CN118932169A - Method, device, equipment and medium for controlling furnace temperature in heating section of annealing furnace - Google Patents

Abstract

The present invention discloses a method, device, equipment and medium for controlling the furnace temperature of the heating section of an annealing furnace, and belongs to the field of metallurgical technology. The method comprises: judging whether there is a transition steel coil between a first formal steel coil and a second formal steel coil, wherein the first formal steel coil is a formal steel coil of a current specification currently heated in the heating section of the annealing furnace, and the second formal steel coil is a formal steel coil of a new specification to be heated next in the heating section; if there is a transition steel coil between the first formal steel coil and the second formal steel coil, the furnace temperature of the heating section is controlled according to a preset first transition strategy; if there is no transition steel coil between the first formal steel coil and the second formal steel coil, the furnace temperature of the heating section is controlled according to a preset second transition strategy. The method makes the control of the transition more accurate and timely, thereby reducing the length of the steel strip that does not meet the annealing temperature requirements and saving steel strip energy.

Description

Control method, device, equipment and medium for furnace temperature of heating section of annealing furnace

Technical Field

The invention relates to the technical field of metallurgy, in particular to a method, a device, equipment and a medium for controlling the furnace temperature of a heating section of an annealing furnace.

Background

The strip steel in the continuous annealing furnace may require frequent replacement of specifications, resulting in frequent transition of the process of the heating section. During transition, the furnace temperature of the heating section needs to be adjusted so that the annealing temperature of the strip steel with the new specification meets the requirement.

In actual transition, the furnace temperature of the heating section is gradually adjusted according to the difference of the strip steel with different specifications before and after the transition, and the strip steel with the annealing temperature meeting the requirement is processed according to the adjusted furnace temperature of the heating section after the transition is finished.

However, during transition, the furnace temperature of the heating section is manually adjusted by an operator, the operator adjusts the furnace temperature of the heating section to a proper temperature by virtue of working experience, inaccurate or untimely adjustment often occurs in the adjusting process, the outlet temperature of the long-distance strip steel does not meet the requirement of annealing temperature, and more serious waste of strip steel energy is caused.

Disclosure of Invention

In view of the above problems, the invention provides a control method, a device, equipment and a medium for the furnace temperature of the heating section of the annealing furnace, which can select different transition strategies when a transition strip steel coil exists and when the strip steel in the heating section of the annealing furnace is to be transited from the strip steel in the current specification to the strip steel in other specifications, that is to say, the heating section passes through different furnace temperature transition strategies, so that the transition control is more accurate and timely, the length of the strip steel which does not meet the annealing temperature requirement can be reduced, and the energy of the strip steel can be saved.

In a first aspect, the invention provides a method for controlling the furnace temperature of a heating section of an annealing furnace, which comprises the following steps:

Judging whether a transition steel strip coil exists between a first formal steel strip coil and a second formal steel strip coil, wherein the first formal steel strip coil is a formal steel strip coil of the current specification which is currently heated by a heating section of an annealing furnace, and the second formal steel strip coil is a formal steel strip coil of the new specification which is to be heated next to the heating section;

If the transition band steel coil exists between the first formal band steel coil and the second formal band steel coil, controlling the furnace temperature of the heating section according to a preset first transition strategy;

and if the transition band steel coil is not arranged between the first formal band steel coil and the second formal band steel coil, controlling the furnace temperature of the heating section according to a preset second transition strategy.

Optionally, the controlling the furnace temperature of the heating section according to a preset first transition strategy includes:

Acquiring a second annealing temperature and a second thickness of the second formal strip steel coil, a third thickness of the transition strip steel coil and the running speed of strip steel in the heating section;

determining a first target furnace temperature of the heating section according to the second annealing temperature, the second thickness, the third thickness and the running speed;

and when the distance between the head of the transition band steel coil and the inlet of the heating section is smaller than a preset first distance threshold value, controlling the heating section to heat at the first target furnace temperature.

Optionally, the determining the first target furnace temperature of the heating section according to the second annealing temperature, the second thickness, the third thickness and the running speed includes:

determining a first required furnace temperature required by the heating section to heat the transition steel coil to the second annealing temperature according to the third thickness and the running speed, and taking the first required furnace temperature as the first target furnace temperature when the distance between the head of the transition steel coil and the inlet of the heating section is smaller than the first distance threshold and the distance between the tail of the transition steel coil and the inlet of the heating section is larger than or equal to a preset second distance threshold;

And determining a second required furnace temperature required by the heating section to heat the second formal strip steel coil to the second annealing temperature according to the second thickness and the running speed, and taking the second required furnace temperature as the first target furnace temperature when the distance between the tail of the transition strip steel coil and the inlet of the heating section is smaller than the second distance threshold.

Optionally, the controlling the furnace temperature of the heating section according to a preset second transition strategy includes:

acquiring a first annealing temperature and a first thickness of the first formal strip steel coil, a second annealing temperature and a second thickness of the second formal strip steel coil, and a current furnace temperature of the heating section and a running speed of strip steel in the heating section;

Determining a third distance threshold according to a thickness difference between the first thickness and the second thickness, and an annealing temperature difference between the first annealing temperature and the second annealing temperature;

determining a second target furnace temperature of the heating section according to the current furnace temperature, the second annealing temperature, the second thickness and the running speed;

And when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than the third distance threshold, controlling the heating section to heat at the second target furnace temperature.

Optionally, the determining the second target furnace temperature of the heating section according to the current furnace temperature, the second annealing temperature, the second thickness and the running speed includes:

determining an outlet predicted strip temperature of the second formal strip steel coil when the heating section heats the second formal strip steel coil by adopting the current furnace temperature according to the second thickness and the running speed;

if the third difference between the predicted outlet strip temperature and the second annealing temperature is smaller than a preset error threshold, determining a third required furnace temperature required by the heating section to heat the second formal strip coil to the second annealing temperature according to the second thickness and the running speed, and determining the second target furnace temperature according to the third required furnace temperature and the current furnace temperature.

Optionally, after the second target furnace temperature is determined according to the third required furnace temperature and the current furnace temperature, the method further includes:

If the third difference value is greater than or equal to the error threshold value, acquiring a first annealing temperature and a first thickness of the first formal steel strip coil, and determining a fourth required furnace temperature required by the heating section when the first formal steel strip coil is heated to a third annealing temperature according to the first thickness and the running speed, wherein the third annealing temperature is the sum or difference of the first annealing furnace temperature and the error threshold value;

When the distance between the tail of the first formal steel coil and the inlet of the heating section is smaller than the third distance threshold and larger than a preset fourth distance threshold, taking the fourth required furnace temperature as the second target furnace temperature;

And when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than or equal to the fourth distance threshold, taking the third required furnace temperature as the second target furnace temperature.

Optionally, the determining the third distance threshold according to the thickness difference between the first thickness and the second thickness, the annealing temperature difference between the first annealing temperature and the second annealing temperature includes:

Determining a transition difficulty level of the furnace temperature of the heating section of the annealing furnace according to the thickness difference between the first thickness and the second thickness and the annealing temperature difference between the first annealing temperature and the second annealing temperature;

and determining a third distance threshold corresponding to the transition difficulty level.

In a second aspect, the invention provides a control device for the furnace temperature of a heating section of an annealing furnace, which comprises:

the judging module is used for judging whether a transition steel coil exists between a first formal steel coil and a second formal steel coil, wherein the first formal steel coil is a formal steel coil with the current specification which is currently heated by a heating section of the annealing furnace, and the second formal steel coil is a formal steel coil with the new specification which is to be heated next to the heating section;

The first control module is used for controlling the furnace temperature of the heating section according to a preset first transition strategy if the transition steel coil exists between the first formal steel coil and the second formal steel coil;

and the second control module is used for controlling the furnace temperature of the heating section according to a preset second transition strategy if the transition steel coil is not arranged between the first formal steel coil and the second formal steel coil.

In a third aspect, the present invention provides an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively coupled to each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the method according to the first aspect.

In a fourth aspect, the present invention provides a computer readable storage medium storing computer instructions for causing a computer to perform the method of the first aspect.

The technical scheme provided by the embodiment of the invention has at least the following technical effects or advantages:

The embodiment of the invention provides a control method, a device, equipment and a medium for the furnace temperature of a heating section of an annealing furnace, which are used for judging whether a transition strip steel coil exists between a first formal strip steel coil and a second formal strip steel coil, wherein the first formal strip steel coil is a formal strip steel coil with the current specification which is currently heated by the heating section of the annealing furnace, and the second formal strip steel coil is a formal strip steel coil with the new specification which is to be heated next to the heating section; if a transition steel strip coil is arranged between the first formal steel strip coil and the second formal steel strip coil, controlling the furnace temperature of the heating section according to a preset first transition strategy, which shows that the first transition strategy can meet the annealing temperature of the first formal steel strip coil and the second formal steel strip coil by sacrificing the transition steel strip coil in transition; if no transition steel coil exists between the first formal steel coil and the second formal steel coil, the furnace temperature of the heating section is controlled according to a preset second transition strategy, and the second transition strategy is indicated to only meet the annealing temperature of one formal steel coil in the first formal steel coil and the second formal steel coil. The method ensures that the transition control is more accurate and timely, thereby reducing the length of the strip steel which does not meet the requirement of the annealing temperature and saving the energy of the strip steel.

The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present invention more readily apparent.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a flow chart of a method for controlling the furnace temperature of a heating section of an annealing furnace provided by an embodiment of the invention;

FIG. 2 is a graph showing the variation of the running speed and thickness of a coil of strip according to an embodiment of the present invention;

FIG. 3 is a graph of outlet belt temperature provided by an embodiment of the present invention;

fig. 4 is a block diagram of a device for controlling the temperature of a heating section of an annealing furnace according to an embodiment of the invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

Fig. 1 is a flowchart of a method for controlling the temperature of a heating section of an annealing furnace according to an embodiment of the present invention, as shown in fig. 1, the method includes steps S110 to S130.

And step S110, judging whether a transition strip steel coil exists between the first formal strip steel coil and the second formal strip steel coil.

The first formal steel coil is a formal steel coil with the current specification which is currently heated by a heating section of the annealing furnace, and the second formal steel coil is a formal steel coil with the new specification which is to be heated next to the heating section.

In this embodiment, when the strip steel in the heating section of the annealing furnace is to be transited from the strip steel with the current specification to the strip steel with the new specification, the change of the furnace temperature of the heating section may be caused, the process of changing the furnace temperature is to ensure the working stability of the heating section, and simultaneously, the tail part of the final coil of formal strip steel coil with the current specification and the head part of the first coil of formal strip steel coil with the new specification are ensured to be as little as possible or the condition that the annealing temperature is unqualified in a short distance is ensured.

In general, when the second thickness and the second annealing temperature of the second formal steel coil are not changed compared with the first thickness and the first annealing temperature of the first formal steel coil, the furnace temperature of the heating section is not required to be changed, and the furnace temperature transition is not performed, so that the control method of the furnace temperature of the heating section of the annealing furnace in the embodiment is not required to be executed. However, when the second thickness and the second annealing temperature of the second formal steel coil are changed compared to the first thickness and the first annealing temperature of the first formal steel coil, then the furnace temperature of the heating section may need to be adjusted, at which point the execution of step S110 is started.

Specifically, compared with the first formal strip coil, the second formal strip coil has unchanged annealing temperature and thickness, and belongs to the category without transition; the annealing temperature is unchanged, the thickness is increased, and the annealing temperature is in the category of needing to be heated; the annealing temperature is unchanged, the thickness is reduced, and the annealing temperature is in the category of needing to be cooled; the annealing temperature is increased, the thickness is increased, and the annealing temperature is in the category of being difficult to raise the temperature and transition; the annealing temperature is increased, the thickness is thinned, and the annealing temperature belongs to the category which can be heated or cooled and is easier to transition; the annealing temperature is reduced, the thickness is increased, and the annealing temperature belongs to the category which can be heated or cooled and is easier to transition; the annealing temperature is reduced, the thickness is thinned, and the annealing temperature is required to be reduced, and the transition is difficult.

The first thickness and the first annealing code of the first formal strip steel coil and the second thickness and the second annealing code of the second formal strip steel coil can be obtained from a production plan, the first annealing temperature corresponding to the first annealing code and the second annealing temperature corresponding to the second annealing code are obtained through table lookup, the difference between the first thickness and the second thickness is calculated to obtain a thickness difference, and the difference between the first annealing temperature and the second annealing temperature is calculated to obtain an annealing temperature difference. The coil number of the strip coil can also be obtained from the production plan.

In this embodiment, in order to ensure the stability of the furnace temperature transition, the annealing temperature of the first formal steel coil and the second formal steel coil is ensured by the transition steel coil, and whether the transition steel coil is added between the first formal steel coil and the second formal steel coil is determined when the production schedule is good.

When the strip steel is heated, the deviation between the outlet strip temperature and the annealing temperature of the strip steel is allowed to be within an error range, and the requirement of the annealing temperature is met. The deviation between the outlet band temperature of the band steel and the annealing temperature is not in the error range, and the band steel does not meet the annealing temperature requirement.

Illustratively, the error range is + -10deg.C, and the annealing temperature is 800deg.C, and the outlet band temperature is 790-810 deg.C, which all meet the annealing temperature requirement.

And step S120, if a transition strip coil is arranged between the first formal strip coil and the second formal strip coil, controlling the furnace temperature of the heating section according to a preset first transition strategy.

In the embodiment, the transition strategies adopted by the transition strip steel coil and the transition strip-free steel coil are different, the protection emphasis point is also different, the transition of the furnace temperature is more stable through the two transition strategies, the manual intervention of operators is reduced, the hit rate of the annealing temperature is improved, the method has important significance for saving energy, reducing cost and enhancing efficiency and the like, and the method can be popularized to the furnace temperature transition of any continuous annealing furnace and heating sections under various different working conditions, and realizes dynamic heat tracking and real-time visualization.

Optionally, step S120 includes steps S1201 to S1203.

Step S1201, obtaining a second annealing temperature and a second thickness of a second formal strip coil, a third thickness of a transition strip coil and a running speed of strip steel in a heating section.

In this embodiment, the annealing temperature, thickness and running speed of the strip steel affect the furnace temperature and outlet strip temperature of the heating section, so the second annealing temperature and second thickness of the second formal strip coil, the third thickness of the transition strip coil and the running speed of the strip steel are also obtained here.

Wherein the second annealing temperature, the second thickness, the third thickness, and the running speed are available from the production schedule.

In this embodiment, in order to better identify whether the coil of strip is a formal coil or a transitional coil, product property codes are set, and the product property codes of the formal coil of strip and the transitional coil of strip are different. For example, the product property code of the formal steel coil is QZA, and the product property code of the transitional steel coil is YGA.

Exemplary, the parameters for the obtained coil are shown below:

TABLE 1

The strip steel coil with the coil number S1124515900300 is a first formal strip steel coil, the strip steel coil with the coil number S1124515900501 is a transition strip steel coil, and the strip steel coil with the coil number S1124515900100 is a second formal strip steel coil. The thickness difference obtained by calculation is 0.979-0.68=0.299 mm, the annealing temperature difference is 820-790=30 ℃, and the transition difficulty grade is high.

Step S1202, determining a first target furnace temperature of the heating section according to the second annealing temperature, the second thickness, the third thickness and the running speed.

In this embodiment, the annealing temperature, thickness and running speed are all factors affecting the furnace temperature of the heating section, and the annealing temperature of the first formal coil is generally ensured during the transition period of the furnace temperature of the transition strip steel coil, so the factors affecting the furnace temperature of the heating section finally are the second annealing temperature, the second thickness, the third thickness and the running speed.

Optionally, step S1202 includes:

And determining a first required furnace temperature required by the heating section for heating the transition strip steel coil to the second annealing temperature according to the third thickness and the running speed, and taking the first required furnace temperature as a first target furnace temperature when the distance between the head of the transition strip steel coil and the inlet of the heating section is smaller than a first distance threshold and the distance between the tail of the transition strip steel coil and the inlet of the heating section is larger than or equal to a preset second distance threshold.

In this embodiment, the outlet strip temperature of the strip steel in the heating section may be predicted using a pre-built outlet strip temperature prediction model, and the furnace temperature of the heating section may be predicted using a pre-built furnace temperature prediction model. The specific construction method can refer to the prior art, and will not be described herein.

In this embodiment, the transition strip coil has an annealing code of its own, from which a corresponding third annealing temperature can be obtained, in particular from a production schedule. However, in the furnace temperature transition process, the annealing temperatures of the first formal coil and the second formal coil are mainly guaranteed, so that the annealing temperature of the transition band steel coil cannot be guaranteed, the annealing temperature of the transition band steel coil is adjusted to be the second annealing temperature of the second formal band steel coil, namely, the annealing temperatures of the second formal band steel coil and the transition band steel coil are the same, before the annealing temperatures of the transition band steel coil are adjusted, operators adjust the annealing temperatures according to working experience, the uncertainty of the furnace temperature transition is increased, the annealing temperature of the transition band steel coil can be directly adjusted to be the second annealing temperature of the second formal band steel coil, the accuracy of the furnace temperature transition is improved, and the annealing quality is guaranteed.

Illustratively, as shown in Table 1, the annealing temperature of the treated transition coil was 820℃, which is the same as the annealing temperature of the second formal coil of strip, 820℃.

Therefore, the third thickness, the second annealing temperature and the running speed are input into the furnace temperature prediction model, the first required furnace temperature required by the heating section to heat the transition strip steel coil to the second annealing temperature can be predicted, and the first required furnace temperature is taken as the first target furnace temperature in the early stage of the furnace temperature transition.

The first annealing temperature requirement of the outlet belt Wen Manzu at the tail of the first main coil of the last coil is ensured, so when the distance between the head of the transition belt steel coil and the inlet of the heating section is smaller than a first distance threshold value, the transition of the furnace temperature is formally started, and the period from the distance between the head of the transition belt steel coil and the inlet of the heating section is smaller than the first distance threshold value to the distance between the tail of the transition belt steel coil and the inlet of the heating section is larger than or equal to a preset second distance threshold value is used as the earlier stage of the furnace temperature transition of the transition belt steel coil, wherein the first target furnace temperature is the first required furnace temperature.

Wherein the first distance threshold may be 0, the second distance threshold is generally the longest transition length, and the longest transition length may be 800m.

And a second step of determining a second required furnace temperature required by the heating section to heat the second formal strip steel coil to a second annealing temperature according to the second thickness and the running speed, and taking the second required furnace temperature as a first target furnace temperature when the distance between the tail of the transition strip steel coil and the inlet of the heating section is smaller than a second distance threshold.

In this embodiment, in the later stage of the transition of the furnace temperature of the transition strip coil, the furnace temperature is adjusted to the second required furnace temperature required by the heating section to heat the second formal strip coil to the second annealing temperature, so as to ensure that the outlet strip temperature can be quickly converted into the second annealing temperature when the heating section heats the second formal strip coil.

Specifically, the second thickness, the second annealing temperature and the running speed are input into a furnace temperature prediction model, so that a second required furnace temperature required by the heating section for heating the second formal strip steel coil to the second annealing temperature can be obtained, and the second required furnace temperature is used as a first target furnace temperature in the later stage of the transition of the furnace temperature of the transition strip steel coil.

And taking the period from the tail of the transition strip steel coil to the position where the distance between the tail of the transition strip steel coil and the inlet of the heating section is smaller than a second distance threshold value to the position where the outlet strip temperature of the second formal strip steel coil is the second annealing temperature as the later stage of the furnace temperature transition of the transition strip steel coil. That is, the transition period of the furnace temperature with the transition steel coil starts from the distance between the head of the transition steel coil and the inlet of the heating section being smaller than the first distance threshold value until the outlet belt temperature of the second formal steel coil is the second annealing temperature.

And step S1203, when the distance between the head of the transition zone steel coil and the inlet of the heating section is smaller than a preset first distance threshold value, controlling the heating section to heat at a first target furnace temperature.

It is understood that the furnace temperature of the heating section is adjusted to the first target furnace temperature during the furnace temperature transition when the transition strip coil is present. And it follows from the above that the first target furnace temperature is different in the early and late stages of the furnace temperature transition. And the furnace temperature of the heating section is still the current furnace temperature before the furnace temperature transition is carried out.

And step 130, if no transition steel coil exists between the first formal steel coil and the second formal steel coil, controlling the furnace temperature of the heating section according to a preset second transition strategy.

In this embodiment, when the transition strip coil is not used during the furnace temperature transition, the furnace temperature transition is performed by adopting the second transition strategy.

Optionally, step S130 includes steps S1301 to S1304.

Step S1301, obtaining a first annealing temperature and a first thickness of the first formal strip steel coil, a second annealing temperature and a second thickness of the second formal strip steel coil, and a current furnace temperature of the heating section and a running speed of strip steel in the heating section.

In this embodiment, the current furnace temperature may be the furnace temperature detected by the sensor in real time, or may be the target furnace temperature set in the heating section control system. However, in order to increase the accuracy of the transition, it is preferable to use the actual furnace temperature of the heating section, i.e. the furnace temperature detected by the sensor.

Step S1302, determining a third distance threshold according to the thickness difference between the first thickness and the second thickness, and the annealing temperature difference between the first annealing temperature and the second annealing temperature.

In this embodiment, the third distance threshold is used to characterize the transition length from the first formal coil to the second formal coil, and the furnace temperature transition is initiated when the transition length remains in the first formal coil.

Optionally, step S1302 includes:

determining the transition difficulty level of the furnace temperature of the heating section of the annealing furnace according to the thickness difference between the first thickness and the second thickness and the annealing temperature difference between the first annealing temperature and the second annealing temperature; and determining a third distance threshold corresponding to the transition difficulty level.

It can be understood that the thickness difference and the annealing temperature difference directly influence the difficulty of furnace temperature transition, and the larger the thickness difference or the annealing temperature difference is, the larger the furnace temperature transition difficulty is, and the smaller the thickness difference and the annealing temperature difference is, the smaller the furnace temperature transition difficulty is.

When the thickness difference is smaller than a first thickness threshold value and the annealing temperature difference is smaller than a first annealing temperature threshold value, determining that the transition difficulty level of the furnace temperature of the heating section of the annealing furnace is general; when the thickness difference is larger than or equal to the first thickness threshold value and smaller than the second thickness threshold value, or the annealing temperature difference is larger than or equal to the first annealing temperature threshold value and smaller than the second annealing temperature threshold value, determining that the transition difficulty level of the furnace temperature of the heating section of the annealing furnace is medium; and when the thickness difference is larger than or equal to a second thickness threshold value or the annealing temperature difference is larger than or equal to a second annealing temperature threshold value, determining that the transition difficulty level of the furnace temperature of the heating section of the annealing furnace is high, and the like.

Wherein the first thickness threshold may be 0.1mm, the second thickness threshold may be 0.3mm, the first annealing temperature threshold may be 10 ℃, and the second annealing temperature threshold may be 30 ℃.

In this embodiment, the width difference between the first formal strip steel coil and the second formal strip steel coil may also be obtained, and the transition difficulty level may be determined according to the thickness difference, the annealing temperature difference, and the width difference, so that the determination of the transition difficulty level may be more accurate.

Further, the transition difficulty level is general, which indicates that the furnace temperature of the heating section is not changed greatly; the transition difficulty level is medium or high, which indicates that the furnace temperature of the heating section is changed greatly.

In this embodiment, the number of coils of the transition band steel coil may also be determined according to the transition difficulty level. The number of rolls may be one roll, two rolls or three rolls. The higher the transition difficulty level, the more volumes may be.

Specifically, according to the statistical data of the production site, the experience of operators and the response time of the annealing furnace, a corresponding relation table of a third distance threshold and the transition difficulty level is designed, so that the third distance threshold corresponding to the transition difficulty level can be obtained by looking up the table. As the level of difficulty in transition increases, the third distance threshold increases.

When the transition from the transition strip steel coil to the formal strip steel coil is performed, the transition length is a second distance threshold, namely the maximum transition length; when the transition from the formal strip coil to the transition strip coil is performed, the transition length is a first distance threshold, namely the minimum transition length can be 0; when the transition from the formal strip steel coil to the formal strip steel coil is carried out, the transition length is a third distance threshold value.

Wherein, the value range of the transition length can be 0-800m.

Step S1303, determining a second target furnace temperature of the heating section according to the current furnace temperature, the second annealing temperature, the second thickness and the running speed.

In this embodiment, when there is no transition coil, the first annealing temperature requirement of the outlet band Wen Manzu at the tail of the first formal coil of the last coil is first ensured, and the outlet band temperature of the head of the second formal coil of the first coil is sacrificed. The factors affecting the second target furnace temperature of the heating section at this time are the current furnace temperature, the second annealing temperature, the second thickness and the running speed.

Optionally, step S1303 includes:

and the first step, determining the predicted strip temperature of the outlet of the second formal strip steel coil when the heating section heats the second formal strip steel coil by adopting the current furnace temperature according to the second thickness and the running speed.

In this embodiment, the second thickness, the running speed and the current furnace temperature are input into the strip temperature prediction model, and when the predicted heating section heats the second formal strip steel coil by adopting the current furnace temperature, the strip temperature is predicted by the outlet of the second formal strip steel coil. That is, it is predicted whether the second formal strip coil can be heated to meet the second annealing temperature without changing the furnace temperature of the heating section.

And a second step of determining a third required furnace temperature required by the heating section to heat the second formal strip steel coil to the second annealing temperature according to the second thickness and the running speed if a third difference value between the outlet predicted strip temperature and the second annealing temperature is smaller than a preset error threshold value, and determining a second target furnace temperature according to the third required furnace temperature and the current furnace temperature.

The error threshold may be a boundary value of the foregoing error range, and is exemplified by 10 ℃.

Specifically, if the third difference between the predicted outlet strip temperature and the second annealing temperature is smaller than the preset error threshold, it is indicated that the outlet strip temperature of the second formal strip coil heated by the current furnace temperature meets the second annealing temperature requirement, and an appropriate furnace temperature exists to enable the outlet temperatures of the first formal strip coil and the second formal strip coil after heating to meet the corresponding annealing temperature requirement.

At this time, if the third difference between the outlet predicted strip temperature and the second annealing temperature is smaller than the preset error threshold, and the outlet predicted strip temperature is smaller than the second annealing temperature, which indicates that the heating section needs to be heated, the sum of the first annealing temperature and the error threshold is used as the third annealing temperature, and then the third annealing temperature, the first thickness and the running speed are input into a furnace temperature prediction model, and the furnace temperature required for heating the outlet strip temperature of the first formal strip steel coil to the third annealing temperature is predicted, namely the highest furnace temperature required by the first annealing temperature of the outlet strip Wen Manzu of the first formal strip steel coil. If the highest furnace temperature is smaller than the third required furnace temperature, selecting one furnace temperature from the current furnace temperature and the highest furnace temperature as a second target furnace temperature; and if the highest furnace temperature is greater than or equal to the third required furnace temperature, selecting one furnace temperature from the current furnace temperature and the third required furnace temperature as a second target furnace temperature.

If the third difference between the outlet predicted strip temperature and the second annealing temperature is smaller than the preset error threshold, and the outlet predicted strip Wen Dayu is the second annealing temperature, which indicates that the heating section needs to be cooled, the difference of the first annealing temperature minus the error threshold is taken as the third annealing temperature, then the third annealing temperature, the first thickness and the running speed are input into a furnace temperature prediction model, and the furnace temperature required for heating the outlet strip temperature of the first formal strip steel coil to the third annealing temperature is predicted, namely the lowest furnace temperature required by the first annealing temperature of the outlet strip Wen Manzu of the first formal strip steel coil. If the lowest furnace temperature is greater than the third required furnace temperature, selecting one furnace temperature from the current furnace temperature and the lowest furnace temperature as a second target furnace temperature; and if the lowest furnace temperature is less than or equal to the third required furnace temperature, selecting one furnace temperature from the current furnace temperature and the third required furnace temperature as a second target furnace temperature.

If the predicted strip temperature of the outlet is equal to the second annealing temperature, the furnace temperature of the heating section is not required to be regulated, transition is not required, and the process is exited.

Optionally, after the second step, the method further comprises a third step of:

if the third difference value is greater than or equal to the error threshold value, acquiring a first annealing temperature and a first thickness of the first formal strip steel coil, and determining a fourth required furnace temperature required by the heating section when the first formal strip steel coil is heated to the third annealing temperature according to the first thickness and the running speed, wherein the third annealing temperature is the sum or difference of the first annealing furnace temperature and the error threshold value;

when the distance between the tail of the first formal strip steel coil and the inlet of the heating section is smaller than a third distance threshold and larger than a preset fourth distance threshold, taking the fourth required furnace temperature as a second target furnace temperature;

and when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than or equal to a fourth distance threshold value, taking the third required furnace temperature as a second target furnace temperature.

In this embodiment, if the third difference is greater than or equal to the error threshold, it indicates that no suitable furnace temperature can simultaneously make the heated first formal steel coil and the heated second formal steel coil meet the requirements. At the moment, heating the first formal strip steel coil to the highest furnace temperature or the lowest furnace temperature meeting the first annealing temperature requirement as a second target furnace temperature in the early stage of furnace temperature transition of the transition-free strip steel coil; and in the later stage of the transition of the furnace temperature of the transition-free strip steel coil, using the third required furnace temperature as a second target furnace temperature so as to enable the heated second formal strip steel coil to rapidly meet the second annealing temperature requirement.

Specifically, if the third difference value is greater than or equal to the error threshold value and the outlet predicted strip temperature is less than the second annealing temperature, which means that the heating section needs to be heated, the sum of the first annealing temperature and the error threshold value is used as the third annealing temperature, then the third annealing temperature, the first thickness and the running speed are input into a furnace temperature prediction model, and the furnace temperature required by the third annealing temperature is predicted to enable the outlet strip temperature of the first formal strip steel coil, namely, the outlet strip temperature of the first formal strip steel coil is heated to the highest furnace temperature meeting the requirement of the first annealing temperature, and is used as the fourth required furnace temperature.

If the third difference is greater than or equal to the error threshold and the second annealing temperature of the outlet prediction tape Wen Dayu indicates that the heating section needs to be cooled, the difference of the first annealing temperature minus the error threshold is taken as the third annealing temperature, then the third annealing temperature, the first thickness and the running speed are input into a furnace temperature prediction model, and the outlet tape temperature of the first formal tape steel coil is predicted to be heated to the lowest furnace temperature meeting the requirement of the first annealing temperature and is taken as the fourth required furnace temperature.

And then, taking the fourth required furnace temperature as the second target furnace temperature when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than a third distance threshold and larger than a preset fourth distance threshold and the maximum furnace temperature is smaller than the third required furnace temperature, namely, in the early stage of the transition of the furnace temperature of the transition-free strip steel coil.

If the predicted strip temperature of the outlet is equal to the second annealing temperature, the furnace temperature transition is not needed, and the flow is directly exited.

And the period from the fact that the distance between the tail of the first formal strip steel coil and the inlet of the heating section is smaller than or equal to a fourth distance threshold value to the fact that the outlet strip temperature of the second formal strip steel coil is the second annealing temperature is taken as the later stage of the furnace temperature transition of the transition-free strip steel coil. Therefore, the transition period of the furnace temperature of the transition-free strip coil starts from the fact that the distance between the tail part of the first formal strip coil and the inlet of the heating section is smaller than a third distance threshold value, and the strip temperature of the outlet of the second formal strip coil is the second annealing temperature.

Illustratively, the fourth distance threshold may be 0.

It should be noted that the running speed of the strip steel in the heating section may be the running speed of the first formal strip coil. If the operation speed of the transition steel coil when the transition steel coil is heated by the heating section or the operation speed of the second formal steel coil when the second formal steel coil is heated can be obtained, the operation speed used when the temperature of the heating furnace and the outlet belt temperature of the transition steel coil are calculated is the operation speed of the transition steel coil, and the operation speed used when the temperature of the heating furnace and the outlet belt temperature of the second formal steel coil are calculated is the operation speed of the second formal steel coil.

And step 1304, when the distance between the tail of the first formal strip steel coil and the inlet of the heating section is smaller than a third distance threshold, controlling the heating section to heat at a second target furnace temperature.

It is understood that the furnace temperature of the heating section is adjusted to the second target furnace temperature during the transition of the furnace temperature of the transition-free steel coil. Moreover, as can be seen from the above, the second target furnace temperature is different between the early stage and the late stage of the furnace temperature transition of the transition-free strip coil, and the outlet strip temperature of the second formal strip coil can rapidly meet the second annealing temperature requirement while ensuring the first annealing temperature requirement of the outlet strip Wen Manzu of the first formal strip coil, so that the length of the second formal strip coil which does not meet the second annealing temperature requirement is shorter, and the energy of strip steel is saved.

For example, fig. 2 is a graph of the change of the running speed and thickness of a strip coil according to an embodiment of the present invention, and as shown in fig. 2, the running speed and thickness of three strip coils in table 1 are plotted as a change curve, curve 1 is thickness, curve 2 is running speed, the abscissa is the length of the strip coil entering the heating section, and the ordinate is thickness and running speed.

Fig. 3 is an outlet band temperature curve chart provided in the embodiment of the present invention, as shown in fig. 3, by adopting the control method of the heating section of the annealing furnace in this embodiment, the obtained outlet band temperatures of the three strip coils in table 1 are plotted, curve 3 is the upper limit value of the annealing temperature range, curve 5 is the lower limit value of the annealing temperature range, curve 4 is the outlet band temperature of the strip coil, the abscissa is the length of the strip coil entering the heating section, and the ordinate is the temperature.

Based on the same inventive concept, the embodiment of the invention also provides a device for controlling the furnace temperature of the heating section of the annealing furnace, fig. 4 is a block diagram of the device for controlling the furnace temperature of the heating section of the annealing furnace, and as shown in fig. 4, the device 400 comprises a judging module 401, a first control module 402 and a second control module 403.

The judging module 401 is configured to judge whether a transition steel coil exists between a first formal steel coil and a second formal steel coil, where the first formal steel coil is a formal steel coil of a current specification that is currently heated in a heating section of the annealing furnace, and the second formal steel coil is a formal steel coil of a new specification that is to be heated next in the heating section;

the first control module 402 is configured to control a furnace temperature of the heating section according to a preset first transition strategy if a transition coil is between the first formal coil and the second formal coil;

and the second control module 403 is configured to control the furnace temperature of the heating section according to a preset second transition strategy if there is no transition coil between the first formal coil and the second formal coil.

Optionally, the first control module 402 includes:

the first acquisition unit is used for acquiring the second annealing temperature and the second thickness of the second formal strip steel coil, the third thickness of the transition strip steel coil and the running speed of strip steel in the heating section;

the first determining unit is used for determining a first target furnace temperature of the heating section according to the second annealing temperature, the second thickness, the third thickness and the running speed;

and the first control unit is used for controlling the heating section to heat at a first target furnace temperature when the distance between the head of the transition strip steel coil and the inlet of the heating section is smaller than a preset first distance threshold value.

Optionally, the first control unit is further configured to:

According to the third thickness and the running speed, determining a first required furnace temperature required by the heating section for heating the transition strip steel coil to the second annealing temperature, and taking the first required furnace temperature as a first target furnace temperature when the distance between the head part of the transition strip steel coil and the inlet of the heating section is smaller than a first distance threshold value and the distance between the tail part of the transition strip steel coil and the inlet of the heating section is larger than or equal to a preset second distance threshold value;

And determining a second required furnace temperature required by the heating section to heat the second formal strip steel coil to a second annealing temperature according to the second thickness and the running speed, and taking the second required furnace temperature as a first target furnace temperature when the distance between the tail of the transition strip steel coil and the inlet of the heating section is smaller than a second distance threshold.

Optionally, the second control module 403 includes:

the second acquisition unit is used for acquiring the first annealing temperature and the first thickness of the first formal strip steel coil, the second annealing temperature and the second thickness of the second formal strip steel coil, and the running speed of strip steel in the current furnace temperature heating section of the heating section;

A second determining unit configured to determine a third distance threshold according to a thickness difference between the first thickness and the second thickness, an annealing temperature difference between the first annealing temperature and the second annealing temperature;

a third determining unit, configured to determine a second target furnace temperature of the heating section according to the current furnace temperature, the second annealing temperature, the second thickness, and the running speed;

and the second control unit is used for controlling the heating section to heat at a second target furnace temperature when the distance between the tail part of the first formal steel coil and the inlet of the heating section is smaller than a third distance threshold.

Optionally, the third determining unit is further configured to:

Determining the predicted strip temperature of the outlet of the second formal strip steel coil when the heating section heats the second formal strip steel coil by adopting the current furnace temperature according to the second thickness and the running speed;

If the third difference between the predicted strip temperature and the second annealing temperature is smaller than the preset error threshold, determining a third required furnace temperature required by the heating section to heat the second formal strip steel coil to the second annealing temperature according to the second thickness and the running speed, and determining a second target furnace temperature according to the third required furnace temperature and the current furnace temperature.

Optionally, the third determining unit is further configured to:

if the third difference value is greater than or equal to the error threshold value, acquiring a first annealing temperature and a first thickness of the first formal strip steel coil, and determining a fourth required furnace temperature required by the heating section when the first formal strip steel coil is heated to the third annealing temperature according to the first thickness and the running speed, wherein the third annealing temperature is the sum or difference of the first annealing furnace temperature and the error threshold value;

when the distance between the tail of the first formal strip steel coil and the inlet of the heating section is smaller than a third distance threshold and larger than a preset fourth distance threshold, taking the fourth required furnace temperature as a second target furnace temperature;

and when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than or equal to a fourth distance threshold value, taking the third required furnace temperature as a second target furnace temperature.

Optionally, the second determining unit is further configured to:

determining the transition difficulty level of the furnace temperature of the heating section of the annealing furnace according to the thickness difference between the first thickness and the second thickness and the annealing temperature difference between the first annealing temperature and the second annealing temperature;

And determining a third distance threshold corresponding to the transition difficulty level.

It will be appreciated that the apparatus provided in the above embodiment is only exemplified by the division of the above functional modules, and in practical application, the above functional allocation may be performed by different functional modules according to needs, that is, the internal structure of the apparatus is divided into different functional modules, so as to perform all or part of the functions described above.

Embodiments of the present invention also provide an electronic device that may include a processor and a memory, where the processor and the memory may be communicatively coupled to each other via a bus or other means.

The processor may be a central processing unit (Central Processing Unit, CPU), or an Application SPECIFIC INTEGRATED Circuit (ASIC), or may be configured as one or more integrated circuits that implement embodiments of the present application.

The memory may include mass storage for data or instructions. By way of example, and not limitation, the memory may comprise a hard disk drive (HARD DISK DRIVE, HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or universal serial bus (Universal Serial Bus, USB) drive, or a combination of two or more of these. The memory may include removable or non-removable (or fixed) media, where appropriate. The memory may be internal or external to the electronic device, where appropriate. In particular embodiments, the memory may be a non-volatile solid state memory.

In one example, the Memory may be a Read Only Memory (ROM). In one example, the ROM may be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

The processor reads and executes the computer program instructions stored in the memory to realize the control method of the furnace temperature of the heating section of the annealing furnace in any one of the embodiments.

In one example, the electronic device may also include a communication interface and a bus. The processor, the memory and the communication interface are connected through a bus and complete communication with each other. The communication interface is mainly used for realizing communication among the modules, the devices, the units and/or the equipment in the embodiment of the application. The bus may include one or more buses, where appropriate.

In addition, in combination with the control method of the furnace temperature of the heating section of the annealing furnace in the embodiment, the embodiment of the invention can be realized by providing a computer readable storage medium. The computer readable storage medium has stored thereon computer program instructions; the computer program instructions, when executed by a processor, implement the method for controlling the temperature of the heating section of the annealing furnace in any one of the above embodiments.

The technical scheme provided by the embodiment of the application at least has the following technical effects or advantages:

The embodiment of the invention provides a control method, a device, equipment and a medium for the furnace temperature of a heating section of an annealing furnace, which are used for judging whether a transition strip steel coil exists between a first formal strip steel coil and a second formal strip steel coil, wherein the first formal strip steel coil is a formal strip steel coil with the current specification which is currently heated by the heating section of the annealing furnace, and the second formal strip steel coil is a formal strip steel coil with the new specification which is to be heated next to the heating section; if a transition steel strip coil is arranged between the first formal steel strip coil and the second formal steel strip coil, controlling the furnace temperature of the heating section according to a preset first transition strategy, which shows that the first transition strategy can meet the annealing temperature of the first formal steel strip coil and the second formal steel strip coil by sacrificing the transition steel strip coil in transition; if no transition steel coil exists between the first formal steel coil and the second formal steel coil, the furnace temperature of the heating section is controlled according to a preset second transition strategy, and the second transition strategy is indicated to only meet the annealing temperature of one formal steel coil in the first formal steel coil and the second formal steel coil. The method ensures that the transition control is more accurate and timely, thereby reducing the length of the strip steel which does not meet the requirement of the annealing temperature and saving the energy of the strip steel. In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be construed as reflecting the intention that: i.e., the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

Claims (10)

1. The method for controlling the furnace temperature of the heating section of the annealing furnace is characterized by comprising the following steps:

Judging whether a transition steel strip coil exists between a first formal steel strip coil and a second formal steel strip coil, wherein the first formal steel strip coil is a formal steel strip coil of the current specification which is currently heated by a heating section of an annealing furnace, and the second formal steel strip coil is a formal steel strip coil of the new specification which is to be heated next to the heating section;

If the transition band steel coil exists between the first formal band steel coil and the second formal band steel coil, controlling the furnace temperature of the heating section according to a preset first transition strategy;

and if the transition band steel coil is not arranged between the first formal band steel coil and the second formal band steel coil, controlling the furnace temperature of the heating section according to a preset second transition strategy.

2. The method for controlling the furnace temperature of the heating section of the annealing furnace according to claim 1, wherein the controlling the furnace temperature of the heating section according to the preset first transition strategy comprises:

Acquiring a second annealing temperature and a second thickness of the second formal strip steel coil, a third thickness of the transition strip steel coil and the running speed of strip steel in the heating section;

determining a first target furnace temperature of the heating section according to the second annealing temperature, the second thickness, the third thickness and the running speed;

And when the distance between the head of the transition band steel coil and the inlet of the heating section is smaller than a preset first distance threshold, controlling the heating section to heat at the first target furnace temperature.

3. The method of controlling a furnace temperature of a heating section of an annealing furnace according to claim 2, wherein said determining a first target furnace temperature of the heating section based on the second annealing temperature, the second thickness, the third thickness, and the running speed comprises:

determining a first required furnace temperature required by the heating section to heat the transition steel coil to the second annealing temperature according to the third thickness and the running speed, and taking the first required furnace temperature as the first target furnace temperature when the distance between the head of the transition steel coil and the inlet of the heating section is smaller than the first distance threshold and the distance between the tail of the transition steel coil and the inlet of the heating section is larger than or equal to a preset second distance threshold;

And determining a second required furnace temperature required by the heating section to heat the second formal strip steel coil to the second annealing temperature according to the second thickness and the running speed, and taking the second required furnace temperature as the first target furnace temperature when the distance between the tail of the transition strip steel coil and the inlet of the heating section is smaller than the second distance threshold.

4. The method for controlling the furnace temperature of the heating section of the annealing furnace according to claim 1, wherein the controlling the furnace temperature of the heating section according to the preset second transition strategy comprises:

acquiring a first annealing temperature and a first thickness of the first formal strip steel coil, a second annealing temperature and a second thickness of the second formal strip steel coil, and a current furnace temperature of the heating section and a running speed of strip steel in the heating section;

Determining a third distance threshold according to a thickness difference between the first thickness and the second thickness, and an annealing temperature difference between the first annealing temperature and the second annealing temperature;

determining a second target furnace temperature of the heating section according to the current furnace temperature, the second annealing temperature, the second thickness and the running speed;

And when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than the third distance threshold, controlling the heating section to heat at the second target furnace temperature.

5. The method of controlling a furnace temperature of a heating section of an annealing furnace according to claim 4, wherein said determining a second target furnace temperature of said heating section based on said current furnace temperature, said second annealing temperature, said second thickness, and said running speed comprises:

determining an outlet predicted strip temperature of the second formal strip steel coil when the heating section heats the second formal strip steel coil by adopting the current furnace temperature according to the second thickness and the running speed;

if the third difference between the predicted outlet strip temperature and the second annealing temperature is smaller than a preset error threshold, determining a third required furnace temperature required by the heating section to heat the second formal strip coil to the second annealing temperature according to the second thickness and the running speed, and determining the second target furnace temperature according to the third required furnace temperature and the current furnace temperature.

6. The method for controlling a furnace temperature of a heating section of an annealing furnace according to claim 5, wherein after said second target furnace temperature is determined based on said third required furnace temperature and said current furnace temperature, said method further comprises:

If the third difference value is greater than or equal to the error threshold value, determining a fourth required furnace temperature required by the heating section when the first formal strip steel coil is heated to a third annealing temperature according to the first thickness and the running speed, wherein the third annealing temperature is the sum or difference of the first annealing furnace temperature and the error threshold value;

When the distance between the tail of the first formal steel coil and the inlet of the heating section is smaller than the third distance threshold and larger than a preset fourth distance threshold, taking the fourth required furnace temperature as the second target furnace temperature;

And when the distance between the tail part of the first formal strip steel coil and the inlet of the heating section is smaller than or equal to the fourth distance threshold, taking the third required furnace temperature as the second target furnace temperature.

7. The method according to claim 4, wherein determining the third distance threshold based on the thickness difference between the first thickness and the second thickness, and the annealing temperature difference between the first annealing temperature and the second annealing temperature, comprises:

Determining a transition difficulty level of the furnace temperature of the heating section of the annealing furnace according to the thickness difference between the first thickness and the second thickness and the annealing temperature difference between the first annealing temperature and the second annealing temperature;

and determining a third distance threshold corresponding to the transition difficulty level.

8. A control device for the temperature of a heating section of an annealing furnace, which is characterized by comprising:

the judging module is used for judging whether a transition steel coil exists between a first formal steel coil and a second formal steel coil, wherein the first formal steel coil is a formal steel coil with the current specification which is currently heated by a heating section of the annealing furnace, and the second formal steel coil is a formal steel coil with the new specification which is to be heated next to the heating section;

The first control module is used for controlling the furnace temperature of the heating section according to a preset first transition strategy if the transition steel coil exists between the first formal steel coil and the second formal steel coil;

and the second control module is used for controlling the furnace temperature of the heating section according to a preset second transition strategy if the transition steel coil is not arranged between the first formal steel coil and the second formal steel coil.

9. An electronic device, comprising: a memory and a processor in communication with each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the method of any of claims 1-7.

10. A computer readable storage medium having stored thereon computer instructions for causing the computer to perform the method of any one of claims 1-7.