EP3623068B1 - Application devices for cooling lines with second connection - Google Patents

Description

Field of technology

• wobei eine Steuereinrichtung der Kühlstrecke dynamisch einen jeweiligen Soll-Ansteuerzustand für ein in einer jeweiligen Versorgungsleitung angeordnetes jeweiliges Regelventil ermittelt und das jeweilige Regelventil entsprechend ansteuert,
• wobei einer Anzahl von Aufbringeinrichtungen der Kühlstrecke über die jeweilige Versorgungsleitung entsprechend der Ansteuerung des jeweiligen Regelventils durch die Steuereinrichtung ein jeweiliger Basisstrom eines flüssigen, auf Wasser basierenden Kühlmittels zugeführt wird,
• wobei die jeweilige Versorgungsleitung den jeweiligen Basisstrom einem jeweiligen Pufferbereich der jeweiligen Aufbringeinrichtung zuführt, von dem ausgehend mittels der jeweiligen Aufbringeinrichtung ein jeweiliger Kühlstrom des Kühlmittels auf das heiße Walzgut aufgebracht wird.

The present invention is based on an operating method for a cooling section which is arranged within a rolling train or is arranged upstream or downstream of the rolling train and by means of which a hot rolling stock made of metal is cooled,

• wherein a control device of the cooling section dynamically determines a respective target control state for a respective control valve arranged in a respective supply line and controls the respective control valve accordingly,
• wherein a respective base flow of a liquid, water-based coolant is fed to a number of application devices of the cooling section via the respective supply line in accordance with the activation of the respective control valve by the control device,
• wherein the respective supply line feeds the respective base flow to a respective buffer area of the respective application device, from which a respective cooling flow of the coolant is applied to the hot rolling stock by means of the respective application device.

The present invention is also based on a control device for a cooling section, which is arranged within a rolling train or upstream or downstream of the rolling train and by means of which a hot rolled metal is cooled, the control device for a number of application devices of the cooling section being dynamic determines the respective target control state for a respective control valve arranged in a respective supply line and controls the respective control valve accordingly, so that a respective buffer area of the respective application device corresponds to the activation of the respective control valve a respective base flow of a liquid, water-based coolant is supplied by the control device via the respective supply line.

The present invention is further based on a computer program that includes machine code that can be processed by a software-programmable control device for a cooling section, the processing of the machine code by the control device causing the control device to set the respective target control state for the according to the procedure just explained determines the respective control valve and controls the respective control valve accordingly.

• wobei die Kühlstrecke innerhalb einer Walzstraße angeordnet ist oder der Walzstraße vor- oder nachgeordnet ist,
• wobei mittels der Kühlstrecke ein heißes Walzgut aus Metall gekühlt wird,
• wobei die Kühlstrecke eine Anzahl von Aufbringeinrichtungen aufweist, die über eine jeweilige Versorgungsleitung mit einer Quelle für ein flüssiges, auf Wasser basierendes Kühlmittel verbunden sind,
• wobei in der jeweiligen Versorgungsleitung ein jeweiliges Regelventil angeordnet ist,
• wobei die Aufbringeinrichtungen einen jeweiligen Pufferbereich aufweisen, der mit der jeweiligen Versorgungsleitung verbunden ist, so dass die jeweilige Versorgungsleitung dem jeweiligen Pufferbereich der jeweiligen Aufbringeinrichtung einen jeweiligen Basisstrom des Kühlmittels zuführt und ausgehend von dem jeweiligen Pufferbereich mittels der jeweiligen Aufbringeinrichtung ein jeweiliger Kühlstrom des Kühlmittels auf das heiße Walzgut aufgebracht wird,
• wobei die Kühlstrecke eine Steuereinrichtung aufweist, welche das jeweilige Regelventil steuert. Ein gattungsgemässes Verfahren sowie eine gattungsgemässe Vorrichtung sind aus EP 2 767 352 A1 bekannt.

The present invention is also based on a cooling section,

• wherein the cooling section is arranged within a rolling train or is upstream or downstream of the rolling train,
• whereby a hot rolled metal is cooled by means of the cooling section,
• wherein the cooling section has a number of application devices which are connected via a respective supply line to a source for a liquid, water-based coolant,
• a respective control valve being arranged in the respective supply line,
• wherein the application devices have a respective buffer area which is connected to the respective supply line, so that the respective supply line supplies a respective base flow of coolant to the respective buffer area of the respective application device and, starting from the respective buffer area, a respective cooling flow of the coolant to the hot rolling stock is applied,
• wherein the cooling section has a control device which controls the respective regulating valve. A generic method and a generic device are from EP 2 767 352 A1 known.

State of the art

The above items are well known to those skilled in the art.

In the cooling section of a rolling mill, a metallic rolling stock is cooled after rolling. The rolling stock can consist of steel or aluminum, for example. Depending on requirements, it can be a flat rolled product (strip or heavy plate), a rod-shaped rolled product or a profile. Exact temperature control in the cooling section is customary in order to set the desired material properties and keep them constant with a lower degree of variation. In particular, in a cooling section downstream of the rolling train, several spray bars are installed along the cooling section, by means of which a liquid coolant, usually water, is applied to the rolling stock from above and / or from below to cool the hot rolling stock. The amount of water flowing through the respective spray bar should be adjustable as quickly and as precisely as possible.

To adjust the amounts of water supplied to the spray boom, it is known, for example, to arrange switching valves or control valves in the supply lines. Switching valves can only be controlled in a purely binary manner. So are either fully open or fully closed. Control valves, on the other hand, can be adjusted continuously so that the amount of water supplied to the respective spray bar can also be continuously adjusted.

In the case of control valves, the valves can be designed as control flaps or ball valves. Control dampers are relatively simple and inexpensive. However, they can only be operated with relatively small pressure differences of usually a maximum of 1 bar. Otherwise cavitations will occur, which will damage the control valve very quickly. Control flaps are therefore not particularly suitable for intensive cooling.

But they are also often a disadvantage in a laminar cooling section. In particular, they often show a switching hysteresis. The switching hysteresis causes the set flap angle is different, depending on whether the control flap is to be adjusted starting from a more open or from a more closed position to the new position to be assumed. Ball valves do not have a flap, but a pierced ball that is rotated in a pipe. Depending on the rotational position of the ball, a larger or smaller cross-section is made available to the coolant for the flow. Ball valves can be operated with higher pressure differences of up to approx. 3 bar. Hysteresis does not occur with them or is negligibly small. However, ball valves are expensive.

In another solution, the coolant is continuously fed to the spray boom. However, there is a controllable deflection plate. Depending on the position of the baffle plate, the coolant is either fed to the rolling stock or flows off to the side without contributing to the cooling of the rolling stock. With this arrangement, quick switching operations are possible without pressure surges. However, it is not possible to continuously adjust the amount of water. Furthermore, the full coolant flow has to be pumped permanently.

All types of valves and also the baffle plates require appropriate actuators. Pneumatically driven servomotors are common. Position control is also required for control valves. This continuously compares the actual position of the respective control valve with its target position and readjusts the actual position until there is sufficient agreement with the target position.

What all arrangements have in common is that there must be an external supply of coolant. The coolant can, for example, be taken from an elevated tank or transported via a larger pipeline from a pump station further away. Combinations of these approaches are also possible. For example, with so-called intensive cooling, the water is often first taken from a high tank. The pressure is then increased via booster pumps in increased to a variable extent and thus made available with a correspondingly variable pressure of the intensive cooling. The intensive cooling is provided with several spray bars to which the coolant is fed individually via a respective supply line, starting from the booster pumps. Ball valves are arranged in the supply lines, which are controlled to adjust the amount of coolant supplied to the respective spray bar.

• Bei Schaltventilen gibt es Druckschläge beim Abschalten. Daher können Schaltventile nicht beliebig schnell abgeschaltet werden. Übliche Schaltzeiten liegen oberhalb von 1 Sekunde, manchmal bei bis zu 2 Sekunden.
• Mit Regelklappen und Kugelventilen werden ähnliche Regelzeiten erreicht. Weiterhin ist für jedes Regelventil eine Positionsregelung erforderlich. Die erreichbare Genauigkeit liegt bei ca. 1 % bis 2 %.
• Auch bei Regelventilen gibt es Druckschläge beim Abschalten. Daher können auch Regelventile nicht beliebig schnell geschlossen werden. Übliche Schaltzeiten liegen im Bereich von ca. 1 Sekunde.

Various disadvantages exist in the prior art.

• With switching valves there are pressure surges when switching off. Therefore, switching valves cannot be switched off as quickly as desired. Usual switching times are above 1 second, sometimes up to 2 seconds.
• Similar control times are achieved with control flaps and ball valves. Position control is also required for each control valve. The achievable accuracy is approx. 1% to 2%.
• There are also pressure surges when switching off control valves. Therefore, control valves cannot be closed as quickly as desired. Usual switching times are in the range of approx. 1 second.

From the US 2012/0 298 224 A1 the predictive operation of a pump is known in the context of a rolling mill with a downstream cooling section. However, this pump does not directly feed application devices by means of which the cooling medium is applied to the hot rolling stock, but only conveys the cooling medium into a reservoir so that it is always filled to a sufficient extent. The application of the coolant to the rolling stock itself is not explained in more detail.

Summary of the invention

The object of the present invention is to create possibilities by means of which a cooling section with superior operating properties can be implemented in a simple and reliable manner.

The object is achieved by an operating method with the features of claim 1. Advantageous refinements of the operating method are the subject matter of the dependent claims 2 to 7.

• dass die Steuereinrichtung zusätzlich dynamisch einen jeweiligen weiteren Soll-Ansteuerzustand für eine jeweilige aktive Einrichtung ermittelt und die jeweilige aktive Einrichtung entsprechend ansteuert,
• dass die jeweilige aktive Einrichtung dem jeweiligen Pufferbereich entsprechend der Ansteuerung der jeweiligen aktiven Einrichtung durch die Steuereinrichtung über eine jeweilige weitere Versorgungsleitung einen jeweiligen Zusatzstrom eines weiteren Mediums zuführt,
• dass der jeweilige Kühlstrom sowohl von dem das jeweilige Regelventil durchströmenden jeweiligen Basisstrom als auch von dem über die jeweilige aktive Einrichtung strömenden jeweiligen Zusatzstrom abhängt,
• dass der jeweilige Zusatzstrom je nach dem jeweiligen weiteren Ansteuerzustand der jeweiligen aktiven Einrichtung positiv oder negativ ist und
• dass die Steuereinrichtung den jeweiligen Zusatzstrom durch die entsprechende Ansteuerung der jeweiligen aktiven Einrichtung derart einstellt, dass der jeweilige Kühlstrom einem mittels der jeweiligen Aufbringeinrichtung auf das heiße Walzgut aufzubringenden jeweiligen Soll-Strom jederzeit so weit wie möglich angenähert wird.

According to the invention, an operating method of the type mentioned at the outset is designed by

• that the control device additionally dynamically determines a respective further target control state for a respective active device and controls the respective active device accordingly,
• that the respective active device supplies a respective additional flow of a further medium to the respective buffer area in accordance with the activation of the respective active device by the control device via a respective further supply line,
• that the respective cooling flow depends both on the respective base flow flowing through the respective control valve and on the respective additional flow flowing through the respective active device,
• that the respective additional current is positive or negative depending on the respective further control state of the respective active device and
• that the control device adjusts the respective additional flow by activating the respective active device in such a way that the respective cooling flow is at any time as close as possible to a respective target flow to be applied to the hot rolling stock by means of the respective application device.

The respective active device can be operated with a significantly higher dynamic than a control valve with a corresponding design. It is therefore possible to use control valves in the supply lines to the application devices - as in the prior art - and to control them accordingly. Despite the relatively long delay times when adjusting the setting of the control valves However, due to the higher dynamics of the active devices, the cooling flows can still be set with a relatively short delay time and thus with high dynamics.

In this way, depending on the activation state of the respective active device, for example the pressure in the buffer area of the respective application device can be briefly increased or decreased. In the event of an increased pressure, more coolant briefly flows out of the respective buffer area as the respective cooling flow than is supplied to the respective buffer area as the respective base flow. It is the other way around when the pressure is reduced. On average over time, however, the cooling flow and the base flow correspond to one another.

In the simplest case, the respective active device is designed as a pair of air valves, one of which is connected to a pressure reservoir and the environment. However, this configuration, which is possible in principle, is not preferred. Rather, it is preferred that the respective active device is a device that actively promotes the further medium.

The further medium can in particular be air or water. In the case of air, the device actively conveying the further medium is a fan, an air pump or a turbine. In the case of water, the device actively conveying the further medium is a pump.

In the case of air, it is possible to obtain it directly from the environment and - in the case of a negative additional flow - to release it directly to the environment. Alternatively, the further medium can be taken from a respective storage device. In this case, the additional medium can be air or water.

It is possible that the further medium in the respective storage device is not under a respective pressure. This is possible in particular when the further medium is water and there is an air cushion in the upper area of the respective storage device, which is via an opening is in connection with the environment, so that, as required, air can flow into the respective storage device or can flow out of the respective storage device. Alternatively, it is possible for the further medium in the respective storage device to be under a respective pressure. As a result, in particular the adjustment range that has to be handled by the active device can be kept small.

The respective pressure is preferably set in the respective storage device via a respective control line connected to the respective storage device. This makes it possible, in every static operating state of the respective application device, to set the pressure in the respective storage device in such a way that the respective active device has to consume as little energy as possible for the highly dynamic setting of the respective cooling flow. In particular, it is possible for the respective pressure in the respective storage device to be tracked as a function of the setpoint current or a respective pressure prevailing in the respective buffer area. In this case it is even possible to set every static operating state of the respective application device without the respective active device having to consume energy to maintain this state.

The object is also achieved by a control device having the features of claim 8. Advantageous refinements of the control device are the subject matter of the dependent claims 9 to 11.

• dass die Steuereinrichtung zusätzlich dynamisch einen jeweiligen weiteren Soll-Ansteuerzustand für eine jeweilige aktive Einrichtung ermittelt und die jeweilige aktive Einrichtung entsprechend ansteuert, so dass die jeweilige aktive Einrichtung entsprechend der Ansteuerung der jeweiligen aktiven Einrichtung durch die Steuereinrichtung dem jeweiligen Pufferbereich über eine jeweilige weitere Versorgungsleitung einen jeweiligen Zusatzstrom eines weiteren Mediums zuführt, so
• dass ein von dem jeweiligen Pufferbereich ausgehender und mittels der jeweiligen Aufbringeinrichtung auf das heiße Walzgut aufgebrachter jeweiliger Kühlstrom des Kühlmittels sowohl von dem das jeweilige Regelventil durchströmenden jeweiligen Basisstrom als auch von dem über die jeweilige aktive Einrichtung strömenden jeweiligen Zusatzstrom abhängt und
• dass die Steuereinrichtung den jeweiligen Zusatzstrom derart auf positive und negative Werte einstellt, dass der jeweilige Kühlstrom einem mittels der jeweiligen Aufbringeinrichtung auf das heiße Walzgut aufzubringenden jeweiligen Soll-Strom jederzeit so weit wie möglich angenähert wird.

According to the invention, a control device of the type mentioned is designed in that

• that the control device additionally dynamically determines a respective further target control state for a respective active device and controls the respective active device accordingly, so that the respective active device according to the control of the respective active device by the control device supplies a respective additional flow of a further medium to the respective buffer area via a respective further supply line, see above
• that a respective cooling flow of the coolant emanating from the respective buffer area and applied to the hot rolling stock by means of the respective application device depends both on the respective base flow flowing through the respective control valve and on the respective additional flow flowing via the respective active device and
• that the control device sets the respective additional flow to positive and negative values in such a way that the respective cooling flow is always as close as possible to a respective setpoint flow to be applied to the hot rolling stock by means of the respective application device.

If the further medium is taken from a respective storage device and is under a respective pressure in the respective storage device, the control device preferably sets the respective pressure in the respective storage device via a respective control line connected to the respective storage device. This makes it possible to reduce the energy consumption of the respective active device in every static operating state of the respective application device. This is particularly true when the control device tracks the pressure in the respective storage device as a function of the setpoint current or a pressure prevailing in the respective buffer area. In this case, the energy consumption can ideally even be reduced to zero.

The control device is preferably designed as a software-programmable device that is programmed with a computer program that includes machine code that can be processed by the control device. In this case, the processing of the machine code by the control device causes the corresponding determination of the respective target control state for the respective control valve and the respective further Target control state for the respective active device and the corresponding control of the respective control valve and the respective active device.

The object is also achieved by a computer program with the features of claim 12. According to the invention, the processing of the computer program by a software-programmable control device of the type mentioned causes the control device to determine the respective target control state for the respective control valve and the respective further target control state for the respective active device and the respective control valve and the respective active device controls accordingly.

The object is also achieved by a cooling section with the features of claim 13. Advantageous configurations of the cooling section are the subject matter of the dependent claims 14 to 17.

• dass dem jeweiligen Pufferbereich eine jeweilige aktive Einrichtung zugeordnet ist, mittels derer dem Pufferbereich über eine weitere Versorgungsleitung ein Zusatzstrom eines weiteren Mediums zuführbar ist, so dass der jeweilige Kühlstrom sowohl von dem das jeweilige Regelventil durchströmenden Basisstrom als auch von dem über die jeweilige aktive Einrichtung strömenden jeweiligen Zusatzstrom abhängt, und
• dass die Kühlstrecke eine Steuereinrichtung nach einem der Ansprüche 8 bis 11 aufweist, welche nicht nur das jeweilige Regelventil, sondern zusätzlich auch die jeweilige aktive Einrichtung steuert.

According to the invention, a cooling section of the type mentioned is designed in that

• that a respective active device is assigned to the respective buffer area, by means of which an additional flow of a further medium can be fed to the buffer area via a further supply line, so that the respective cooling flow both from the base flow flowing through the respective control valve and from that flowing via the respective active device respective additional current depends, and
• that the cooling section has a control device according to one of claims 8 to 11, which controls not only the respective regulating valve, but also the respective active device.

As a result, the same advantages can be achieved as for the operating method.

The advantageous configurations of the cooling section and also the advantages brought about by them are already the subject of the corresponding claims on the operating method. Reference is therefore made to the relevant explanations.

Brief description of the drawings

FIG 1

eine einer Walzstraße nachgeordnete Kühlstrecke,

FIG 2

eine einer Walzstraße vorgeordnete Kühlstrecke

FIG 3

eine innerhalb einer Walzstraße angeordnete Kühlstrecke,

FIG 4

eine einzelne Aufbringeinrichtung,

FIG 5

eine Modifikation der Aufbringeinrichtung von FIG 4 und

FIG 6

eine weitere Aufbringeinrichtung.

The properties, features and advantages of this invention described above and the manner in which they are achieved will become clearer and more clearly understood in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings. Here show in a schematic representation:

FIG 1

a cooling section downstream of a rolling mill,

FIG 2

a cooling section upstream of a rolling mill

FIG 3

a cooling section arranged within a rolling train,

FIG 4

a single application device,

FIG 5

a modification of the applicator of FIG FIG 4 and

FIG 6

another application device.

Description of the embodiments

According to FIG 1 a hot rolling stock 1 made of metal is to be cooled in a cooling section 2. The cooling section 2 is according to FIG 1 downstream of a rolling mill. Is shown in FIG 1 only one roll stand 3 of the rolling train, namely the last roll stand 3 of the rolling train. As a rule, however, the rolling train has a plurality of rolling stands 3 through which the hot rolling stock 1 traverses sequentially one after the other. In the case of the arrangement according to FIG 1 the hot rolling stock 1 enters the cooling section 2 immediately after rolling in the last roll stand 3 of the rolling train. A time interval between the rolling in the last roll stand 3 of the rolling train and the entry into the cooling section 2 is generally in the range of a few seconds.

Alternatively, the cooling section 2 could be as shown in FIG FIG 2 be upstream of the rolling mill. Is shown in FIG 2 likewise only a single roll stand 4 of the rolling train, namely the first roll stand 4 of the rolling train. In the case of the arrangement according to FIG 2 the hot rolling stock 1 is rolled immediately after leaving the cooling section 2 in the first roll stand 4 of the rolling train. A time interval between the cooling in the cooling section 2 and the rolling in the first roll stand 4 of the rolling train is often in the range of a few minutes. But it can also be just a few seconds.

Alternatively, the cooling section 2 could be as shown in FIG FIG 3 be arranged within the rolling train. Are shown in FIG 3 two roll stands 5 of the rolling train. In this case, the cooling takes place in the cooling section 2 between the rolling in the two roll stands 5 of the rolling train. A time interval between the cooling in the cooling section 2 and the rolling in the two successive rolling stands 5 of the rolling train is in the range of a few seconds. As shown in FIG 3 the cooling section 2 is arranged between two successive roll stands 5 of the rolling train. It could, however, also extend over a larger area, so that the cooling section 2 passes through at least one in FIG 3 not shown further roll stand is divided into a corresponding number of sections.

The rolling stock 1 consists of metal. For example, the rolling stock 1 can consist of steel or aluminum. Other metals are also possible. In the case of steel, a temperature of the rolling stock 1 in front of the cooling section 2 is generally between 750 ° C. and 1,200 ° C. In the cooling section 2, cooling to a lower temperature takes place. In individual cases it is possible that the lower temperature is only slightly below the temperature in front of the cooling section 2. In particular in the event that the cooling section 2 is arranged downstream of the rolling train, the rolling stock 1 is generally cooled to a significantly lower temperature, for example to a temperature between 200 ° C. and 700 ° C.

The hot rolling stock 1 is fed to the cooling section 2 in a horizontal transport direction x. When passing through the cooling section 2, the hot rolling stock 1 does not change its transport direction x. It is therefore also transported horizontally within the cooling section 2. After leaving the cooling section 2, the rolling stock 1 can either maintain or change its transport direction. If the hot rolling stock 1 is a strip, it can, for example, be deflected obliquely downwards in order to feed it to a reel. Furthermore, it is possible for the hot rolling stock 1 to reverse its transport direction x (reverse), to run through the cooling section 2 again and then to be rolled again. This is possible with both heavy plate and a pre-slab.

The cooling section 2 has a number of application devices 6. A coolant 7 is applied to the rolling stock 1 by means of the application devices 6. As shown in the FIGS. 1 to 3 the coolant 7 is applied to the rolling stock 1 from above. However, it could also be applied from below and / or from the side, both alternatively and additionally. The coolant 7 is water. If necessary, small amounts of additives (maximum 1 percent to 2%) can be added to the water. In any case, however, the coolant 7 is a liquid, water-based coolant. The application devices 6 can be designed, for example, as conventional spray bars.

At least one single application device 6 is present. In many cases, however, several application devices 6 are present. For example, the application devices 6 can according to the representation in FIG FIG 1 be arranged one behind the other. In this case, the application devices 6 apply their respective portion of the coolant 7 sequentially one after the other to the rolling stock 1. The term “sequentially one after the other” relates in this context to a specific section of the rolling stock 1, since this runs sequentially one after the other through regions in which the individual application devices 6 each have their respective share of the coolant 7 apply the corresponding section of the rolling stock 1. The number of application devices 6 is often in the two-digit, sometimes even in the upper two-digit range, in rare cases also in the three-digit range. A sequential arrangement one behind the other is generally implemented in particular when the cooling section 2 is arranged downstream of the rolling train. But it can also be given in other cases.

The application devices 6 are connected via a respective supply line 8 to a reservoir 9 of the coolant 7 (or another source for the coolant 7). In the present case, the reservoir 9 is the same for all application devices 6. However, several reservoirs 9 independent of one another could also be present. A respective control valve 10 is arranged in each supply line 8. The control valves 10 can in principle be arranged at any desired points within the supply lines 8. In practice, however, it is advantageous if the control valves 10 are arranged as close as possible to the application devices 6. If necessary, one or more pumps 11 can be arranged upstream of the control valves 10. The mode of operation of the pump 11 or the pumps 11 is not the subject of the present invention.

In the following - as a representative of all application devices 6 - in connection with FIG 4 the operation of one of the application devices 6 is explained in more detail. The other application devices 6 are operated in basically the same way. For each application device 6, however, the respective mode of operation can be determined individually. It is therefore possible, but not necessary, to operate the application devices 6 in the same way. It is also possible for some of the application devices 6 to be operated in a manner other than that according to the invention.

The application device 6 is supplied with a base flow F1 of the coolant 7 from the reservoir 9 via the supply line 8 and the control valve 10. The base current F1 has the unit m ³ / s on. The supply line 8 is connected to a buffer area 12 of the application device 6. As a result, the base current F1 is first fed to the buffer area 12 of the application device 6. For example, the application device 6 can be shown in FIG FIG 4 be designed as a spray bar which has a certain storage volume, the storage volume being filled to a variable extent with the coolant 7 and otherwise with air. Starting from the buffer area 12, a cooling flow F is applied to the hot rolling stock 1 by means of the application device 6. A distance between the application device 6 - for example spray nozzles - from the rolling stock 1 is generally between 20 cm and 200 cm.

The cooling section 2 is controlled by a control device 13. As a rule, the control device 13 is designed as a software-programmable control device. In this case, the control device 13 is programmed with a computer program 14. The computer program 14 comprises machine code 15 which can be processed directly by the control device 13. In this case, the processing of the machine code 15 by the control device 13 causes the control device 13 to carry out an operating method for the cooling section 2, as will be explained in more detail below.

The control device 13 dynamically determines a setpoint control state S1 * for the control valve 10. It controls the control valve 10 accordingly. By activating the control valve 10 in accordance with the determined target control state S1 *, the control device 13 sets the base current F1, which is fed to the application device 6 via the supply line 8 and the control valve 10.

The control device 13 of the cooling section 2 is aware of a setpoint current F * which is to be applied to the hot rolling stock 1 by means of the application device 6. The target current F * is usually not constant over time, but rather variable, that is to say a function of time. It is possible for the control device 13 to set the target control state S1 * for the control valve 10 as a function determined from the setpoint current F * of the coolant 7. In this case, the control device 13 can determine the control state S1 *, for example, in such a way that in every operating state the base current F1 flowing through the control valve 10 is always as close as possible to the setpoint current F *. Then the operation of the control valve 10 corresponds to the operation of the prior art. However, other approaches are also possible. This will be discussed later.

In addition, an active device 16 is assigned to the buffer area 12. The active device 16 is connected to the buffer area 12 via a further supply line 17. The term “active device” means that the control device 13 controls the active device 16 in accordance with a setpoint control state S2 * and that the active device 16 reacts accordingly. The control device 13 also dynamically determines the further target control state S2 * and controls the active device 16 accordingly. The setpoint control state S2 * for the active device 16 is referred to below to distinguish it from the setpoint control state S1 * for the control valve 10 as a further setpoint control state S2 *. Corresponding to the activation of the active device 16 by the control device 13, the active device 16 feeds an additional flow F2 of a further medium 18 to the buffer area 12 via the further supply line 17. ^{The additional flow F2 has the unit m 3} / s - analogously to the base flow base flow F1. It can be positive or negative. It is therefore alternatively possible to supply the further medium 18 to the buffer area 12 or to withdraw it from the buffer area 12. Whether the additional current F2 is positive or negative depends on the further target control state S2 *. Regardless of the specific value of the additional flow F2 and also regardless of the type of further medium 18, the cooling flow F depends not only on the base flow F1 flowing through the control valve 10, but also on the additional flow F2 flowing through the active device 16.

The present invention is based on the principle that the control device 13 adjusts the additional flow F2 by the corresponding activation of the active device 16 in such a way that the cooling flow F is always as close as possible to the setpoint flow F *.

In order to be able to determine the further target control state S2 *, the control device 13 must know various values. On the one hand, this is the target current F *. The target current F * can be preset to the control device 13, for example, or it can be determined by the control device 13 on the basis of other data - for example the temperature or the enthalpy of a certain section of the rolling stock 1 in conjunction with a desired temperature or enthalpy curve. If, as in the case of the design according to FIG 4 if the additional medium 18 is air, the control device 13 must know a nominal current F0 and an associated nominal pressure p0. The nominal current F0 is the amount of coolant 7 which is applied per unit of time from the buffer area 12 to the hot rolling stock 1 when the nominal pressure p0 prevails in the buffer area 12. The values F0, p0 can be determined in advance, for example, by a one-off measurement.

der zugehörige erforderliche Druck p ermittelt werden, der im Pufferbereich 12 herrschen muss. Der Nennstrom F0 ist die Menge an Kühlmittel 7, die pro Zeiteinheit aus dem Pufferbereich 12 auf das heiße Walzgut 1 aufgebracht wird, wenn im Pufferbereich 12 der Nenndruck p0 herrscht. Die Steuereinrichtung 13 steuert die aktive Einrichtung 16 somit derart an, dass sie im Pufferbereich 12 den Druck p hervorruft.If, for example, the target current F * is increased rapidly in such a case, the relationship $$p=\frac{{\mathrm{F.}}^{\ast 2}}{\mathrm{F.}{0}^2}\cdot p0$$

the associated required pressure p can be determined, which must prevail in the buffer area 12. The nominal current F0 is the amount of coolant 7 which is applied per unit of time from the buffer area 12 to the hot rolling stock 1 when the nominal pressure p0 prevails in the buffer area 12. The control device 13 thus controls the active device 16 in such a way that it causes the pressure p in the buffer area 12.

The active device 16 is preferably a device actively conveying the further medium 18, for example a turbine. In this case, the turbine is driven by an electric drive. For example, the drive can be converter-controlled. Such controls are generally known to those skilled in the art and therefore do not need to be explained in more detail. An electric drive can typically be accelerated from 0 to maximum speed with a time constant of 0.1 s and, conversely, also decelerated from maximum speed to 0 with a time constant of 0.1 seconds.

The active device 16 can thus be controlled with high dynamics. Driving through the full setting range (for example from 0 to maximum speed) can typically take place in a time window of less than 0.2 s. Often only 0.1 s or less are required. The cooling flow F can thus be adapted with this short time constant, although the control valve 10 has only relatively low dynamics, for example a time constant of 1.5 s. During this period, the base current F1 deviates from the desired target current F * . In the case of the cooling flow F, however, this time delay is not noticeable because the pressure p in the buffer area 12 can be set in a highly dynamic manner by means of the turbine as required.

The additional current F2 can be positive or negative. If it is positive, the turbine pumps air into the buffer area 12, so that the pressure p in the buffer area 12 is increased. If it is negative, the turbine sucks air out of the buffer area 12, so that the pressure p in the buffer area 12 is reduced. However, the cooling flow F does not depend directly on the base flow F1, but rather on the pressure p in the buffer area 12. It only has to be ensured that there is any coolant 7 in the buffer area 12 that can be applied to the hot rolling stock 1.

The base current F1 does not have to follow the target current F * directly. It only has to be set in such a way that the buffer area 12 neither becomes empty nor overflows. For this it is like before mentioned, possible to determine the target control state S1 * as in the prior art also as a function of the target current F *. Alternatively, it is possible, for example, to determine a fill level of the storage area 12 and to regulate it to a specific setpoint value. The setpoint can be constant or vary as required. In this case, the level can be measured directly or indirectly, for example. An indirect measurement is possible, for example, using pressure measurement cells, by means of which the weight of the application device 6 is recorded. The fill level can also be determined with the aid of a model based on the base flow F1 and the cooling flow F. The difference between the base current F1 and the cooling current F corresponds to the change in the level at any point in time. By integrating this difference over time, starting from a known initial fill level, the current fill level can be determined at any time. The base flow F1 can be measured, for example, and the cooling flow F can be determined on the basis of the easily measurable pressure p.

To determine the target control state S2 * for the active device 16, the control device 13 can proceed as follows, for example:
The buffer area 12 has a total volume V. The buffer area 12 is partially filled with the coolant 7, the rest with air. The volume occupied by the coolant 7 is denoted below with V1 and the air volume with V2. It goes without saying that the relationship applies $$\mathrm{V.}=\mathrm{V.}1+\mathrm{V.}2$$

ermittelt werden. FR ist ein Referenzstrom des Kühlmittels 7, der bei vollständig geöffnetem Regelventil 10 fließt, wenn die Druckdifferenz zwischen der Eingangsseite des Regelventils 10 und dem Pufferbereich 12 gleich dem Nenndruck p0 ist. Der Wert FR kann beispielsweise durch eine einmalige Messung vorab ermittelt werden. p1 ist der Druck eingangsseitig des Regelventils 10. f(x) ist die relative Durchflussmenge des Regelventils 10 in Abhängigkeit von der Ventilstellung x des Regelventils 10. Sie liegt für x = 0 (Regelventil 10 vollständig geschlossen) bei 0 und für x = 1 (Regelventil 10 vollständig geöffnet) bei 1. Zwischen x = 0 und x = 1 ist sie monoton - oftmals streng monoton - steigend. Die Kennlinie f als solche kann vorab bekannt sein. In der Regel wird sie vom Hersteller des Regelventils 10 einmalig vorab erfasst und kann danach dem Datenblatt des Regelventils 10 entnommen werden.The pressure p prevails in the air volume V2. The same pressure p also prevails in the coolant 7. The base current F1 flows into the buffer area 12 via the control valve 10 and the supply line 8. The base current F1 can be determined using the relationship $$\mathrm{F.}1=\mathit{FR}\cdot \sqrt{\frac{p1-p}{p}}\cdot ƒ\left(x\right)$$

be determined. FR is a reference flow of the coolant 7 which flows when the control valve 10 is fully open when the pressure difference between the inlet side of the control valve 10 and the buffer area 12 is equal to the nominal pressure p0. The value FR can be determined in advance, for example, by a one-off measurement. p1 is the pressure on the inlet side of the control valve 10.f (x) is the relative flow rate of the control valve 10 depending on the valve position x of the control valve 10. It is 0 for x = 0 (control valve 10 completely closed) and at 0 for x = 1 ( Control valve 10 fully open) at 1. Between x = 0 and x = 1, it is monotonic - often strictly monotonic - increasing. The characteristic curve f as such can be known in advance. As a rule, it is recorded once in advance by the manufacturer of the control valve 10 and can then be taken from the data sheet of the control valve 10.

The following applies to the change in the volume V1 occupied by the coolant 7 $$\dot{\mathrm{V.}}1=\mathrm{F.}1-\mathrm{F.}$$

The following applies to the amount of air M contained in the air volume V2 $$\mathrm{M.}=p\cdot \mathrm{V.}2$$

It is assumed that the temperature of the air is constant. If the temperature is variable, the calculation is a bit more complex, but in principle remains similar.

The additional flow F2 causes a change in the amount of air M and thus in the air volume V2 and / or in the pressure p in the buffer area 12. It is therefore true $$\dot{\mathrm{M.}}=\dot{p}\cdot \mathrm{V.}2+p\cdot \dot{\mathrm{V.}}2=\frac{\dot{p}}{p}\cdot \mathrm{M.}-p\cdot \left(\mathrm{F.}1-\mathrm{F.}\right)$$

By inserting equation (1) and equation (3), the following relationship can be determined as the resulting equation for the change in the amount of air M over time: $$\dot{\mathrm{M.}}=\frac{\dot{p}}{p}\cdot \mathrm{M.}+p\cdot \left(\sqrt{\frac{p}{p0}}\cdot \mathrm{F.}0-\sqrt{\frac{p1-p}{p0}}\cdot \mathit{FR}\cdot ƒ\left(x\right)\right)$$

The control device 13 also knows the characteristic curve K of the turbine. The characteristic curve K relates the speed n of the turbine, the pressure difference δp on the inlet side and the outlet side of the turbine and the amount of air conveyed per unit of time, i.e. the time derivative of the amount of air M, with one another. If two of the three variables speed n of the turbine are specified - pressure difference δp - time derivative of the air quantity M, the third variable in each case is determined on the basis of the characteristic curve K. The characteristic curve K can be determined, for example, by measurement or on the basis of a data sheet from the manufacturer of the turbine. A function can therefore be specified by means of which the associated speed n of the turbine can be determined for a given pressure difference δp and a given time derivative of the air quantity M. The required pressure difference δp results directly from the desired target current F *. With the time derivative of the amount of air M, the additional flow F2 is also determined.

As a result, the speed n of the turbine is determined by the following relationship: $$n=K\left(p,\frac{\dot{p}}{p}\cdot \mathrm{M.}+p\cdot \left(\sqrt{\frac{p}{p0}}\cdot \mathrm{F.}0-\sqrt{\frac{p1-p}{p0}}\cdot \mathit{FR}\cdot ƒ\left(x\right)\right)\right)$$

This equation is exclusively dependent on the pressure p in the buffer area 12, the position x of the control valve 10, the instantaneous amount of air M and the time derivative of the pressure p in the buffer area 12. The other quantities are just constant parameters. The amount of air M is a state variable that can easily be determined by means of an observer. All that is required is to solve equation (7) with a suitable initial value.

Observers are well known in the art. Purely by way of example, reference is made to the textbook " Systems theory - an introduction "by R. Unbehauen, Volume 1, Springer Verlag Berlin, Heidelberg referenced. The other variable quantities are easily measurable or - in the case of the time derivative of the pressure p - can be derived without further ado on the basis of the measured pressure p.

The pressure p in the buffer area 12 and thus, as a result, the cooling flow F can therefore be set as quickly as the speed n of the turbine can be set. However, the setting of the speed of the turbine is possible with an accuracy of 1% and better with a time constant of 0.2 s and better.

It only has to be ensured that the volume V1 of the coolant 7 in the buffer area 12 remains within the permissible limits. However, this can easily be achieved. Only the position x of the control valve 10 has to be constantly adjusted accordingly, so that the volume V1 tends towards a predetermined setpoint. Corresponding regulators are generally known. The controller can - for example - be designed as a P controller, as a PI controller or as a state controller, all with or without precontrol. Implementation as a two-point controller is also possible.

When designing according to FIG 4 the active device 16 simply removes the air from the environment or releases it to the environment. Alternatively, it is as shown in FIG 5 possible that the active device 16 takes the air from a storage device 19 and releases it into the storage device 19. Otherwise, the design of FIG 5 with the design of FIG 4 match. The design of FIG 5 points to the design of FIG 4 has the advantage that the air in the storage device 19 can be under a pressure p '. The pressure p 'is preferably selected such that it is between 0 and a maximum pressure, the maximum pressure being the pressure at which the application device 6 operates at a maximum.

If the storage device 19 is dimensioned large enough, it is possible for the pressure p 'to be approximately constant. In this case, the pressure p 'should be approximately half the maximum pressure. If the storage device 19 is dimensioned smaller, the pressure p 'in the storage device 19 decreases in accordance with the amount of air removed and increases again in accordance with the amount of air supplied. This can definitely be advantageous, since an increase in pressure in the storage device 19 counteracts an excessive reduction in the air volume V2 in the buffer area 12 and vice versa.

Alternatively, it is as shown in FIG 5 It is possible for the control device 13 to set the pressure p ′ via a control line 20 which is connected to the storage device 19. In this case, the control device 13 can in particular track the pressure p ′ as a function of the setpoint current F * or the pressure p. For example, the control device 13 can control valves 21, 22 with corresponding control signals S3 *, S4 *, so that - depending on the control of the valves 21, 22 - compressed air is supplied to the storage device 19 as required or air is released from the storage device 19 into the environment .

The control of the turbine changes due to the pressure p ', since the first argument of the characteristic curve K depends on the pressure difference δp. Otherwise, the derivation of the required speed n of the turbine remains unchanged. It is therefore only necessary to determine the speed n of the turbine using the following relationship: $$n=K\left(p-p\prime ,\frac{\dot{p}}{p}\cdot \mathrm{M.}+p\cdot \left(\sqrt{\frac{p}{p0}}\cdot \mathrm{F.}0-\sqrt{\frac{p1-p}{p0}}\cdot \mathit{FR}\cdot ƒ\left(x\right)\right)\right)$$

The design of FIG 5 offers compared to the design of FIG 4 various advantages. On the one hand, the turbine is always operated in a clean air environment. On the other hand, the Energy consumption of the turbine can be reduced by adjusting the pressure p 'as required. This can be useful in particular when the cooling flow F and thus the required pressure p in the buffer area 12 remains constant for a long time or at least remains essentially constant.

Both in the design according to FIG 4 as well as in the design according to FIG 5 the coolant 7 of the application device 6 must be taken relatively far below, since - of course - the air volume V2 is in the upper area and the volume V1 of coolant 7 is in the lower area of the buffer area 12. However, this is easily possible.

The design of the FIG 4 and 5 is particularly useful with a laminar cooling section. In principle, however, it can also be implemented with intensive cooling.

The design of FIG 6 corresponds over long distances with that of FIG 5 . Even with the design of FIG 6 the active device 16 is preferably a device actively promoting the further medium 18. When designing FIG 6 however, the further medium 18 is not air but water (or generally the coolant 7). The active device 16 is therefore a pump. The pump is - analogous to the turbine of the FIG 4 and 5 - driven by an electric drive. For example, the drive can be converter-controlled. An electric drive can typically be accelerated from 0 to maximum speed with a time constant of 0.1 s and, conversely, also decelerated from maximum speed to 0 with a time constant of 0.1 seconds. As a result, depending on the speed and direction of rotation, the pump can be used to supply additional water to the buffer area 12 in a highly dynamic manner in addition to the base current F1 supplied via the supply line 8, or a part of the base current F1 supplied via the supply line 8 to the buffer area 12 can be removed. In this case, the cooling flow F results directly from the sum of the base flow F1 and the additional flow F2, where the latter can be positive or negative depending on the control of the pump.

Preferably also in the embodiment according to FIG 6 the further medium in the storage device 19 under pressure p '. Furthermore, preferably also in the embodiment according to FIG 6 the control device 13 inputs the pressure p 'via a control line 20 connected to the storage device 19. Compressed air is preferably supplied to the storage device 19 via the control line 20, or air is discharged from the storage device 19. The control device 13 can control the pressure p 'as in the embodiment according to FIG FIG 5 track as a function of the pressure p.

eingehalten werden.The control device 13 can determine the target control state S2 * for the pump, for example, as follows:
As before, according to equation (1), the pressure p can be determined which is required so that the cooling flow F is equal to the setpoint flow F *. The base current F1 also obeys equation (3). Since in the case of the design according to FIG 6 However, the buffer area 12 is always completely filled with coolant 7 or water (= additional medium 18), it is always the case that the sum of the base flow F1 and the additional flow F2 is equal to the cooling flow F. In order to set the cooling flow F to the target flow F *, the relationship must therefore always be $$\mathrm{F.}2={\mathrm{F.}}^{\ast }-\mathrm{F.}1$$

be respected.

die erforderliche Drehzahl n der Pumpe ermittelt werden.Analogous to the above statements on the characteristic curve K of the turbine, there is a similar characteristic curve K for the pump. Only the change in the amount of air over time is replaced by the conveyed volume flow, i.e. the additional flow F2. With the known pressure p in the buffer area 12, the pressure p 'in the storage area 19 and the required additional flow F2, it is therefore possible immediately according to the relationship $$n=K\left(p-p\prime ,\sqrt{\frac{p}{p0}}\cdot \mathrm{F.}0-\sqrt{\frac{p1-p}{p0}}\cdot \mathit{FR}\cdot ƒ\left(x\right)\right)$$

the required speed n of the pump can be determined.

Analogous to the designs of the FIG 4 and 5 It must be ensured that the base current F1 corresponds to the cooling current F on average over time. The procedure can be analogous to the embodiments of FIG 4 and 5 be realized.

The design of FIG 6 is particularly useful for intensive cooling. In principle, however, it can also be implemented with a laminar cooling section.

Both in the configurations of FIG 4 and 5 as well as in the design of FIG 6 it makes sense to actually measure the position x of the control valve 10. This is easily possible. It is also sensible and easy to implement to measure the pressure p in the buffer area 12. A measurement is possible, but not necessary, for the pressure p ′ in the storage device 19. In the designs of the FIG 4 and 5 it also makes sense to also measure the amount of coolant 7 in the buffer area 12. In addition to the options already mentioned, the level can also be measured directly, for example with a float, an ultrasonic transmitter or a capacitive sensor. In an analogous manner, in the case of the embodiment of FIG 6 the amount of water in the storage area 19 can be measured. The conveyed flows - that is to say the base flow F1, the additional flow F2 and the cooling flow F - are generally not measured, even if this is of course possible in principle.

Both in the configurations of FIG 4 and 5 as well as in the design of FIG 6 it is possible that the target current F * of the control device 13 is specified directly and immediately. Preferably, however, the control device 11 knows the thermodynamic energy state H of the rolling stock 1 immediately before it reaches the application device 6. With the thermodynamic Energy state H can in particular be the enthalpy or the temperature of a respective section of the rolling stock 1. In this case, the control device 13 first determines the target current F * as a function of the thermodynamic energy state H and then based on the target current F * at least the associated target control state S2 *, possibly also the associated target control state S1 *. In particular, it is possible for the control device 13 to be given a local or temporal setpoint profile of the thermodynamic energy state H, which should be maintained if possible. The control device 13 can therefore determine which thermodynamic energy state H should be present immediately after the application device 6. By comparing with the actual thermodynamic energy state H immediately before the application device 6, the control device 13 can therefore determine which amount of coolant 7 has to be applied to the corresponding section of the rolling stock 1 so that the actual thermodynamic energy state H immediately behind the application device 6 reaches the desired target state corresponds as well as possible. The required amount of coolant 7 then defines the target current F * in connection with the time which the corresponding section of the rolling stock 1 needs to pass through the application device 6.

The thermodynamic energy state H of the corresponding section of the rolling stock 1 varies from application device 6 to application device 6. In particular, it is changed by each of application devices 6. For the application device 6, which first applies its portion of coolant 7 to the rolling stock 1, the thermodynamic energy state H of the control device 13 can be specified as such. For example, according to the representation in FIG 1 A temperature measuring station 23 can be arranged on the input side of the cooling section 2, by means of which the temperature or, in general, the energy state H is recorded for the individual sections of the rolling stock 1. The recorded energy state H is then assigned to the respective section.

Path tracking is implemented for each section during its passage through the cooling section 2. For each additional application device 6 that applies its share of coolant 7 later, however, the corresponding thermodynamic energy state H of the rolling stock 1 (or of the corresponding section of the rolling stock 1) must be updated. Here, the control device 13 takes into account in particular the thermodynamic energy state H immediately before the immediately preceding application device 6 and the amount of coolant 7 which the immediately preceding application device 6 applies to the rolling stock 1. With regard to the amount of coolant 7, the control device 13 can alternatively take into account the setpoint flow F * or the cooling flow F of the immediately preceding application device 6. It thus sequentially determines the thermodynamic energy state H of the rolling stock 1 for the application devices 6 one after the other. If necessary, the control device 13 can apply and iteratively solve a heat conduction equation and a phase conversion equation in this context.

In many cases, the rolling stock 1 is a flat rolling stock, for example a strip or a heavy plate. In this case it is possible for the liquid coolant 7 to be applied to the rolling stock 1 from both sides by means of each individual application device 6. This procedure is often taken in the case of a cooling section 2 which is arranged upstream of the rolling train or is arranged in the rolling train. But it can also be taken when the cooling section 2 is arranged downstream of the rolling train. In particular, when the cooling section 2 is arranged downstream of the rolling train, the liquid coolant 7 is usually applied to the rolling stock 1 from only one side, in particular from above or below, by means of each individual application device 6. Of course, it is also possible in this case to apply coolant 7 to both sides of the flat rolling stock 1. In this case, however, this takes place by means of application devices 6 that are different from one another.

In the extreme case, it is possible that the application devices 6 each have only a single spray nozzle. As a rule, however, the application devices 6 each have a plurality of spray nozzles. The spray nozzles can be arranged one behind the other as seen in the transport direction x of the rolling stock 1. The spray nozzles can for example be arranged one behind the other within a single spray bar. A plurality of spray bars arranged one behind the other in the transport direction x can also be combined to form one (1) application device 6. This applies regardless of whether the respective spray bar as such has several spray nozzles arranged one behind the other or not.

As an alternative or in addition to an arrangement of spray nozzles one behind the other, the application devices 6 can furthermore have a plurality of spray nozzles which are arranged next to one another as seen transversely to the transport direction x of the rolling stock 1. Such a configuration can be useful in particular in the case of a flat rolled stock 1, that is to say in the case of a strip or a heavy plate. In this case, the application devices 6 can extend over the full width of the rolling stock 1. Alternatively, it is possible for the application devices 6 to extend only over part of the width. In this case, several application devices 6 are arranged next to one another, each of which is supplied with coolant 7 via its own supply line 8 and its own control valve 10.

All of the procedures explained above in connection with one of the application devices 6 and their associated components can also be carried out in a completely analogous manner for the other application devices 6. The above-mentioned procedure is also carried out, as already mentioned, for one section of the rolling stock 1.

The present invention has many advantages. In particular, a highly dynamic setting of the cooling flows F is possible. As a dead time of the application devices 6, only the usually very short times that the coolant 7 needs occur, in order to strike the rolling stock 1, calculated from the point at which it emerges from the respective application device 6. Switching off the cooling flow F is possible in the range of a few tenths of a second (often less than 0.2 s, sometimes even less than 0.1 s). The same applies when the cooling flow F is started up. The drives for the active devices 16 can be controlled very precisely. A usual accuracy of the speed n is in the range of 0.1%. The cooling flow F for the respective application device 6 can also be set with the same or a similar accuracy. Taking into account the response behavior of the drives 12, it should in all probability be possible to track the cooling flow F with 1% accuracy in less than 0.5 s, possibly even in 0.2 s to 0.3 s and drives is low. Typical downtimes for pump bearings are, for example, 100,000 hours and more. Similar values apply to turbine bearings. Furthermore, pressure surges are avoided, since the respective cooling flow F is reduced very quickly, but not the respective base flow F1. Therefore, inexpensive control dampers can be used in a laminar cooling section. In particular in the case of pre-strip cooling, it is still possible to cool the so-called rail points in the pre-strip in a targeted manner differently than the rest of the pre-strip. This is not possible in the prior art due to a lack of corresponding dynamics. But even with normal cooling sections, there are shorter delay times and thus more precise temperature control of the rolling stock 1.

If a laminar cooling section is provided with application devices 6 according to the invention, the "air version" ( FIG 4 and 5 ) typically requires a turbine with an output of around 2 kW each. In the case of intensive cooling or pre-strip cooling, the "water version" ( FIG 6 ) used. The power required for the pump is typically around 25 kW.

Although the invention has been illustrated and described in more detail by the preferred exemplary embodiment, it is The invention is not restricted by the examples disclosed, and other variants can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention.

List of reference symbols

1

Rolling stock

2

Cooling section

3 to 5

Roll stands

6th

Application devices

7th

Coolant

8, 17

Supply lines

9

reservoir

10

Control valves

11

pump

12th

Buffer area

13th

Control device

14th

Computer program

15th

Machine code

16

active establishment

18th

another medium

19th

Storage facility

20th

Control line

21, 22

Valves

23

Temperature measuring station

F.

Cooling flow

F1

Base current

F2

Additional electricity

F *

Target current

p, p '

Press

S1 *, S2 *

Target control states

S3 *, S4 *

Control signals

x

Transport direction

Claims (17)

1. Operating method for a cooling section (2) which is arranged within a rolling train or upstream or downstream of the rolling train and by means of which a hot rolled product (1) made of metal is cooled,

   - wherein a control device (13) of the cooling section (2) dynamically determines a respective setpoint actuation state (S1*) for a respective control valve (10) arranged in a respective supply line (8) and actuates the respective control valve (10) accordingly,

   - wherein a respective basic flow (F1) of a liquid, water-based coolant (7) is fed to a number of application devices (6) of the cooling section (2) via the respective supply line (8) in accordance with the actuation of the respective control valve (10) by the control device (13),

   - wherein the respective supply line (8) feeds the respective basic flow (F1) to a respective buffer region (12) of the respective application device (6), from which region a respective cooling flow (F) of the coolant (7) is applied to the hot rolled product (1) by means of the respective application device (6),

   characterized

   - in that the control device (13) additionally dynamically determines a respective further setpoint actuation state (S2*) for a respective active device (16) and actuates the respective active device (16) accordingly,

   - in that the respective active device (16) feeds a respective additional flow (F2) of a further medium (18) to the respective buffer region (12) via a respective further supply line (17) in accordance with the actuation of the respective active device (16) by the control device (13),

   - in that the respective cooling flow (F) depends both on the respective basic flow (F1) flowing through the respective control valve (10) and on the respective additional flow (F2) flowing via the respective active device (16),

   - in that the respective additional flow (F2) is positive or negative depending on the respective further actuation state (S2*) of the respective active device (16), and

   - in that the control device (13) sets the respective additional flow (F2) in such a way, by correspondingly actuating the respective active device (16), that the respective cooling flow (F) is approximated as closely as possible at all times to a respective setpoint flow (F*) of the coolant (7) to be applied to the hot rolled product (1) by means of the respective application device (6).
2. Operating method according to Claim 1,
   characterized
   in that the respective active device (16) is a device which actively delivers the further medium (18).
3. Operating method according to Claim 2,
   characterized
   in that the further medium (18) is air or water.
4. Operating method according to Claim 1, 2 or 3,
   characterized
   in that the further medium (18) is taken from a respective storage device (19).
5. Operating method according to Claim 4,
   characterized
   in that the further medium (18) in the respective storage device (19) is under a respective pressure (p').
6. Operating method according to Claim 5,
   characterized
   in that the respective pressure (p') in the respective storage device (19) is set via a respective control line (20) connected to the respective storage device (19).
7. Operating method according to Claim 5 or 6,
   characterized
   in that the respective pressure (p') in the respective storage device (19) is corrected in accordance with the setpoint flow (F*) or with a respective pressure (p) prevailing in the respective buffer region (12).
8. Control device for a cooling section (2) which is arranged within a rolling train or upstream or downstream of the rolling train and by means of which a hot rolled product (1) made of metal is cooled, wherein the control device dynamically determines, for a number of application devices (6) of the cooling section (2), a respective setpoint actuation state (S1*) for a respective control valve (10) arranged in a respective supply line (8) and actuates the respective control valve (10) accordingly, with the result that a respective basic flow (F1) of a liquid, water-based coolant (7) is fed to a respective buffer region (12) of the respective application device (6) via the respective supply line (8) in accordance with the actuation of the respective control valve (10) by the control device (13),
   characterized

   - in that the control device additionally dynamically determines a respective further setpoint actuation state (S2*) for a respective active device (16) and actuates the respective active device (16) accordingly, with the result that the respective active device (16) feeds a respective additional flow (F2) of a further medium (18) to the respective buffer region (12) via a respective further supply line (17) in accordance with the actuation of the respective active device (16) by the control device (13), with the result that a respective cooling flow (F) of the coolant (7) emanating from the respective buffer region (12) and applied to the hot rolled product (1) by means of the respective application device (6) depends both on the respective basic flow (F1) flowing through the respective control valve (10) and on the respective additional flow (F2) flowing via the respective active device (16), and

   - in that the control device sets the respective additional flow (F2) to positive and negative values in such a way that the respective cooling flow (F) is approximated as closely as possible at all times to a respective setpoint flow (F*) to be applied to the hot rolled product (1) by means of the respective application device (6).
9. Control device according to Claim 8,
   characterized
   in that the further medium (18) is taken from a respective storage device (19), in that the further medium (18) in the respective storage device (19) is under a respective pressure (p'), and in that the control device sets the respective pressure (p') in the respective storage device (19) via a respective control line (20) connected to the respective storage device (19).
10. Control device according to Claim 9,
    characterized
    in that the control device corrects the pressure (p') in the respective storage device (19) in accordance with the setpoint flow (F*) or with a pressure (p) prevailing in the respective buffer region (12).
11. Control device according to Claim 8, 9 or 10,
    characterized
    in that the control device is designed as a software-programmable device which is programmed with a computer program (14) comprising machine code (15) that can be executed by the control device, and in that the execution of the machine code (15) by the control device effects the corresponding determination of the respective setpoint actuation state (S1*) for the respective control valve (10) and of the respective further setpoint actuation state (S2*) for the respective active device (16) and the corresponding actuation of the respective control valve (10) and of the respective active device (16).
12. Computer program comprising machine code (15) that can be executed by a software-programmable control device (13) for a cooling section, wherein the execution of the machine code (15) by the control device (13) has the effect that, in accordance with Claim 8, the control device (13) determines the respective setpoint actuation state (S1*) for the respective control valve (10) and the respective further setpoint actuation state (S2*) for the respective active device (16) and actuates the respective control valve (10) and the respective active device (16) accordingly.
13. Cooling section,

    - wherein the cooling section is arranged within a rolling train or is arranged upstream or downstream of the rolling train,

    - wherein a hot rolled product (1) made of metal is cooled by means of the cooling section,

    - wherein the cooling section has a number of application devices (6), which are connected to a source (9) of a liquid, water-based coolant (7) via a respective supply line (8),

    - wherein a respective control valve (10) is arranged in the respective supply line (8),

    - wherein the application devices (6) have a respective buffer region (12) which is connected to the respective supply line (8), with the result that the respective supply line (8) feeds a respective basic flow (F1) of the coolant (7) to the respective buffer region (12) of the respective application device (6) and, starting from the respective buffer region (12), a respective cooling flow (F) of the coolant (7) is applied to the hot rolled product (1) by means of the respective application device (6),

    - wherein the cooling section has a control device (13) which controls the respective control valve (10),

    characterized

    - in that the respective buffer region (12) is assigned a respective active device (16), by means of which an additional flow (F2) of a further medium (18) can be fed to the buffer region (12) via a further supply line (17), with the result that the respective cooling flow (F) depends both on the basic flow (F1) flowing through the respective control valve (10) and on the respective additional flow (F2) flowing via the respective active device (16), and

    - in that the cooling section has a control device (13) according to any one of Claims 8 to 11 which controls not only the respective control valve but additionally also the respective active device (16).
14. Cooling section according to Claim 13,
    characterized
    in that the respective active device (16) is a device which actively delivers the further medium.
15. Cooling section according to Claim 14,
    characterized
    in that the further medium (18) is air or water.
16. Cooling section according to Claim 13, 14 or 15,
    characterized
    in that the further medium (18) is taken from a respective storage device (19).
17. Cooling section according to Claim 16,
    characterized
    in that the further medium (18) in the respective storage device (19) is under a respective pressure (p').

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