JPH11248126A - Burning position and burn up position detecting system for waste incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance detection accuracy of burning position and burn up position in a waste incinerator. SOLUTION: Image in a furnace is binarized to produce a binarized image. Continuous region of the binarized image is then detected and subjected to filtering with first and second threshold value dependent on the burning position and burn up position. Based on a resulting image, a project histogram is obtained and then the burning position and burn up position are determined from the break of projection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a combustion position and a burn-out position in a refuse incinerator,
The present invention relates to a detection method for detecting a combustion position and a burn-off point position in a furnace using a furnace image obtained by imaging with a television camera.

[0002]

2. Description of the Related Art Generally, in a refuse incinerator, various kinds of refuse are supplied into the furnace and burned, so that the combustion state changes with time. That is, in a refuse incinerator, refuse is supplied from a hopper into the furnace by a feeder. A stoker is provided at the bottom of the combustion chamber, and refuse to be burned is placed on the stoker and moved in the combustion chamber from the entrance side of the refuse to the exit direction. This stalker is typically divided into zones. The refuse supplied to the refuse incinerator is transported by the movement of the stoker in each zone, and receives radiant heat during that time to be dried, heated, and ignited.

[0003] Generally, the operation of the feeder is repeatedly performed at a preset cycle, but the amount of waste supplied to the furnace in each cycle varies considerably depending on the quality of waste and the accumulation state of the waste in the furnace. If the supply of refuse becomes excessive, the refuse supplied by the feeder operation transfers only the surface layer of the refuse accumulated in the furnace and disturbs the drying, heating, ignition, and combustion processes performed by the stoker. And make combustion unstable. In addition, when the supply is too small, garbage is withered, and the combustion is rapidly deteriorated.

Conventionally, such combustion control in a refuse incinerator has been performed by an automatic combustion control device. The automatic combustion control device operates the boiler installed for the utilization of residual heat, such as the amount of generated steam, the temperature in the furnace, the oxygen concentration of the combustion exhaust gas, and the like, and the image information of the flame in the furnace, that is, Using the information on the burn-off point position, the forced air flow as the primary combustion air, and the information on the secondary combustion air flow, etc., the temporal change in the combustion state is captured, and the amount of refuse supplied,
Combustion was stabilized by manipulating the amount of waste transferred, the flow rate and temperature of the forced air and the distribution ratio to the zone, and the flow rate and temperature of the secondary combustion air.

[0005]

Among them, the information on the combustion position and the burn-off point position is important as an index of the in-furnace state in order to improve the control performance in the automatic combustion control device.
These indices can be calculated by processing an image of a television camera monitoring the inside of the furnace with an image processing device.

This type of image processing is disclosed in, for example,
5125 etc., and its outline will be described.

(1) The entire in-furnace image is binarized using an appropriate binarization threshold. (2) Create a projection histogram projected from the binarized image onto an axis in the direction of dust movement (usually the vertical direction of the image). (3) A projection break is determined from the projection histogram obtained in the above (2), and a combustion position and a burn-off point position are calculated therefrom. Calculate by such a procedure.

FIG. 3 schematically shows an in-furnace image used for such image processing. In FIG. 3, the flame area is bright and can be distinguished from other areas.
However, actually, there is a relatively large unburned combustion region as shown in FIG. 4, or a small unburned combustion region exists as shown in FIG. In this case, in the above method, the combustion position that should be detected on line A in FIG. 4 is erroneously detected on line B in FIG. 4 or the burn-off point that should be detected on line C in FIG. Line D is erroneously detected.

Accordingly, an object of the present invention is to improve the detection accuracy of a combustion position and a burn-off point position, and as a result, to improve the combustion control performance.

[0010]

According to the present invention, there are provided a plurality of zones provided at the bottom of a combustion chamber for mounting waste to be burned and moving the combustion chamber from the entrance side to the exit side of the waste. In a refuse incinerator comprising a stoker and a television camera for imaging the combustion chamber, and an image processing device for processing the obtained in-furnace image based on an image processing program, the image processing device is predetermined. A first step of binarizing the in-furnace image using the binarization threshold
And a second step of extracting a continuous region in the binarized image, a third step of calculating the area of the extracted continuous region, and detecting the combustion position, A fourth step of extracting only a continuous area in which the area of the continuous area is larger than a preset first threshold, a fifth step of projecting the extracted image on an axis in a moving direction of the refuse, and projection. A projection histogram is created for the selected image to determine a break in the projection, and the position is calculated as a combustion position.
And a method for detecting a combustion position in a refuse incinerator.

In order to detect the burn-off point position,
Following the third step, a seventh step of extracting only a continuous area in which the area of the continuous area is smaller than the first threshold value and larger than a second threshold value; Processing including an eighth step of projecting on the axis in the moving direction, and a ninth step of creating a projection histogram for the projected image, determining a break in the projection, and calculating the position as a burn-off point position Is executed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a configuration of a horizontal stoker type incinerator to which the present invention is applied and an instrumentation system thereof. The refuse 11 to be incinerated is supplied to a hopper 12, and is supplied into a combustion chamber 14 of an incinerator by a periodic on / off operation of a feeder 13 provided at the bottom of the hopper 12. At the bottom of the combustion chamber 14, a stoker 16 for placing the waste 11 supplied into the combustion chamber 14 and moving the waste toward an outlet 15 of the combustion chamber 14, that is, an outlet of the incineration ash is provided. Stalker 16
Is divided into four zones 16-1 to 16-4, and the speed of the stoker 16, that is, the transfer speed of the refuse, can be controlled for each zone. Zone 16-
In the lower areas of Nos. 1 to 16-4, respectively, hoppers 17-1 to 17-1
17-4 are sectioned.

Below the stoker 16, there is provided a duct 18 for supplying forced air, that is, primary combustion air. This duct 18 is provided with each hopper 17-1 to 17
-4 below the four openings. Each of the four openings has a damper 19-1 for controlling the amount of forced air supplied to each of the zones 16-1 to 16-4.
To 19-4. In addition, hoppers 17-1 to 17-1
17-4, respectively, pressure gauges 20-1 to 20-4,
Flow meters 21-1 to 21-4 are arranged. Duct 1
At the entrance side of 8, a flow meter 22 is arranged. In the lower part of the stoker 16, thermometers 23-1 to 23-23 are provided for each zone.
-4 are arranged.

On the other hand, a pressure gauge 25 is provided in the combustion chamber 14 to measure the pressure in the furnace. The combustion chamber 14 is also provided with a secondary combustion air supply port 26, and the secondary combustion air is sent into the combustion chamber 14. Further, an in-furnace camera 27 is provided on the inner wall near the outlet 15 in the combustion chamber 14 for capturing an image of the accumulation state and the combustion state of the dust in the combustion chamber 14. An exhaust gas outlet 28 is provided at the ceiling of the combustion chamber 14. An oxygen concentration meter 29 is provided at the outlet 28.
Is provided. A flow meter 30 is provided at the secondary combustion air supply port 26.

An image obtained from the in-furnace camera 27 is used for detecting a burn-off point position and a combustion position by an image processing device. Also, at the outlet side of the combustion chamber 14,
A boiler will be installed to use the residual heat.

An automatic combustion control device (not shown) measures the measured values from the various measuring instruments described above, the burn-off point position, the combustion position, and the like.
Further, the combustion state is optimized by controlling the operation cycle and on / off of the feeder 13, the opening degree of each of the dampers 19-1 to 19-4, the amount of secondary combustion air, and the like in response to the amount of steam generated by the boiler. Such control is performed. In particular, the dampers 19-1 to 19-4
Is controlled so that the distribution of the amount of pushed air to each of the zones 16-1 to 16-4 is optimized. Since such control is not the gist of the present invention, a detailed description is omitted here.

Next, a method of detecting the combustion position and the burn-off point position, which is a feature of the present embodiment, will be described with reference to FIG. This embodiment has the same configuration as the method described in the related art in the sense that the in-furnace image is processed by the image processing device to detect the combustion position and the burn-off point position, but the image processing algorithm is as follows. This solves the problem of the conventional method.

First, the IM1 is transmitted by the TV camera 27.
Is obtained in the furnace. In step S1, the entire image is binarized with respect to the in-furnace image using a predetermined threshold for binarization based on the luminance value of each pixel. This means that, for example, in the in-furnace image, pixels having a brightness equal to or higher than the threshold are displayed in a black manner, and pixels having a brightness lower than the threshold are displayed in a white manner.

In step S2, a continuous area is extracted from the binarized image. In order to extract such a continuous area, a generally known image processing algorithm can be used. As a result, from the in-furnace image IM1,
An extracted image indicated by IM2 is obtained. This extracted image IM2
Include a normal combustion area AR1 and an unburned combustion area AR2.
And are included. In step S3, the extracted image IM2
, The area of the continuous area, that is, the area of the normal combustion area AR1 and the area of the unburned combustion area AR2 are calculated. Thereafter, the image processing is performed in steps S4 to S6 for detecting the combustion position.
And steps S7 to S9 for detecting the burn-off point position. Steps S4 to S6 and steps S7 to S9 are performed in parallel.

In step S4, only those whose continuous area is larger than a first threshold value are filtered to detect the combustion position. The first threshold value is set so that only a continuous area larger than a certain level can be extracted. Here, the binarized image IM3 of the normal combustion area AR1 is extracted. In step S5, the extracted binarized image IM3 of the normal combustion area AR1 is projected on an axis in the direction of garbage transfer (vertical axis direction) to create a projection histogram as indicated by H1. The projection histogram is represented by measuring the number of black pixels for each scanning line, and projecting the measured value in the vertical axis direction. In step S6, a break in the projection of the projected projection histogram is determined,
The position of the cut is calculated as the combustion position.

On the other hand, in step S7, only those where the area of the continuous area is larger than a second threshold value set in advance are filtered to detect the burn-off point position. The second threshold is used to remove fine noise, and is set to be sufficiently smaller than the first threshold so that a small continuous area can be extracted. As a result, here, the binarized image IM4 including the binarized image of the normal combustion region AR1 and the binarized image of the unburned combustion region AR2.
Is extracted. In step S7, the binarized image IM4 is projected on the axis in the direction of the transfer of the refuse, and a projection histogram as indicated by H2 is created. In step S9, a break in the projection of the projected projection histogram is determined, and the position of the break is calculated as a burn-off point.

Even in the furnace images as shown in FIGS. 4 and 5 where there is a possibility of erroneous determination in the conventional method, the area of the flame which is the center of the combustion and the area of the unburned combustion are actually clear. There is a difference. Therefore, by using the image processing algorithm as described above, the first and the second for discriminating the difference in the area are performed.
Threshold can be determined during commissioning of the refuse incinerator,
This makes it possible to distinguish between the flame that is the center of combustion and the flame of unburned combustion. Note that the second threshold value used for filtering for detecting the burn-off point position is set for the purpose of eliminating noise in image processing, and a relatively small value is empirically set.

According to the above-mentioned method, the combustion position is detected on the line A and the burn-off point position is detected on the line B even in the furnace images as shown in FIGS. Erroneous determination can be eliminated.

Although the above embodiment is directed to a horizontal stoker type incinerator, it can be applied to a stoker type incinerator of other shapes.

[0025]

The detection method of the combustion position and the burn-off point position according to the present invention improves the reliability of the detection. This leads to a further improvement in the stability of the control by the automatic combustion control device using the detection result, stabilizes the generated steam flow rate of the boiler attached to the refuse incinerator, and further reduces CO2.
The production of toxic substances such as and dioxins can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a refuse incinerator to which the present invention is applied.

FIG. 2 is a flowchart for explaining a flow of image processing by an image processing algorithm applied in the present invention.

FIG. 3 is a diagram showing an example of an in-furnace image.

FIG. 4 is a diagram showing an example of an in-furnace image when there is unburned combustion.

FIG. 5 is a diagram showing another example of an in-furnace image when there is unburned combustion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Dust 12 Hopper 13 Feeder 14 Combustion chamber 15 Exit 16 Stalker 16-1 to 16-4 Zone 17-1 to 17-4 Hopper 18 Duct 19-1 to 19-4 Damper 20-1 to 20-4, 25 Pressure gauge 21-1 to 21-4, 22, 30 Flow meter 26 Secondary combustion air supply port 27 In-furnace camera 28 Combustion exhaust gas discharge port 29 Oxygen concentration meter

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 23, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (2)

[Claims] 1. A stoker comprising a plurality of zones provided at a bottom portion of a combustion chamber for placing refuse to be burned and moving the refuse from the entrance side to the exit side of the refuse in the combustion chamber to image the combustion chamber. In a refuse incinerator equipped with a television camera and an image processing device that processes the obtained in-furnace image based on an image processing program, the image processing device uses a predetermined threshold for binarization, A first step of binarizing the in-furnace image, a second step of extracting a continuous region from the binarized image, and a third step of calculating the area of the extracted continuous region A fourth step of extracting only a continuous area in which the area of the continuous area is larger than a preset first threshold value for detecting a combustion position; and extracting an image of the extracted result as an axis in a moving direction of the refuse. To Performing a process including a fifth step of projecting, and a sixth step of creating a projection histogram for the projected image to determine a break in the projection and calculating the position as a combustion position. A method for detecting the combustion position in a garbage incinerator. 2. The method for detecting a combustion position according to claim 1, wherein the detection is performed subsequent to the third step for detecting a burn-off point position, and the area of the continuous region is determined by the first area.
A seventh step of extracting only a continuous area that is smaller than the second threshold and is larger than a second threshold, an eighth step of projecting the extracted image on an axis in the direction of movement of the garbage, A ninth step of generating a projection histogram to determine a break in the projection and calculating the position as a burn-out point position. Position detection method.