ENERGY-EFFICIENT CONTROL OF A DEVICE FOR CONTINUOUSLY CONVEYING MATERIAL

Abstract

A control system for a device for continuously conveying material is provided for at least one conveyor belt device adapted for continuously conveying the material and having at least one conveyor belt. The conveyor belt device can be operated by one or more drives in working processes to provide a predeterminable setpoint conveyor flow. The control system is configured to register at least one value of a power and/or energy consumed by at least one of the drives during a working process and to determine an energy efficiency for the respective working process and for the predetermined setpoint conveyor flow with the aid of the at least one value of the consumed power and/or energy. The control system also configured to provide control data relating to drive speed for the at least one drive as a function of the energy efficiency.

Claims

1.-16. (canceled)

17. A control system for a device for continuously conveying material that includes a conveyor belt and a conveyor belt device adapted to continuously convey the material, wherein the conveyor belt device is configured to be operated by way of a drive in working processes to provide a predeterminable setpoint conveyor flow, wherein the conveyor belt device includes an occupancy sensor, wherein the control system is configured to: determine a length-referenced belt occupancy by integrating a conveyor belt speed with respect to time, wherein a material lifting power is given by a height profile and therefore by a height variation of a load; determine an instantaneous lifting power as a sum-product of work due to gravity and a lifting speed of a respective section segment; determine a cleaned total running power from a total drive power minus the material lifting power; register a value of power and/or energy consumed by the drive during one of the working processes and to determine an energy efficiency for the respective working process and for the predeterminable setpoint conveyor flow and/or for an instantaneous actual conveyor flow with the aid of the value of power and/or energy consumed, wherein a ratio of the total running power to a momentum of the material that is moved permits quantitative evaluation of the energy efficiency for pure horizontal transport; and provide control data relating to drive speed, including control data for a frequency converter, for the drive as a function of the energy efficiency.

18. The control system of claim 17 configured to calculate a ratio of total consumed energy of the drive within one of the working processes to the setpoint conveyor flow and/or to an instantaneous conveyor flow to determine the energy efficiency.

19. The control system of claim 17 configured to provide the device with control data regarding a subsequent working process as a function of the energy efficiency determined for the working process.

20. The control system of claim 19 configured to receive sensor data and calculate the control data as a function of the sensor data.

21. The control system of claim 17 wherein to determine the energy efficiency, the control system is configured to determine an energy efficiency coefficient as the value of the total energy consumed by the drive within one of the working processes divided by a total volume or a total mass of the material that is conveyed during the working process.

22. The control system of claim 21 wherein drive power consumed by the drive is used to determine the energy efficiency coefficient.

23. The control system of claim 17 configured to obtain an optimized variation parameter by which the energy efficiency is increased in comparison with other values of the optimized variation parameter, by varying at least one variation parameter over the working processes.

24. The control system of claim 23 wherein the drive comprises a first drive and a second drive, wherein each working process successively comprises an at least approximately constant conveyor movement by the first drive and at least one accelerating and/or decelerating drive actuation by the second drive, wherein the variation parameter comprises a value of a conveyor movement and/or a value of drive actuation.

25. The control system of claim 24 configured to provide the device with control data regarding a subsequent working process as a function of the energy efficiency determined for the working process, wherein the control data are based on an optimized value of conveyor movement and an optimized speed of the drive actuation, wherein the control system is configured to calculate the optimized speed of the drive actuation from the product of a predetermined speed of the drive actuation times a ratio of a predetermined value of the conveyor movement to the optimized value of the conveyor movement.

26. The control system of claim 23 wherein the variation parameter comprises a maximum conveyor rate.

27. The control system of claim 23 comprising a user interface for adjusting the variation parameter.

28. The control system of claim 17 configured to determine a total energy efficiency of the working processes.

29. A device for continuously conveying material, the device comprising a conveyor belt device adapted for continuously conveying the material and a conveyor belt, wherein the conveyor belt device is configured to be operated via a drive in working processes to provide a predeterminable setpoint conveyor flow with variable drive speeds, the device comprising the control system of claim 17.

30. The device of claim 29 configured as a conveyor belt system.

31. A method for controlling a device for continuously conveying material, the device comprising a conveyor belt device adapted to continuously convey the material, wherein the device comprising a conveyor belt, wherein the conveyor belt device is configured to be operated by a drive in working processes to provide a predeterminable setpoint conveyor flow, wherein the method comprises: registering a value of power and/or energy consumed by the drive during one of the working processes; determining a length-referenced belt occupancy by integrating a conveyor belt speed with respect to time; determining a cleaned total running power from a total drive power minus a material lifting power, wherein the material lifting power is based on a height profile based on a height variation of a load, wherein an instantaneous lifting power is determined as a sum-product of work due to gravity and a lifting speed of a respective section segment; determining an energy efficiency for the respective working process and for the predeterminable setpoint conveyor flow and/or for an instantaneous actual conveyor flow with the aid of the a value of the power and/or energy consumed, wherein a ratio of the total running power to a momentum of the material that is moved allows quantitative evaluation of the energy efficiency for pure horizontal transport; and providing control data relating to a drive speed, including control data for a frequency converter, for the drive as a function of the energy efficiency.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The parts shown in the figures are not necessarily true to scale; rather, the emphasis is on presenting the principles of the invention.

[0042] FIG. 1 schematically shows by way of example a view of a device for continuously conveying medium in a configuration as a conveyor belt device;

[0043] FIG. 2 schematically shows by way of example a control system of the device according to FIG. 1.

DETAILED DESCRIPTION

[0044] In the following detailed description, reference is made to the appended drawing, in which the way that the invention may be implemented in practice is shown by illustrating specific embodiments.

[0045] FIG. 1 shows a control system 1 which is coupled to, or is integrated in, a device 10 for continuously conveying material. The device 10 comprises one or more conveying drives 2 arranged successively in a material flow direction, which drive a conveyor belt 4 by means of which the material 3 is conveyed. A material throughput monitor 5 having at least one sensor (optionally having a plurality of measurement units at a plurality of measurement points) allows more in-depth analysis of the material throughput (instantaneous conveyor performance). For example, the material throughput monitor 5 comprises an occupancy sensor which is adapted to register a layer height of the material 3. The conveyor belt or belts 4 (conveyor belt segments) may also, for example, respectively have individual gradients or inclinations. An intermediate bunker may respectively also be provided at material transfer positions, in particular also between individual conveyor belts.

[0046] The conveyor belt 4 conveys an instantaneously moved material mass with an individual instantaneous belt speed. A rotational speed may in this case be specified to the at least one drive, in particular as a function of a respective individual instantaneous drive power. The technical control/regulation interaction is indicated by the arrows between the conveying components and the control system 1.

[0047] FIG. 1 also illustrates a smoothing function of intermediate bunkers at material transfer positions. In particular, the storage/buffer function of the respective intermediate bunker allows smooth variation of a downstream belt speed, in particular while taking into account the instantaneous bunker filling level, which may for example be registered by means of sensors 5.

[0048] Referring to FIG. 1, the following parameters may in particular also be described: instantaneous conveyor quantities at entry and exit transfer points; layer height and cross-sectional area for material flow (in particular registered by an occupancy sensor); section lengths of individual section segments with a constant inclination; instantaneously moved material masses on the respective section segments; instantaneous rotational drive speed and belt speed; instantaneous drive power; inclination of a respective section segment; layer height and length-referenced material flow mass of the bulk material at the longitudinal coordinate “x”; maximum allowed material flow height (particularly in order to avoid pileup).

[0049] FIG. 2 shows the control system 1 of the device 10. The control system 1 comprises a plurality of inputs 20 and a plurality of outputs 21. At the inputs 20, the control system 1 is connected to a further control unit or one or more drives of the device 10, specifically in such a way that it can register at least one value of a power (in particular electrical power) consumed by at least one of the drives 12 during a working process. Optionally, the control system 1 may register values of the power consumed during a working process by a plurality, in particular all of the drives. The value or the values may indicate the power consumed overall during the entire working process. Optionally, the control system 1 is adapted to receive sensor data, which indicate a rate of advance and/or a conveyor performance (in particular a conveyed material volume and/or a conveyed material mass) through the inputs 20. As an alternative or in addition, the control system 1 may be adapted to receive sensor data, which for example indicate a current material composition (for example from at least one radar, ultrasound or laser sensor) and/or environmental data through the inputs 20.

[0050] The control system 1 comprises a computer unit 24, which obtains the value or the values of the consumed power. The control system 1 furthermore receives an indication of the amount of material, for example the material volume and/or the material weight, conveyed in the time period in which the consumed power was consumed. The indication specifies, for example, the material volume and/or the material weight which has been taken up by the bucket wheel 101 (or in general the working member) in the corresponding working process. The material may be weighed and/or measured. As an alternative or in addition, the weight and/or the volume may be estimated. The device 10, in particular the control system 1, may comprise one or more corresponding sensors, which may for example be arranged on the conveyor belt.

[0051] With the aid of the value or the values of the consumed power and the indication of the amount of material conveyed, the control system 1 determines an energy efficiency for the working process. For this purpose, the control system calculates (by means of the computer unit 24) an energy efficiency coefficient as the at least one value of the consumed power divided by the total volume or the total mass of the material taken up during the working process. The energy efficiency coefficient is optionally separate for individual segments along the conveyor section and/or individual drives. A series of energy efficiency coefficients may be determined for a part or for all of the procedure.

[0052] The control system 1 comprises a user interface 22 having a display device 220. The control system 1 displays the energy efficiency that has been determined, in particular the energy efficiency coefficient that has been calculated, by means of the display device 220. A user can read from this information how energy-efficient the settings selected in the associated working process were, and optionally may manually adapt settings accordingly.

[0053] The user interface 22 furthermore comprises an input means 221. Optionally a user may be able to make or adapt settings (for example material feed at transfer positions, drive speed and/or target feed rate), which the control system 1 then sets for a current working process and/or one or more subsequent working processes, via the input means 221. In order to make settings, the control system 1 is connected via the outputs 21 to a further control unit and/or to one or more drives. Via the outputs 21, the control system 1 then for example outputs corresponding control data.

[0054] In this way, it is possible to improve the energy efficiency of the device 10, for example in respect of a substantially unchanged conveyor rate.

[0055] The user interface 22 may for example comprise a display screen as a display device 220, and as input means 221 the display screen may be touch-sensitive, or as an alternative or in addition a keypad or the like may be provided. Furthermore, it is also possible to provide the user interface 22 by means of a web application, for example as a website.

[0056] Furthermore, the control system 1 comprises a memory 25 for storing computer-readable data. An optional optimization module 26 is stored in the memory 25. A plurality of variation parameters 27 are stored in the memory 25. The memory 25 allows ongoing storage and analysis of values. The memory 25 may be permanently installed or removable. The memory 25 is a computer program product.

[0057] The control system 1 runs the optimization module 26 by means of the computer unit 24. The optimization module 26 receives at least one variation parameter 27, for example in respect of at least one drive speed. The control system 1 varies the at least one variation parameter 27 over a plurality of working processes and/or over consecutive components. The optimization module 26 determines that value of the at least one variation parameter for which the highest energy efficiency has been determined, in particular for which the energy efficiency coefficient is minimized, as an optimized variation parameter. The optimization module 26 may evaluate the variation parameter after each cycle and/or optimize it iteratively over a plurality of working processes. Optionally, the optimization module 26 optimizes a plurality of variation parameters, for example successively.

[0058] For a current working process and/or one or more subsequent working processes, the control system 1 then makes settings according to the optimized variation parameter, for example by outputting corresponding control data through the outputs 21. Optionally, the optimization module 26 optimizes a variation parameter, for example a drive speed, and adjusts another parameter proportionally or inversely proportionally thereto. For example, the optimization module 26 (in general the control system 1) changes a drive speed proportionally to the change in the material feed at transfer positions. In this way, the desired conveyor rate may also be supervised.

[0059] More energy-efficient material transport may thus be achieved while complying with desired setpoint conveyor performances.

[0060] Optionally, the respective parameters or values are optimized for individual section segments and respectively from working process to working process.

[0061] In one optional configuration, the optimization module 26 optimizes a maximum conveyor rate, in particular the target conveyor rate, as a variation parameter. In some cases, a task is not time-critical, for example if more time is available for providing a predetermined material volume than is required with the maximum adjustable conveyor rate. Then, as an alternative or in addition to other variation parameters, the target conveyor rate may be optimized as a variation parameter.

[0062] Optionally, by using the input means 221 it is possible to adjust which adjustable parameter should be optimized as a variation parameter.

[0063] The control system 1 may be the central control system of the device 10. Alternatively, it is an additional control system 1 actively connected to one or more other control units of the device 10. Optionally, the control system 1 may be retrofitted to an existing conveyor belt device. Optionally, the control system 1 may be brought into communicative connection with an existing machine control and/or with sensors (and/or other control members, for example at least one frequency converter) by means of analog interfaces and/or a field bus system, for example by means of a conventional industrial communication interface.

[0064] The individual components of the control system 1, as are shown in FIG. 2, may be mounted on or in a common housing. As an alternative, some or all components are arranged at different locations (for example at different positions of the device 10) and are actively connected to one another.

[0065] By the adaptive energy-efficient regulation, a control method with stepwise variation of values or parameters in a defined sequence may therefore be provided for the continuously conveying device. This allows a stepwise approach of the specific energy demand (expressed in terms of the material volume conveyed) to a minimum possible value while maintaining a predetermined conveyor performance.

[0066] The device for continuously conveying material has been described above by way of example as a conveyor belt device or a conveyor belt system. Naturally, the indications above also apply correspondingly for other continuously working apparatuses.

[0067] The control system described above, a device equipped therewith, and the method allow and provide in particular one or more of the following operating modes.

[0068] The entire energy outlay for the material take-up, material conveying and material deposition may be minimized for a defined conveyor quantity.

[0069] An energy minimization (and cost minimization) for the transport of a predetermined amount of material is possible while specifying an allowed conveyor performance reduction or a maximum conveyor time for this amount.

[0070] Furthermore, automatic adaptation of material buffering, in particular at material transfer positions, to the varying material feed by upstream extraction apparatuses is possible with the aim of maintaining the conveyor performance efficiency and/or energy efficiency.

[0071] As used here, the terms “comprising”, “having”, “including”, and similar open terms which indicate the presence of elements or features mentioned, do not however exclude additional elements or features. It should be pointed out that the present invention is not restricted by the description given above, nor is it restricted by the appended drawings. Rather, the present invention is restricted only by the following claims and legal equivalents thereof.

LIST OF REFERENCES

[0072] 1 control system [0073] 2 drive [0074] 3 material [0075] 4 conveyor belt [0076] 5 material throughput monitor (sensor/measurement units) [0077] 10 device for continuously conveying material [0078] 20 input [0079] 21 output [0080] 22 user interface [0081] 220 display device [0082] 221 input means [0083] 24 computer unit [0084] 25 memory [0085] 26 optimization module [0086] 27 variation parameter [0087] x longitudinal direction or conveyor direction