Method for controlling a production plant for the thermal treatment of metallic workpieces, production plant for the thermal treatment of metallic workpieces

Abstract

The present invention relates to a method for controlling a production plant (1) for the thermal treatment of metallic workpieces. Furthermore, the invention relates to a production plant (1) for the thermal treatment of metallic workpieces.

Description

[0001] The present invention relates to a method for controlling a production plant for the thermal treatment of metallic workpieces and to a production plant for the thermal treatment of metallic workpieces.

[0002] Production plants for the thermal treatment of metallic workpieces typically include multiple temperature-changing devices for heating the workpieces. For example, conventional furnaces powered by fossil fuels are used in such plants. Electricity-based temperature-changing devices, such as furnaces with resistance heating elements or induction heating systems, are also well known and described in the prior art. Furthermore, the use of temperature-changing devices for cooling metallic workpieces is known. Such devices can include active or passive cooling elements.

[0003] Modern production facilities for the thermal treatment of metallic workpieces typically employ a combination of several temperature-changing devices of the same or different types to accommodate the required product range. Controlling such a production facility with multiple temperature-changing devices presents a challenge due to the various influencing factors of the different devices, such as efficiency, the lifespan of the heating elements, the response times of the devices, as well as the desired product quality, output quantity, and other thermal treatment requirements.Particularly when changing products on such a production plant, a challenge lies in shortening settling times during the adjustment of new required target temperatures in order to consistently achieve the required product quality.

[0004] The present invention is based on the objective of providing a method for controlling a production plant for the thermal treatment of metallic workpieces, with which optimal operation of the production plant can always be ensured taking into account a large number of different influencing factors and process requirements for the thermal treatment.

[0005] The problem underlying the present invention is solved by a method for controlling a production plant according to claim 1. Advantageous embodiments are described in the dependent claims.

[0006] More precisely, the problem underlying the present invention is solved by a method for controlling a production plant for the thermal treatment of metallic workpieces, wherein the production plant comprises a first temperature-changing device and a second temperature-changing device. The first temperature-changing device is configured to change the temperature of a metallic workpiece located in the first temperature-changing device, and the second temperature-changing device is configured to change the temperature of a metallic workpiece located in the second temperature-changing device. The production plant includes a control device that is data-connected to the first temperature-changing device and / or to the second temperature-changing device. The method comprises the following steps: - Determining a first operating value of at least one first operating parameter of the first temperature change device as a function of a desired result of the thermal treatment of the metallic workpiece and as a function of at least one influencing factor relating to the thermal treatment of the metallic workpiece, - Determining a second operating value of at least one second operating parameter of the second temperature change device depending on the desired result of the thermal treatment of the metallic workpiece, and - Setting at least one initial operating parameter of the initial temperature changing device to the initial operating value, and / or - Setting at least one second operating parameter of the second temperature changing device to the second operating value.

[0007] This method has the advantage of reducing the settling times of the production plant. The thermal treatment of metallic workpieces requires specific target temperatures depending on the desired result. These target temperatures are set to specific operating values ​​by determining and adjusting the operating parameters of the temperature control devices. However, the temperature control devices exhibit an inherent inertia, which means that the actual target temperatures are delayed compared to when the operating parameters necessary to achieve these target temperatures are set.During this period, the so-called settling-in time, the process conditions for the thermal treatment of metallic materials are not constant, and in particular not those required for the desired result. Therefore, there is a risk of not achieving the desired outcome, such as a required product quality. By considering at least one additional influencing factor related to the thermal treatment of the metallic workpiece when determining the operating parameters, the time lag can be reduced, thus shortening the settling-in time of the production system. This ensures that the desired result from the thermal treatment of the metallic workpiece is consistently achieved.A further advantage of such a process is that by taking at least one influencing factor into account, the service life of the production plant and / or the first and / or second temperature change device can be increased. This also makes it possible to achieve the desired result of the thermal treatment of the metallic workpiece at reduced, and in some cases minimized, costs.

[0008] Settling times typically occur whenever a change occurs during the ongoing thermal treatment of metallic materials. Such a change occurs, for example, when a product change takes place during production. A product change typically requires a different outcome, such as a different required product quality. Furthermore, influencing factors related to the thermal treatment of the metallic workpiece can change, such as its geometric dimensions, alloy composition, the temperature-changing devices used, or other factors.

[0009] The production plant may include additional equipment for the mechanical and / or thermal treatment of metallic workpieces. For example, the production plant may include a rolling device, a cutting device, a winding device, or other equipment for the mechanical treatment of metallic workpieces. Furthermore, the production plant may include equipment for the surface treatment of metallic workpieces. For example, the production plant may include an oxidation device, a reduction device, a coating device, and / or other equipment for surface treatment.

[0010] The thermal treatment of metallic workpieces can include heating and / or cooling the metallic workpieces.

[0011] The first temperature changing device can be configured to increase or decrease the temperature of a metallic workpiece located in the first temperature changing device.

[0012] The second temperature changing device can be configured to increase or decrease the temperature of a metallic workpiece located in the second temperature changing device.

[0013] The first and / or second temperature-changing device may include or be designed as a furnace. The furnace may be configured for the combustion of fossil fuels, such as natural gas, coal, or petroleum. The furnace may also be configured for the combustion of non-fossil fuels, such as synthetic fuels, hydrogen, or biogases.

[0014] The furnace can have a housing that at least partially limits the heating volume. Within this heating volume, the temperature of the metallic workpiece can be changed, preferably increased.

[0015] The furnace can have one or more heating zones. Preferably, the one or more heating zones are arranged in a common housing. A heating zone can have at least one heating element. A heating element can, for example, be designed as an induction coil for heating metallic workpieces. A heating element can be designed as an electrically operated resistance heating element. A heating element can be designed as a fuel-operated heating element.

[0016] The oven can, for example, have two or more heating zones, one of which has a heating element designed as an electrically operated resistance heating element, and another of which has a heating element designed as a fuel-operated heating element.

[0017] The first and / or the second temperature change device may include a burner, for example a direct flame impingement (DFI) burner.

[0018] The first and / or the second temperature changing device may include an induction heating device or be designed as such.

[0019] The metallic workpiece can be moved through the production plant along a conveying direction. Preferably, the production plant includes a conveying device configured to move the metallic workpiece along the conveying direction at a conveying speed. The metallic workpiece can be designed as an endless workpiece or as a workpiece of a defined length.

[0020] The first and / or the second temperature changing device can be arranged in a position that does not change in the production plant, particularly in the conveying direction, so that a metallic workpiece moving along the conveying direction performs a relative movement to the first and / or the second temperature changing device.

[0021] The first temperature-changing device can be positioned upstream of the second temperature-changing device with respect to the conveying direction. In other words, a metallic workpiece moving in the conveying direction first passes through the first temperature-changing device and then through the second temperature-changing device.

[0022] The first temperature-changing device can be spaced apart from the second temperature-changing device with respect to the conveying direction. Between the first and second temperature-changing devices, one or more devices for the mechanical and / or thermal treatment of metallic workpieces can be arranged. In other words, a metallic workpiece moving in the conveying direction can first pass through the first temperature-changing device, then through one or more devices for mechanical and / or thermal treatment, and finally through the second temperature-changing device.

[0023] The production plant may include one or more additional temperature-changing devices.

[0024] The control device can be configured to control the first temperature changing device and / or the second temperature changing device, preferably depending on the result to be achieved and / or the at least one influencing factor.

[0025] The statement that the first operating value of the first operating parameter of the first temperature change device is determined as a function of the desired result of the thermal treatment of the metallic workpiece and as a function of an influencing factor relating to the thermal treatment of the metallic workpiece describes a functional relationship between the determination of the operating value, the desired result, and the influencing factor. In other words, the operating value of the first operating parameter is determined as a function of the desired result and the influencing factor.

[0026] The operating values ​​of the first and / or second operating parameter can be directly adjustable on the first and / or second temperature-changing device. A directly adjustable operating value could, for example, be the relative speed of the metallic workpiece with respect to the first and / or second temperature-changing device.

[0027] Furthermore, the first and / or second operating parameter(s) can be automatically set to a first and / or second operating value. For example, the first and / or second operating parameter(s) can be automatically set to a first and / or second operating value depending on a change in the desired result and / or the influencing factor.

[0028] Alternatively, the first and / or second operating parameter(s) can be manually set to a first and / or second operating value, for example by operator input.

[0029] The influencing factor concerning the thermal treatment of the metallic workpiece is preferably not directly adjustable. In other words, the influencing factor preferably results from predetermined production conditions and requirements. For example, an influencing factor defined as the efficiency of the first temperature-changing device is predetermined by the first temperature-changing device. Another example is an influencing factor defined as a material property of the metallic workpiece, determined by the metallic workpiece itself, for example, its material composition. Furthermore, an influencing factor defined as a material property can be variable during the thermal treatment.

[0030] Preferably, the step of determining a second operating value of at least one second operating parameter of the second temperature change device is carried out as a function of at least one influencing factor relating to the thermal treatment of the metallic workpiece. The influencing factor as a function of which the first operating value of at least one first operating parameter of the first temperature change device is determined, and the influencing factor as a function of which the second operating value of at least one second operating parameter of the second temperature change device is determined, can be the same or different from each other.

[0031] The desired outcome of the thermal treatment of the workpiece can be a single target variable or multiple target variables. For example, the desired outcome of the thermal treatment of the metallic workpiece can be represented as a vector with multiple entries, where each entry represents a target variable.

[0032] Preferably, the method is designed such that the first temperature changing device is arranged directly adjacent to the second temperature changing device with respect to a conveying direction.

[0033] If the first temperature-changing device is located immediately adjacent to the second temperature-changing device with respect to the conveying direction, a metallic workpiece moving in the conveying direction can first pass through the first temperature-changing device and immediately afterwards through the second temperature-changing device. In particular, a metallic workpiece conveyed in the conveying direction cannot pass through any further mechanical and / or thermal treatment devices between the first and second temperature-changing devices.

[0034] The first and second temperature change devices can be arranged in a common housing.

[0035] Preferably, the method comprises the following steps: - Determining information on at least one influencing factor concerning the thermal treatment of the metallic workpiece, and / or - Determining information about the desired result of the thermal treatment of the metallic workpiece.

[0036] The control device can be designed to determine the information about at least one influencing factor and / or information about the result to be achieved.

[0037] The step of determining information on at least one influencing factor concerning the thermal treatment of the metallic workpiece can be carried out before and / or while the metallic workpiece is in the production plant, preferably in the first and / or second temperature-changing device. The step of determining information on the desired result of the thermal treatment of the metallic workpiece can also be carried out before and / or while the metallic workpiece is in the production plant, preferably in the first and / or second temperature-changing device.

[0038] Preferably, the method is designed such that the step of setting the at least one first operating parameter of the first temperature changing device to the first operating value takes place before and / or while the metallic workpiece is in the production plant, and / or the step of setting the at least one second operating parameter of the second temperature changing device to the second operating value takes place before and / or while the metallic workpiece is in the production plant.

[0039] This method has the advantage of further reducing the settling times of the production plant. If the operating parameters can already be set to the required values ​​before the metallic workpiece is in the first and / or second temperature-changing device, the first and / or second temperature-changing device can already reach the operating conditions required for the desired result before the metallic workpiece is even in the first and / or second temperature-changing device.

[0040] Furthermore, the method developed in this way has the advantage that it allows for a faster response to changes in production conditions while a metallic workpiece is in the production plant.

[0041] Preferably, the method is designed such that the step of setting the at least one first operating parameter of the first temperature changing device to the first operating value takes place before and / or while the metallic workpiece is in the first temperature changing device, and / or the step of setting the at least one second operating parameter of the second temperature changing device to the second operating value takes place before and / or while the metallic workpiece is in the first temperature changing device and / or in the second temperature changing device.

[0042] Preferably, the method is designed such that the step of determining the second operating value of the at least one second operating parameter of the second temperature changing device is dependent on the step of determining the first operating value of the at least one first operating parameter of the first temperature changing device.

[0043] This method has the advantage of improving the achievement of the desired result from the thermal treatment of the metallic workpiece. By using the first operating value to determine the second operating value, in addition to the desired result and at least one influencing factor, the second operating value can be determined in such a way as to reduce potential deviations in the desired result.For example, if the second temperature-changing device has a lower inertia than the first, but a lower efficiency, then after a product change, the temperature of the second device can initially be set to a predetermined value. This allows the desired thermal treatment result for the metallic workpiece to be achieved even if the first device has not yet reached the temperature required for that result. In other words, the second device compensates for the first device's insufficient temperature during this period.Once the first temperature-changing device has reached its required temperature, the temperature of the second device can be reduced to a lower value. This reduces the overall settling time of the production plant, thus improving the results of the thermal treatment.

[0044] The statement that the second operating value is determined as a function of the first operating value describes a functional relationship between the determination of the second operating value and the first operating value. In other words, the second operating value is determined as a function of the first operating value.

[0045] Preferably, the method is designed such that the step of determining the second operating value of the at least one second operating parameter of the second temperature changing device takes place simultaneously or after the step of determining the first operating value of the at least one first operating parameter of the first temperature changing device.

[0046] Alternatively, the step of determining the second operating value of the at least one second operating parameter of the second temperature changing device can take place before the step of determining the first operating value of the at least one first operating parameter of the first temperature changing device.

[0047] Preferably, the method is designed such that the result to be achieved includes a previously determined quality of the metallic workpiece after the thermal treatment.

[0048] A predetermined quality of the metallic workpiece can comprise one or more material properties that can be adjusted and / or produced by thermal treatment. For example, the predetermined quality of the metallic workpiece can comprise a predetermined degree of hardness. The predetermined degree of hardness can be a hardness value on a hardness scale known to those skilled in the art, such as Martens, Rockwell, Brinell, Vickers, and / or another known hardness scale. Furthermore, the predetermined quality of the metallic workpiece can comprise a specific tensile strength, a specific modulus of elasticity, a specific Poisson's ratio, or other material properties.

[0049] Alternatively or additionally, the previously determined quality of the metallic workpiece can include a specific alloy composition of the metallic workpiece. For example, the previously determined alloy composition can include a previously determined carbon content and / or nitrogen content at a previously determined penetration depth of the metallic material.

[0050] The achievable quality of the metallic workpiece can depend on the first operating value of the first operating parameter of the first temperature control device, the second operating value of the second operating parameter of the second temperature control device, and at least one influencing factor relating to the thermal treatment of the metallic workpiece. In other words, different operating values ​​of the temperature control device parameters and different influencing factors relating to the thermal treatment of the metallic workpiece can result in different quality of the metallic workpiece.

[0051] The method may include a step for adjusting the desired result of the thermal treatment of the metallic workpiece depending on at least one influencing factor, preferably depending on several influencing factors, relating to the thermal treatment of the metallic workpiece.

[0052] The previously determined quality of the metallic workpiece after heat treatment can be adjusted during the heat treatment process. In other words, the desired result regarding the previously determined quality of the metallic workpiece can be adjusted during the heat treatment.

[0053] The method may include a step to determine the current quality of the metallic workpiece while the metallic workpiece is in the production plant, preferably in the first and / or second temperature changing device.

[0054] Determining the current quality of the metallic workpiece can be done, for example, by measurement and / or by calculation using a mathematical model and / or based on previously determined measured values.

[0055] The measurement can be used to determine information such as the yield strength, tensile strength, recrystallization, and / or the r-value of the metallic workpiece. The r-value can be determined, for example, according to DIN EN ISO 10113 and is also known as the Lankford coefficient.

[0056] The measurement can, for example, include an X-ray measurement or an ultrasonic measurement of the metallic workpiece. The measurement is preferably carried out using a suitable measuring device.

[0057] The process may include a step to adjust the desired result with respect to the previously determined quality of the metallic workpiece, depending on the current quality of the metallic workpiece.

[0058] This allows, for example, the determination during a heat treatment of whether a previously defined quality of a metallic workpiece can be achieved. If it is determined that the previously defined quality of the metallic workpiece can no longer be achieved by the end of the heat treatment, the previously defined quality of the metallic workpiece can be adjusted based on its current quality. For example, the previously defined quality can be modified by utilizing the existing

[0059] Preferably, the method is designed such that the result to be achieved includes minimized costs of the thermal treatment of the metallic workpiece.

[0060] The minimized cost of a thermal treatment of a metallic workpiece is the cost of the thermal treatment of the metallic workpiece for a value of at least one influencing factor relating to the thermal treatment of the metallic workpiece, and for a first operating value of at least one first operating parameter of the first temperature changing device, and for a second operating value of at least one second operating parameter of the second temperature changing device, which, compared to all other operating values ​​of at least one first operating parameter of the first temperature changing device and at least one second operating parameter of the second temperature changing device, exhibits the lowest cost value of the thermal treatment of the metallic workpiece.

[0061] Preferably, the method is designed such that in the step of determining the first operating value of the at least one first operating parameter of the first temperature change device and / or in the step of determining the second operating value of the at least one second operating parameter of the second temperature change device, the previously determined quality of the metallic workpiece after the thermal treatment takes precedence over the minimized cost of the thermal treatment of the metallic workpiece.

[0062] This developed process has the advantage that the required product quality is achieved while minimizing the costs of thermal treatment.

[0063] The statement that the previously determined quality of the metallic workpiece after thermal treatment takes precedence over the minimized cost of the thermal treatment can also be expressed as follows: in the steps of determining the first operating value of the first operating parameter and determining the second operating value of the second operating parameter, only those first operating values ​​of the first operating parameter and those second operating values ​​of the second operating parameter are available for determining the first operating value of the first operating parameter and for determining the second operating value of the second operating parameter for achieving minimized costs of thermal heat treatment, for which the previously determined quality of the metallic material after thermal treatment is achieved. In other words, the determination of the first and second operating values ​​takes place in two steps.In a first step, all operating values ​​for the first and second operating parameters are determined for which the previously defined quality of the metallic workpiece is achieved. These operating values ​​form a first subset of all operating values. In a second step, from this first subset of operating values, those operating values ​​are determined for which the costs of the thermal treatment of the metallic workpiece are minimized.

[0064] Preferably, the method comprises the following steps: - Determining information on k influencing factors concerning the thermal treatment of the metallic workpiece, and - Determining a first operating value for each of the n first operating parameters of the first temperature change device depending on the desired result of the thermal treatment of the metallic workpiece and depending on the k influencing factors relating to the thermal treatment of the metallic workpiece, and / or - Determining a second operating value for m second operating parameters of the second temperature change device depending on the desired result of the thermal treatment of the metallic workpiece.

[0065] This method offers the advantage of further reducing the settling times of the production plant. By determining operating values ​​for a multitude of operating parameters depending on a variety of influencing factors, it is possible to react more effectively to changing production conditions, such as product changes.

[0066] Preferably, the step of determining a second operating value for m second operating parameters of the second temperature changing device is carried out as a function of l influencing factors relating to the thermal treatment of the metallic workpiece. The k influencing factors, each of which determines an operating value for n first operating parameters of the first temperature changing device, and the l influencing factor, each of which determines a second operating value for m second operating parameters of the second temperature changing device, can be at least partially the same, preferably all the same, or at least partially different from each other, preferably all different from each other.

[0067] k can have a value greater than or equal to 2, preferably greater than or equal to 5, and particularly preferably greater than or equal to 10. m can have a value greater than or equal to 2, preferably greater than or equal to 5, and particularly preferably greater than or equal to 10. n can have a value greater than or equal to 2, preferably greater than or equal to 5, and particularly preferably greater than or equal to 10.

[0068] m and n can have the same value. In other words, the number of first operating parameters can equal the number of second operating parameters. m and n can have values ​​different from k. k and l can have the same value. Alternatively, k and l can have different values. Preferably, m, n, l, and k have different values.

[0069] Preferably, the method is designed such that the at least one first operating parameter of the first temperature changing device and / or the at least one second operating parameter of the second temperature changing device is selected from the following group: - a relative velocity of the metallic workpiece with respect to the first and / or second temperature change device, and / or - an operating performance of the first and / or second temperature changing device, and / or - an operating power change rate of the temperature change device, and / or - an operating temperature of the first and / or second temperature changing device, and / or - an operating temperature change rate of the first and / or second temperature change device, and / or - an operating atmosphere composition of the first and / or second temperature changing device, and / or - a flow rate of a fluid in the first and / or the second temperature change device, and / or - an operating pressure of a fluid in the first and / or the second temperature changing device, and / or - an operating setting of a conveying device for conveying a fluid in the first and / or the second temperature changing device.

[0070] The relative velocity of the metallic workpiece is the speed at which the metallic workpiece moves relative to the first temperature-changing device and / or the second temperature-changing device along the conveying direction. If, for example, the metallic workpiece is moved through the production plant by means of the conveying device at a conveying speed, and the first and second temperature-changing devices are arranged in a fixed position within the production plant, the relative velocity of the metallic workpiece corresponds to the conveying speed. If the first and / or the second temperature-changing device is designed, for example, as a continuous furnace, the relative velocity can also be referred to as the throughput velocity through the continuous furnace.

[0071] Operating power is the power delivered to the metallic workpiece by the first and / or second temperature-changing device. Operating power can include thermal power, electrical power, and / or magnetic power. The operating power of the first and / or second temperature-changing device can also be referred to as output power. For example, operating power can include the heat output from an electrically driven resistance heating element of the first temperature-changing device.

[0072] The operating power change rate of the first and / or the second temperature-changing device is the rate at which the operating power is to be changed within a specified time. The operating power change rate can be expressed in kilowatts per second (kW / s) or in kilowatts per minute (kW / min).

[0073] The operating temperature of the first and / or second temperature changing device is the temperature that must be present in the first and / or second temperature changing device to achieve the desired result of the thermal treatment of the metallic workpiece. For example, the operating temperature can be the required temperature in a temperature changing device designed as a furnace.

[0074] The operating temperature change rate of the first and / or second temperature changing device is the rate at which the operating temperature is to be changed within a specified time. The operating temperature change rate can be expressed in Kelvin per second (K / s) or in Kelvin per minute (K / min).

[0075] The operating atmosphere composition of the first and / or second temperature-changing device is the atmospheric composition that must be present in the first and / or second temperature-changing device to achieve a desired result in the thermal treatment of the metallic workpiece. For example, the operating atmosphere composition can be the required atmospheric composition of a heating volume in a first temperature-changing device designed as a furnace. The process designed in this way has the advantage that a predetermined quality of the metallic workpiece can be improved. For example, a predetermined alloy composition can include a predetermined carbon content at a predetermined penetration depth of the metallic material.

[0076] The flow rate of a fluid in the first and / or the second temperature change device can, for example, be the flow velocity of a fluid, such as air, within a temperature change device designed as a continuous furnace.

[0077] The operating pressure of a fluid in the first and / or the second temperature change device can, for example, be the pressure of a fluid, such as air, within a temperature change rate designed as a continuous furnace.

[0078] The operating setting of a conveying device for conveying a fluid in the first and / or the second temperature change device can, for example, include a rotational speed. The conveying device can, for example, include a pump and / or a fan.

[0079] Preferably, the method is designed such that at least one influencing factor relating to the thermal treatment of the metallic workpiece is selected from the following group: - a maximum relative speed of the metallic workpiece with respect to the first and / or second temperature change device, and / or - a heat transfer rate between an environment around the metallic workpiece and the metallic workpiece itself, and / or - an operating power capacity of the first and / or second temperature change device, and / or - a maximum operating value of an operating parameter of the first and / or second temperature change device, and / or - a power requirement of the first and / or second temperature change device, and / or - an efficiency of the first and / or second temperature change device, and / or - Energy carrier costs of one or more energy carriers used to operate the first and / or second temperature changing device, and / or - geometric dimensions of the metallic workpiece, and / or - maximum geometric dimensions of the metallic workpiece, and / or - Material properties of the metallic workpiece, and / or - a service life of at least one component of the first and / or second temperature change device, and / or - an available production capacity of at least one component of the first and / or second temperature change device; and / or - Spare part costs of at least one component of the first and / or second temperature changing device, and / or - Production plant downtime, and / or - a production program of the production plant.

[0080] The maximum relative speed of the metallic workpiece is the maximum speed at which the metallic workpiece can be moved relative to the first temperature changing device and / or to the second temperature changing device along the conveying direction.

[0081] The heat transfer rate is the amount of thermal energy transferred per unit of time into the metallic workpiece from its surrounding environment. The heat transfer rate can be specified in kW, for example. It can also be expressed as a per-area value in kW / m². 2 or volume-related in kW / m² 3The heat transfer rate between the environment surrounding the metallic workpiece and the metallic workpiece itself can be determined by a heat transfer coefficient, which defines the intensity of heat transfer at an interface between the metallic workpiece and the environment surrounding it. The heat transfer coefficient can be expressed in the unit W / m². 2 K must be specified. The environment surrounding the metallic workpiece can be its immediate surroundings. If, for example, the first temperature changing device and / or the second temperature changing device is designed as a continuous furnace, the environment surrounding the metallic workpiece can include or be the operating atmosphere inside the continuous furnace.

[0082] The operating power capacity is the maximum installed power of the first and / or second temperature changing device. The operating power capacity therefore represents an upper limit to the operating power of the first and / or second temperature changing device.

[0083] The maximum operating value of an operating parameter of the first and / or second temperature-changing device is the maximum adjustable operating value of that parameter. For example, if the first and / or second temperature-changing device is designed as an induction heating device, an operating parameter could be the voltage applied to the induction heating device and / or the frequency of an alternating current. The maximum operating value could, for example, be the maximum adjustable voltage and / or frequency of an alternating current that is to flow through one or more coils of the induction heating device.

[0084] The power requirement of the first and / or second temperature-changing device is the power needed to achieve the required operating performance. For example, the power requirement may include the electrical power necessary to deliver a required heat output from an electrically driven resistance heating element of the first temperature-changing device.

[0085] The efficiency of the first and / or second temperature-changing device is the ratio of its operating power to its corresponding power consumption. For example, a required heat output of 900 kW from an electrically operated resistance heating element in the first temperature-changing device may require an electrical power consumption of 1000 kW. In this case, the efficiency of the first temperature-changing device is 90%.

[0086] Energy carrier costs are the cost of a specific quantity of energy from a particular energy source. For example, electricity can have a specific price per kilowatt-hour. Alternatively, oil or coal can have a specific price per liter or ton. Due to the energy content contained in oil or coal and released through combustion, costs for a specific quantity of power or energy can also be calculated for these energy carriers. Energy carrier costs can vary over time. In particular, energy carrier costs can differ at different times of day. For example, electricity may be cheaper at night than during the day.A process that takes energy carrier costs into account has the advantage that the desired result is achieved with improved results and minimized costs of thermal treatment of the metallic workpiece, since the energy carrier with the lowest energy carrier costs can always be used.

[0087] The geometric dimensions of the metallic workpiece can include its geometric characteristics, in particular its external dimensions with respect to length, width, and thickness. The geometric dimensions of the metallic workpiece can also include information on the ratio of the surface area to the volume of the metallic workpiece.

[0088] The maximum geometric dimensions of the metallic workpiece represent an upper limit to the geometric dimensions of the metallic workpiece. In other words, the maximum geometric dimensions of the metallic workpiece represent an upper limit for metallic workpieces that can be thermally treated using the first and / or second temperature change device.

[0089] The material properties of a metallic workpiece can include, for example, density, specific heat capacity, thermal conductivity, electrical conductivity, magnetic conductivity, and / or other material properties. These properties can be influenced by the composition of the metallic workpiece, such as its alloy composition. A process that takes material properties into account offers the advantage of achieving the desired result with improved accuracy.

[0090] The service life of at least one component of the first and / or second temperature-changing device can be a period specified in hours, days, months, or years during which the component remains functional. In other words, the component does not need to be replaced due to a defect or malfunction within its service life. The component's service life depends on the set operating parameters of the first and / or second temperature-changing device. For example, if the operating parameters are set such that the temperature-changing devices are always operated at their performance limits, this can reduce the component's service life. The component could, for example, be an intermittently stressed component such as a heating element.For example, if the first temperature changing device is always operated in such a way that the operating temperature change rate is always set to its maximum value when changing products, the service life of the heating elements of the first temperature changing device may be shortened.

[0091] A method that considers the service life of at least one component of the first and / or second temperature-changing device has the advantage of achieving the desired result with minimized costs. If a component's service life is exceeded, the production line may have to be stopped to replace the component. This results in downtime, which increases the cost of the thermal treatment. By considering the service life when determining operating parameters, the increased cost of thermal treatment due to production line downtime can be factored in. For example, the operating parameters can be set so that the service life of at least one component is not exceeded before scheduled maintenance for that component.

[0092] The available production capacity of at least one component of the first and / or second temperature-changing device can represent a period defined in time and / or number of metallic workpieces and / or number of load cycles, until a planned production line shutdown, such as a maintenance shutdown. For example, the operating parameters can be adjusted so that the production rate of the production line is reduced, at least temporarily, thus achieving a planned maintenance shutdown without first exceeding downtime due to unplanned downtime, such as exceeding the service life of a component of the first and / or second temperature-changing device. This allows for improved prevention of unplanned downtime and thus reduces the costs of thermal treatment.

[0093] The spare part costs for at least one component of the first and / or second temperature-changing device may include the cost of replacing the component. These spare part costs may include the cost of replacing the component.

[0094] Production plant downtime can include any period during which the plant is not performing thermal treatment on a metallic workpiece. For example, scheduled and / or unscheduled maintenance work on the production plant can lead to downtime. Furthermore, repair work on the production plant can also result in downtime.

[0095] The production program of the production plant can include the products scheduled for production within a predetermined timeframe. The products to be produced are preferably the metallic workpieces that are to undergo thermal treatment using the production plant. For example, the production program can include the products to be produced within one week. The production program can include a sequencing plan for the products to be produced. This sequencing plan can be variable. A method that takes the production program into account has the advantage that the costs of the thermal treatment of the metallic workpieces can be further minimized, while simultaneously allowing for a response to unforeseen events during production.

[0096] Preferably, the method is designed such that the step of determining the first operating value of the at least one first operating parameter of the first temperature changing device and / or the step of determining the second operating value of the at least one second operating parameter of the second temperature changing device is carried out using one or more optimization methods selected from the following group: - a continuous optimization process, and / or - a discrete optimization method, and / or - a machine learning method, and / or - a combination of a continuous optimization method and / or a discrete optimization method and / or a machine learning method.

[0097] The continuous optimization method can be, for example, a gradient method, a probabilistic algorithm for global optimization such as simulated annealing, and / or another method.

[0098] The discrete optimization method can be a genetic algorithm, a branch-and-bound method, and / or another method.

[0099] The machine learning method can be a method using a neural network, a support vector machine, a k-means algorithm and / or another method.

[0100] The problem underlying the present invention is further solved by a production plant for the thermal treatment of metallic workpieces, wherein the production plant comprises a first temperature-changing device configured to change the temperature of a metallic workpiece located in the first temperature-changing device, and a second temperature-changing device configured to change the temperature of a portion of the metallic workpiece located in the second temperature-changing device. The production plant includes a control device that is data-connected to the first temperature-changing device and / or to the second temperature-changing device, wherein the control device is configured to execute a previously described method.

[0101] A production plant designed in this way has the advantage that the settling times of the production plant are reduced.

[0102] The production plant can, for example, be designed as a casting and rolling mill. A casting and rolling mill includes, in particular, at least one primary forming device, such as a continuous casting device, and at least one forming device.

[0103] The production plant can, for example, be designed as a galvanizing plant. A galvanizing plant includes, in particular, at least one cleaning device, one oxidation device, one reduction device, and one coating device.

[0104] Preferably, the production plant is designed such that the control device has a communication device, wherein the communication device is configured for: - To determine information on at least one influencing factor concerning the thermal treatment of the workpiece, and - To determine information on the desired result of the thermal treatment of the metallic workpiece.

[0105] Further advantages, details, and features of the invention will become apparent from the exemplary embodiments described below. Specifically, the following will be shown: Fig. 1: a production plant for the thermal treatment of metallic workpieces according to a first embodiment; Fig. 2: a production plant for the thermal treatment of metallic workpieces according to a second embodiment; Fig. 3: a production plant for the thermal treatment of metallic workpieces according to a third embodiment; Fig. 4: a flowchart of a first embodiment of a method for controlling the production plant according to one of the Fig. 1 to 3; Fig. 5: a flowchart of a second embodiment of a method for controlling the production plant according to one of the Fig. 1 to 3; Fig. 6: a flowchart of the first embodiment of the method for controlling the production plant according to Fig. 2; and Fig. 7: a flowchart of the first embodiment of the method for controlling the production plant according to Fig. 3.

[0106] In the following description, identical reference numerals denote identical components or identical features, so that a description of a component in relation to one figure also applies to the other figures, thus avoiding repetitive descriptions. Furthermore, individual features described in connection with one embodiment can also be used separately in other embodiments.

[0107] Fig. Figure 1 shows a schematic representation of a production plant 1 for the thermal treatment of metallic workpieces. The production plant 1 has a first temperature changing device 10, which is configured to change the temperature of a metallic workpiece located in the first temperature changing device 10. The production plant 1 also has a second temperature changing device 20, which is configured to change the temperature of a metallic workpiece located in the second temperature changing device 20.

[0108] The first temperature changing device 10 is spaced apart from the second temperature changing device 20 with respect to a conveying direction R1. A device 40 for the mechanical treatment of metallic workpieces is arranged between the first temperature changing device 10 and the second temperature changing device 20.

[0109] Production plant 1 also includes a conveying device 50, which is configured to move the metallic workpiece along the conveying direction R1. When a metallic workpiece is located in production plant 1, it is moved through production plant 1 along the conveying direction R1 and first passes the first temperature changing device 10, then the device 40 for the mechanical treatment of the metallic workpiece, and finally the second temperature changing device 20.

[0110] Production plant 1 further comprises a control device 30 which is data-connected to the first temperature changing device 10 and to the second temperature changing device 20, and is configured to operate a Fig. 4 and / or in Fig. 5. To carry out the procedure shown.

[0111] The control device 1 has a communication device 31 which is configured to determine information on at least one influencing factor relating to the thermal treatment of the workpiece and to determine information on a result to be achieved from the thermal treatment of the metallic workpiece.

[0112] Fig. Figure 2 shows a schematic representation of a production plant 1 for the thermal treatment of metallic workpieces, wherein the production plant 1 is designed as a galvanizing plant 2. The galvanizing plant 2 has an unwinding device 110, a cleaning device 120 arranged behind the unwinding device 110 in the conveying direction R1, an oxidation device 130, a reduction device 140 and a coating device 150, as well as a winding device 100.

[0113] The galvanizing plant 2 further comprises a first and a second temperature changing device 10, 20, wherein the first temperature changing device 10 is arranged directly adjacent to the second temperature changing device 20 with respect to the conveying direction R1. The galvanizing plant 2 further comprises a third temperature changing device 60, wherein the third temperature changing device 60 is arranged at a distance from the second temperature changing device 20 with respect to the conveying direction R1.

[0114] The galvanizing plant 2 further comprises a control device 30 which is data-connected to the first temperature changing device 10, the second temperature changing device 20 and the third temperature changing device 60, and is configured to operate a Fig. 6. To carry out the procedure shown.

[0115] Fig. Figure 3 shows a schematic representation of a production plant 1 for the thermal treatment of metallic workpieces, wherein the production plant 1 is designed as a casting and rolling plant 3. The casting and rolling plant 3 comprises a primary forming device 90, two devices 40 each designed as forming devices 41 for mechanical treatment, and a winding device 100.

[0116] Furthermore, the casting and rolling machine 3 has a third temperature-changing device 60, which is configured to change the temperature of a metallic workpiece located in the third temperature-changing device 60. The casting and rolling machine 3 also has a fourth temperature-changing device 70, which is configured to change the temperature of a metallic workpiece located in the fourth temperature-changing device 70. Finally, the casting and rolling machine 3 has a fifth temperature-changing device 80, which is configured to change the temperature of a metallic workpiece located in the fifth temperature-changing device 80.

[0117] The first temperature changing device 10 is arranged directly adjacent to the second temperature changing device 20 with respect to the conveying direction R1. This allows a metallic workpiece moving in the conveying direction R1 to first pass through the first temperature changing device 10 and immediately afterwards through the second temperature changing device 20.

[0118] The third temperature changing device 60 is arranged directly adjacent to the fourth temperature changing device 70 with respect to the conveying direction R1. This allows a metallic workpiece moving in the conveying direction R1 to pass through the third temperature changing device 60 and immediately afterwards the fourth temperature changing device 70.

[0119] A forming device 41 is arranged between the second temperature changing device 20 and the third temperature changing device 60. A further forming device 41 is arranged between the fourth temperature changing device 70 and the fifth temperature changing device 80.

[0120] In the conveying direction R1, upstream of the first temperature-changing device 10, a primary forming device 10 is also arranged. Finally, in the conveying direction R1, downstream of the fifth temperature-changing device 80, a winding device 100 is arranged. On the winding device 100, for example, a metallic workpiece formed as a metal strip, moved by the casting and rolling machine 3, can be wound.

[0121] The casting and rolling mill 3 further comprises a control device 30 which is data-connected to the first temperature-changing device 10, the second temperature-changing device 20, the third temperature-changing device 60, the fourth temperature-changing device 70 and the fifth temperature-changing device 80, and is configured to control a Fig. 7. To carry out the procedure shown.

[0122] Fig. Figure 4 shows a flowchart of a first embodiment of a method for controlling the production plant 1 for the thermal treatment of metallic workpieces according to one of the Fig. 1 to 3. The procedure comprises the following steps: - Determine S1 of information on at least one influencing factor concerning the thermal treatment of the metallic workpiece, and - Determine S2 of information on an achievable result of the thermal treatment of the metallic workpiece, and - Determining S3 of a first operating value of at least one first operating parameter of the first temperature change device 10 as a function of the result to be achieved of the thermal treatment of the metallic workpiece and as a function of the at least one influencing factor relating to the thermal treatment of the metallic workpiece, - Determining S4 of a second operating value of at least one second operating parameter of the second temperature change device 20 as a function of the desired result of the thermal treatment of the metallic workpiece, and - Setting S5 of at least one first operating parameter of the first temperature changing device 10 to the first operating value, and - Setting S6 of at least one second operating parameter of the second temperature changing device 20 to the second operating value.

[0123] Fig. Figure 5 shows a flowchart of a second embodiment of a method for controlling the production plant 1 for the thermal treatment of metallic workpieces according to one of the Fig. 1 to 3. The procedure comprises the following steps: - Determine S7 of information on k influencing factors concerning the thermal treatment of the metallic workpiece, and - Determine S2 of information on an achievable result of the thermal treatment of the metallic workpiece, and - Determine S8 of each first operating value for n first operating parameters of the first temperature change device 10 as a function of the result to be achieved of the thermal treatment of the metallic workpiece and as a function of the k influencing factors relating to the thermal treatment of the metallic workpiece, and - Determine S9 of each second operating value for m second operating parameters of the second temperature change device 20 as a function of the desired result of the thermal treatment of the metallic workpiece, and - Setting S5 of at least one first operating parameter of the first temperature changing device 10 to the first operating value, and - Setting S6 of at least one second operating parameter of the second temperature changing device 20 to the second operating value.

[0124] Fig. Figure 6 shows a flowchart of the first embodiment of a method for controlling the production plant 1, designed as a galvanizing plant 2, for the thermal treatment of metallic workpieces according to Fig. 2. In addition to the steps according to Fig. 4. The following steps: - Determining S10 of a third operating value of at least one third operating parameter of the third temperature change device 60 as a function of the desired result of the thermal treatment of the metallic workpiece, and - Setting S13 of at least one third operating parameter of the third temperature changing device 60 to the third operating value.

[0125] Fig. Figure 7 shows a flowchart of the first embodiment of a method for controlling the production plant 1, designed as a casting and rolling plant 2, for the thermal treatment of metallic workpieces according to Fig. 3. In addition to the steps according to Fig. 4. The following steps: - Determining S10 of a third operating value of at least one third operating parameter of the third temperature change device 60 as a function of the result to be achieved of the thermal treatment of the metallic workpiece and as a function of the at least one influencing factor relating to the thermal treatment of the metallic workpiece, - Determining S11 of a fourth operating value of at least one fourth operating parameter of the fourth temperature change device 70 as a function of the result to be achieved of the thermal treatment of the metallic workpiece and as a function of the at least one influencing factor relating to the thermal treatment of the metallic workpiece, - Determining S12 of a fifth operating value of at least one fifth operating parameter of the fifth temperature change device 80 as a function of the result to be achieved of the thermal treatment of the metallic workpiece and as a function of at least one influencing factor relating to the thermal treatment of the metallic workpiece, - Setting S13 of at least one third operating parameter of the third temperature changing device 60 to the third operating value, - Setting S14 of at least one fourth operating parameter of the fourth temperature changing device 70 to the fourth operating value. - Setting S15 of at least one fifth operating parameter of the fifth temperature changing device 80 to the fifth operating value. Reference symbol list 1 production plant 2 galvanizing plants 3 Casting and rolling mill 10. First temperature change device 20 second temperature change device 30 Control device 31 Communication device 40 Device for mechanical treatment 41 Forming device 50 Conveyor device 60 third temperature change device 70 fourth temperature changing device 80 fifth temperature change device 90 Primary forming device 100 winding device 110 Unwinding device 120 cleaning device 130 Oxidation device 140 Reduction device 150 coating device S1 Procedure step S2 process step S3 process step S4 Procedure step S5 Procedure step S6 Procedure step S7 Procedure step S8 Procedure step S9 Procedure step S10 Procedure step S11 Procedure step S12 Procedure step S13 Procedure step S14 Procedure step S15 Procedure step R1 Conveyor direction

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