, N is the interstitial content of equidistantly dividing along the sotck thinkness direction, and N is odd number; T _CharNodeThe temperature of inner i node when (i) entering stove for blank, unit is ℃; T _SurfThe surface temperature that detects when entering stove for blank, unit is a ° C; H is the thickness of blank, and unit is m; Δ h is blank adjacent two internodal thickness, and unit is m; I=0 represents the node of blank lower surface; I=N-1 represents the node of blank upper surface.

The 5th step judged whether blank steps to the position of coming out of the stove.

Judge according to the blank current location data that blank location tracking module is returned whether blank steps to the position of coming out of the stove.

(1) if blank not yet steps to the position of coming out of the stove, then got back to for the 3rd step;

(2) if blank has stepped to the position of coming out of the stove, then calculate deviation and the blank section temperature difference of blank temperature and target tapping temperature.And judge that the deviation of blank temperature and target tapping temperature and the blank section temperature difference are whether in allowed band.Simultaneously, calculate the temperature rise rate of blank in each stove section of process furnace.

The calculating of the deviation of blank temperature and target tapping temperature and the blank section temperature difference: referring to the 4th step of specification sheets, also can number content in the diamond on 5 right sides referring to schema, obtain the temperature field of blank inside by finding the solution blank heat conduction governing equation, it is the node temperature of blank inside, if divide N node (N is odd number) in the sotck thinkness direction, the mean value of N node temperature was as the tapping temperature T of blank when (1) then blank was come out of the stove, the target tapping temperature T when blank is come out of the stove _DischargeFor known, so the deviation of blank temperature and target tapping temperature is T-T _Discharge(2) absolute value of the difference of the 1st node of thickness direction and (N+1)/2 node temperature is as the upper section temperature difference △ T1 of blank, the absolute value of the difference of N node of thickness direction and (N+1)/2 node temperature is as the lower section temperature difference △ T2 of blank, the blank section temperature difference △ T that the maximum value of △ T1, △ T2 is blank when coming out of the stove.

Blank in each stove section of process furnace temperature rise rate and the calculating of heating curve:

Heating curve: blank in process furnace during different positions its inner temperature distribution be different, that is to say that there is corresponding with it blank interior temperature distribution blank each position in process furnace, can be easy to obtain blank from entering process furnace to the heating curve of coming out of the stove by fitting of a curve.

Temperature rise rate: blank is when the A position, and the medial temperature of its thickness direction is Blank is when the B position, and the medial temperature of its thickness direction is

Blank is τ in the time that moves to the B position from the A position _A-BThen blank is at the temperature rise rate that moves to the B position from the A position

Described in the literary composition be " each stove section of process furnace in temperature rise rate " so in like manner, establish blank and in the medial temperature that enters this stove Duan Shiqi thickness direction be

Blank in the medial temperature that goes out this stove Duan Shiqi thickness direction is

The run duration of blank in this stove section is τ _A-B, then the temperature rise rate of blank in this stove section is

If one of the deviation of blank tapping temperature and target tapping temperature or section temperature difference are discontented with the foot-eye value then are called furnace temperature of heating furnace system amendment module 5, and according to deviation and the temperature rise rate of blank in each stove section of process furnace of blank temperature and target tapping temperature furnace temperature system is revised, then get back to second step and continue to calculate with revised furnace temperature system.The modification method back of furnace temperature system can describe in detail;

If all satisfying target value, the deviation of blank tapping temperature and target tapping temperature and the section temperature difference call furnace temperature of heating furnace system amendment module 5, and revise furnace temperature system according to deviation and the blank of blank temperature and target tapping temperature at the temperature rise rate of each stove section of process furnace, counter n adds one, call simultaneously the area that the alternative objective function computing module 6 calculating blank heating curves of the interior blank integration of process furnace and time inside furnace surround, be designated as Area (n-1).The area that the blank heating curve that calculates for the first time and time inside furnace surround is designated as Area (0).Then getting back to second step continues to calculate with revised furnace temperature system.

Described furnace temperature of heating furnace system is revised by following formula:

$T_{\mathrm{fur}\_u,i}^{n+1}=c_u\&CenterDot;T_{\mathrm{fur}\_u,i}^n\&CenterDot;(1-c_{1\_u,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002502567800011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{2\_u,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

$T_{\mathrm{fur}\_b,i}^{n+1}=c_b\&CenterDot;T_{\mathrm{fur}\_b,i}^n\&CenterDot;(1-c_{1\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002502567800011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{2\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

In the formula,

Be respectively the furnace temperature of the upper and lower burner hearth of process furnace i stove section when carrying out the n time furnace temperature system correction, unit is K;

Be respectively the furnace temperature to the n time upper and lower burner hearth of the revised process furnace of furnace temperature system i stove section, and as the initial value of the n+2 time furnace temperature system correction, unit is K; c _u, c _bFor effectively revising the relevant coefficient of number of times with furnace temperature system; c _{1_u, i}, c _{1_b, i}Be respectively the furnace temperature system modifying factor of i stove section; c _{2_u, i}, c _{2_b, i}Be respectively i stove section blank temperature rise rate modifying factor; Δ T is the deviation of blank tapping temperature and target tapping temperature, and unit is K; T _DischargeBe the target tapping temperature of blank, unit is K;

Be the relative deviation of blank at i stove section temperature rise rate.When furnace temperature system is effectively revised number of times and is referred to that the deviation of blank tapping temperature and target tapping temperature and the section temperature difference all satisfy target value, the correction number of times that furnace temperature system is carried out.Each coefficient value such as following table in the formula:

Table 1 furnace temperature correction relation conefficient value

Coefficient	c u	c b	c 1_u，i	c 2_b，i	c 2_u，i	c 2_b，i
							Value	1.0	1.0	1.3	1.25	0.013	0.0125

According to such scheme, until reaching the optimization times N of appointment, counter n calculates termination, the area that the last blank heating curve that calculates and time inside furnace surround is designated as Area (N-1).From Area (i), select the numerical value minimum one, and with the blank heating curve of this calculating optimization heating curve as this blank.Wherein, i=0,1 ..., N-1.Also namely, adopt the blank surface temperature rise to the blank integration of heat-up time in process furnace

$J={\&Integral;}_{t1}^{t2}{T}_{\mathrm{surf}}\left(t\right)\mathrm{dt}$

The integration of consumption of acting as a fuel substitutes objective function, if the temperature of blank surface is minimum to the integrated value of time, the fuel consumption when then being equivalent to heating is minimum.In the formula t1, t2 be respectively steel billet enter the stove time with come out of the stove the time T _Surf(t) be billet surface temperature function over time in the heat-processed, J represents fuel consumption size, the i.e. value of described objective function.

Embodiment

One. hot charging blank node temperature calculates:

● embodiment 1

For the hot charging blank, by method provided by the present invention, calculate and obtain its initial internal node temperature, as shown in table 2.

Table 2 hot charging blank node temperature calculates

● embodiment 2

For the hot charging blank, by method provided by the present invention, calculate and obtain its initial internal node temperature, as shown in table 3.

Table 3 hot charging blank node temperature calculates

● embodiment 3

For the hot charging blank, by method provided by the present invention, calculate and obtain its initial internal node temperature, as shown in table 4.

Table 4 hot charging blank node temperature calculates

Two. the embodiment of the invention

● embodiment 1

Call blank parameter initialization module 1, to the calculating parameter initialize, blank significant parameter initialization value such as table 5, process furnace significant parameter initialization value such as table 6.

Table 5 blank parameter

Parameter name	Width (m)	Thickness (m)	Density (kg/m 3)	Blackness	Charging temperature (℃)
						Parameter value	1.20	0.24	7850	0.8	300

Table 6 heater parameters

Utilize method provided by the invention to calculate blank and optimize heating curve, obtain this blank and optimize heating curve, the blank position array that it comprises and blank top and the bottom medial temperature array such as table 7.

Table 7 blank is optimized heating curve

● embodiment 2

Call blank parameter initialization module 1, to the calculating parameter initialize, blank significant parameter initialization value such as table 8, process furnace significant parameter initialization value such as table 9.

Table 8 blank parameter

Parameter name	Width (m)	Thickness (m)	Density (kg/m 3)	Blackness	Charging temperature (℃)
						Parameter value	1.45	0.32	7850	0.8	30

Table 9 heater parameters

Utilize method provided by the invention to calculate blank and optimize heating curve, obtain this blank and optimize heating curve, the blank position array that it comprises and blank top and the bottom medial temperature array such as table 10.

Table 10 blank is optimized heating curve

● embodiment 3

Call blank parameter initialization module 1, to the calculating parameter initialize, blank significant parameter initialization value such as table 11, process furnace significant parameter initialization value such as table 12.

Table 11 blank parameter

Parameter name	Width (m)	Thickness (m)	Density (kg/m 3)	Blackness	Charging temperature (℃)
						Parameter value	1.45	0.32	7850	0.8	30

Table 12 heater parameters

Utilize method provided by the invention to calculate blank and optimize heating curve, obtain this blank and optimize heating curve, the blank position array that it comprises and blank top and the bottom medial temperature array such as table 13.

Table 13 blank is optimized heating curve

Claims (10)

1. blank is optimized the heating curve computing system in the heating-furnace, it is characterized in that comprising:

Blank stepping and location tracking module are carried out step-by-step operation and are returned current position blank;

The blank temperature tracking module is followed the tracks of the internal temperature field of blank in the process furnace;

Furnace temperature of heating furnace system amendment module according to temperature parameter, is revised furnace temperature system;

The fuel consumption computing module, for the blank that satisfies the target tapping temperature with integration substitute objective function characterize its from enter stove to the fuel consumption of the whole heat-processed of coming out of the stove what;

Above-mentioned each module links to each other successively.

2. system according to claim 1 is characterized in that: also comprise blank parameter initialization module, initialize stove blank to be entered geometric parameter transitivity parameter; Furnace temperature of heating furnace system enactment module is carried out initialize to the correlation parameter of process furnace; Timing register, timing also judges whether to reach stepping or the temperature tracking cycle.

3. the method for calculation of system according to claim 1 and 2 is characterized in that, comprising:

S1) call blank parameter initialization module, initialize stove blank to be entered geometric parameter transitivity parameter; Simultaneously, given blank charging temperature;

S2) call furnace temperature of heating furnace system enactment module, initialize process furnace correlation parameter;

S3) whether timing register timing and the time of judging reach the process furnace stepping period, if do not reach the process furnace stepping period, then timing register continues timing; If reach the process furnace stepping period, then carry out blank stepping module, according to the stepwise operation of stepping period emulation blank in process furnace of process furnace, and realization is to the real-time prediction of blank position in the stove;

S4) whether timing register continuation timing and the time of judging reach the blank temperature tracking cycle, if do not reach the blank temperature tracking cycle, then timing register continues timing; If reach the blank temperature tracking cycle, then carry out the blank temperature tracking module, to the blank of different size specification in process furnace in different time inside furnaces, the different stove internal temperature field of position follow the tracks of;

S5) the blank current location data that returns according to blank location tracking module judges whether blank steps to the position of coming out of the stove, if blank not yet steps to the position of coming out of the stove, then gets back to step S3; If blank has stepped to the position of coming out of the stove, then enter next step;

S6) temperature parameter of calculating blank, comprise the blank tapping temperature and the blank section temperature difference when coming out of the stove, compare with blank target value tapping temperature, if not in target tapping temperature allowed band, then call furnace temperature of heating furnace system amendment module, former furnace temperature is revised, then turned back to step S2; If in the target value allowed band, then blank is carried out match formation blank optimization heating curve from entering stove to the temperature rise of coming out of the stove, then call the fuel consumption computing module, for the blank that satisfies the target tapping temperature with integration substitute objective function characterize its from enter stove to the fuel consumption of the whole heat-processed of coming out of the stove what;

S7) judge whether blank optimization heating curve calculation times reaches the calculation times of setting, if do not reach, then blank optimization heating curve calculation times adds 1, then calls furnace temperature of heating furnace system amendment module, furnace temperature is revised, then turned back to step S2; If reach the calculation times of setting, then export blank and optimize heating curve.

4. method according to claim 3, it is characterized in that: among the step S1, the blank geometric parameter comprises charge length and thickness; The blank physical parameter comprises blank density, specific heat capacity, thermal conductivity and blackness.

5. method according to claim 3, it is characterized in that: among the step S2, the process furnace correlation parameter comprises that process furnace tapping cycle, process furnace stepping rhythm, each stove segment length of process furnace, the total furnace superintendent of process furnace, each stove section thermopair of process furnace distribute and the initial furnace temperature set(ting)value of the upper and lower burner hearth of each stove section of process furnace.

6. method according to claim 3 is characterized in that: among the step S3, by the stepping of following formula control blank:

L＝L-d

In the formula, L be blank apart from the distance of furnace outlet fire door, d is the step distance of a stepping period of process furnace walking beam.

7. method according to claim 3 is characterized in that: the concrete grammar that step S4 carries out the blank temperature tracking module comprises:

At first, according to current furnace temperature system, adopt blanket thermal absorptivity method to determine the upper and lower surface heat flow of blank, its calculating formula is:

In the formula, q _u, q _bBe respectively the heat flow density on the upper and lower surface of blank; T _{Fur_u}, T _{Fur_b}Be respectively the upper and lower burner hearth furnace temperature of process furnace of blank place stove section; T _{Surf_u}, T _{Surf_b}Be respectively the current upper and lower surface temperature of blank; σ is this fence-Boltzmann of making a mistake; φ _{CF_u}, φ _{CF_b}Be respectively the blanket thermal absorptivity coefficient of the upper and lower burner hearth of the corresponding process furnace of blank current position;

Then, by following heat conduction governing equation solution blank internal temperature field T (y, τ):

$\mathrm{\&rho;}\left(T\right)c\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;\mathrm{\&tau;}}=\frac{\&PartialD;}{\&PartialD;y}\left[\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}\right]$

The starting condition of heat conduction governing equation is:

(1) for the cold charge blank,

T(y,τ)| _τ＝0＝T ₀ (0≤y≤h)

(2) for the hot charging blank,

T(y,τ)| _τ＝0＝T(y) (0≤y≤h)

The final condition of heat conduction governing equation is:

$q_u\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=0}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

$q_b\left(\mathrm{\&tau;}\right)=\mathrm{\&lambda;}\left(T\right)\frac{\&PartialD;T(y,\mathrm{\&tau;})}{\&PartialD;y}{|}_{y=0}(0<\mathrm{\&tau;}<{\mathrm{\&tau;}}_{\mathrm{TimeInFur}})$

In the formula, ρ (T) is blank density, and c (T) is the blank specific heat capacity, and λ (T) is the blank thermal conductivity, T ₀Be envrionment temperature, T (y) is the temperature distribution function of hot charging sotck thinkness direction, τ _TimeInFurBe the heat-up time of blank in process furnace, h is sotck thinkness, and T=T (y, τ) is blank temperature field distribution function, and y is the coordinate of sotck thinkness direction, and τ is the time.

8. method according to claim 7 is characterized in that, the temperature distribution function T (y) of hot charging sotck thinkness direction determines by the following method:

The blank through-thickness is divided, and T (y) value that then begins i node from the blank lower surface is:

（1）i＝0

T _CharNode(i)＝T _Surf

（2）i＝1～(N-1)/2

T _CharNode(i)＝-4.621+0.01762·h+1.014·T _Surf+0.01387·Δh·i (0°C≤T _Surf≤350°C)

T _CharNode(i)＝-89.8+0.1979·h+1.122·T _Surf+0.157·Δh·i (350°C＜T _Surf≤700°C)

T _CharNode(i)＝-387.5+0.7166·h+1.345·T _Surf+0.6436·Δh·i (700°C＜T _Surf≤1050°C)

T _CharNode(i)＝-526.6+0.5363·h+0.5191·T _Surf+0.5004·Δh ·i (1050°C＜T _Surf≤1400°C)

（3）i＝(N-1)/2+1～N-1

T _CharNode(i)＝T _CharNode(j) (j＝N-1-i)

In the formula, N is the interstitial content of equidistantly dividing along the sotck thinkness direction, and N is odd number, T _CharNodeThe temperature of inner i node when (i) entering stove for blank, T _SurfThe surface temperature that detects when entering stove for blank, Δ h is blank adjacent two internodal thickness, and i=0 represents the node of blank lower surface, and i=N-1 represents the node of blank upper surface.

9. method according to claim 3 is characterized in that, the method that step S6 revises furnace temperature system comprises:

Revise as follows:

$T_{\mathrm{fur}\_b,i}^{n+1}=c_b\&CenterDot;T_{\mathrm{fur}\_b,i}^n\&CenterDot;(1-c_{1\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-c_{2\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

$T_{\mathrm{fur}\_b,i}^{n+1}=c_b\&CenterDot;T_{\mathrm{fur}\_b,i}^n\&CenterDot;(1-c_{1\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;T}}{T_{\mathrm{Disch}\arg e}})\&CenterDot;(1-c_{2\_b,i}\&CenterDot;\frac{\mathrm{\&Delta;}{k}_i}{k_i})$

In the formula,

Be respectively the furnace temperature of the upper and lower burner hearth of process furnace i stove section when carrying out the n time furnace temperature system correction,

Be respectively the furnace temperature to the n time upper and lower burner hearth of the revised process furnace of furnace temperature system i stove section, and as the initial value of the n+2 time furnace temperature system correction, c _u, c _bFor effectively revising the relevant coefficient of number of times, c with furnace temperature system _{1_u, i}, c _{1_b, i}Be respectively the furnace temperature system modifying factor of i stove section, c _{2_u, i}, c _{2_b, i}Be respectively i stove section blank temperature rise rate modifying factor, Δ T is the deviation of blank tapping temperature and target tapping temperature, T _DischargeBe the target tapping temperature of blank,

Be the relative deviation of blank at i stove section temperature rise rate.

10. method according to claim 3, it is characterized in that, the method that step S6 calls the fuel consumption computing module is: calculate the area that blank heating curve and blank time inside furnace surround, be designated as Area (n-1), the area that the blank heating curve that calculates for the first time and time inside furnace surround, be designated as Area (0), the area that the last blank heating curve that calculates and time inside furnace surround is designated as Area (N-1), from Area (i), select the numerical value minimum one, and with the blank heating curve of this calculating optimization heating curve as this blank, wherein, i=0,1, ..., N-1.

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