Method for estimating the combustion cutoff position of a waste incinerator and apparatus for estimating the combustion cutoff position of a waste incinerator

Abstract

To provide a burn-out position 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.SOLUTION: A burn-out position estimation method of a refuse incinerator for estimating a burn-out position of refuse incinerated on the top face of a stoker mechanism ST on the basis of an image of a combustion state taken from a downstream side of the stoker mechanism using an imaging device executes: flame region extraction processing for binarizing the image with a predetermined binarization threshold and extracting a flame region FA; burn-out position estimation processing for estimating, as a burn-out position, the position on the most downstream side where the ratio of the number of pixels in which a virtual straight line VL and the flame region FA are overlapped with each other and the number of pixels of the virtual straight line is a predetermined ratio when the virtual straight line VL along an incinerator width direction is scanned from the lower side to the upper side of the flame region FA; area calculation processing for calculating an area of a convex hull flame region obtained by subjecting an area of the flame region and a contour of the flame region to convex hull processing; and burn-out position adjusting processing for adjusting the predetermined ratio on the basis of a relative value of the area of the convex hull flame region to the area of the flame region.SELECTED DRAWING: Figure 5

Description

Technical Field

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[0001] The present invention relates to a method for estimating a burning end position of a garbage incinerator and an apparatus for estimating a burning end position of a garbage incinerator, which estimate a burning end position of garbage incinerated on the upper surface of a stoker mechanism based on an image obtained by imaging a combustion state from the downstream side of the stoker mechanism using an imaging device.

Background Art

[0002] Patent Document 1 proposes a garbage incinerator including an imaging device that images a flame generated by garbage incinerated on the upper surface of a stoker mechanism from the downstream side of the stoker mechanism, and an image processing device that extracts a flame region from image data obtained by the imaging device and estimates the most downstream position of the extracted flame region as the burning end position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the state of the flame generated by the garbage incinerated on the upper surface of the stoker mechanism always varies, when estimating the most downstream position of the flame region imaged by the imaging device as the burning end position as in the garbage incinerator described in Patent Document 1, as a result, the estimated value of the burning end position frequently varies. Based on such an estimated value of the burning end position, for example, even if automatic combustion control such as control of the feeding speed of the garbage by the stoker mechanism or control of the supply amount of the primary combustion air is executed, there is a risk that the control characteristics deteriorate and it becomes difficult to maintain a stable combustion state.

[0005] Furthermore, if a lumpy object is present inside or in front of the flame region as viewed from the imaging device, some of the flame may be obstructed by the lumpy object, resulting in the detected combustion cutoff position being shifted further upstream than it actually is. In such cases, continuing automatic combustion control could increase the rate at which the stoker mechanism feeds the waste, potentially leading to the discharge of unburned waste.

[0006] Therefore, if the aforementioned supervisor monitors the image showing the combustion state of the incinerator displayed on the monitor screen and determines that there is a risk of unburned waste being discharged, it is necessary to interrupt the automatic combustion control and manually reduce the waste feeding speed by the stoker mechanism, which is a complicated operational intervention.

[0007] In view of the above-mentioned prior art, the object of the present invention is to provide a method for estimating the combustion cutoff position of a waste incinerator and a device for estimating the combustion cutoff position of a waste incinerator that minimizes the workload of the monitoring personnel and enables the continuation of automatic operation control. [Means for solving the problem]

[0008] To achieve the above objective, the first characteristic configuration of the waste incinerator burnout position estimation method according to the present invention is a waste incinerator burnout position estimation method that estimates the burnout position of waste incinerated on the upper surface of the stoker mechanism based on an image of the combustion state taken from the downstream side of the stoker mechanism using an imaging device, comprising: a flame region extraction process that extracts a flame region composed of one or more closed regions by binarizing the image with a predetermined binarization threshold; and a burnout position estimation process that estimates the burnout position as the furthest downstream position where, when a virtual straight line along the furnace width direction is scanned from below to above the flame region, 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 is a predetermined ratio. Area calculation process to calculate the area of ​​the flame region and the area of ​​the convex hull flame region obtained by convex hull processing of the contour of the flame region, and a combustion cutoff position adjustment process to adjust the predetermined ratio based on the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region, The key is to execute it.

[0009] An image including the flame generated when waste is incinerated on the top surface of the stoker mechanism is captured by an imaging device from the downstream side of the stoker mechanism. Flame region extraction processing is performed on the image captured by the imaging device, and the flame region is extracted by binarizing the pixel values ​​at a predetermined binarization threshold. Next, a burnout position calculation process is performed on the image from which the flame region has been extracted, and a virtual straight line along the furnace width direction is scanned from below to above the flame region, and the position at the furthest downstream where the ratio of the number of pixels of the virtual line and the flame region overlap to the number of pixels of the virtual line is a predetermined ratio is estimated as the burnout position. By estimating the burnout position as the position where the number of flame pixels overlapping the virtual line on the downstream side of the flame region is a predetermined ratio, it is possible to suppress the drastic fluctuations in the estimated burnout position compared to when the downstream side of the flame region is used as the burnout position.

[0010] In addition, If flame-retardant or non-combustible lumps are present in the material being incinerated on the top surface of the stoker mechanism, the flame tends to be obstructed by the lumps, resulting in a smaller flame region extracted by the flame region extraction process. This can make it difficult to distinguish between a decrease in combustion and a reduction in the flame region. Therefore, an area calculation process is performed to calculate the area of ​​the flame region and the area of ​​the convex-hulled flame region obtained by convex-hull processing the outline of the flame region. The area of ​​the convex-hulled flame region includes at least the area of ​​the flame obstructed by the lumps, allowing for an assessment of the degree of influence from the lumps. This is because the area of ​​the convex-hulled flame region when obstructed by lumps tends to be larger than the area of ​​the convex-hulled flame region when combustion decreases and the flame region shrinks. Therefore, by adjusting a predetermined ratio based on the relative value of the area of ​​the convex flame region to the area of ​​the flame region through a combustion cutoff position adjustment process, the risk of misjudging the combustion cutoff position to be upstream of the actual position due to lumpy material can be reduced.

[0011] Same number two The characteristic configuration is as described above. oneIn addition to the characteristic configuration, the fuel cut-off position adjustment process is a process that adjusts the relative value to decrease as the relative value increases when the relative value is greater than a predetermined threshold.

[0012] The size of the flame region obstructed by the lumpy material can be evaluated as a relative value, and if a predetermined ratio is constant, the larger the relative value, the more likely the cutoff position is to shift upstream. Therefore, assuming that there is a higher risk of misjudging the cutoff position as being upstream of its actual position when the relative value is greater than a predetermined threshold, the predetermined ratio is adjusted to decrease as the relative value increases, that is, to determine that the cutoff position is downstream.

[0013] Same number three The characteristic configuration is as described above. one or the two In addition to its characteristic configuration, the relative value is the difference or ratio of the area of ​​the convex hull flame region to the area of ​​the flame region.

[0014] It is preferable to use the difference or ratio of the area of ​​the convex hull flame region to the area of ​​the flame region as the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region. When using the difference, it can be assumed that the larger the difference, the higher the risk of misjudging the burn-out position as being upstream of the actual position. When using the ratio, it can be assumed that the larger the ratio, the higher the risk of misjudging the burn-out position as being upstream of the actual position.

[0015] Same number fourThe characteristic configuration of the method for estimating the burnout position of waste being incinerated on the upper surface of a stoker mechanism is that the method estimates the burnout position of the waste being incinerated on the upper surface of the stoker mechanism based on an image of the combustion state taken from the downstream side of the stoker mechanism using an imaging device, and the method performs a flame region extraction process that extracts a flame region composed of one or more closed regions by binarizing the image with a predetermined binarization threshold, a convex hull process that generates a convex hull flame region which is the smallest convex polygon that encompasses all the contour points of the flame region, and a burnout position estimation process that estimates the burnout position as the downstreammost position where, when a virtual 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 line and the convex hull flame region overlap to the number of pixels of the virtual line is a predetermined ratio.

[0016] If flame-retardant or non-combustible lumps are present in the material being incinerated on the upper surface of the stoker mechanism, the flame tends to be obstructed by the lumps, resulting in a smaller flame region extracted during the flame region extraction process. This can make it difficult to distinguish between this case and a case where the flame region shrinks due to a decrease in combustion state without the presence of lumps. Therefore, by performing a convex hull process, the convex hull flame region, which reflects both the influence of the flame region when obstructed by lumps and the influence of the flame region when the combustion state decreases and the flame region shrinks, is made the target of the burnout position estimation process, thereby enabling the appropriate estimation of the burnout position. In the burnout position calculation process, a virtual straight line along the furnace width direction is scanned from below to above the convex hull flame region, and the downstream position where 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 is estimated as the burnout position.

[0017] The first characteristic configuration of the combustion completion position estimation device for a garbage incinerator according to the present invention is a combustion completion position estimation device for a garbage incinerator that estimates the combustion completion position of the garbage incinerated on the upper surface of the stoker mechanism based on an image obtained by photographing the combustion state from the downstream side of the stoker mechanism using an imaging device, comprising a flame region extraction processing unit that extracts a flame region by binarizing the image with a predetermined binarization threshold, and a combustion completion position estimation processing unit that estimates, as the combustion completion position, the most downstream 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 becomes a predetermined ratio when the virtual straight line along the furnace width direction is scanned upward from below the flame region. An area calculation processing unit that calculates the area of ​​the flame region and the area of ​​the convex hull flame region obtained by convex hull processing of the contour of the flame region, and a combustion cutoff position adjustment processing unit that adjusts the predetermined ratio based on the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region, It is in the point of having this.

[0018] Same as the two The characteristic configuration of this is, in addition to the characteristic configuration of the above-mentioned one that when the relative value is greater than a predetermined threshold, the combustion completion position adjustment processing unit adjusts so that the predetermined ratio decreases as the relative value increases.

[0019] Same as the three The characteristic configuration of this is, in addition to the characteristic configuration of the above-mentioned one or the two that the relative value is the difference or ratio of the area of the convex hull flame region to the area of the flame region.

[0020] Same as the four The characteristic configuration of this is a combustion completion position estimation device for a garbage incinerator that estimates the combustion completion position of the garbage incinerated on the upper surface of the stoker mechanism based on an image obtained by photographing the combustion state from the downstream side of the stoker mechanism using an imaging device, comprising a flame region extraction processing unit that extracts a flame region, which is composed of a single or a plurality of closed regions, by binarizing the image with a predetermined binarization threshold, a convex hull processing unit that generates a convex hull flame region, which is the smallest convex polygon that includes all the contour points of the flame region, and a combustion completion position estimation processing unit that estimates, as the combustion completion position, the most downstream position at which 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 becomes a predetermined ratio when the virtual straight line along the furnace width direction is scanned upward from below the convex hull flame region. It is in the point of having this.

Advantages of the Invention

[0021] As described above, according to the present invention, it has become possible to provide a method for estimating the burnout position of a waste incinerator and a device for estimating the burnout position of a waste incinerator that can reduce the labor of monitors as much as possible and enable the continuation of automatic driving control.

Brief Description of the Drawings

[0022] [Figure 1] It is an explanatory diagram of a stoker-type waste incinerator. [Figure 2] It is an enlarged view of the main part of a stoker-type waste incinerator. [Figure 3] (a) and (b) are functional block configuration diagrams of a combustion control device. [Figure 4] (a) is an explanatory diagram showing the relative position between the waste burning on the stoker and the imaging device, and (b) is an explanatory diagram of the estimation of the burnout position based on the combustion flame imaged by the imaging device. [Figure 5] (a) is an explanatory diagram of the adjustment principle of the burnout position based on the area S1 of the combustion flame imaged by the imaging device and the area S'1 of the flame obtained by performing a convex hull processing on the combustion flame, and (b) is an explanatory diagram of the adjustment principle of the burnout position based on the area S2 of the combustion flame imaged by the imaging device and the area S'2 of the flame obtained by performing a convex hull processing on the combustion flame. [Figure 6] It is an explanatory diagram of the adjustment principle of the burnout position based on the areas S11 and S12 into which the combustion flame imaged by the imaging device is separated due to the influence of lumps, and the areas S'11 and S'12 of the flames obtained by performing a convex hull processing on the respective combustion flames. [Figure 7] It is a flowchart showing the procedure of combustion control. [Figure 8] It is a flowchart showing the procedure of the burnout position estimation process. [Figure 9] It is a flowchart showing the procedure of the property determination process.

Embodiments for Carrying Out the Invention

[0023] The following describes the method for estimating the combustion cutoff position of a waste incinerator and the apparatus for estimating the combustion cutoff position of a waste incinerator according to the present invention, based on the drawings.

[0024] [Structure of a waste incinerator] Figure 1 shows a stoker-type waste incinerator 1. It includes a platform A into which garbage trucks enter, a waste pit B for accumulating the waste collected by the garbage trucks, a waste input hopper D, a waste crane C for transferring waste from waste pit B to waste input hopper D, a furnace chamber E, a waste heat boiler F and economizer G installed in the space above furnace chamber E. The combustion exhaust gas generated in furnace chamber E is purified by exhaust gas treatment equipment such as a cooling tower H and dust collector I arranged along the flue before being exhausted through the chimney J. An induced draft fan L is installed in the flue to maintain negative pressure in furnace chamber E.

[0025] By opening the double-hinged garbage input door K, which is located between platform A and garbage pit B to prevent odor leakage and ensure safety, the garbage collected and transported by the garbage truck is dumped into garbage pit B.

[0026] The waste collected in waste pit B is grasped by a grab bucket type waste crane C, which is operated automatically or by an operator in a control room, and transported to an opening formed at the top of the waste input hopper D before being dropped into it.

[0027] A dust supply device P is provided at the bottom of the waste input hopper D, and the waste filled in the waste input hopper D is pushed into the furnace chamber E. The waste filled in the waste input hopper D functions as a sealing mechanism that blocks the inflow of outside air from the waste input hopper D into the furnace chamber E, and the furnace chamber is maintained under negative pressure.

[0028] The furnace chamber E is equipped with a main combustion chamber 2 and a secondary combustion chamber 3 for the complete combustion of the exhaust gas produced in the main combustion chamber 2. Multiple water tubes WT of the waste heat boiler F are embedded in the wall of the secondary combustion chamber 3.

[0029] As shown in Figure 2, the main combustion chamber 2 is equipped with a stoker mechanism ST in which a fixed grate and a movable grate are alternately arranged along the direction of waste transport. The movable grate is driven back and forth relative to the fixed grate by hydraulic mechanisms h1, h2, and h3, thereby agitating and transporting the waste downstream.

[0030] Four wind boxes W1, W2, W3, and W4 are installed at the bottom of the stoker mechanism ST, in order from upstream to downstream, and main combustion air is supplied from a forced-air fan. The upstream region corresponding to wind box W1 of the stoker mechanism ST is the dry 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.

[0031] 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. Furthermore, 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.

[0032] The waste pushed from the dust supply device P into the main combustion chamber 2 is mainly heated and dried in the drying zone ST1, then gasified and burned in the combustion zone ST2, and the waste that has been carbonized by gasified combustion is in the combustion zone ST2 From the downstream side, the material is solid-burned in the post-combustion zone ST3 and turned to ash, and after being turned to ash, it falls into the ash chute from the end of the post-combustion zone ST3.

[0033] A constricted section is formed in the front wall 2F and rear wall 2R of the furnace chamber E, extending from the main combustion chamber 2 to the inlet of the secondary combustion chamber 3, and a gas supply mechanism 4 is provided in this constricted section. The gas supplied from the gas supply mechanism 4 agitates and rectifies the combustion exhaust gas flowing into the secondary combustion chamber 3, allowing for complete combustion in the secondary combustion chamber 3.

[0034] The gas supplied from the gas supply mechanism 4 may be air for secondary combustion, exhaust gas drawn from the main combustion chamber 2, recirculated exhaust gas branched from the flue downstream of the dust collector I, or exhaust gas branched from other exhaust gas flow paths, or a mixture of air and each of the aforementioned exhaust gases.

[0035] The total amount of main combustion air and secondary combustion air should be adjusted so that the theoretical air-to-incineration ratio is approximately 1.3. For example, if all the air is supplied by the main combustion air so that the theoretical air-to-incineration ratio is approximately 1.3, the gas supplied from the gas supply mechanism 4 may be only the exhaust gas drawn from the flue. Alternatively, the system may be configured so that approximately 1.0 of the air is supplied by the main combustion air and approximately 0.3 by the secondary combustion air. A temperature sensor and a gas sensor are provided at the outlet of the secondary combustion chamber 3.

[0036] An industrial television camera (ITV), acting as an imaging device 5, is installed on the rear wall 2R of furnace chamber E, and the combustion state, including the combustion flame of the waste being transported and incinerated on the upper surface of the stoker mechanism ST, is captured.

[0037] [Configuration of combustion control device] Figure 3 shows the configuration of a combustion control device 10 that controls the combustion state of the waste incinerated in the waste incinerator 1 described above 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 supplied to the main combustion chamber 2 by the dust supply device P, a transport control unit 12 that controls the transport speed of the dry 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 wind box 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.

[0038] The calculation processing unit 14 includes a combustion cut-off position estimation unit 15 that estimates the combustion cut-off position of waste in the combustion zone ST2, a property determination unit 16 that determines the presence or absence of lumpy material mixed in the waste and the properties of the waste such as waste depletion, and a steam amount adjustment unit 17 that adjusts the amount of steam generated by the waste heat boiler F. It also includes a control command generation unit 18 that generates control commands to be output to each control unit 11, 12, and 13 according to an index obtained based on the calculation results of each calculation unit. The detection values ​​of each of the above-mentioned pressure sensors, flow rate sensors, gas sensors, temperature sensors, and steam amount sensors, as well as images taken by the imaging device 5, are input to the calculation processing unit 14.

[0039] The combustion control device 10 is comprised of a CPU board, a memory board, an input / output interface board, a display device, an input device, and the like. The 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 above-mentioned functional blocks.

[0040] Specifically, as shown in Figure 7, the combustion control device 10 receives values ​​from various sensors such as the pressure sensor, flow sensor, temperature sensor, and gas sensor (SA1), acquires combustion images captured by the imaging device 5 (SA2), and performs combustion cutoff position estimation processing (SA3), property determination processing (SA4), and vapor amount adjustment processing (SA5) based on this input information. Then, based on these results, it performs various control calculations, including PID calculations, to generate control commands to be output to each control unit 11, 12, and 13 (SA6), and repeatedly performs dust supply control processing via the dust supply control unit 11 (SA7), transport control processing via the transport control unit 12 (SA8), and air supply control processing via the air supply control unit 13 (SA9) 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 few seconds to several tens of seconds.

[0041] [Burnout position estimation unit] The combustion cutoff position estimation unit 15 is a calculation unit that estimates the combustion cutoff position based on image information showing the combustion state of the waste being incinerated on the upper surface of the stoker mechanism ST, which is captured by the imaging device 5.

[0042] The combustion cutoff position estimation unit 15 comprises the following functional blocks: a flame region extraction processing unit 15A, a combustion cutoff position estimation processing unit 15B, an area calculation processing unit 15C, and a combustion cutoff position adjustment processing unit 15D.

[0043] As shown in Figure 7, the burnout position estimation unit 15 is configured to repeatedly perform the following processes over time, that is, to repeat them at predetermined time intervals: flame region extraction processing by flame region extraction processing unit 15A, burnout position estimation processing by burnout position estimation processing unit 15B, area calculation processing by area calculation processing unit 15C, and burnout position adjustment processing by burnout position adjustment processing unit 15D.

[0044] Figure 8 shows the procedure for the combustion cutoff position estimation process performed by the combustion cutoff position estimation unit 15. The flame region extraction processing unit 15A includes a memory for storing moving images captured by the imaging device 5, and a binarization processing unit that extracts flame regions composed of one or more closed regions by binarizing the pixel values ​​of predetermined frame images extracted from the moving images stored in the memory using a predetermined binarization threshold. The image can be composed of any type of pixels, such as a grayscale image or an RGB color image, as long as it can distinguish between flame regions and other regions, and brightness values ​​or RGB component values ​​can be appropriately used as the pixel values ​​for extracting flame regions. Furthermore, the binarization threshold is not limited to a specific value, and can be set as appropriate as long as it is a value that can extract flame regions.

[0045] The flame region extraction processing unit 15A binarizes the frame image to obtain one or more flame regions (SB1), and distinguishes and extracts first flame regions FA whose size (area) is equal to or greater than the first threshold, and second flame regions FAs whose size (area) is smaller than the first threshold and less than or equal to the second threshold (SB2, SB3). The value of the first threshold should be such that the largest combustion flame burning on the upper surface of the stoker mechanism can be extracted, and the main combustion flame can be extracted even if it is divided into multiple flames due to the influence of a lump-like object described later. The second threshold should be such that the minute combustion flames excluding the main combustion flame can be extracted.

[0046] The burnout position estimation processing unit 15B is a functional block that estimates the burnout position of waste from one or more first flame regions FA whose size (area) is equal to or greater than a first threshold among the extracted flame regions.

[0047] More specifically, a virtual straight line VL (in this embodiment, a horizontal straight line) is generated along the furnace width direction for the binarized image, and this virtual straight line VL is scanned (translated) from below (downstream) to above (upstream) the first flame region FA (SB4). The number of pixels where the virtual straight line VL and the first flame region FA overlap is calculated (SB5), and the ratio of this number to the total number of pixels of the virtual straight line VL is calculated and this process is repeated (SB6). The first (farthest downstream) position where the ratio obtained in step SB6 is greater than or equal to a predetermined ratio R is estimated as the burnout position (SB12, SB13).

[0048] In light of the fact that the size of the first flame region FA varies depending on whether or not lumpy material is mixed in with the waste incinerated in the combustion zone ST2, the predetermined ratio R is adjusted according to the following procedure.

[0049] The adjustment procedure is described below. The 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 the contour of the first flame region FA (SB7, SB8, SB9). A convex hull is the smallest convex polygon that encloses all the given points, and convex hull processing is the process of generating the smallest convex polygon that encloses all the contour points of the flame image as the convex hull flame region.

[0050] The combustion cutoff position adjustment processing unit 15D calculates the relative value RV of the area S' of the convex hull flame region with respect to the area S of the first flame region FA (SB10), and adjusts a predetermined ratio R referenced by the combustion cutoff position estimation processing unit 15B based on the calculated relative value RV (SB11). As the relative value RV, the difference (S'-S) of the area S' of the convex hull flame region with respect to the area S of the first flame region FA, or the ratio (S' / S), can be used.

[0051] The fuel cut-off position adjustment processing unit 15D adjusts the fuel cut-off position so that, when the relative value RV is greater than a predetermined threshold, the predetermined ratio R decreases as the relative value increases, that is, the fuel cut-off position is corrected to the downstream side. When the relative value RV is less than or equal to the predetermined threshold, the initial value is adopted as the predetermined ratio R. The threshold value of the relative value RV can be determined in advance by testing with an actual machine or the like.

[0052] In other words, if flame-retardant or non-combustible lumps are present in the waste incinerated on the upper surface of the stoker mechanism ST, the flame tends to be obstructed by the lumps, resulting in a smaller size of the first flame region FA extracted by the flame region extraction process. This can make it difficult to distinguish between this case and a case where the combustion state deteriorates without the presence of lumps, causing the first flame region FA to shrink.

[0053] Therefore, an area calculation process is performed 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 the contour of the first flame region FA. Since the area S' of the convex hull flame region is the area that includes at least the flame that is obstructed by the lumpy material, the degree of influence of the lumpy material can be understood 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 it is obstructed by the lumpy material tends to be larger than the area S' of the convex hull flame region when the combustion state decreases and the first flame region FA becomes smaller.

[0054] Therefore, by adjusting a predetermined ratio R based on the relative value of the area S' of the convex hull flame region to the area S of the flame region through a combustion cutoff position adjustment process, the risk of misjudging the combustion cutoff position to be upstream of the actual position due to lumpy material can be reduced.

[0055] Figure 4(a) shows an imaging device 5 installed on the rear wall of the furnace chamber E, which photographs the combustion state of waste being incinerated on the upper surface of the stoker mechanism ST from the downstream side of the stoker mechanism ST. In this embodiment, the left-right center of the imaging device 5 is adjusted to the center in the furnace width direction, and the vertical center is adjusted to the center of the vertical length along the transport direction of the drying zone ST1 and combustion zone ST2 of the stoker mechanism ST.

[0056] Figure 4(b) shows an image captured by the imaging device 5. The first flame region FA and the second flame regions FAs, which are generated by gasification combustion in the combustion zone ST2, are hatched. The waste that is gasified and carbonized in the combustion zone ST2 is transported to the post-combustion zone ST3, where it is burned into embers and reduced to ash, which then falls into the 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.

[0057] The upper part of Figure 5(a) shows a binarized image of the first flame region FA (the dashed line represents the image lost due to binarization). When a virtual straight line VL (shown as a dashed line) along the furnace width direction is scanned (translated) from below (downstream side of the furnace) to above (upstream side of the furnace) the first flame region FA, the virtual straight line VL and 1 When the flame region FA comes into contact with the virtual line VL (indicated as "lower end position" in the diagram), and scanning (moving) further upwards, the virtual line VL 1 The flame region FA will overlap. The overlapping region is shown by a thick solid line.

[0058] The combustion cutoff position estimation processing unit 15B increases the scanning amount (movement amount) of the virtual straight line VL, 1 The downstream position where the ratio of the number of pixels PF in the superimposed region of the flame region FA to the total number of pixels PV in the virtual line VL (PF / PV) is a predetermined ratio R is estimated as the burn-out position.

[0059] By estimating the combustion cutoff position in this way, the operation of the stoker mechanism ST and the fluctuations in the combustion state determine the first flame area Even when the lower end of the FA region fluctuates frequently, this technology can mitigate the effects and accurately and stably estimate the fuel cut-off position.

[0060] The predetermined ratio R is not particularly limited, but in this embodiment, it is set to R=0.3 (30%) as an initial value. For example, in the case of a video corresponding to full HD with a horizontal pixel count of 1920, the total number of pixels of the virtual line VL becomes 1920. 1 The burn-out position is determined when the number of pixels PF in the superimposed area of ​​the flame region FA is 1920 × 0.3 = 576 pixels. To reduce the computational load, the system may be configured to calculate the ratio (PF / PV) for an image obtained by downsampling the image at a predetermined rate.

[0061] 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, and a portion of the combustion flame captured by the imaging device 5 is blocked by the lump MT, the binarized image is obtained. 1 The flame region FA may split into multiple parts or shrink in size. As a result, the downstream position where the ratio of the number of pixels PF in the first flame region FA to the total number of pixels PV in the virtual line VL (PF / PV) in the overlapping region with the first flame region FA is a predetermined ratio R shifts upstream compared to the position when no lump-like object MT exists. In other words, it is incorrectly determined that the combustion cutoff position is upstream. Therefore, the predetermined ratio R is adjusted using the procedure described above.

[0062] The lower parts of Figures 5(a) and (b) show the areas S1 and S2 of the hatched flame regions and the areas S1' and S2' of the convex polygons that have undergone convex hull treatment, respectively. When the difference (S'-S) is used as the relative value RV, the relative value RV2 = (S2'-S2) when there is a lump MT in the combustion zone ST2 tends to be larger than the relative value RV1 = (S1'-S1) when there is no lump MT in the combustion zone ST2.

[0063] The fuel cut-off position adjustment processing unit 15D determines that the fuel cut-off position has shifted upstream due to the presence of a lump when the relative value RV = (S1'-S1) is greater than a predetermined threshold, and adjusts the fuel cut-off position so that the predetermined ratio R decreases as the relative value increases, i.e., so that the fuel cut-off position moves downstream. If the relative value RV is below the predetermined threshold, it is determined that the effect of the lump is small even if it is present, and the fuel cut-off position is maintained at a preset fixed value. The predetermined threshold and adjustment ratio can be determined based on the correlation between the relative value RV at which the fuel cut-off position is judged to be in an appropriate position and the predetermined ratio, which can be determined by conducting tests in advance.

[0064] Figure 6 shows the first by the lump-like substance MT. flame area An example is shown in which FA is separated into two. In this case, the downstream position where the ratio (PF / PV) of the total number of pixels in the superimposed region of each first flame region FA and the virtual line VL to the total number of pixels in the virtual line VL is a predetermined ratio R is estimated to be the burn-out position.

[0065] In this case as well, as described above, if the relative value RV = {(S11'-S11)+(S12'-S12)} is greater than a predetermined threshold, it is determined that the combustion cutoff position has shifted upstream due to the presence of the lump MT, and the predetermined ratio R decreases as the relative value RV increases, that is, the combustion cutoff position is adjusted to move downstream.

[0066] Furthermore, the first flame area If FA is assigned to two or more areas, multiple first flame area Of the FAs, the first one has the largest area. flame area With respect to FA, the downstream position where the ratio (PF / PV) of the total number of pixels PF in the superimposed region of the first flame region FA and the virtual line VL to the total number of pixels PV in the virtual line VL is a predetermined ratio R may be estimated as the burn-off position.

[0067] [Property determination department] The properties determination unit 16 is a calculation unit that determines the properties of waste based on image information captured by the imaging device 5 of the waste being incinerated on the upper surface of the stoker mechanism ST.

[0068] As shown in Figure 3(b), the property determination unit 16 includes the following functional blocks: a flame region extraction processing unit 16A, a debris depletion estimation processing unit 16B, an area calculation processing unit 16C, and a clump-like object 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 aforementioned burnout position estimation unit 15.

[0069] As shown in Figure 7, similar to the burnout position estimation unit 15, the property determination unit 16 is configured to repeatedly perform the flame region extraction process by the flame region extraction processing unit 16A, the waste depletion estimation process by the waste depletion estimation processing unit 16B, the area calculation process by the area calculation processing unit 16C, and the lump-like object determination process by the lump-like object determination processing unit 16D over time, that is, repeatedly at predetermined time intervals.

[0070] Figure 9 shows the procedure for the property determination process performed by the property determination unit 16. As explained in the flame region extraction unit 15A, the flame region extraction unit 16A distinguishes and extracts from the single or multiple flame regions obtained by binarizing the frame image, a first flame region FA whose size (area) is equal to or greater than the first threshold, and a second flame region FAs whose size (area) is smaller than the first threshold and less than or equal to the second threshold (SC1, SC2, SC3).

[0071] The area calculation processing unit 16C 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 the contour of the first flame region FA (SC4, SC5, SC6). The clump determination processing unit 16D determines whether or not there are clumps of debris 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 region with respect to the area S of the first flame region FA. As the relative value RV, 1 The difference (S'-S) or ratio (S' / S) between the area S of the flame region FA and the area S' of the convex hull flame region can be used.

[0072] The lump-forming object determination processing unit 16D determines that a lump-forming object MT exists (SC8) when the relative value RV=(S'-S) is greater than a predetermined threshold (SC7,Y), and determines that a lump-forming object MT does not exist (SC9) when the relative value RV=(S'-S) is less than or equal to a predetermined threshold (SC7,N). Furthermore, the lump-forming object determination processing unit 16D determines that the lump-forming object MT is a combustible lump-forming object (SC11) when the relative value RV decreases over time (SC10,Y), and determines that the lump-forming object MT is a non-combustible lump-forming object (SC12) when the relative value RV does not decrease over time (SC10,N).

[0073] Furthermore, as shown in Figure 6, if the first flame region 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.

[0074] The waste depletion estimation processing unit 16B estimates whether there is a tendency for waste depletion based on the combustion cut-off position estimated by the cut-off position estimation processing unit 15B and the second flame regions FAs extracted by the flame region extraction processing unit 16A. Specifically, the waste depletion estimation processing unit 16B estimates that there is a tendency for waste depletion if the second flame regions FAs are scattered downstream of the combustion cut-off position (SC13,Y) (SC14). Specifically, it estimates that there is a tendency for waste depletion if the number of second flame regions FAs located downstream of the combustion cut-off position is greater than a preset waste depletion threshold.

[0075] When the thickness of the debris layer upstream of the combustion cutoff point decreases, combustion air supplied from below the stoker mechanism ST blows through, causing debris to be blown downstream of the combustion cutoff point, resulting in the phenomenon of scattered small flame regions downstream of the combustion cutoff point. The debris depletion estimation processing unit 16B can estimate that there is a tendency towards debris depletion if the number of scattered second flame regions downstream of the combustion cutoff point exceeds the debris depletion threshold. The value of the debris depletion threshold can be set appropriately to a value of 2 or greater.

[0076] [Combustion control by combustion control device] The control command generation unit 18 calculates a control value for the transport speed of the stoker mechanism ST based on a predetermined index, and controls the hydraulic mechanisms h1, h2, and h3 via the transport control unit 12 to adjust the transport speeds of the dry zone ST1, combustion zone ST2, and post-combustion zone ST3 that constitute the stoker mechanism ST. In other words, the transport control processing unit is composed of the control command generation unit 18 and the transport control unit 12. The hydraulic mechanisms h1, h2, and h3 are adjusted so that the dry zone ST1, combustion zone ST2, and post-combustion zone ST3 maintain a constant speed ratio while their speeds are controlled.

[0077] Furthermore, the transport control processing unit is configured to correct the transport speed of the stoker mechanism ST based on a predetermined index when the lump object determination processing unit 16D determines that a lump object MT is present. Specifically, lump object determination process Part 16 D If the bulk material MT is determined to be a combustible bulk material, the transport control processing unit reduces the transport speed to ensure sufficient burning time for the bulk material MT. process Part 16 D If the bulk material MT is determined to be non-combustible bulk material MT, the transport control processing unit increases the transport speed to quickly discharge the bulk material MT from the stoker mechanism ST (inside the furnace).

[0078] This transport control processing, performed by the transport control processing unit, automatically controls the transport speed of the stoker mechanism ST appropriately based on pre-set indicators, thereby reducing the need for manual intervention by the operator.

[0079] Furthermore, the transport control unit is configured to prevent waste depletion from occurring by increasing the transport speed of the stoker mechanism ST based on a predetermined indicator when the waste depletion estimation unit 16B estimates that there is a tendency for waste depletion.

[0080] As a predetermined indicator, the waste ignition position estimated by the waste ignition position estimation unit 15 can be used. Specifically, the control command generation unit 18 calculates a control value for the transport speed of the stoker mechanism ST so that the estimated waste ignition position is maintained within a preset control range. At the same time, the control command generation unit 18 calculates a control value for the dust supply device P, and the dust supply speed by the dust supply device P is adjusted via the dust supply control unit 11. At this time, the dust supply speed is increased or decreased in conjunction with the increase or decrease correction of the transport speed of the stoker mechanism ST.

[0081] The amount of steam generated by the waste heat boiler F can also be used as a predetermined indicator. The steam amount adjustment unit 17 calculates a target steam amount based on the furnace outlet temperature detected by the temperature sensor and the amount of steam detected by the steam amount sensor so that a predetermined amount of steam is generated. The control command generation unit 18 calculates control values ​​for the amount of combustion air supplied, the transport speed of the stoker mechanism ST, and the dust supply speed of the dust supply device P so that the target amount of steam is obtained. Each control value is input to the air supply control unit 13, the transport control unit 12, and the dust supply control unit 11, and the air supply amount, transport speed, and dust supply speed are controlled.

[0082] Furthermore, if a layer thickness calculation unit is provided in addition to, or separately from, the waste depletion estimation processing unit 16B, for calculating the layer thickness of waste incinerated by the stoker mechanism ST, it is also possible to control the transport speed of the stoker mechanism using the waste layer thickness calculated by the layer thickness calculation unit as an indicator. For example, as a layer thickness calculation unit, an image obtained by binarizing the combustion image of waste captured by an infrared camera to remove the flames can be obtained, and the average height from the floor surface of the combustion zone ST2 to the surface of the waste can be detected from this image as the waste layer thickness. The specific configuration of the layer thickness calculation unit is not particularly limited, and an existing configuration of a layer thickness calculation unit can be adopted.

[0083] When the waste depletion estimation processing unit 16B described above estimates that there is a tendency for waste depletion, the combustion cutoff position it refers to may be a combustion cutoff position other than the combustion cutoff position estimated by the combustion cutoff position estimation unit 15. For example, the first flame areaThe downstream position of the FA (Fuel Assist) may be used as the fuel cut-off position.

[0084] In the above-described embodiment, the flame extinction position estimation unit 15 determines the flame region (first flame region) from the frame image captured by the imaging device. FA A flame region extraction processing unit 15A extracts the flame region (first flame region) along a virtual straight line along the furnace width direction. FA When scanning from below to above, the virtual line and flame region (first flame region) are observed. FA The configuration described includes a combustion cutoff position estimation processing unit 15B that calculates the position at the furthest downstream where the ratio of the number of pixels where the two superimposed elements overlap to the number of pixels of the virtual line is a predetermined ratio, an area calculation processing unit 15C that calculates the area of ​​the convex hull flame region obtained by convex hull processing the area of ​​the flame region and the contour of the flame region, and a combustion cutoff position adjustment processing unit 15D that 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. However, the combustion cutoff position estimation unit 15 may be configured with only a flame region extraction processing unit 15A and a combustion cutoff position estimation processing unit 15B, without the area calculation processing unit 15C and the combustion cutoff position adjustment processing unit 15D.

[0085] Furthermore, the burnout position estimation unit 15 may be configured to include: a flame region extraction processing unit that binarizes an image with a predetermined binarization threshold to extract flame regions composed of one or more closed regions; a convex hull processing unit that generates a convex hull flame region, which is the smallest convex polygon that encompasses all the contour points of the flame region; and a burnout position estimation processing unit that estimates the downstream position as the burnout position when a virtual line along the furnace width direction is scanned from below to above the convex hull flame region, and the ratio of the number of pixels where the virtual line and the convex hull flame region overlap to the number of pixels of the virtual line is a predetermined ratio.

[0086] It should be noted that the embodiments described above are merely examples of the present invention, and the specific configuration of each part can be appropriately modified and designed within the scope of achieving the effects of the present invention. [Explanation of Symbols]

[0087] 1: Garbage 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: Conveyance Control Unit 13: Air supply control unit 14: Processing Unit 15: Burnout position estimation part 15A: Flame region extraction processing unit 15B: Burnout position estimation processing unit 15C: Area Calculation Processing Unit 15D: Fuel cut-off position adjustment processing unit 16:Property determination section 16A: Flame region extraction processing unit 16B: Waste depletion estimation processing unit 16C: Area Calculation Processing Unit 16D: Block-like object detection processing unit 17: Steam volume control unit 18: Control Command Generation Unit A: Platform B: Garbage pit C: Crane mechanism D: Garbage input hopper E: Furnace room F: Waste heat boiler G: Economizer FA: Flame Domain VL: Virtual Line

Claims

1. A method for estimating the burnout position of waste being incinerated on the upper surface of a waste incinerator, which estimates the burnout position of the waste being incinerated on the upper surface of the 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 that extracts flame regions composed of one or more closed regions by binarizing the aforementioned image with a predetermined binarization threshold, A burn-out position estimation process estimates the burn-out position as the position at which the ratio of the number of pixels where the virtual line and the flame region overlap to the number of pixels of the virtual line is a predetermined ratio when a virtual line along the furnace width direction is scanned from below to above the flame region. Area calculation process to calculate the area of ​​the convex hull flame region obtained by performing convex hull processing on the area of ​​the flame region and the contour of the flame region, A combustion cutoff position adjustment process that adjusts the predetermined ratio based on the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region, A method for estimating the burnout position of a waste incinerator.

2. The method for estimating the burn-off position of a waste incinerator according to claim 1, wherein the burn-off position adjustment process is a process that adjusts the relative value to decrease as the relative value increases when the relative value is greater than a predetermined threshold.

3. The method for estimating the burnout position of a waste incinerator according to claim 1 or 2, wherein the relative value is the difference or ratio of the area of ​​the convex hull flame region to the area of ​​the flame region.

4. A method for estimating the burnout position of waste being incinerated on the upper surface of a waste incinerator, which estimates the burnout position of the waste being incinerated on the upper surface of the 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 that extracts flame regions composed of one or more closed regions by binarizing the aforementioned image with a predetermined binarization threshold, A convex hull process that generates a convex hull flame region which is the smallest convex polygon that encompasses all the contour points of the flame region, A burn-out position estimation process estimates the burn-out position as the position at which the ratio of the number of pixels where the virtual line and the convex flame region overlap to the number of pixels of the virtual line is a predetermined ratio when a virtual line along the furnace width direction is scanned from below to above the convex flame region. A method for estimating the burnout position of a waste incinerator.

5. A waste incinerator combustion cutoff position estimation device that estimates the combustion cutoff position of waste being incinerated on the upper surface of the stoker mechanism based on an image taken of the combustion state from the downstream side of the stoker mechanism using an imaging device, A flame region extraction processing unit that binarizes the aforementioned image with a predetermined binarization threshold and extracts the flame region, A combustion cutoff position estimation processing unit calculates the downstream position as the combustion cutoff position when a virtual straight line along the furnace width direction is scanned from below to above the flame region, and 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 is a predetermined ratio. An area calculation processing unit that calculates the area of ​​the convex hull flame region obtained by performing convex hull processing on the area of ​​the flame region and the contour of the flame region, A combustion cutoff position adjustment processing unit adjusts the predetermined ratio based on the relative value of the area of ​​the convex hull flame region to the area of ​​the flame region, A waste incinerator combustion cutoff position estimation device equipped with the following:

6. The combustion cutoff position estimation device for a waste incinerator according to claim 5, wherein the combustion cutoff position adjustment processing unit adjusts the predetermined ratio to decrease as the relative value increases when the relative value is greater than a predetermined threshold.

7. The burnout position estimation device for a waste incinerator according to claim 5 or 6, wherein the relative value is the difference or ratio of the area of ​​the convex hull flame region to the area of ​​the flame region.

8. A waste incinerator combustion cutoff position estimation device that estimates the combustion cutoff position of waste being incinerated on the upper surface of the stoker mechanism based on an image taken of the combustion state from the downstream side of the stoker mechanism using an imaging device, A flame region extraction processing unit that binarizes the aforementioned image with a predetermined binarization threshold and extracts flame regions consisting of one or more closed regions, A convex hull processing unit that generates a convex hull flame region which is the smallest convex polygon that encompasses all the contour points of the flame region, A combustion cut-off position estimation processing unit estimates the downstream position as the combustion cut-off position when a virtual straight line along the furnace width direction is scanned from below to above the convex flame region, and the ratio of the number of pixels where the virtual straight line and the convex flame region overlap to the number of pixels of the virtual straight line is a predetermined ratio. A waste incinerator combustion cutoff position estimation device equipped with the following:

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