JPH0262776B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for detecting the boundary between the flame part and the ash part, that is, the burnout level, in a garbage incinerator or the like. Background Art In the garbage incinerator related to the present invention, garbage is incinerated as follows. The garbage thrown in from the garbage inlet is guided onto the grate in the combustion chamber, first dried by hot air supplied from below, and then burned as it moves through the combustion chamber, turning into ash. In such garbage incineration processing, the combustion state constantly changes depending on the substances contained in the garbage and the condition of the garbage, so it is necessary to control the combustion in order to completely burn the garbage. For this reason, the combustion chamber of a waste incinerator is divided into several areas, such as a drying area, a combustion area, and an after-combustion area, from the upstream side where waste moves, and the amount and temperature of air supplied to each area is adjusted. Combustion control is then performed. Conventionally, the combustion state of a waste incinerator for controlling combustion has been determined by directly observing the inside of the incinerator or by visually observing an image obtained by imaging the inside of the incinerator with a television camera. However, with such prior art, it is difficult to objectively control the combustion state of the incinerator, and in recent years, combustion control has been performed based on image information obtained by imaging the inside of the incinerator with a television camera. It is. Problems to be Solved by the Invention In combustion control based on image information as described above, it is extremely important to detect the boundary between the flame part and the ash part of the material to be incinerated in the combustion chamber, the so-called burnout level. This burnout level is detected by converting the combustion state inside the incinerator into a signal corresponding to brightness using image information obtained from a television camera, and integrating this signal for each horizontal scanning line to determine the average brightness. This is done by determining the brightness distribution for one screen based on the average brightness corresponding to the position of the combustion chamber, and comparing the brightness value at each position with a reference value. In such conventional burnout level detection methods, the reference value is set to a constant, or is determined by multiplying the maximum value of the brightness distribution by a constant K ₀ , or is determined by a constant distribution of the maximum and minimum brightness differences of the brightness distribution. It is also calculated by multiplying the ratio K by ₁ . By the way, the intensity of incineration of garbage, that is, the flame brightness indicating the temperature during combustion, varies greatly depending on its composition. The brightness distribution is not only the flame distribution.
It also changes depending on the brightness of the flame. Therefore, when setting the reference value of the burnout level based on the luminance distribution, the burnout level may not be detected with high accuracy unless the reference value is corrected according to the intensity of combustion. FIG. 9 is a graph showing the brightness distribution, which is the relationship between the position in the combustion chamber in the moving direction of dust indicated by the horizontal scanning line number on the image display screen and the average brightness with respect to that position. For example, if the reference value KM is set as shown in FIG. 9 1 based on the distribution ratio K ₁ corresponding to low-temperature combustion in consideration of the combustion control of the incinerator, the reference value KM is set as shown in FIG. 9 2. In the state of high-temperature combustion, a burnout level L 1 is detected in the direction of the dry region upstream from the burnout level L (hereinafter referred to as the actual burnout level) visually observed in an actual furnace, which is _one of the evaluation methods. This causes a detection error _E1 .
In combustion control using the reference value KM ₁ in Figure 9 2,
Problems arise such as the discharge of unburned garbage.
Conversely, if the reference value KM is set based on the distribution ratio K ₁ for high-temperature combustion as shown in Figure 9-3, the reference value KM ₂ becomes smaller in the low-temperature combustion state as shown in Figure 9-4. Therefore, even small local combustion that should be ignored as combustion in the furnace is detected, and a burnout level L ₂ is detected, resulting in a detection error E ₂ . Alternatively, if the constant _K0 is used as the reference value KM as shown in FIG. 9, the brightness distribution may differ from the actual one due to dirt on the camera lens, deterioration of the image pickup tube, etc., as shown in FIG. The disadvantage is that the reference value KM ₃ needs to be optimally readjusted each time it deviates from the distribution. The purpose of the present invention is to solve the above-mentioned technical problems,
To provide a method for easily and reliably detecting the burnt-out level in an incinerator. Means for Solving the Problems The present invention images the combustion section in the incinerator with a color television camera installed so that the scanning line of the screen is perpendicular to the direction of movement of the materials to be incinerated in the incinerator. The signal of the red component contained in the color image signal obtained from the color television camera is converted into a multilevel signal corresponding to the intensity of red color, this is integrated for each horizontal scanning line, and this integrated value is used as a reference value. This is a burnout level detection method characterized by detecting a burnout level by comparing with the burnout level. Effect According to the present invention, a color television camera images the combustion part in the incinerator, separates red component information from the color image information, and uses this red component information to determine the burnout level of the incinerator. Since it detects
The burnout level can be detected reliably and easily. Embodiment FIG. 1 is a system diagram of a waste incinerator S implemented in connection with the present invention. Garbage 2 thrown in from a garbage inlet 1 provided in the garbage incinerator S freely descends and enters the combustion chamber 4 through the combustion chamber inlet 3. The garbage 2 that has moved onto the drying stage grate 5 is dried by hot air supplied from below the drying stage grate 5, and then burned in the combustion upper stage grate 6 and the lower combustion stage grate 7 located downstream thereof. I am forced to do it. Garbage 2 left unburned in the lower combustion grate 7
is further burned in the post-combustion stage grate 8 to produce residual ash 9
The ash is periodically dropped into the ash feeding means 10. The high-temperature gas generated by combustion undergoes heat exchange by the boiler BL and is then discharged to the outside. boiler
Steam from BL is supplied to a turbine etc. via pipe PL. The detector DT interposed in the conduit PL is
It is provided to detect the flow rate of the steam. Facing the window 14 installed in the wall of the incinerator S,
A color industrial television camera 15 is installed to image the inside of the combustion chamber 4. TV camera 15
has an optical central axis 12 near the boundary 11 between the upper combustion grate 6 and the lower combustion grate 7, and images the entire flame 13 in the combustion chamber 4. In the present invention, the inside of the combustion chamber 4 is imaged by the camera 15, the color image signal S1 is processed by the image signal processing device 16, and the burnt-out level in the garbage incinerator S is detected. The display processing device M and the monitor television 17 are provided to display an image of the combustion state within the combustion chamber 4. The display processing device M has a function of reproducing the signal S1 from the television camera 15 and the signal S4 obtained from the image signal processing device 16 on the monitor television 17 together. The signal S8 output from the image signal processing device 16 is given to the combustion control mechanism of the incinerator. First, the principle of detecting the burnout level in the garbage incinerator S according to the present invention will be explained. Generally, objects begin to emit light when the temperature reaches 700°C or higher, and it is known that the relationship shown in Table 1 holds between the color of the flame and the temperature.

[Table] In other words, it is known that as the temperature increases, the color of the flame changes from red to reddish-yellow and then to a bluish, dazzling white. This is because as the temperature rises, the component of blue wavelength, which is a short wavelength, contained in light increases relatively. When garbage is being burned in a garbage incinerator, the intensity of the red component contained in the flame within the incinerator does not change significantly from high-temperature combustion to low-temperature combustion. On the other hand, the intensity of the green or blue component becomes much stronger in the case of high-temperature combustion than in the case of low-temperature combustion. If we calculate the flame distribution using the brightness, which is the sum of the intensity of the red, green, and blue components, we can calculate not only the flame distribution but also the flame intensity, which indicates the combustion temperature. become. Therefore, according to the present invention, when determining the flame distribution in the incinerator in order to detect the burnout level, which is the boundary between flame and ash, the flame distribution is determined using only the intensity of the red component of the flame. Once determined, the flame distribution from high-temperature combustion to low-temperature combustion can be determined with high accuracy. Based on the above, the present invention will be implemented as follows. The garbage incinerator is imaged with a color television camera, and the color image signal is divided into three colors: red, green, and blue.
Separates into primary color signals, converts these signals into multi-value signals corresponding to their respective strengths, integrates each multi-value signal for each horizontal scanning line, and compares this integrated value with a reference value. to detect the burnout level. FIG. 2 is a graph showing the distribution of integrated values of the multilevel signal obtained by the inventor's experiment using a garbage incinerator having the configuration shown in FIG. . In this experiment, regular household garbage was incinerated, and the incineration conditions were changed.
Steam was generated in a boiler and the flow rate of the steam was detected. Figure 2 1 shows that the calorific value of waste is approximately 1000 kcal/Kg.
Figure 2 shows low-temperature combustion with a steam flow rate of 16t/H, and Fig. 2 shows that the waste calorific value is approximately 1500kcal/Kg and the steam flow rate is
It shows normal combustion of 19t/H, and Fig. 2 and 3 show high temperature combustion with waste calorific value of about 2200kcal/Kg and steam flow rate of 24t/H. In a waste incinerator, waste moves from the drying stage grate of the combustion chamber to the post-combustion stage grate. The inside of the combustion chamber was imaged so that the horizontal scanning direction of the image display screen was perpendicular to the direction of movement of the debris. Therefore, the scan line number on the image display screen indicates the position within the combustion chamber in the direction of movement of the debris. Furthermore, the integrated value of the multivalued signal as described above was determined by setting the intensity of each color component to 16 gradations and setting the number of pixels included in one horizontal scanning line to 128. The integrated value, which is the vertical axis in FIG. 2, is the value obtained by integrating the red component level WR, green component level WG, and blue component level WB for each horizontal scanning line. The horizontal axis in FIG. 2 indicates the scan line number corresponding to the position within the combustion chamber in the direction of movement of the debris. Line l1 shows the red component,
Line l2 shows the distribution of the sum of the red component and green component, and line l3 shows the distribution of luminance that is the sum of the red component, green component, and blue component. Further, reference mark L indicates the actual burnout level and the burnout level detected according to the present invention with respect to the reference value KM,
Reference marks La to Lc indicate detected burnout levels with respect to reference values KMa to KMc in the prior art described with reference to FIG. 9, and reference marks Ea to Ec indicate detection errors thereof. Even if the actual burnout level L is almost the same, the distribution of the integrated values becomes as shown in FIG. 2 1 during low-temperature combustion, and as shown in FIG. 2 2 during normal combustion, During high-temperature combustion, the combustion occurs as shown in FIG. 2. That is, the distribution of the red component in the color image signal is almost the same regardless of the combustion state, as shown by diagonal lines in the figure. On the other hand, in the distribution of green and blue components, the sum of the red, green, and blue components, that is, the proportion of the integrated component that is the brightness, increases as the temperature changes from low-temperature combustion to high-temperature combustion. It changes over time. Therefore, in the conventional technique disclosed in Japanese Patent Application Laid-Open No. 59-107112, in which burnout levels La to Lc are detected by comparing the luminance integrated value and a reference value based on the luminance distribution, the second As shown in Figures 1 to 2 and 3, the actual burnout level L in each combustion state
Detection errors Ea to Ec occur. In order to reduce this detection error Ea~Ec, the reference value KMa~
It is necessary to modify KMc according to the intensity of combustion. On the other hand, according to the present invention, the red component level is determined based on the distribution of the red component indicated by line l1.
Burnout level L by comparing WR and standard value KM
As shown in FIGS. 2-1 to 2-3, the variation in the distribution of the red component is extremely small compared to the distribution of the green and blue components. Therefore, the burnout level L, which is the boundary between the flame part and the ash part, can be detected with high accuracy over a wide range from low-temperature combustion to high-temperature combustion. According to the inventor's experiments, a localized high-temperature combustion zone H may also occur in the combustion chamber 4, as shown in FIG. In this case as well, there is no major difference in the distribution of the red component shown by line l1 between the high-temperature combustion part H and other parts, so if the burnout level L is detected based on the distribution of the red component according to the present invention, Detection can be performed with high accuracy regardless of the presence or absence of the high-temperature combustion section H. In the conventional method of detecting the burnout level Ld using the luminance distribution, the green component or blue component increases greatly in the local high-temperature combustion area H, so the detection error Ed with respect to the actual burnout level L increases. arise. Therefore, in detecting the burnout level Ld using the conventional brightness distribution, it is necessary to modify the reference value KMd depending on the local combustion intensity.
The present invention solves this problem as described above. FIG. 4 shows the image signal processing device 1 required to detect the burnt-out level in the garbage incinerator S.
FIG. 6 is a block diagram showing the configuration of one embodiment of FIG. The above processing operation will be specifically explained with reference to a block diagram showing the configuration of the image signal processing device 19 shown in FIG. The image signal S1 from the television camera 15 is input to a color separation circuit that separates signals of the three primary colors of red, green, and blue, and to a clock synchronization signal generation circuit 96. Based on the image signal S1, the clock synchronization signal generation circuit 96 generates a clock signal C0, a vertical synchronization signal C1, and a horizontal synchronization signal C2 for sampling the color image signal S1. The red wavelength component signal S9 separated by the color separation circuit 95 is input to the multi-value conversion circuit 97. The multilevel conversion circuit 97 converts the red wavelength component signal S9 from analog to digital in synchronization with the clock signal C0.
The multivalued red wavelength component signal S12 is output to the image memory circuit 98. FIG. 5 shows signal waveforms associated with the image processing device 16. FIG. 51 shows the signal waveform of the color image signal S1. The multi-value converting circuit 97 outputs the signal S12 and at the same time outputs an analog/digital (A/D) output timing signal S10 as shown in FIG. 2. A/D output timing signal S10 is input to image memory control circuit 99. When the image memory write request signal S13 as shown in FIG. 5 is set by the arithmetic processing circuit 100, the image memory control circuit 99 writes the image as shown in FIG. A memory write clock signal S11 is output. On the other hand, the signal S input to the image memory circuit 98
12 is an image memory write clock signal S11
It is written into the image memory in the image memory circuit 98 in synchronization with . When one screen worth of images is written into the image memory, the image memory circuit 98 outputs an image input end signal S14 as shown in FIG. 5 to the image memory control circuit 99. The image memory control circuit 99 synchronizes with the input signal S14.
outputs an image memory set signal S15 as shown in FIG. 5 to the arithmetic processing circuit 100. The arithmetic processing circuit 10 synchronizes with the signal S15.
0 reads the multivalued red wavelength component image data S16 from the image memory circuit 98 after resetting the image memory write request signal S13. FIG. 6 is a diagram showing a scanning state in a monitor color television, and FIG. 7 is a diagram showing a state in which data is stored in an image memory. As shown in FIG. 6, when the number of samples in one scanning line of the monitor television is n, the m-th sample point of scanning line 1 is ln+m of the image memory shown in FIG.
It is written in the second. The image data S16 written in the image memory in this manner is sequentially read by the arithmetic processing circuit 100 and subjected to arithmetic processing. At this time, the arithmetic processing circuit 100 makes the image data S16 correspond to the monitor television screen shown in FIG. 6, and arranges the multivalued red component image data as shown in FIG. , processing is performed as a digital image of the multivalued red wavelength component. The arithmetic processing circuit 100 horizontally integrates the image data of the red component arranged as shown in FIG.
Calculate the integrated value of the red component for each horizontal scanning line. Next, the maximum integrated value L _nax is determined from the integrated value LL of the red component for each horizontal scanning line in one screen. A reference value LT is obtained by multiplying this maximum value L _nax by a constant ratio α as shown in the following first equation. LT=α・L _nax ...(1) Compare the integrated value LL and the reference value LT for each scanning line, and if LL≧LT, it is a combustion part (flame part), and if LL<LT, it is a ash part. conduct. Next, examine the characteristics of each scanning line from the top of the screen, that is, in order of decreasing scanning line number, and after the scanning line corresponding to the flame area exists N ₁ or more consecutive times, the scanning line corresponding to the gray area exists consecutively. hand
N If it occurs more than _once , the scan line number of the boundary point
Make Li correspond to burnout level. In addition, on one screen, multiple burnout levels Li ₁ , Li ₂ ,...
When Lin is detected, the one with the largest scanning line number is set as the final burnout level.
Referring again to FIG. 4, after the position detection as described above is performed, the arithmetic processing circuit 100 outputs the burnout level information signal S17 and the burnout level information signal output timing signal S18 to the latch circuit 1.
01 respectively. Also, the arithmetic processing circuit 10
0 is the new multivalued red wavelength component signal S
12 into the image memory circuit 98.
An image memory write request signal S13 is set in synchronization with a vertical synchronization signal as shown in FIG. The image memory control circuit 99 resets the image memory set signal S15 at the same time as the image memory write request signal S13 is set, as shown in FIGS. 6 and 6. On the other hand, the latch circuit 101 to which the signal S17 indicating the burnout level and the burnout level signal output timing signal S18 are input holds the burnout level information signal S17 in synchronization with the signal S18, and then the signal S18 is inputted. Until input, level signals S4 and S8 indicating the burnout level are output. As described above, the burnout level signals S4 and S8 in the garbage incinerator 1 are output from the image processing device 16 and input to the display processing device M and the combustion control mechanism of the incinerator, respectively. The reference values in the above embodiments can be changed as appropriate. In the above-described embodiments, the present invention is applied to a waste incinerator, but the present invention can also be applied to detect the final burnout level in a stoker-type coal combustion furnace or the like. Furthermore, in the above-described embodiment, the multilevel signal is integrated for each horizontal scanning line, but in another embodiment of the present invention, the multilevel signal may be integrated for each of a plurality of scanning lines. Effects of the Invention As described above, according to the present invention, the intensity of combustion,
By focusing on the red component signal, which is not affected much by weakness, and integrating it for each horizontal scanning line, it is possible to accurately detect the burnt-out level of the combustion furnace even if the combustion state is constantly changing. In other words, the brightness of the image signal varies greatly depending on the strength of combustion, but the level of the red component signal hardly changes. Therefore, by integrating the level of the red component for each horizontal scanning line, The integrated value corresponds to the spread of the burning area, and can be captured as the burning area, including areas that are burning strongly and areas that are burning weakly. Therefore, there is no need to change constants depending on the combustion state, and the process of determining the burnout level can be easily performed. Furthermore, according to the present invention, the color image signal obtained from the color television camera is fed to the color separation circuit to separate the red component signal, so the burnout level can be detected at low cost using a commercially available color television camera. It can be carried out.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing the configuration of a waste incinerator S implemented in connection with the present invention, and Fig. 2 shows the distribution state of the integrated values of the red component, green component, and blue component according to the inventor's experiment. FIG. 3 is a graph showing the distribution state of integrated values of red component, green component, and blue component when a local high-temperature combustion zone H occurs, and FIG. 4 is an image carried out in connection with the present invention. 5 is a block diagram showing the configuration of the signal processing device 16. FIG. 5 is a diagram showing signal waveforms output in relation to the image processing device 16. FIG. 7 is a diagram for explaining data in the image memory included in the image memory circuit 98, FIG. 8 is a diagram for explaining the correspondence between the image memory included in the image memory circuit 98 and the screen of the monitor television 17, FIG. 9 is a graph showing the distribution of integrated luminance values. 2... Garbage, 4... Combustion chamber, 5... Drying stage grate, 6... Combustion upper stage grate, 7... Combustion lower stage grate, 8... Post combustion stage grate, 15... Television camera, 16... Image signal processing device, S... Garbage incinerator.

Claims (1)

[Claims] 1. The combustion section in the incinerator is imaged by a color television camera installed so that the scanning line of the screen is perpendicular to the moving direction of the materials to be incinerated in the incinerator, and the color image signal obtained from the color television camera is is applied to the color separation circuit to separate the red component signal, convert this red component signal into a multilevel signal corresponding to the intensity of the red color, integrate this for each horizontal scanning line, and calculate this integrated value. A burnout level detection method characterized by detecting a burnout level by comparing it with a reference value.