JPS5960120A - Detecting method of burning-out point - Google Patents

Abstract

PURPOSE:To enable grasping of a reliable combustion condition through detection of a burning-out point, by a method wherein a burning way is decided based on not only the magnitude of brightness but also dispersion thereof. CONSTITUTION:A burning-out point is detected through utilization of the fact that a range under combustion on a furnace floor within a furnace, an ash bed part, and a burning-out point being a boundary therebetween can be sorted based on the average of brightness of a picture photographed by an industrial television camera 10 installed to a window 9 formed in the rear wall on the ash discharge port side of a combustion furnace and on a basis of dispersion of timing brightness and brightness on a plane. Namely, a burning-out point and other combustion conditions are converted into a numerical value by displaying a picture on an ITV monitor 11 and operating the brightness and unevenness of the picture by means of a picture processing arithmetic unit 12. The result is outputted from an output part 13 comprising an alarm, a control device and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for accurately and automatically detecting the burnout point of a hearth-L in a combustion furnace.

The method of observing the combustion state of a garbage incinerator is to take an image of the inside of the incinerator using a commercial television (1'rv), and on one screen -F, the burnout point (of the hearth -V in the incinerator) is recorded. Methods were first proposed in which humans visually observed the position and changes in the boundary between the burning area and the ash layer that burned out and turned into ash, and the brightness of one screen was image-processed using a microcomputer, etc. has been done. However, constant human monitoring of the ITV is quite a difficult task, and the method of judging based on the brightness level is
If there is a bulge in the ash layer in the field of view of the ITV camera, there is a risk of misjudging the burnout point.

This will be explained in detail with reference to the drawings. Fig. 1 shows the combustion situation inside the waste incinerator, and Fig. 2 shows the screen inside the incinerator as shown on the ITV. In Figures 1 and 2, l is the flue of the garbage incinerator, and 2 is the fire bed.

3 is a stoker, 4 is an industrial television that records images inside the furnace, 5 is a moxibustion device, 6 is an arrow indicating the direction of garbage movement, 7 is burning garbage, and 8 is an ash layer after the garbage is completely burned. It is.

As shown in FIG. 2, when the pile of ash begins to block the burnout point Q, the burnout point Q is mistakenly judged to be the top P or P' of the ash layer.

The present invention solves the above-mentioned drawbacks and proposes a method for accurately and reliably automatically detecting the burnout point in a waste incinerator or the like. It is characterized by subdividing the screen showing the combustion status of the subdivided area, calculating the spatial or temporal average brightness and spatial or temporal brightness variation for each subdivided area, and detecting the burnout point from these calculated values. A burnout point detection method is provided.

In the method of the present invention, the combustion zone of the furnace hearth,
The burnout point is determined by using the fact that the ash layer and the burnout point, which is the boundary between these areas, can be divided by the average brightness of the screen photographed by a TV camera and the temporal and planar brightness dispersion (variation). Detect.

The method of the present invention will be explained in detail below with reference to one embodiment.

In Figure 3, 10 is a window 9 installed in the rear wall on the ash υF exit side of a combustion furnace such as a garbage incinerator. is 1.
A TV monitor, 12 an image processing arithmetic unit, 18 an output section thereof, and an output section 13 connected to a controller, an alarm device, etc. Components with the same reference numerals as in FIG. 1 indicate the same components, and therefore their explanation will be omitted.

In such a device, a screen is displayed on an ITV monitor 11, and a two-image processing arithmetic unit 12 calculates the brightness of this screen and its dispersion to quantify combustion conditions such as the burnout point.

This is outputted by an output unit 18 consisting of an alarm, control equipment, etc.

The operation of the image processing arithmetic unit 12, which is a feature of this method, will be explained. The brightness on the screen is sequentially scanned and quantized in the X and Y directions of the screen shown in FIG. Takes of this are collected at regular time intervals to create one time series signal x +
, 7 (obtains 11. Now select a subdivision S on one screen and find the brightness in it X1. + (t) (' + r is the element number in s. [is (1o ~ I o + nΔto) Regarding the sample link time (0 times within).

Spatial average xs (Average brightness of all shadows in s) Temporal = 1' average ” +++ (1 (specific shadow in s)
(temporal average brightness for each position island) and spatial variation S, (variation due to position at each time) and temporal variation ST (temporal variation at each position island). Usually SA, 57 is the difference from the average value of 2
Take the sum of the squares. On the other hand, if we observe how it burns in an actual incinerator, if we take the ``time'' to be sufficiently smaller than the 113 constant of combustion, the result is as follows.

a. Combustion learn...High brightness and relatively stable.

1) Burnout point: The brightness has a boundary between light and dark, and it fluctuates greatly depending on time and position.

C1 gray layer: low brightness and stable in terms of time and position.

Therefore, the phenomenon described in - corresponds to the second order.

a is Xs + X i, i (Q is large + SA, ST is relatively small.

In b, B, ζ wander is large or medium + SA, ST is large.

In C, Otsu, double shoulders are small + SA, ST is small.

That is, + Xs l xi + (tl, SA + 57
The combustion status can be determined by calculating the following for each category. An example of the above-mentioned judgment is shown in FIG.

The method of the present invention detects the burnout point by determining the burnout not only in terms of the magnitude of brightness, but also in conjunction with its dispersion (variation), as described below, compared to the conventional method based only on the magnitude of brightness. It is possible to prevent misjudgments that occur during combustion and accurately grasp the combustion situation.

Note that the method of the present invention is applied to, for example, monitoring and automatic control of combustion in garbage incinerators, combustion in coal stoker furnaces, etc.

[Brief explanation of the drawing]

Figures 1 and 2 show the previously proposed burnout point detection method, of which Figure 1 is an overview diagram and Figure 2 is an ITV
FIG. 8 and FIG. 4 are explanatory diagrams showing the in-furnace screen shown in FIG. 1... flue, 2... grate, 3... stoker, 4.
10...TTV camera, 11...ITV monitor, 1
2... Image processing arithmetic device, 18... Output unit.

Claims (1)

[Claims] A screen showing the combustion situation in the combustion furnace photographed by a television camera is subdivided, and the spatial or temporal average brightness and spatial or temporal brightness variation for each subdivided area are calculated,
A burnout point detection method characterized by detecting a burnout point from these calculated values.