Method for estimating combustion state of a waste incinerator, device for estimating combustion state of a waste incinerator, method for controlling transport of a waste incinerator, and device for controlling transport of a waste incinerator

Abstract

To provide a combustion state estimation method of a refuse incinerator that reduces labor of a monitoring person as much as possible, and enables automated operation control to be continued by appropriately determining a state of refuse running-out.SOLUTION: A combustion state estimation method of a refuse incinerator for estimating a combustion state of refuse incinerated on the top face of a stoker mechanism on the basis of an image of a combustion state taken from the downstream side of the stoker mechanism using an imaging device executes the following processing: flame region extraction processing for binarizing a pixel value of the image with a predetermined binarization threshold and extracting a flame region composed of a single or a plurality of closed regions; burn-out position estimation processing for estimating a burn-out position of refuse from a first flame region whose size is a first threshold or larger of the extracted flame region; and refuse running-out estimation processing for estimating that there is a tendency of running-out of refuse when second flame regions whose size is a second threshold or less smaller than the first threshold are scattered on the downstream side of the burn-out position estimated in the burn-out position estimation processing.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for estimating the combustion state of a waste incinerator, a device for estimating the combustion state of a waste incinerator, a method for controlling transport in a waste incinerator, and a device for controlling transport in a waste incinerator. [Background technology]

[0002] Patent document 1 proposes a waste incinerator equipped with an imaging device that captures images of the flames generated by waste being incinerated on the upper surface of the stoker mechanism from the downstream side of the stoker mechanism, and an image processing device that extracts the flame area from the image data obtained by the imaging device and estimates the most downstream position of the extracted flame area as the burn-out position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-94055 Summary of the Invention [Problem to be solved by the invention]

[0004] In the waste incinerator described above, the waste feeding speed by the dust feeding device and the waste transport speed by the stoker mechanism are controlled so that the estimated waste burn-off position is maintained within a predetermined target range.

[0005] However, because the combustion conditions differ between easily combustible and less combustible waste, even if the burn-off position is properly controlled, if the thickness of the waste upstream of the burn-off position becomes thin and a state of waste starvation occurs, the combustion conditions deteriorate, the amount of steam generated in the waste heat boiler decreases, and so it takes a long time to restore the appropriate combustion conditions, resulting in a significant drop in incineration efficiency.

[0006] Therefore, if an inspector monitors the combustion status and determines that there is a risk of the garbage running out, he or she must switch from automatic to manual operation control, increase the amount of dust fed, or increase the conveying speed, which places a heavy burden on the inspector, and there is also the problem that only an experienced inspector can make an appropriate judgment.

[0007] In view of the above-mentioned conventional technology, the object of the present invention is to provide a method for estimating the combustion state of a waste incinerator, a combustion state estimation device for a waste incinerator, a transport control method for a waste incinerator, and a transport control device for a waste incinerator that minimize the workload of monitors and properly determine whether the waste is depleted, thereby enabling continued automatic operation control. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the first characteristic configuration of the combustion state estimation method for a waste incinerator according to the present invention is a method for estimating the combustion state of waste being incinerated on the upper surface of a stoker mechanism based on an image of the combustion state photographed from the downstream side of the stoker mechanism using an imaging device, and comprises the following steps: a flame area extraction process that binarizes the pixel values ​​of the image using a predetermined binary threshold to extract a flame area consisting of a single or multiple closed areas; a burn-out position estimation process that estimates the burn-out position of the waste based on the image of the extracted flame area; and a waste depletion estimation process that estimates that there is a tendency for waste to deplete if one or more independent flame areas exist downstream of the burn-out position estimated by the burn-out position estimation process.

[0009] A flame region extraction process is performed on the image captured in the imaging process to extract a flame region consisting of a single or multiple closed regions, and a burn-off position estimation process is performed to estimate the waste burn-off position from the extracted flame region. To ensure proper incineration of waste on the top surface of the stoker mechanism, waste transport control by the stoker mechanism is performed based on preset indicators. If the waste layer thickness upstream of the burn-off position becomes thin, combustion air supplied from below the stoker mechanism will blow through, blowing the waste downstream of the burn-off position and resulting in the formation of small scattered flame regions downstream of the burn-off position. The waste decay estimation process makes it possible to estimate a tendency for waste decay when one or more independent flame regions exist downstream of the burn-off position.

[0010] The second characteristic feature of the same method is that, in addition to the first characteristic feature described above, the burn-out position estimation process is a process in which, when a virtual straight line along the furnace width direction is scanned from bottom to top, the first position at which the ratio of the number of pixels where the virtual straight line and the flame region overlap to the number of pixels of the virtual straight line reaches a predetermined ratio is estimated as the burn-out position.

[0011] In the combustion-cut position calculation process, an imaginary line along the furnace width direction is scanned from bottom to top, and the most downstream position where the ratio of the number of pixels where the imaginary line and the flame region overlap to the number of pixels of the imaginary line is a predetermined ratio is estimated as the combustion-cut position. This makes it possible to suppress drastic fluctuations in the combustion-cut position compared to when the downstream side of the flame region is used as the combustion-cut position.

[0012] The third characteristic configuration of the present invention, in addition to the second characteristic configuration described above, includes: an area calculation process for calculating the area of ​​the flame region and the area of ​​a convex envelope flame region obtained by performing convex hull processing on the outline of the flame region; and a burn-out position adjustment process for adjusting the predetermined ratio based on a relative value of the area of ​​the convex envelope flame region with respect to the area of ​​the flame region. The point is that it further has the following features.

[0013] If lumps mixed with the waste being incinerated on the upper surface of the stoker mechanism are present near the burn-off position, the lumps may block the flame, reducing the size of the flame region and potentially leading to an erroneous determination that the burn-off position is further upstream than it actually is. Even in such a case, the area calculation process calculates the area of ​​the flame region and the area of ​​the convex hull flame region obtained by convex hull processing of the outline of the flame region, and the burn-off position adjustment process adjusts a predetermined ratio based on the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region, thereby reducing the risk of the lumps causing an erroneous determination that the burn-off position is further upstream than it actually is. This is because the area of ​​the convex hull flame region includes at least the area of ​​the flame blocked by the lumps, and the extent of the impact of the lumps can be determined from the area of ​​the flame region and the area of ​​the convex hull flame region.

[0014] The first characteristic configuration of the combustion state estimation device for a waste incinerator according to the present invention is a combustion state estimation device for a waste incinerator that estimates the combustion state of waste being incinerated on the upper surface of a stoker mechanism based on an image of the combustion state photographed from downstream of the stoker mechanism using an imaging device, and is equipped with a flame area extraction processing unit that binarizes the pixel values ​​of the image using a predetermined binarization threshold to extract a flame area consisting of a single or multiple closed areas, a burn-out position estimation processing unit that estimates the burn-out position of the waste based on the image of the extracted flame area, and a waste depletion estimation processing unit that estimates that there is a tendency for waste to deplete if one or more independent flame areas exist downstream of the burn-out position estimated by the burn-out position estimation processing unit.

[0015] The second characteristic feature of the present invention is that, in addition to the first characteristic feature described above, the burn-off position estimation processing unit estimates, as the burn-off position, the first position at which the ratio between the number of pixels where the virtual line and the flame region overlap and the number of pixels of the virtual line reaches a predetermined ratio when scanning a virtual line along the furnace width direction from bottom to top.

[0016] The third characteristic configuration is that, in addition to the second characteristic configuration described above, it further includes an area calculation processing unit that calculates the area of ​​the flame region and the area of ​​a convex envelope flame region obtained by convex hull processing of the area of ​​the flame region and the outline of the flame region, and a burn-off position adjustment processing unit that adjusts the predetermined ratio based on the relative value of the area of ​​the convex envelope flame region with respect to the area of ​​the flame region.

[0017] A first characteristic configuration of the transport control method for a waste incinerator according to the present invention is a transport control method for a waste incinerator that controls the transport of waste to be incinerated on the upper surface of a stoker mechanism, The system executes a transport control process that controls the transport speed of the stoker mechanism based on a predetermined index; a flame area extraction process that binarizes the pixel values ​​of the image using a predetermined binary threshold to extract a flame area consisting of a single or multiple closed areas; a burn-out position estimation process that estimates the burn-out position of the garbage based on the image of the extracted flame area; and a garbage depletion estimation process that estimates that there is a tendency for the garbage to run out if one or more independent flame areas exist downstream of the burn-out position estimated by the burn-out position estimation process.When the garbage depletion estimation process estimates that the garbage is in a depleted state, the transport control process is configured to increase or correct the transport speed of the stoker mechanism based on the index.

[0018] The transport control process controls the waste transport speed by the stoker mechanism based on a preset index. If the waste depletion estimation process estimates that the layer thickness of the waste transported by the stoker mechanism is tending to become thinner, the waste transport speed is corrected to increase, thereby preventing waste depletion from occurring.

[0019] The second characteristic feature of the same method is that, in addition to the first characteristic feature described above, the burn-out position estimation process is a process in which, when a virtual straight line along the furnace width direction is scanned from bottom to top, the first position at which the ratio of the number of pixels where the virtual straight line and the flame region overlap to the number of pixels of the virtual straight line reaches a predetermined ratio is estimated as the burn-out position.

[0020] The third characteristic configuration is that, in addition to the second characteristic configuration described above, it further includes an area calculation process that calculates the area of ​​the flame region and the area of ​​a convex envelope flame region obtained by convex hull processing of the area of ​​the flame region and the outline of the flame region, and a burn-out position adjustment process that adjusts the predetermined ratio based on the relative value of the area of ​​the convex envelope flame region with respect to the area of ​​the flame region.

[0021] The first characteristic configuration of the waste incinerator conveying control device according to the present invention is a waste incinerator conveying control device that controls the conveying of waste to be incinerated on the upper surface of a stoker mechanism, comprising: a conveying control processing unit that controls the conveying speed of the stoker mechanism based on a predetermined index; an imaging device that images the burning state of the waste from downstream of the stoker mechanism; a flame area extraction processing unit that binarizes the image obtained by the imaging device using a predetermined binarization threshold to extract a flame area consisting of a single or multiple closed areas; a burn-out position estimation processing unit that estimates the burn-out position of the waste based on the image of the extracted flame area; a waste depletion estimation processing unit that estimates that there is a tendency for the waste to run out if one or more independent flame areas exist downstream of the burn-out position estimated by the burn-out position estimation processing unit; and when the waste depletion estimation processing unit estimates that there is a tendency for the waste to run out, the conveying control processing unit is configured to increase or decrease the conveying speed of the stoker mechanism based on the index.

[0022] The second characteristic feature of the present invention is that, in addition to the first characteristic feature described above, the burn-off position estimation processing unit estimates, as the burn-off position, the first position at which the ratio between the number of pixels where the virtual line and the flame region overlap and the number of pixels of the virtual line reaches a predetermined ratio when scanning a virtual line along the furnace width direction from bottom to top.

[0023] The third characteristic configuration is that, in addition to the second characteristic configuration described above, it further includes an area calculation processing unit that calculates the area of ​​the flame region and the area of ​​a convex envelope flame region obtained by convex hull processing of the area of ​​the flame region and the outline of the flame region, and a burn-off position adjustment processing unit that adjusts the predetermined ratio based on the relative value of the area of ​​the convex envelope flame region with respect to the area of ​​the flame region. [Effects of the Invention]

[0024] As described above, according to the present invention, it is possible to provide a method for estimating the combustion state of a waste incinerator, a combustion state estimation device for a waste incinerator, a transport control method for a waste incinerator, and a transport control device for a waste incinerator, which minimize the workload of monitors and properly determine whether the waste is depleted, thereby enabling automatic operation control to continue. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is an explanatory diagram of a stoker-type waste incinerator. [Figure 2] This is an enlarged view of the main parts of a stoker-type waste incinerator. [Figure 3] 1(a) and 1(b) are functional block diagrams of a combustion control device. [Figure 4] 1A is an explanatory diagram showing the relative positions of the image capture device and the waste burning on the stoker, and FIG. 1B is an explanatory diagram showing the burn-out position estimation based on the combustion flame captured by the image capture device. [Figure 5] 1(a) is an explanatory diagram of the principle of adjusting the burn-off position based on the area S1 of the combustion flame imaged by the imaging device and the area S1' of the flame obtained by convex hull processing of the combustion flame, and FIG. 1(b) is an explanatory diagram of the principle of adjusting the burn-off position based on the area S2 of the combustion flame imaged by the imaging device and the area S2' of the flame obtained by convex hull processing of the combustion flame. [Figure 6] This is an explanatory diagram of the principle of adjusting the burn-off position based on the areas S11' and S12' of the flames obtained by convex hull processing when a combustion flame imaged by an imaging device is separated into two parts with areas S11 and S12 due to the influence of a lump of material. [Figure 7] 4 is a flowchart showing a procedure of combustion control. [Figure 8] 10 is a flowchart showing a procedure for a burn-off position estimation process. [Figure 9] 10 is a flowchart showing the procedure of a property determination process. DETAILED DESCRIPTION OF THE INVENTION

[0026] The combustion state estimation method for a refuse incinerator, the combustion state estimation device for a refuse incinerator, the transport control method for a refuse incinerator, and the transport control device for a refuse incinerator according to the present invention will be described below with reference to the drawings.

[0027] [Waste incinerator structure] Figure 1 shows a stoker-type waste incinerator 1. It is equipped with a platform A where waste collection trucks enter, a waste pit B where waste collected by the waste collection trucks accumulates, a waste input hopper D, a waste crane C that transfers waste from the waste pit B to the waste input hopper D, a furnace chamber E, a waste heat boiler F installed in the space above the furnace chamber E, an economizer G, etc., and the combustion exhaust gas generated in the furnace chamber E is purified by exhaust gas treatment equipment such as a superheater H and dust collector I arranged along the flue before being exhausted from a chimney J. An induced draft fan L is installed in the flue to maintain a negative pressure in the furnace chamber E.

[0028] By opening the double-door garbage dump door K, which is installed between platform A and garbage pit B to prevent odor leakage and ensure safety, garbage collected and transported by garbage trucks is dumped into garbage pit B.

[0029] The garbage accumulated in the garbage pit B is picked up by a crab bucket garbage crane C, which is operated automatically or by an operator in the control room, and transported to an opening formed at the top of the garbage hopper D, where it is dropped into the garbage pit.

[0030] A dust feeder P is provided at the bottom of the garbage hopper D, and the garbage filled in the garbage hopper D is pushed into the furnace chamber E. The garbage filled in the garbage hopper D functions as a sealing mechanism that blocks the inflow of outside air from the garbage hopper D into the furnace chamber E, maintaining the furnace chamber at negative pressure.

[0031] The furnace chamber E is equipped with a main combustion chamber 2 and a secondary combustion chamber 3 that completely burns the combustion exhaust gas generated in the main combustion chamber 2, and multiple water tubes WT of the waste heat boiler F are embedded in the wall of the secondary combustion chamber 3.

[0032] As shown in Figure 2, the main combustion chamber 2 is equipped with a stoker mechanism ST in which fixed grates and movable grates are alternately arranged along the direction of waste transport. The movable grates are driven back and forth relative to the fixed grates by hydraulic mechanisms h1, h2, and h3, thereby agitating the waste and transporting it downstream.

[0033] Four wind boxes W1, W2, W3, and W4 are installed below the stoker mechanism ST in this order from upstream to downstream, and main combustion air is supplied from a forced draft fan. The upstream region corresponding to wind box W1 of the stoker mechanism ST is the drying zone ST1, the midstream region corresponding to wind boxes W2 and W3 is the combustion zone ST2, and the downstream region corresponding to wind box W4 is the post-combustion zone ST3.

[0034] Pressure sensors PS1, PS21, PS22, and PS3 are provided in each of the wind boxes W1, W2, W3, and W4, and a pressure sensor PS is provided in the main combustion chamber 2, so that the pressure difference between each wind box and the main combustion chamber 2 can be detected.In addition, a flow sensor QS is provided to detect the flow rate of combustion air flowing into the main combustion chamber 2 via the stoker mechanism ST.

[0035] The waste pushed into the main combustion chamber 2 from the dust feeder P is mainly heated and dried in the drying zone ST1, and then gasified and burned in the combustion zone ST2. The waste carbonized by gasification and combustion is burned as a solid in the post-combustion zone ST3 downstream of the combustion zone S2 and turned to insh. After being turned to insh, the waste falls into an ash chute from the end of the post-combustion zone ST3.

[0036] A constricted portion is formed in the front wall 2F and rear wall 2R of the furnace chamber E from the main combustion chamber 2 to the inlet of the secondary combustion chamber 3, and a gas supply mechanism 4 is provided in the constricted portion. The gas supplied from the gas supply mechanism 4 agitates and straightens the combustion exhaust gas flowing into the secondary combustion chamber 3, and the combustion exhaust gas is completely combusted in the secondary combustion chamber 3.

[0037] The gas supplied from the gas supply mechanism 4 may be air for secondary combustion, exhaust gas extracted from the main combustion chamber 2, recirculated exhaust gas branched from the flue downstream of the dust collector I, or exhaust gas branched from another exhaust gas flow path, or a mixture of air and any of the above exhaust gases.

[0038] The total amount of main combustion air and secondary combustion air needs to be adjusted so that the theoretical air ratio to the material to be incinerated is approximately 1.3. For example, if all the air is supplied by main combustion air so that the theoretical air ratio is approximately 1.3, the gas supplied from the gas supply mechanism 4 may be only flue gas extracted from the flue. Alternatively, the system may be configured so that approximately 1.0% of the air is supplied by main combustion air and approximately 0.3% by secondary combustion air. A temperature sensor and a gas sensor are provided at the outlet of the secondary combustion chamber 3.

[0039] An industrial television camera (ITV) serving as an imaging device 5 is installed on the rear wall 2R of the furnace chamber E, and captures the combustion state, including the combustion flame, of the waste being transported and incinerated on the top surface of the stoker mechanism ST.

[0040] [Configuration of combustion control device] 3 shows the configuration of a combustion control device 10 that controls the combustion state of waste incinerated in the above-mentioned waste incinerator 1 and controls the amount of steam generated in the waste heat boiler F. The combustion control device 10 includes a dust supply control unit 11 that adjusts the amount of waste fed into the main combustion chamber 2 by the dust feeder P, a transport control unit 12 that controls the transport speeds of the drying zone ST1, combustion zone ST2, and post-combustion zone ST3 by hydraulic mechanisms h1, h2, and h3, an air supply control unit 13 that adjusts the amount of main combustion air supplied from each of the wind boxes W1 to W4 and also adjusts the amount of air supplied from the gas supply mechanism 4, and an arithmetic processing unit 14 that outputs control commands to each of the control units 11, 12, and 13.

[0041] The calculation processing unit 14 includes calculation units, such as a burn-off position estimation unit 15 that estimates the burn-off position of the waste in the combustion zone ST2, a property determination unit 16 that determines the presence or absence of lumps mixed in the waste and the properties of the waste such as withering, and a steam amount adjustment unit 17 that adjusts the amount of steam generated in the waste heat boiler F, and a control command generation unit 18 that generates control commands to be output to the respective control units 11, 12, 13 according to indices obtained based on the calculation results of the respective calculation units. The detection values ​​of the above-mentioned pressure sensors, flow rate sensors, gas sensors, temperature sensors, and steam amount sensors, as well as images captured by the imaging device 5, are input to the calculation processing unit 14.

[0042] The combustion control device 10 is configured with a CPU board, a memory board, an input / output interface board, a display device, an input device, etc. A combustion control program is installed in the memory on the memory board, and the combustion control program is executed by the CPU on the CPU board, thereby realizing each of the functional blocks described above.

[0043] That is, as shown in FIG. 7 , the combustion control device 10 inputs values ​​from various sensors, such as the pressure sensor, flow rate sensor, temperature sensor, and gas sensor (SA1), acquires combustion images captured by the imaging device 5 (SA2), and executes a burn-out position estimation process (SA3), a property determination process (SA4), and a steam amount adjustment process (SA5) based on the input information. Then, based on the results, it executes various control calculations, including PID calculations, to generate control commands to be output to the respective control units 11, 12, and 13 (SA6). It then repeatedly executes a dust supply control process (SA7) via the dust supply control unit 11, a transport control process (SA8) via the transport control unit 12, and an air supply control process (SA9) via the air supply control unit 13 at predetermined time intervals (SA10). The repetition period of each calculation process is not particularly limited and can be set as appropriate. For example, it is preferable to set the repetition period to a period ranging from several seconds to several tens of seconds.

[0044] [Burnout position estimator] The burn-off position estimation unit 15 is a calculation unit that estimates the burn-off position based on image information showing the burning state of the waste being incinerated on the upper surface of the stoker mechanism ST, which is photographed by the imaging device 5.

[0045] The burn-off position estimation unit 15 includes functional blocks of a flame region extraction processing unit 15A, a burn-off position estimation processing unit 15B, an area calculation processing unit 15C, and a burn-off position adjustment processing unit 15D.

[0046] As shown in FIG. 7, the burn-off position estimation unit 15 is configured to repeatedly execute the following processes over time, that is, at predetermined time intervals: flame region extraction processing by a flame region extraction processing unit 15A; burn-off position estimation processing by a burn-off position estimation processing unit 15B; area calculation processing by an area calculation processing unit 15C; and burn-off position adjustment processing by a burn-off position adjustment processing unit 15D.

[0047] 8 shows the procedure for the burn-out position estimation process executed by the burn-out position estimation unit 15. The flame region extraction processing unit 15A includes a memory for storing video images captured by the imaging device 5 and a binarization processing unit that binarizes pixel values ​​of predetermined frame images extracted from the video images stored in the memory using a predetermined binarization threshold to extract a flame region consisting of a single or multiple closed regions. The image may be composed of any type of pixels, such as a grayscale image or an RGB color image, as long as it can distinguish between a flame region and other regions. Luminance values, RGB component values, etc. can be appropriately used as pixel values ​​for extracting the flame region. Furthermore, the binarization threshold is not limited to a specific value, and can be set appropriately as long as it is a value that allows the flame region to be extracted.

[0048] The flame region extraction processor 15A binarizes the frame image to obtain a single or multiple flame regions (SB1), and then distinguishes between a first flame region FA whose size (area) is equal to or greater than a first threshold and a second flame region FAs whose size (area) is equal to or less than a second threshold (SB2, SB3). The first threshold value can be any value that can extract the largest combustion flame burning on the top surface of the stoker mechanism and can extract the main combustion flame even if it is divided into multiple flames due to the influence of a mass (described later). The second threshold value can be any value that can extract small combustion flames excluding the main combustion flame.

[0049] The burn-off position estimation processing unit 15B is a functional block that estimates the burn-off position of the waste from one or more first flame regions FA whose size (area) is equal to or greater than a first threshold value among the extracted flame regions.

[0050] In more detail, a virtual line VL (a horizontal line in this embodiment) along the furnace width direction is generated for the binarized image, and the virtual line VL is scanned (translated) from below (downstream) to above (upstream) the first flame area FA (SB4). The number of pixels where the virtual line VL overlaps the first flame area FA is calculated (SB5), and the ratio of the virtual line VL to the total number of pixels at that time is calculated, and this process is repeated (SB6). The first (most downstream) position where the ratio calculated in step SB6 is equal to or greater than a predetermined ratio R is estimated as the burn-out position (SB12, SB13).

[0051] Here, considering that the size of the first flame area FA varies depending on whether the waste being incinerated in the combustion zone ST2 contains lumps or not, the specified ratio R is adjusted according to the following procedure.

[0052] The adjustment procedure is explained below. Area calculation processing unit 15C calculates the area S of the first flame region FA and the area S' of the convex hull flame region obtained by convex hull processing of the outline of the first flame region FA (SB7, SB8, SB9). A convex hull is the smallest convex polygon that contains all given points, and convex hull processing is a process that generates the smallest convex polygon that contains all outline points of the flame image as the convex hull flame region.

[0053] The burn-off position adjustment processor 15D calculates the relative value RV of the area S' of the convex hull flame region relative to the area S of the first flame region FA (SB10), and adjusts the predetermined ratio R referenced by the burn-off position estimation processor 15B based on the calculated relative value RV (SB11). The relative value RV can be the difference (S'-S) or the ratio (S' / S) of the area S' of the convex hull flame region relative to the area S of the first flame region FA.

[0054] When the relative value RV is greater than a predetermined threshold, the burn-off position adjustment processor 15D adjusts the predetermined ratio R so that it decreases as the relative value increases, that is, so that the burn-off position is corrected downstream. When the relative value RV is equal to or less than the predetermined threshold, an initial value is used as the predetermined ratio R. The threshold for the relative value RV can be determined in advance by testing using an actual machine, for example.

[0055] In other words, if there are flame-retardant or non-combustible lumps in the waste being incinerated on the upper surface of the stoker mechanism ST, the lumps tend to block the flame, reducing the size of the first flame area FA extracted by the flame area extraction process, and it may be difficult to distinguish between this and a case where there are no lumps actually present and the combustion state is reduced, resulting in a smaller first flame area FA.

[0056] Therefore, an area calculation process is executed to calculate the area S of the first flame region FA and the area S' of the convex hull flame region obtained by convex hull processing of the outline of the first flame region FA. The area S' of the convex hull flame region is the area that includes at least the flame blocked by the lumps, so the extent of the influence of the lumps can be grasped from the area S of the first flame region FA and the area S' of the convex hull flame region. This is because the area S' of the convex hull flame region when blocked by the lumps tends to be larger than the area S' of the convex hull flame region when the combustion state deteriorates and the first flame region FA becomes smaller.

[0057] Therefore, by using the burn-off position adjustment process, the predetermined ratio R is adjusted based on the relative value of the area S' of the convex hull flame region to the area S of the flame region, thereby reducing the risk that the burn-off position will be erroneously determined to be upstream of its actual position due to a lump of material.

[0058] 4(a) shows that an imaging device 5, which photographs the burning state of waste being incinerated on the top surface of the stoker mechanism ST from the downstream side of the stoker mechanism ST, is installed on the rear wall of the furnace chamber E. In this embodiment, the left-right center of the imaging device 5 is adjusted to the center in the furnace width direction, and the up-down center is adjusted to the center of the up-down length along the conveying direction of the drying zone ST1 and combustion zone ST2 of the stoker mechanism ST.

[0059] Figure 4(b) shows an image captured by the imaging device 5. The first flame region FA and second flame region FAs resulting from gasification and combustion in the combustion zone ST2 are hatched. The waste that has been gasified and carbonized in the combustion zone ST2 is transported to the post-combustion zone ST3, where it is burned and converted to inhes, and then falls into an ash chute. In Figure 4(b), the upper part of the flame that extends above the field of view of the imaging device 5 is approximately flat.

[0060] The upper part of Figure 5(a) shows a binarized image of the first flame region FA (the dashed line indicates the image lost due to binarization). When an imaginary straight line VL (shown by a two-dot chain line) running along the furnace width direction is scanned (translated) from below the first flame region FA (the downstream side of the furnace) to above (the upstream side of the furnace), the imaginary straight line VL and the flame region FA come into contact (denoted as the "lower end position" in the figure). When the imaginary line VL is scanned (moved) further upward, the imaginary line VL and the flame region FA begin to overlap. The overlapping region is shown by a thick solid line.

[0061] The burn-off position estimation processing unit 15B increases the scanning amount (movement amount) of the virtual straight line VL, and estimates the most downstream position where the ratio (PF / PV) of the number of pixels PF in the overlapping area of ​​the flame area FA to the total number of pixels PV of the virtual straight line VL becomes a predetermined ratio R as the burn-off position.

[0062] By estimating the burn-off position in this manner, even if the lower end of the area of ​​the first combustion flame FA frequently fluctuates due to the operation of the stoker mechanism ST and fluctuations in the combustion state, the influence of this fluctuation can be reduced and an accurate and stable burn-off position can be estimated.

[0063] The predetermined ratio R is not particularly limited, but in this embodiment, the initial value is set to R = 0.3 (30%). For example, in the case of a moving image corresponding to full high definition with 1920 horizontal pixels, the total number of pixels of the virtual straight line VL is 1920, and the position where the number of pixels PF in the overlapping region of the flame region FA is 1920 × 0.3 = 576 pixels is the burn-out position. Note that, in order to reduce the calculation load, the ratio (PF / PV) may be calculated for an image obtained by thinning out the image at a predetermined thinning rate.

[0064] As shown in the upper part of Figure 5(b), when a lump MT is introduced into the furnace and reaches the combustion zone ST2, a portion of the combustion flame captured by the imaging device 5 is blocked by the lump MT. This causes the binarized flame region FA to split into multiple pieces or become smaller. As a result, the most downstream position where the ratio (PF / PV) of the number of pixels PF of the first flame region FA to the number of total pixels PV of the virtual line VL in the overlapping region with the first flame region FA reaches a predetermined ratio R shifts upstream from the position where the lump MT does not exist. In other words, this results in an erroneous determination that the burn-out position is located upstream. Therefore, the predetermined ratio R is adjusted using the procedure described above.

[0065] The areas S1 and S2 of the hatched flame regions and the areas S1' and S2' of the convex polygons processed as convex hulls are shown at the bottom of Figures 5(a) and 5(b). When the difference (S' - S) is used as the relative value RV, the relative value RV2 = (S2' - S2) when there are clumps MT in the combustion zone ST2 tends to be larger than the relative value RV1 = (S1' - S1) when there are no clumps MT in the combustion zone ST2.

[0066] If the relative value RV = (S1' - S1) is greater than a predetermined threshold, the burn-off position adjustment processor 15D determines that the burn-off position has shifted upstream due to the presence of lumps, and adjusts the predetermined ratio R so that it decreases as the relative value increases, that is, so that the burn-off position moves downstream. Note that if the relative value RV is equal to or less than the predetermined threshold, it is determined that the presence of lumps will have little effect, and the value is maintained at a preset fixed value. The predetermined threshold and adjustment rate can be determined based on a correlation between the relative value RV and the predetermined ratio, at which the burn-off position is determined to be appropriate, determined in advance through testing or the like.

[0067] 6 shows an example in which the primary combustion flame FA is separated into two by a lump MT. In this case, the most downstream position where the ratio (PF / PV) of the total number of pixels PF in the overlapping area of ​​each primary flame region FA and the virtual line VL to the total number of pixels PV in the virtual line VL becomes a predetermined ratio R is estimated as the burn-out position.

[0068] In this case, as in the case described above, if the relative value RV = {(S11' - S11) + (S12' - S12)} is greater than a predetermined threshold value, it is determined that the burn-off position has shifted upstream due to the presence of the lump MT, and the predetermined ratio R is adjusted so that it decreases as the relative value RV increases, that is, so that the burn-off position moves downstream.

[0069] In addition, when the first combustion flame FA is divided into two or more regions by a lump MT, the most downstream position of the first combustion flame FA having the largest area among the multiple first combustion flames FA, where the ratio (PF / PV) of the total number of pixels PF in the overlapping region of the first flame region FA and the virtual straight line VL to the total number of pixels PV of the virtual straight line VL is a predetermined ratio R, may be estimated as the burn-out position.

[0070] [Property determination department] The property determining unit 16 is a calculation unit that determines the property of the waste based on image information obtained by photographing the waste being incinerated on the top surface of the stoker mechanism ST with the imaging device 5.

[0071] 3(b), the property determination unit 16 includes functional blocks of a flame region extraction processing unit 16A, a refuse withering estimation processing unit 16B, an area calculation processing unit 16C, and a lump determination processing unit 16D. The flame region extraction processing unit 16A and the area calculation processing unit 16C are shared by the flame region extraction processing unit 15A and the area calculation processing unit 15C that constitute the burn-out position estimation unit 15 described above.

[0072] As shown in Figure 7, similar to the burn-out position estimation unit 15, the property determination unit 16 is configured to repeatedly execute the flame area extraction process by the flame area extraction processing unit 16A, the garbage withering estimation process by the garbage withering estimation processing unit 16B, the area calculation process by the area calculation processing unit 16C, and the lump object determination process by the lump object determination processing unit 16D over time, i.e., at predetermined time intervals.

[0073] 9 shows the procedure of the property determination process executed by the property determination unit 16. As explained in the flame region extraction processing unit 15A, the flame region extraction processing unit 16A distinguishes between and extracts, from a single or multiple flame regions obtained by binarizing a frame image, a first flame region FA whose size (area) is equal to or greater than a first threshold value and a second flame region FAs whose size (area) is equal to or less than a second threshold value that is smaller than the first threshold value (SC1, SC2, SC3).

[0074] The area calculation processor 16C calculates the area S of the first flame area FA and the area S' of the convex hull flame area obtained by convex hull processing the outline of the first flame area FA (SC4, SC5, SC6). The lump determination processor 16D determines whether or not there is a lump of garbage MT on the upper surface of the stoker mechanism ST based on the relative value RV of the area S' of the convex hull flame area to the area S of the first flame area FA. The relative value RV can be the difference (S'-S) or the ratio (S' / S) of the area S' of the convex hull flame area to the area S of the flame area FA.

[0075] The lump determination processing unit 16D determines that a lump MT is present (SC8) if the relative value RV = (S' - S) is greater than a predetermined threshold (SC7, Y), and determines that a lump MT is not present (SC9) if the relative value RV = (S' - S) is equal to or less than the predetermined threshold (SC7, N).Then, the lump determination processing unit 16D determines that the lump MT is a combustible lump (SC11) if the relative value RV decreases over time (SC10, Y), and determines that the lump MT is a non-combustible lump (SC12) if the relative value RV does not decrease over time (SC10, N).

[0076] In addition, as shown in Figure 6, when the first flame area FA is separated into two or more parts, the lump determination processing unit 16D determines that a lump MT exists regardless of the relative value RV = (S' - S), and determines that the lump MT is a combustible lump MT.

[0077] The waste withering estimation processor 16B estimates whether there is a tendency for waste to wither based on the burn-out position estimated by the burn-out position estimation processor 15B and the second flame regions FAs extracted by the flame region extraction processor 16A. Specifically, the waste withering estimation processor 16B estimates that there is a tendency for waste to wither (SC14) when second flame regions FAs are scattered downstream of the burn-out position (SC13, Y). Specifically, it estimates that there is a tendency for waste to wither when the number of second flame regions FAs present downstream of the burn-out position is greater than a preset waste withering threshold.

[0078] When the thickness of the garbage layer upstream of the burn-off position becomes thin, the combustion air supplied from below the stoker mechanism ST blows through, blowing the garbage downstream of the burn-off position and causing small flame areas to be scattered downstream of the burn-off position. The garbage depletion estimation processing unit 16B can estimate that there is a tendency for garbage to deplete if the number of second flame areas scattered downstream of the burn-off position is greater than the garbage depletion threshold. The garbage depletion threshold value can be set appropriately to a value greater than or equal to 1.

[0079] [Combustion control by combustion control device] The control command generation unit 18 is configured to calculate a control value for the conveying speed of the stoker mechanism ST based on a predetermined index, and to adjust the conveying speeds of the drying zone ST1, combustion zone ST2, and post-combustion zone ST3 that constitute the stoker mechanism ST by controlling the hydraulic mechanisms h1, h2, and h3 via the conveying control unit 12. In other words, the control command generation unit 18 and the conveying control unit 12 constitute a conveying control processing unit. The hydraulic mechanisms h1, h2, and h3 are adjusted so that the speeds of the drying zone ST1, combustion zone ST2, and post-combustion zone ST3 are controlled while maintaining a constant speed ratio.

[0080] The transport control processing unit is configured to correct the transport speed of the stoker mechanism ST based on the predetermined index when the lump determination processing unit 16D determines that a lump MT is present. Specifically, when the lump determination unit 16D determines that the lump MT is a combustible lump, the transport control processing unit slows down the transport speed to ensure sufficient time for the lump MT to burn. When the lump determination unit 16D determines that the lump MT is a non-combustible lump MT, the transport control processing unit speeds up the transport speed to quickly discharge the lump MT from the stoker mechanism ST (inside the furnace).

[0081] Such transport control processing executed by the transport control processing unit automatically controls the transport speed of the stoker mechanism ST appropriately based on preset indicators, thereby reducing the need for manual intervention by an operator.

[0082] Furthermore, the transport control processing unit is configured to prevent the occurrence of garbage depletion by increasing the transport speed of the stoker mechanism ST based on the specified index when the garbage depletion estimation processing unit 16B estimates that there is a tendency for garbage depletion.

[0083] The predetermined index can be the burn-off position of the waste estimated by the burn-off position estimation unit 15. Specifically, the control command generation unit 18 calculates a control value for the conveying speed of the stoker mechanism ST so that the estimated burn-off position of the waste is maintained within a preset control range. At the same time, the control command generation unit 18 calculates a control value for the dust feeder P, and the dust feed speed by the dust feeder P is adjusted via the dust feed control unit 11. At this time, the dust feed speed is corrected to increase or decrease in speed in conjunction with the correction to increase or decrease the conveying speed of the stoker mechanism ST.

[0084] The amount of steam generated by the waste heat boiler F can also be used as the predetermined index. The steam amount adjustment unit 17 calculates a target steam amount so that a predetermined amount of steam is generated, based on the furnace outlet temperature detected by the temperature sensor and the steam amount detected by the steam amount sensor. The control command generation unit 18 calculates a control value for the amount of combustion air supplied, a control value for the conveying speed of the stoker mechanism ST, and a control value for the dust feeding speed by the dust feeder P so that the target steam amount is obtained. Each control value is input to the air supply control unit 13, the conveying control unit 12, and the dust supply control unit 11, and the air supply amount, the conveying speed, and the dust feeding speed are controlled.

[0085] In addition to the waste decay estimation processing unit 16B, or separately from the waste decay estimation processing unit 16B, if a layer thickness calculation unit that calculates the layer thickness of the waste being incinerated by the stoker mechanism ST is provided, the transport speed of the stoker mechanism can be controlled using the layer thickness calculated by the layer thickness calculation unit as an index. For example, the layer thickness calculation unit can obtain an image of the burning waste taken by an infrared camera by binarizing the image to remove flames, and from the image, detect the average height from the floor of the combustion zone ST2 to the surface of the waste as the layer thickness of the waste. The specific configuration of the layer thickness calculation unit is not particularly limited, and the configuration of an existing layer thickness calculation unit can be adopted.

[0086] The burn-off position referenced when the above-described garbage depletion estimation processing unit 16B estimates that there is a tendency for garbage to deplete may refer to a burn-off position other than the burn-off position estimated by the burn-off position estimation unit 15. For example, the most downstream position of the first combustion flame FA may be used as the burn-off position.

[0087] In the above-described embodiment, the burn-off position estimation unit 15 includes a flame region extraction processing unit 15A that extracts a flame region (first flame region S) from a frame image captured by the imaging device, and a burn-off position estimation processing unit 15B that calculates, as the burn-off position, the downstream-most position where, when a virtual straight line along the furnace width direction is scanned from below to above the flame region (first flame region S), the ratio of the number of pixels where the virtual line and the flame region (first flame region S) overlap to the number of pixels of the virtual line reaches a predetermined ratio. The burn-off position estimation unit 15 also includes an area calculation processing unit 15C that calculates the area of ​​a convex envelope flame region obtained by performing convex hull processing on the area of ​​the flame region and the outline of the flame region, and a burn-off position adjustment processing unit 15D that adjusts the predetermined ratio based on the relative value of the area of ​​the convex envelope flame region to the area of ​​the flame region. However, the burn-off position estimation unit 15 may be configured to include only the flame region extraction processing unit 15A and the burn-off position estimation processing unit 15B, without including the area calculation processing unit 15C and the burn-off position adjustment processing unit 15D.

[0088] The burn-off position estimation unit 15 may also be configured to include a flame region extraction processing unit that binarizes the image using a predetermined binarization threshold and extracts a flame region consisting of a single or multiple closed regions; a convex hull processing unit that generates a convex hull flame region, which is the smallest convex polygon that encompasses all of the contour points of the flame region; and a burn-off position estimation processing unit that estimates, as the burn-off position, the most downstream position at which, when a virtual straight line along the furnace width direction is scanned from below to above the convex hull flame region, the ratio of the number of pixels where the virtual straight line and the convex hull flame region overlap to the number of pixels of the virtual straight line is a predetermined ratio.

[0089] The burn-off position estimation unit 15 may also include a flame area extraction processing unit that binarizes the image using a predetermined binary threshold and extracts a flame area consisting of a single or multiple closed areas, and a burn-off position estimation processing unit that estimates the burn-off position of the garbage based on the image of the extracted flame area, and a garbage withering estimation processing unit that estimates that there is a tendency for garbage to wither when one or more independent flame areas exist downstream of the burn-off position estimated by the burn-off position estimation processing unit.

[0090] In other words, the burn-off position estimation processor is only required to be configured to estimate the burn-off position of the waste based on the flame region binarized by the flame region extraction processor. For example, when multiple flame regions are extracted, the burn-off position may be estimated as the most downstream position of the flame region with the largest area where the ratio of the number of pixels where the imaginary line and the convex hull flame region overlap to the number of pixels of the imaginary line is a predetermined ratio, or a similar process may be performed for the flame region with an average area. Alternatively, the burn-off position may simply be estimated as the most downstream position of the flame region with the largest area.

[0091] In either case, the garbage depletion estimation processing unit should be configured to estimate that there is a tendency for garbage to deplete when there is one or more independent flame areas downstream of the burn-out position estimated by the burn-out position estimation processing unit.

[0092] It goes without saying that the above-described embodiment is merely one example of the present invention, and the specific configuration of each part can be appropriately changed and designed within the scope of the effects of the present invention. [Explanation of symbols]

[0093] 1: Waste incinerator 2: Main combustion chamber 3: Secondary combustion chamber 4: Gas supply mechanism 5: Imaging device 10: Combustion control device 11: Dust supply control unit 12: Transport control unit 13: Air supply control unit 14: Processing unit 15: Burnout position estimation part 15A: Flame region extraction processing section 15B: Burn-off position estimation processing unit 15C: Area calculation processing section 15D: Burn-off position adjustment processing section 16:Property determination section 16A: Flame region extraction processing section 16B: Garbage decay estimation processing unit 16C: Area calculation processing section 16D: Lump determination processing unit 17: Steam volume adjustment section 18: Control command generation unit A: Platform B: Garbage pit C: Crane mechanism D: Garbage hopper E: Furnace room F: Waste heat boiler G: Economizer FA: Flame area VL: Virtual line

Claims

1. A method for estimating the combustion state of a waste incinerator, which estimates the combustion state of waste being incinerated on the upper surface of a stoker mechanism based on an image of the combustion state taken from the downstream side of the stoker mechanism using an imaging device, a flame region extraction process for extracting a flame region consisting of a single or multiple closed regions by binarizing pixel values ​​of the image using a predetermined binarization threshold; A burn-off position estimation process for estimating the burn-off position of the waste based on the extracted image of the flame region; a waste withering estimation process that estimates that there is a tendency for waste to wither when one or more flame regions exist independently downstream of the burn-out position estimated by the burn-out position estimation process; A method for estimating the combustion state of a waste incinerator.

2. 2. The method for estimating the combustion state of a waste incinerator according to claim 1, wherein the burn-off position estimation process is a process for estimating, when scanning a virtual straight line along the furnace width direction from bottom to top, the first position at which the ratio of the number of pixels where the virtual straight line and the flame region overlap to the number of pixels of the virtual straight line reaches a predetermined ratio, as the burn-off position.

3. an area calculation process for calculating the area of ​​the flame region and the area of ​​a convex hull flame region obtained by performing convex hull processing on the outline of the flame region; a burn-off position adjustment process for adjusting the predetermined ratio based on a relative value of an area of ​​the convex hull flame region with respect to an area of ​​the flame region; 3. The method for estimating the combustion state of a refuse incinerator according to claim 2, further comprising:

4. A combustion state estimation device for a waste incinerator that estimates the combustion state of waste being incinerated on the upper surface of a stoker mechanism based on an image of the combustion state taken from the downstream side of the stoker mechanism using an imaging device, a flame region extraction processing unit that binarizes pixel values ​​of the image using a predetermined binarization threshold value to extract a flame region consisting of a single or multiple closed regions; a burn-off position estimation processing unit that estimates the burn-off position of the waste based on the extracted image of the flame region; a waste withering estimation processing unit that estimates that there is a tendency for waste to wither when one or more flame regions exist independently downstream of the burn-off position estimated by the burn-off position estimation processing unit; A combustion state estimation device for a waste incinerator equipped with the device.

5. 5. The combustion state estimation device for a waste incinerator according to claim 4, wherein the burn-off position estimation processing unit estimates as the burn-off position the first position at which, when scanning an imaginary straight line along the furnace width direction from bottom to top, the ratio of the number of pixels where the imaginary straight line and the flame region overlap to the number of pixels of the imaginary straight line becomes a predetermined ratio.

6. an area calculation processing unit that calculates the area of ​​the flame region and the area of ​​a convex hull flame region obtained by performing convex hull processing on the outline of the flame region; a burn-off position adjustment processing unit that adjusts the predetermined ratio based on a relative value of an area of ​​the convex hull flame region with respect to an area of ​​the flame region; 6. The combustion state estimation device for a refuse incinerator according to claim 5, further comprising:

7. A method for controlling the transport of waste to be incinerated on the upper surface of a stoker mechanism in a waste incinerator, comprising: a transport control process for controlling the transport speed of the stoker mechanism based on a preset index; a flame region extraction process for extracting a flame region consisting of a single or multiple closed regions by binarizing pixel values ​​of the image using a predetermined binarization threshold; A burn-off position estimation process for estimating the burn-off position of the waste based on the extracted image of the flame region; a waste withering estimation process that estimates that there is a tendency for waste to wither when one or more flame regions exist independently downstream of the burn-out position estimated by the burn-out position estimation process; Run A transport control method for a waste incinerator, wherein when the waste depletion estimation process estimates that the waste is in a depleted state, the transport control process is configured to increase and correct the transport speed of the stoker mechanism based on the indicator.

8. 8. A method for controlling transport in a waste incinerator as described in claim 7, wherein the burn-off position estimation process is a process for estimating, when scanning a virtual straight line along the furnace width direction from bottom to top, the first position at which the ratio of the number of pixels where the virtual straight line and the flame area overlap to the number of pixels of the virtual straight line becomes a predetermined ratio, as the burn-off position.

9. an area calculation process for calculating the area of ​​the flame region and the area of ​​a convex hull flame region obtained by performing convex hull processing on the outline of the flame region; a burn-off position adjustment process for adjusting the predetermined ratio based on a relative value of an area of ​​the convex hull flame region with respect to an area of ​​the flame region; 9. The method for controlling transport in a refuse incinerator according to claim 8, further comprising:

10. A transport control device for a waste incinerator that controls the transport of waste to be incinerated on the upper surface of a stoker mechanism, a transport control processing unit that controls the transport speed of the stoker mechanism based on a preset index; an imaging device that images the burning state of the waste from the downstream side of the stoker mechanism; a flame region extraction processing unit that binarizes the image obtained by the imaging device using a predetermined binarization threshold and extracts a flame region consisting of a single or multiple closed regions; a burn-off position estimation processing unit that estimates the burn-off position of the waste based on the extracted image of the flame region; a waste withering estimation processing unit that estimates that there is a tendency for waste to wither when one or more flame regions exist independently downstream of the burn-off position estimated by the burn-off position estimation processing unit; A transport control device for a waste incinerator, wherein when the waste depletion estimation processing unit estimates that there is a tendency for waste to deplete, the transport control processing unit is configured to increase the transport speed of the stoker mechanism based on the indicator.

11. 11. A transport control device for a waste incinerator as described in claim 10, wherein the burn-off position estimation processing unit estimates, as the burn-off position, the first position at which the ratio of the number of pixels where the virtual line and the flame area overlap to the number of pixels of the virtual line becomes a predetermined ratio when scanning a virtual line along the furnace width direction from bottom to top.

12. an area calculation processing unit that calculates the area of ​​the flame region and the area of ​​a convex hull flame region obtained by performing convex hull processing on the outline of the flame region; a burn-off position adjustment processing unit that adjusts the predetermined ratio based on a relative value of an area of ​​the convex hull flame region with respect to an area of ​​the flame region; The transport control device for a refuse incinerator according to claim 11, further comprising:

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