Method for operating furnace unit

Abstract

To provide a method for operating a furnace unit that can obtain a constant steam output by keeping the ultimately generated furnace output as constant as possible.SOLUTION: A method for operating a furnace unit including a camera disposed in an edge of a lattice inside a furnace unit to image a combustion material on the lattice and a generated flame includes a step of specifying the burning bed thickness and the burnout zone by an image evaluation part with an image that is captured by the camera.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for operating a furnace unit. This method is important when operating a furnace unit in which a defined amount of material per unit time passes from a feed chute through a furnace grate to a bottom ash discharge. [Background technology]

[0002] During the feeding operation, the hopper on the feed chute is filled with material by the claw. This material is a substance that can be chemically transformed using a positive energy balance, and in the context of this application, is preferably waste material. This material may be wet and heavy and slides quickly through the hopper. This material may adhere to the hopper walls, get stuck in the hopper, or for other reasons not continuously reach the furnace grate area through the hopper.

[0003] This material ignites on the furnace grate and burns with varying intensity and heat release depending on the composition of the waste. When multiple grates are operated in sequence, the waste may also burn in different ways as it is moved over different grate tracks.

[0004] In many cases, the function of a furnace unit, especially a waste incineration plant, is to treat waste in an environmentally friendly manner with the lowest possible emissions and to generate energy. For this purpose, the heat release should be as constant as possible, on the one hand to achieve controlled incineration and, on the other hand, to provide a constant steam output that does not change as much as possible. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is therefore based on the goal of keeping the power output of the furnace, which is generally reflected in the steam output and ultimately produced, as constant as possible. [Means for solving the problem]

[0006] This goal is achieved by a method of operating a furnace unit with a feed chute and a camera for capturing images of the surface of the chute, wherein the chute is provided with a slide over which the material flows to a grate, and changes in the coverage of the chute, in particular the coverage and / or position of the slide with the material, and thus the movement of individual components or surface areas within the chute, are identified by an image evaluation unit.

[0007] The slide here is a surface of the feed chute that is inclined relative to the vertical. The slide can be the bottom or side of the feed chute, along which material placed on the chute slides to reach the furnace unit.

[0008] If the wall material of the slide, which is typically a steel surface, is covered in a specific area and remains stationary or changes coverage depending on the movement of the pusher, it can be assumed that the material is sliding properly into the furnace unit. The movement of the combustible material on the slide toward the furnace is coupled to the movement of the pusher. If the pusher moves, the material moves. If the pusher does not move, the material does not move. If this relationship does not hold and the material moves even when the feeder does not move, or if the feeder moves but the material does not move, a fault exists, indicating that the material is not sliding properly into the furnace unit. The vertical wall area or the area on the slide can be monitored here. Since the surface area of the chute, for example, is larger in the case of faulty sliding, attention is preferably paid to which parts form part of the slide and which have as small an angle as possible with the horizontal.

[0009] As a result, coverage of the bottom side of the chute with material is preferably assessed, while the other side of the chute generally constitutes an additional reference point.

[0010] In a preferred embodiment, at least one boundary point is located in the image, where material covers the chute on one side and the surface of the chute is visible on the other side. It is advantageous when multiple boundary points are located, in which case it is also possible to locate lines connecting the boundary points in the image.

[0011] To determine the filling of the chute, it is also possible to calculate a point defined on the side of the chute, in which case the distance of at least one boundary point from the point defined on the side of the chute is determined.

[0012] In other words, it is advantageous to determine the visible line between the chute and the material. To improve the accuracy of the image evaluation unit, the image of the chute surface can be divided into multiple zones. This makes it possible to determine the coverage of each individual zone using the image evaluation unit. The material flow at any point in the chute can be determined therefrom. The dynamic behavior of the furnace unit can be determined when multiple images are taken at certain time intervals, and the fill level in the chute is determined by the image evaluation unit from changes in the images. This makes it possible, for example, to determine the amount of material flowing into the furnace unit from changes in the images. This amount then also constitutes a possibility for measuring the amount of material flowing into the grate.

[0013] Furthermore, the change in position, and therefore the movement of individual compositions or surface areas within the chute, can be tracked by imaging techniques. It is necessary to take multiple images at a certain time interval. These images can be taken as individual images or as a video. Many compositions or surface areas are selected within the chute after the material is introduced, and their movement is detected (until the selected compositions are covered). This selection can be automatic and based on structures and objects learned by artificial intelligence, on the shape, color, or contour of many of the materials within the chute, or on arbitrary or defined areas within the chute. This method allows for determining the flow of material within the chute, as well as methods for detecting individual points at the transition between the chute and the material. This method can be implemented individually or in addition to detecting individual points at the transition between the chute and the material.

[0014] A defect detected in the area of the feeding chute directly leads to a defect in the incineration of the grate. Therefore, another embodiment is proposed in which an action is taken in the case of a predetermined coverage of the chute or a predetermined change in coverage, specifically a change in the coverage of the slide with a specific material flow depending on the material or the movement of the feeder. This action can be an initial intervention in the regulation of the unit. For example, a removal stroke can be initiated here, or adjustments can be made via air management and / or grate speed in cases where the waste flow cannot be controlled. Intervention in the speed and / or position of the feeder is also possible in cases where the waste flow cannot be controlled to optimize incineration. In addition, auxiliary functions (signals to the crane operator) or direct intervention in the material supply of the chute by the crane in response to the detection of the chute's fill level are possible.

[0015] The use of an image evaluation unit makes it possible to identify the transition from the material to the background as at least one point, preferably a line, in the direction of material flow at the edge of the image. As an alternative or in addition to the coverage of the slide, for example in the case of a stationary camera position, it is possible to evaluate the height of the line in the identified image, which can be identified by the transition from the material to the chute. This allows the identification of individual points or continuous lines, which can also be averaged.

[0016] Another embodiment makes it possible to compare the points or lines with a limit value and to perform actions in case this limit value is exceeded, which actions correspond to those described above.

[0017] However, it has also been found that the use of an image evaluation unit is possible not only at the feed chute, but also at the end of the furnace grate for the control of the furnace unit.

[0018] Furnace units are known that include a grate with a camera positioned at its end. The end of the grate constitutes the area where bottom ash accumulates on the grate. A camera positioned there points from the bottom ash area toward the combustion bed and shows how material is burning in the combustion bed. The brightness here indicates the intensity of combustion, and the location of the brightness indicates where material is burning particularly well on the grate.

[0019] According to the present invention, it is further proposed to combine this camera with an image evaluation unit that identifies the thickness of the combustion bed, and / or the burn-out line, and / or the movement or surface area of individual compositions. When a static camera is used, the image shows static features inside the combustion bed and the furnace chamber. The distance between the static features and the combustion bed is directly proportional to the height of the combustion bed. A combustion bed that is too high represents an operation in which too much material is fed, or a stroke movement that is too weak, moving the material too slowly. A particularly low combustion bed, which can be inferred from a low line in the image, represents a material feed in which not enough material is fed, and / or a stroke movement that is too strong, moving the material too quickly.

[0020] In addition, it is further proposed to combine this camera with an image evaluation unit that identifies the burn-off line. When using a stationary camera, the image shows the transition between burning and burned-off material as the burn-off line. In fact, this contrast constitutes a line either close to the upper edge of the image captured by the camera or close to the lower edge of this image. The height of the line is therefore directly proportional to the fire's position. A fire that is too long in the longitudinal direction of the grid indicates a material supply where too much material has been fed or where the material's combustibility is poor. A particularly short fire, as can be inferred from the image, indicates a material supply where there is not enough material. Furthermore, the change in the burn-off line allows for inferences regarding the action of the grid stroke and the management of the primary air, making it possible to adapt these parameters to improve incineration. The burn-off line also makes it possible to distribute the amount of combustible material evenly between the different grid tracks.

[0021] Additionally, the movement of individual components or segments within the combustion bed can be tracked using imaging techniques. These segments are detectable surface areas due to their structure or the selected surface area. It is necessary to take multiple images at a time interval. Multiple components or segments are selected within the combustion bed after the material is introduced, and their movement is detected until the selected components are covered. This selection can be automatic, based on structures and objects learned by artificial intelligence, based on the shape, color, or contour of multiple components within the chute, or based on arbitrary or defined areas within the chute. This method allows for determining the flow of material inside the combustion bed. This method can be performed individually or in addition to detecting the height of the combustion bed and the length of the fire.

[0022] Thus, image evaluation at the edge of the grid allows inferences to be drawn about the delivery device.

[0023] Therefore, using a well-adjusted image evaluation unit, preferably also a learning system such as a neural network, it is possible to detect a combustion bed that is too thin or too thick, and a fire that is too long or too short, i.e. an incorrect position of the end-of-burn line.

[0024] This information can be compared with target values, allowing for actions to be taken depending on the fire position, and / or the thickness of the combustion bed, and / or the movement or surface area of individual components. This action can then be an intervention in the transport or gas ratio on the grate, as indicated above. Thus, automatic intervention in the control or regulation of the furnace unit depending on the fire position on the grate, in particular the longitudinal position of the grate, and / or the thickness of the combustion bed is proposed as a further embodiment. Thus, it is proposed to control or regulate the grate speed depending on the fire position and / or the thickness of the combustion bed. In this context, it is particularly advantageous if the grate speed of individual grate zones or adjacent grate tracks is controlled or regulated.

[0025] Additionally or alternatively, the air flow of the furnace unit can also be controlled or regulated depending on the thickness of the combustion bed and / or the location of the fire. In particular, the primary air of the furnace unit can be controlled or regulated depending on the location of the fire and / or the thickness of the combustion bed in this regard.

[0026] It is particularly advantageous if the furnace is equipped with individual grate tracks that are analyzed by an image evaluation unit, so that the feeding of the individual grate tracks can be controlled or regulated depending on the thickness of the combustion bed and / or the position of the fire. For this purpose, for example, the stroke length can be adjusted or a zero offset setting of the feeder can be selected.

[0027] It is particularly advantageous if the individual grate tracks have multiple drives, so that the intensity of the stroke movement in the individual grate zones can be controlled or regulated depending on the thickness of the combustion bed and / or the position of the fire. For this purpose, the stroke speed can be adjusted, for example.

[0028] It is advantageous to combine both optical camera systems, so that interventions performed by the camera above the chute can be confirmed by the camera at the end of the combustion bed. By implementing a control loop or neural network, it is possible to optimize the interventions performed.

[0029] Independently from the above-mentioned method steps, a method for operating a furnace unit with at least one grate with multiple grate zones and / or multiple grate tracks and multiple combustible material feeders is proposed, in which the temperature per grate zone and / or per grate track is measured and the combustible material feeders are controlled depending on the measured temperatures in order to achieve uniform heat dissipation on the grate.

[0030] This is particularly advantageous in the case where at least one temperature measuring device is used per grating zone and / or per grating track. The temperature measurement can be performed in parallel with the grating segment or the first waste stream duct. To avoid the accuracy of the temperature measurement being impaired by turbulence, it is proposed to perform the temperature change indication close to the furnace and at the latest at the level at which the flue gas reaches the waste stream duct after 1 to 15 seconds.

[0031] Advantageous embodiment variants are shown in the drawings and are described in detail below. [Brief explanation of the drawings]

[0032] [Figure 1] Schematic of a grate furnace with analysis of chute A, analysis of fire B, and analysis of temperatures at grate track C. [Figure 2] FIG. 1 is a cross-sectional view through the area of the feed chute in the furnace unit. [Figure 3] FIG. 3 is a top view of the chute shown in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of FIG. [Figure 5] This is an image taken by the camera placed at B in Figure 1. [Figure 6] FIG. 1 shows a furnace unit with two waste stream ducts. [Figure 7] FIG. 7 is a perspective view of the furnace unit shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0033] The furnace unit 1 shown in Figure 1 is a grate furnace with a grate 2 under which a primary air supply 3 is arranged. The material 4 being burned on the grate 2 is conveyed over the grate 3 to a bottom ash discharge 5. Flue gas 6 produced during the incineration of the material 4 on the grate 2 reaches a first duct 7 and flows from there into further ducts 8 and 9 to heat water. The heated water is used as steam for an energy generation unit (not shown).

[0034] During operation of the furnace unit 1, waste material 4 moves from the chute 10 through the feed channel 11 to the grate 2 and from there to the bottom ash discharge 5. In this process, a camera 12 is used to capture the surface 13 of the chute, which is shown as image 14.

[0035] Another camera 34 at the end 15 of the grate 2 is aimed at the material 4 on the grate 2 and at the flame 16 generated by the combustion of the material 4. Between them, the flame 16 generated on the grate 2 can be observed from above by a third camera 17.

[0036] FIG. 2 shows how the material 4 is dumped into the feed chute 10 by the claw 20 before it travels from the slide 21 into the channel 4 and from there to the furnace grate 2 .

[0037] The camera 12 is connected to an image evaluation unit 22 which determines the coverage of the chute 10 and in particular the coverage of the slide 21 with material 4 .

[0038] Figure 3, and in particular its enlarged view shown in Figure 4, shows areas 23 and 24 where slider 21 is covered with material 4, as well as areas 43 in this area 24 where the top of slider 21 is visible because it is not covered with material 4.

[0039] Bars 25, 26 and 27 constitute boundary points in image 4, where material 4 covers chute 10 on one side and the surface of chute 10 is visible on the other side.

[0040] The defined points 29, 30, and 31 are represented as vertical bars on the side 28 of the chute 10. This makes it possible to identify the intersections between the horizontal bars 25, 26, and 27 and the vertical bars 29, 30, and 31 to infer the filling of the chute 10.

[0041] 3, a line 33 indicates the transition between the material 4 and the background 33. The height of this line 33 in the image 4 and its deviation from a straight line provides information about the material in the chute 10.

[0042] 5 shows an image 35 taken with the camera 14 at the end of the grate 2 in the direction of flow of material 4. From this image 35, an image evaluation unit 36 determines the thickness 37 of the combustion bed as the distance between line 38 and line 41. Line 38 results from the contrast between the bright area 39 of the flame 16 and the dark area 40 of the bottom ash. The height of line 41 in image 35 can be determined by testing and occurs even in units where there is no material 4 yet on the grate 2.

[0043] The image evaluation devices 22 and 36 are connected to the control system 41 of the furnace unit 1 and are thereby able to intervene in the regulation 41 of the furnace unit in order to control or regulate the speed of the grate and / or the air supply of the furnace unit 1 depending on the limit values detected in the chute 10 and / or the thickness 37 of the combustion bed if the limit values are exceeded.

[0044] Figure 6 shows the furnace grate 2 and above it a first smoke duct 7. The first smoke duct 7 continues to a second smoke duct 8. A temperature measurement device 49 is positioned to measure parallel or horizontally to the grate 2. A temperature measurement level 52 is thus created above a secondary air level 54. Figure 7 shows an exemplary arrangement of temperature measurement devices for a unit with three grate tracks 46, 47, and 48. Each grate track is associated with a temperature measurement device 49, 50, and 51.

Claims

1. 1. A method for operating a furnace unit, characterized in that the thickness (37) of the combustion bed and / or the end-of-combustion line (38) are determined by an image evaluation unit (36) from images taken by a camera (14) arranged at the end (15) of the grate (2).

2. 2. The method of operating a furnace unit according to claim 1, characterized in that an overloaded combustion bed is detected using the image evaluation unit (36) by a learning system such as a neural network or via the characteristic shape of the end-of-burn line (38).

3. 3. A method for operating a furnace unit according to claim 1 or 2, characterized in that actions are taken depending on the thickness (37) of the combustion bed, and / or the end-of-combustion line (38), and / or the movement or surface area of individual compositions.

4. 4. A method for operating a furnace unit according to any one of claims 1 to 3, characterized in that automatic intervention in the control or regulation of the furnace unit (1) is performed depending on the thickness of the combustion bed (37), and / or the end-of-burn line (38), and / or the movement or surface area of individual compositions.

5. 5. A method for operating a furnace unit according to any one of claims 1 to 4, characterized in that the speed of the grate is controlled or regulated depending on the thickness of the combustion bed (37), and / or the end-of-burn line (38), and / or the movement or surface area of individual compositions.

6. 6. A method for operating a furnace unit according to any one of claims 1 to 5, characterized in that the air supply of the furnace unit (1) is controlled or regulated depending on the thickness of the combustion bed (37), and / or the end-of-combustion line (38), and / or the movement or surface area of the individual compositions.

7. 7. A method for operating a furnace unit according to claim 6, characterized in that the primary air of the furnace unit (1) is controlled or regulated depending on the thickness (37) of the combustion bed, and / or the end-of-combustion line (38), and / or the movement or surface area of individual compositions.

8. 8. A method for operating a furnace unit according to any one of claims 1 to 7, characterized in that the feeding in the individual grate tracks (46, 47, 48) of the furnace unit (1) is controlled or regulated depending on the thickness of the combustion bed (37), and / or the end-of-combustion line (38), and / or the movement or surface area of the individual compositions.

9. A method for operating a furnace unit (1) with at least one grate (2), comprising a plurality of grate zones and / or a plurality of grate tracks (46, 47, 48) and a plurality of combustible material feeders (45), 9. A method for operating a furnace unit according to any one of claims 1 to 8, characterized in that in order to achieve uniform heat dissipation in the grate (2), the temperature per grate zone and / or per grate track (46, 47, 48) is measured and the combustible material feeder (45) is controlled depending on the measured temperatures.

10. 10. A method for operating a furnace unit according to claim 9, characterized in that at least one temperature measuring device (49, 50, 51) is used per grating zone and / or per grating track (46, 47, 48).

11. 10. A method for operating a furnace unit according to claim 9, characterized in that the temperature measurement is performed parallel to the grating (2).

12. 10. A method for operating a furnace unit according to claim 9, characterized in that the temperature measurement is performed in the first waste stream duct (7).

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