JPH07133927A - Combustion unit controller - Google Patents

Abstract

PURPOSE:To simultaneously obtain information of color image and information for spectral analysis by one camera by using an exposure controller as means for measuring a light emitting luminance in a combustion unit controller in which radical luminance of a flame in a combustion unit is measured and a fuel-air ratio is calculated. CONSTITUTION:An electronic camera 820 corresponding to RGB for collecting a light emitting image of a flame 241 to be formed by a combustion unit 200 having F1 and F2 combustion units 284, 272 is provided, RGB signals to be output from the camera 820 are sent to a calculator 806 through an image input unit 804 in parallel with outputting of the signal to a color monitor, etc. The calculator 806 measures radial luminance of the flame 241 to calculate a fuel-air ratio, and evaluates its burning state. An output signal of the calculator 806 is sent to an image processor 808, which conducts a pseudo color displaying, a binary process for splitting arbitrary intensity as a boundary, an area calculating, a position calculating and edge processing, etc., for a physical amount image to evaluate the burning state and outputs its result to a monitor 810.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustor control device using a camera capable of obtaining both color image data and spectral analysis data with one unit.

[0002]

2. Description of the Related Art Conventionally, when a camera using a CCD or the like is used for spectroscopic analysis, an external filter is provided on the camera to measure only light of a desired wavelength. In addition, a plurality of filters and cameras are used when performing analysis for a plurality of types of wavelengths or when a normal color image is required. Also, with high resolution,
As a means for preventing overexposure, the number of bits has been increased to 12 bits in order to increase the dynamic range of the detection system.

As an example of actually using the camera for spectroscopy as described above, there is, for example, a flame spectroscopic imaging apparatus for a gas turbine combustor described in Japanese Patent Laid-Open No. 3-207912.

[0004]

However, when switching and using a plurality of filters, there is a problem that a mechanism for driving the filters is required and the structure becomes complicated. It is also possible to provide a camera for each filter. However, in this case, it is necessary to perform operations such as determination of photographing positions and angles, focusing, and the like for the number of cameras to be used, and there is a problem that quick measurement cannot be performed. In particular, in the spectroscopic analysis, each camera needs to be focused on the same portion, which is particularly difficult to operate.

Further, there is a problem that the light emission luminance varies depending on the combustion state, the exposure becomes excessive, and the data used for image processing is saturated. In order to avoid this, it is necessary to increase the dynamic range of devices such as a camera and an image processing device, which causes a problem that the cost of the device becomes high and the processing time becomes long.

It is an object of the present invention to provide a combustor control device using a camera capable of obtaining information of a normal color image with one camera and simultaneously obtaining information for spectral analysis.

Further, by using the combustor control device, low NOx
An object of the present invention is to provide a combustor for thermal power generation that realizes combustion.

[0008]

A combustor controller according to the present invention comprises a combustor that forms a flame using air and fuel, and means for measuring the emission brightness of the radicals of the flame in the combustor. And a means for calculating the fuel-air ratio of the air and the fuel introduced into the combustor from the emission brightness, and a means for controlling the fuel and the air introduced into the combustor from the fuel-air ratio. In addition, the means for measuring the emission luminance has an exposure amount control device.

Further, the combustor control device of the present invention is characterized in that it has means for controlling the shutter speed of the camera included in the means for measuring the emission brightness.

Further, the combustor control device of the present invention is characterized in that it has means for controlling an aperture diameter of a camera included in the means for measuring the emission luminance.

On the other hand, the combustor control method of the present invention measures the emission brightness of radicals in the flame in the combustor driving the gas turbine using a detection system, and the measured emission brightness is applied to the combustor. Calculating the ratio of fuel and air introduced, controlling the amount of fuel and air introduced to the combustor from the ratio, before the detection system is saturated, the detection system is It is characterized by controlling the exposure amount, shutter speed and / or aperture diameter of the camera.

Further, according to the present invention, the emission brightness of radicals in the flame in the combustor driving the gas turbine is measured by image processing, and the fuel and air introduced into the combustor are measured from the measured emission brightness. A combustor control method comprising calculating a ratio and controlling the amounts of fuel and air to be introduced into the combustor from the ratio, when the area to be subjected to the image processing exceeds a predetermined value, It is characterized by comprising controlling the exposure amount, shutter speed and / or aperture diameter of the means for drawing out an image.

Further, it is preferable that the thermal power plant is equipped with the combustor control device of the present invention.

The present invention has been made to achieve the object, and in a first aspect thereof, a plurality of light receiving elements are provided on an image pickup surface, and each light receiving element included in the one light receiving unit includes: There is provided a camera having different detection wavelength ranges and a camera which outputs the light detection signals of the respective light receiving elements separately.

It is preferable that the light receiving elements constituting the one light receiving unit are arranged adjacent to each other on the image pickup surface, and the detection wavelength range of the entire light receiving elements constituting the one light receiving unit is visible. It preferably covers the entire area.

Further, in the camera for observing light of a certain specific wavelength, it is preferable that each of the light receiving units includes a light receiving element having high detection sensitivity in the vicinity of the specific wavelength. As the specific wavelength, CH radicals, C
It is preferable that at least one of the emission wavelengths of ₂ radicals and OH radicals is included.

It is preferable to have means for reducing the exposure amount of the camera when the detection signal from the light receiving element exceeds a certain value in any of the measurement areas.

The means for reducing the amount of exposure has a software or hardware image processing device for detecting overexposure, an input / output interface for outputting the detection signal when overexposure is detected, and a camera exposure control circuit. It has a remote control terminal, and is executed by applying a voltage, a pulse width or the like to the remote control terminal.

The exposure of the camera is adjusted by changing the shutter speed, the aperture diameter, the charge time for changing the CCD sensitivity, or the voltage.

Since the calibration curve showing the relationship between the detection signal and the fuel-air ratio differs with the adjustment of the exposure amount, the fuel-air ratio is calculated using the calibration curve corresponding to the change of the exposure amount. And

As a second aspect of the present invention, the camera of the first aspect and the shutter speed when the input signal to the image processing device exceeds a certain value are set to be high, and when the input signal to the image processing apparatus is set to be less than the certain value, the shutter speed is set to a certain value. It is characterized by having software or hardware for generating a signal to slow down.

There is provided a system comprising an exposure amount control circuit for generating a signal according to a camera control mode at a camera control terminal when the shutter speed changing signal is generated.

As a third aspect of the present invention, when the exposure condition is changed according to the emission intensity, a calibration curve corresponding to the exposure condition is provided, and the fuel-air ratio is calculated using the calibration curve corresponding to the exposure condition. It is characterized by

There is provided a spectroscopic system comprising the camera of the first aspect and a synthesizing means for synthesizing the R, G and B signals respectively by using the output signal of the camera.

As a fourth aspect of the present invention, in a camera having a plurality of light receiving elements on the image pickup surface and separately outputting the light detection signals of the respective light receiving elements, the CH radical of CH radicals is detected in the detection wavelength range. The first light receiving element that includes the emission wavelengths but does not include the emission wavelengths of the C ₂ radicals and the OH radicals, and the detection wavelength range thereof includes the emission wavelengths of the C ₂ radicals, but the emission wavelengths of the CH radicals and the OH radicals are There is provided a camera having two second light receiving elements not included, and the camera having a control terminal.

The fuel-air ratio is calculated from a calibration curve showing the relationship between the emission wavelength of CH and the air ratio and a calibration curve showing the relationship between the emission wavelength of C ₂ and the air ratio.

Further, by taking the ratio of the CH and C ₂ signals, the relationship between the emission intensity and the fuel-air ratio can be obtained more accurately.

As a fifth aspect of the present invention, it is provided with the camera of the first aspect and a synthesizing means for synthesizing the R, G and B signals respectively by using the output signal of the proper exposure of the camera. A spectroscopic system is provided.

In a sixth aspect of the present invention, the so-called three primary colors of light near the wavelength of CH, B and G of the three primary colors near to the wavelength of C ₂ , and the detection sensitivity in the vicinity of the three primary colors R are also present. By using a camera that has two light receiving elements and outputs the detection signals of each light receiving element separately, a plurality of adjacent light receiving elements are set as one light receiving unit. A light receiving element for a color image having a sensitivity curve matching the sensitivity curve of, and a light receiving element for spectroscopic analysis in which the detection wavelength ranges of the respective light receiving elements do not overlap with each other,
A camera is provided which is characterized by including.

As a seventh aspect of the present invention, in a combustion evaluation apparatus for evaluating the combustion state of flame, a camera for photographing the flame and exposure control for performing exposure adjustment using the output signal of the camera. And a display unit for displaying a flame image by using an output signal of the camera, and an arithmetic unit for calculating a physical quantity for evaluating the flammability of the flame by using the output signal of the camera. A combustion evaluation device is provided.

According to an eighth aspect of the present invention, of a burner for burning fuel and air, a supply means for supplying fuel and air to the burner, and a fuel and air supplied to the burner, Adjusting means for adjusting at least one supply amount, a camera for photographing a flame, a displaying means for displaying a flame image by using the output signal of the camera, and an evaluation of flame flammability by using the output signal of the camera There is provided a combustion control system characterized by comprising: a calculation means for obtaining a physical quantity for achieving the above; and a control means for controlling the adjustment means according to the physical quantity obtained by the calculation means.

According to a ninth aspect of the present invention, of a burner for burning fuel and air, a supply means for supplying fuel and air to the burner, and a fuel and air supplied to the burner, Adjusting means for adjusting at least one supply amount, a camera for photographing a flame, a displaying means for displaying a flame image by using the output signal of the camera, and an evaluation of flame flammability by using the output signal of the camera Provided is a plant for thermal power generation, which comprises: a calculation unit for calculating a physical quantity for achieving the above; and a control unit for controlling the adjusting unit according to the physical amount calculated by the calculation unit.

Further, the present invention is an automatic exposure fuel-air ratio evaluation system characterized by decreasing the exposure amount of the camera when the output signal of the camera exceeds a certain value.

Furthermore, the present invention is an image processing apparatus which is provided with a plurality of light receiving elements on an image pickup surface and which inputs a photodetection signal of each light receiving element separately from a camera and which is subjected to image processing. When the value of exceeds a certain value,
It is characterized in that the shutter speed / and / or the aperture diameter of the camera is changed to a certain value or less.

Further, when the value of the area to be subjected to image processing exceeds a certain value and a signal for changing the shutter speed / and / or the aperture diameter of the camera is generated, the voltage and pulse width for remotely operating the camera according to the signal. It is desirable to generate a signal with the control of the mechanism.

Further, when the numerical value of the area to be image-processed exceeds a certain value, a signal for changing the calibration curve showing the relationship between the exposure amount and the fuel-air ratio and a signal for changing the shutter speed and / or the aperture diameter of the camera are respectively sent. It is desirable to have a generating image processing device.

Further, it is desirable to compare the air amount and fuel amount measuring means of the combustion conditions with the radical emission intensity to automatically prepare a calibration curve showing the relationship between the fuel-air ratio and the radical emission.

Further, in the case of overexposure, in a state where the exposure amount is appropriate, the calibration curve showing the relationship between the fuel-air ratio and the radical emission by comparing the air emission and fuel amount measuring means of the combustion condition with the radical emission intensity. It is desirable to automatically generate.

Furthermore, it is desirable to increase or decrease the charge time of the CCD when the output signal of the camera exceeds a certain value.

Furthermore, it is desirable to increase or decrease the attenuation of the optical filter when the output signal of the camera exceeds a certain value.

Furthermore, when the output signal of the camera exceeds a certain value, it is desirable to increase or decrease the voltage applied to the CCD.

[0042]

The exposure adjusting means can detect the light emission intensity due to combustion within a fixed detection wavelength range without saturating the output signals of the respective light receiving elements. Then, an ordinary color image can be obtained by synthesizing the output signals of the light receiving elements R, G, B by the synthesizing means.

The wavelength of 431n is used to evaluate the flame combustion state.
If at least one of the light receiving element B having a high sensitivity in the vicinity of m and the light receiving element G having a high sensitivity in the vicinity of 517 nm is set to the above-mentioned specific wavelength, the emission intensity of the reaction intermediate radical generated by combustion can be detected. it can.

Further, when the numerical value of the area to be subjected to the image processing exceeds a certain value, the shutter and / or the diaphragm is changed, so that the saturation phenomenon does not occur even if the emission intensity becomes strong. When the conventional exposure is constant, if the emission intensity is strong or if the overall intensity is high, there will naturally be an error if the fuel-air ratio is calculated using the calibration curve that is not saturated due to distortion in the detection signal. Occurs. The exposure adjustment of the present invention is automatically performed,
Further, by executing the calculation using the calibration curve corresponding thereto, highly accurate measurement can be performed regardless of the emission intensity.
In particular, the burner of the combustor uses diffusion combustion and NO for stable combustion.
In many cases, premixed combustion is also used to reduce x, and the difference in this combustion method has a large difference in emission intensity. Therefore, it is necessary to optimize the exposure in order to accurately measure both of them. Further, by using the output signals of the R, G, and B light receiving elements for which the exposure is optimized, a color image without halation can be obtained.

In the combustor, the amount of air and the amount of fuel are controlled according to the load demand, and the emission intensity of flame changes. If the exposure conditions of the camera are changed accordingly, the actual light emission intensity and the amount of light received by the light receiving element change. In order to correct this difference in detection sensitivity, it is necessary to create a calibration curve showing the relationship between the signal intensity detected by each light receiving element under each exposure condition and the fuel-air ratio obtained from the measurement results of the fuel amount and the air amount. This can be done and memorized during the trial run. It is also possible to create a calibration curve from the actual measurement values of the successive combustion conditions during commercial operation. In any case, by using the calibration curve corresponding to the exposure condition to perform the calculation, highly accurate measurement becomes possible.

By the way, in order to carry out the measurement under a constant exposure condition without changing the above-mentioned exposure condition, it is conceivable to increase the measurement range or decrease the detection sensitivity, but both of them have the following drawbacks. In order to increase the measurement range, it is necessary to increase the number of digits from the detector to the A / D converter and the calculator, which not only increases the cost of the device but also increases the calculation time, which is not practical. Also, lowering the detection sensitivity lowers the resolution. By making the exposure conditions appropriate in this way, it becomes possible to monitor the combustion state by the flame image displayed on the display means and to evaluate using the physical quantity calculated by the calculation means. Further, the control means controls the adjusting means using the physical quantity. This makes it possible to accurately adjust the amount of fuel and air supplied by the supply means.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A combustion diagnosis according to an embodiment of the present invention and a combustion control system using the diagnosis will be described.

An embodiment in which the spectroscopic camera of the present invention is applied to a combustion system will be described.

[0049] Figure 1, a combustion control system using the combustion diagnosis and its embodiment shown in FIG. 2, F combustor 200
1 and F2 combustors 284, 272, flame 241
To form. The F1 and F2 combustors 284 and 272
The luminescence image of the flame 241 formed by the camera 820
To illuminate. This camera is a so-called RGB compatible electronic camera that can output a red image signal (R signal), a green image signal (G signal), and a blue image signal (B signal) individually or in combination.

The combustion system is characterized in that the combustibility of a plurality of burners is evaluated and controlled by one camera. The field of view of the camera may be located axially, preferably axially, of the combustor as shown to view the flames of the plurality of burners. The RGB signal output from the camera 820 is output in parallel with the output to the color monitor 802 and the like.
It is sent to the image capturing device 804 and the arithmetic device 806. The arithmetic unit 806 performs a fuel-air ratio calculation process or the like for evaluating the combustion state using the G signal and the B signal.
The fuel-air ratio calculation process will be described later in detail with reference to FIG.

The signal processed by the arithmetic unit 806 is
The image processing device 808 is reached. Here, for example, for a physical quantity image for evaluating a combustion state, a pseudo color display process, a binarization process that divides the intensity above and below an arbitrary intensity,
Area calculation for the binarized image, position calculation, edge processing that connects only boundaries with lines, area calculation of the area surrounded by the edge, edge length calculation, average value of the received light intensity of all pixels in the measurement area, and Calculates variance. The results calculated as the above-described feature quantities of the input physical quantity image are output to the comparison device 814 and the image processing result monitor device 810.

On the image processing monitor 810 of the image processing result, the result of the pseudo color display processing of the physical quantity image for mainly evaluating the combustion state is displayed, but the processing result image may be used. Therefore, the image processing monitor 810
Although the flame displayed on the color monitor 802 and the flame displayed on the color monitor 802 are images of the same flame, the displayed image is different from that on the color monitor 802. The image capturing device 804, the arithmetic device 806,
The processing result by the image processing device 808 and the like is stored in the processing result storage device 812 illustrated in FIG. 2 and can be used at a later date.

In the comparison device 814, ideal combustion flame characteristic amount data stored in advance in the storage device 826,
The characteristic data of the actual combustion flame actually input is compared. When the difference between the actual combustion flame and the ideal combustion flame is large, control signals that match within an arbitrary range are output to the fuel amount control device 816, the air amount control device 818, and the like. Fuel amount control device 816, air amount control device 81
8 changes the fuel amount control valve 256 for supplying fuel into the combustor 200 and the opening amounts of the air amount control valves 270, 271 for supplying air into the combustor 200 according to the control signal. For example, when the air is insufficient, the air amount control device 818 increases the supplied air amount. As a result, the optimum combustion state can always be maintained.

The present embodiment is characterized by a configuration for detecting the combustion state under appropriate exposure conditions (that is, the camera 820, the exposure control circuit 850, the arithmetic unit 806, etc.) and the arithmetic corresponding thereto. Further, the combustion condition is controlled by the combustion diagnosis for detecting the combustion state. Therefore, hereinafter, the description will focus on the characteristic points. The combustor 200 is a gas turbine combustor, and includes a diffusion combustion F1 combustor 284 that ejects fuel into the air and a premixed combustion F2 combustor 272 that ejects from a nozzle in a state where air and fuel are premixed. Of course, both the F1 combustor 284 and the F2 combustor 272 may be premixed combustors. Among the image pickup results from the camera, the fuel-air ratio distribution image is displayed on the image processing monitor 810, and the entire fuel-air ratio distribution of the flame zone formed by the F1 combustor 284 and the F2 combustor 272 can be simultaneously measured. Therefore,
The present embodiment has an effect that the combustion states of a plurality of burners can be evaluated and managed at the same time. It is desirable that the flame 243 formed by the F1 combustor 284 and the flame 241 formed by the F2 combustor 272 burn with a uniform fuel-air ratio in each flame, but if they are non-uniform for some reason. There is. According to the present embodiment, it is possible to identify the fact that it is non-uniform and the place where it is non-uniform.

FIG. 2 is an explanatory diagram of an apparatus relating to image processing, display and recording. The signal output from the camera 820 is a type in which a red image signal (R signal), a green image signal (G signal), and a blue image signal (B signal) are independently output.
The color monitor 802 of the GB input terminal synthesizes and outputs the color image of the flame for monitoring. Therefore, the color monitor 802 displays an image of flame similar to that seen with the naked eye. At the same time, it is stored in the image storage device 824 as an unprocessed original image. Therefore, the image can be reproduced at a later date.

The camera 820 of this embodiment uses a red image signal.
(R signal), green image signal (G signal), and blue image signal (B signal) are so-called RGB compatible electronic cameras that can be output individually or in combination. As shown in FIG. 3, the relative detection sensitivity of the camera has a maximum sensitivity at 450 nm for a blue image, at 510 nm for a green image, and at 600 nm for a red image. Therefore, as can be seen by overlapping with the flame emission spectrum of FIG.
When a flame is projected at 20, an image obtained as a blue image signal (B signal) is mainly CH radical light, and an image obtained as a green image signal (G signal) is mainly C ₂ radical light. . The width of each of the detection sensitivities is not extremely narrow but has a certain width. Therefore, for example, the light receiving element that detects blue is not limited to light with a wavelength of 450 nm,
It has the characteristic of detecting light near 450 nm to some extent. However, since the components of the flame light other than the wavelengths shown in the figure are weak, there is no problem when performing analysis.

Furthermore, the camera 820 of this embodiment is capable of detecting light in the entire visible range when viewed as the entire light receiving element.

Next, the principle of calculation of the fuel-air ratio of the flame performed by the arithmetic unit 806 will be described.

The "fuel air ratio" is defined by Q _f / Q _a . Where Q _f is the amount of fuel supplied and Q _f
a is the amount of air supplied.

FIG. 4 shows an example of the emission spectrum of the flame measured by changing the fuel-air ratio conditions.

In FIG. 4, when the fuel-air ratio condition 1 is excessive air, the fuel-air ratio condition 2 is a condition where the air is insufficient. As can be seen from this figure, strong emission of OH radicals, CH radicals, and C ₂ radicals (OH radicals: 310 nm, CH radicals: 431 nm, C ₂
Radicals: 517 nm) are observed, which shows that their intensity changes under the fuel-air ratio condition. That is, by examining the relationship between the emission intensity of each radical and the fuel-air ratio, the fuel-air ratio can be known from the emission intensity of the radical.

FIG. 5 shows the emission intensity of each radical with respect to the fuel-air ratio. The fuel-air ratio on the horizontal axis is shown by the equivalent amount, which is the theoretical value when the fuel amount and the air amount are completely combusted. The air excess region is on the left side of this equivalence, and the air excess ratio increases as the distance from the equivalence increases.

The emission intensity decreases as the air in excess of the OH radicals, CH radicals, and C ₂ radicals increases (the fuel amount decreases). The fuel-air ratio can be obtained by measuring any emission intensity from this figure. However, if only the emission intensity of one radical is investigated, a measurement error of the emission intensity may occur due to the stain on the window for observing the flame or the gain fluctuation of the measurement system. In order to eliminate this, by obtaining the ratio of the emission intensity between the radicals and using this ratio, it is possible to cancel the influence of the dirt on the window and the gain variation.
The result of examining the relationship between the emission intensity ratio between CH / C ₂ radicals and the fuel-air ratio is shown by the line of shutter speed 1/60 in FIG. This line shows the CH radicals and C ₂ radicals of the emission intensity measured by changing the fuel-air ratio and showing the intensity of each. By obtaining the emission intensity ratio in this way, the measurement error described above can be eliminated and the fuel-air ratio of the flame can be known. Since OH radicals are ultraviolet light, commercially available optical components such as glass materials other than quartz are
Will decay. Therefore, it is practical to use the emission of CH radicals and C ₂ radicals, which are lights in the visible range, as light that is easy to handle, that is, to investigate the intensities of light at 431 nm and 517 nm to obtain the fuel-air ratio.

By the way, the above-mentioned F1 combustor and F2 combustor differ greatly in emission brightness due to the difference in their combustion systems. In addition, the light emission brightness of the combustor varies depending on the load required of the generator, even though the fuel-air ratio is the same but the amount is different.
Therefore, it is necessary to increase the dynamic range of the measurement system in order to provide the resolution for obtaining the non-uniformity of the fuel-air ratio from the fuel-air ratio and the emission intensity ratio between CH / C ₂ radicals shown in FIG. However, in order to increase the dynamic range of the measurement system, it is necessary to increase the number of bits of the A / D converter and the arithmetic unit, which not only increases the cost but also increases the arithmetic time, which is not practical. Therefore, it is the present invention to apparently increase the dynamic range without increasing the number of bits. FIG. 7 is an explanatory diagram in the case of controlling overexposure by using a shutter, a diaphragm diameter, etc. in the case of overexposure. FIG. 7 shows a case in which the amount of fuel and the amount of air are large and the emission intensity is large even when the fuel-air ratio is the same, and shows an example in which a saturation phenomenon occurs in the A / D conversion circuit or the like. The emission intensity of the CH radical is in the saturation region, and the image signal from the camera is saturated at the broken line portion. Therefore, CH / C ₂ is different from the emission intensity ratio when it is not saturated. When the fuel-air ratio calculation as shown in FIG. 6 is performed using such an image signal, a calculation error naturally occurs. Therefore, CH / C can be set by taking appropriate exposure conditions such as changing the shutter speed as shown in Fig. 8.
₂ has linearity and can obtain the correct fuel-air ratio distribution with no calculation error.

FIG. 9 is an example showing one means for obtaining proper exposure. The light emission intensity in the combustor differs depending on the combustion conditions, and the image signal captured from the camera into the image processing device may be overexposed or underexposed. However, when the image signal taken in from the camera exceeds a certain value, an SSUP command output for increasing the shutter speed is output as in the flowchart, and the shutter speed of the camera is increased by the shutter control circuit. Conversely, when the image signal taken in from the camera falls below a certain value, an SSDN command output for slowing the shutter speed is output as shown in the flowchart, and the shutter control circuit slows the shutter speed of the camera. In this way, even if the emission intensity differs due to the difference in the combustion conditions, the image signal taken in by the image processing device becomes data with no distortion within a certain range. Here, distortion-free data can be obtained by changing the exposure conditions, but as shown by the shutter speed 1/125 line in FIG.
There is some difference from the one shown by the line of / 60. Here, for the sake of clarity, the line of 1/125 and 1/60
The line is shown slightly enlarged from the measured value. These lines show the emission intensity of CH radicals and C ₂ radicals in the same fuel-air ratio, and show the respective intensity ratios. When the exposure conditions are changed in the same combustion state, some differences occur when the relationship between the emission intensity ratio between the CH / C ₂ radicals and the fuel-air ratio is obtained. This is because there is a region where the received light amount and the signal are not linear in the entire measurement system. Therefore, when the exposure conditions are changed to increase the measurement accuracy, the corresponding calibration curve is used to perform error-free calculation. You can Of course, if the relationship between the emission intensity ratio between radicals and the fuel-air ratio is obtained, it is possible to measure with some accuracy even when the exposure amount is changed.

The calculation of the fuel-air ratio when the exposure conditions are changed in this way is obtained from the fuel-air ratio and the emission intensity ratio obtained for each exposure condition. As described above, the emission intensity ratio of the CH radical and the C ₂ radical is calculated from the detection intensity ratio of the blue image signal (B signal) and the green image signal (G signal) output from the camera,
The fuel-air ratio is calculated from the correlation between the intensity ratio and the fuel-air ratio.
This fuel-air ratio means that the calculation of the intensity ratio is performed for each light receiving unit,
A fuel-air ratio distribution image can be obtained by performing the same light receiving unit between the blue pixel and the green pixel on the screen and for the entire screen or only a desired region. In this case, as shown in FIG. 9, in order to make the calculation time practical, usually only the desired region is calculated. FIG. 10 shows a case where the exposure is constant and the entire region is evaluated the same because the resolution is low. FIG. 11 shows the case of calculation with the proper exposure of the present invention.
Non-uniformity of fuel-air ratio can be measured.

As described above, in the automatic exposure fuel-air ratio evaluation system of this embodiment, one camera can be used to monitor a flame with a normal color image and to obtain a fuel-air ratio distribution image. . Moreover, the time required to obtain the fuel-air ratio distribution image is short and its accuracy is good. In addition, the operation of the device is easy. Therefore, the amounts of fuel and air can be controlled more precisely, and a combustion system that is excellent in environmental friendliness and has high combustion efficiency can be obtained. Moreover, since there is only one camera, focus adjustment is easy.

The camera 820 of this embodiment can be widely used as it is to measure the combustion state of flames. In this case, the fuel that causes the flame can be applied to various liquid and gaseous fuels such as natural gas and heavy oil. This is because all of these fuels contain C, H, etc., and are accompanied by the emission of CH radicals etc. in the flame portion. However, even if C is included, solid fuel such as coal emits radiant heat in addition to radical emission at the time of combustion. Therefore, the camera 820 is not applied as it is, but some measure needs to be taken separately. There is. Needless to say, the sensitivity curve of the light receiving element of the camera can be changed to be used for evaluation of all other combustion states.

Another embodiment will be described.

The automatic exposure fuel-air ratio evaluation apparatus is characterized in that one camera evaluates and controls the combustibility of a plurality of burners in the evaluation area.

12 and 13 show a combustor control system for thermal power generation equipped with the automatic exposure fuel-air ratio evaluation apparatus. Note that a portion not shown in the figure (for example, the color monitor 8
02, arithmetic unit 806, monitor 810, etc.)
Basically, it is similar to the above embodiment.

The combustor 200 is a gas turbine combustor, and includes an F1 combustor 284 and an F2 combustor 272. Image processing is obtained from the image pickup result from the camera 820, and the calculated fuel-air ratio distribution image is displayed on the image processing monitor 810 and the fuel-air ratio of the flame zone formed by the F1 combustor 284 and the F2 combustor 272 is displayed. The entire distribution can be measured simultaneously. Therefore,
The present embodiment has an effect that the combustion states of a plurality of burners can be evaluated and managed at the same time. It is desirable that the flame 243 formed by the F1 combustor 284 and the flame 241 formed by the F2 combustor 272 burn at a uniform fuel-air ratio in each flame zone, but they are non-uniform for some reason. There are cases. According to the present embodiment, it is possible to identify the fact that it is non-uniform and the place where it is non-uniform. As shown in FIGS. 10 and 11, when the combustion state inside the F1 combustor 284 is evaluated, on the screen,
When judging the combustion state of the F2 combustor 272 by making a judgment using the data of the area in which the flame 243 is reflected, it is judged by using only the area in which the flame 241 is reflected on the screen (not shown). Needless to say. Figure 11
When the fuel-air ratios of the nozzles 2 and 5 are different from the fuel-air ratios of the other nozzles as shown in FIG. 11, the unevenness of the fuel-air ratio due to the image processing becomes apparent as shown in the left diagram of FIG. In this figure, the explanation is made for each nozzle for the sake of clarity, but it is also possible to measure the non-uniformity of the fuel-air ratio in the same nozzle. This is because when the light emission distribution of the flame is properly captured, the dynamic range of the light emission distribution of the flame is widened and the resolution is increased. Therefore, the amount of fuel and the amount of air can be adjusted in order to eliminate the non-uniformity of the fuel-air ratio. Alternatively, if the cause of the non-uniformity is structurally related to the combustor itself, the remodeled portion will become apparent. To burn the flame uniformly,
The measurement of the fuel-air ratio distribution is very effective because it improves the combustion efficiency and can reduce the nitrogen oxide concentration in the exhaust gas.

When there are a plurality of objects to be measured and the wavelengths of the light are different depending on the objects to be measured, for example, a hydrocarbon fuel is used for the F1 combustor 284,
When a fuel containing no hydrocarbon is used for the F2 combustor 272, the sensitivity characteristic may be changed by changing at least one of the shutter speed and the aperture diameter according to the position on the image pickup surface of the CCD. . Needless to say, the sensitivity characteristic when measuring the F1 combustor is suitable for observing the light of the F1 combustor 284. On the other hand, the sensitivity characteristic when measuring the peripheral region is assumed to be suitable for the F2 combustor 272.

FIG. 12 is a schematic explanatory view of the entire thermal power generation system.

The fuel is supplied from the fuel tank 244, vaporized by the vaporizer 248, and sent to the fuel supply pipe 264. The fuel is measured by the calorific value measuring device 260, and the fuel quantity control valve 2
The flow rate is controlled at 56 and sent to the gas turbine combustor 200 . Here, when the fuel used is a fuel having a low boiling point such as LNG, a part of the fuel is vaporized in the fuel tank 244 and the pressure in the fuel tank 244 rises. At this time, in order to prevent the destruction of the fuel tank 244, the pressure in the tank is measured by the fuel tank pressure gauge 246, and when the pressure in the tank exceeds the limit value, the fuel tank pressure safety valve 252
Is opened, and a part of the gas in the tank is discharged to the fuel supply pipe 264. Since the gas vaporized in the tank has many components with a low boiling point and is different from the composition of the fuel that is normally supplied, when the pressure safety valve 252 in the fuel tank is opened, the fuel composition and the calorific value change. For this reason, the calorific value measuring device 260 uses the pressure relief valve 2
It is provided after 52.

On the other hand, the air 290 is the air flow rate sensor 230.
After the air flow rate is measured by the air humidity sensor 232 and the humidity is measured by the air humidity sensor 232, high pressure air is drawn into the air compressor 100. The high-pressure air is sent to the gas turbine combustor 200 after the pressure is measured by the air inlet pressure sensor 233 and the temperature is measured by the gas turbine combustor inlet air temperature / humidity sensor 228. Here, if the amount of air taken into the air compressor 100 can be calculated from the atmospheric temperature and humidity and the characteristics of the air compressor 100, or if the amount of air taken into the air compressor 100 is controlled to be constant. The air flow sensor 230 is not necessary if the device is provided.

The gas turbine combustor includes an outer cylinder 274 and an inner cylinder 2.
The high pressure air 271 is composed of 86, and the high pressure air 271 flows between the outer cylinder 274 and the inner cylinder 286.
Supplied to 260. A part of the high pressure air 292 is supplied to the combustion chamber as air for cooling the inner cylinder. A dilution air amount control device is provided on the downstream side of the combustion chamber. When the load on the gas turbine is small, a part of the combustion air is discharged to the downstream side of the combustor as diluted air. Fuel is supplied from the fuel nozzle, mixed with combustion air, and then burned in the F2 combustor 272. Flame stabilizer 242 provided in the F2 combustor 272
By the action of, the circulating flow of the high temperature gas is formed downstream of the flame stabilizer, and the heat from this circulating flow stabilizes the premixed flame. The gas generated from the premixed flame is the air for cooling the inner cylinder,
The high temperature combustion air 298 is mixed with the diluted air, and is introduced into the gas turbine 300 through the transition piece 261. The high-temperature combustion air 298 that drives the gas turbine, the air compressor 100 connected to the gas turbine, and the generator 400 becomes low-temperature combustion exhaust gas 506 and is guided to the flue gas denitration device. Nitrogen oxides in the low-temperature flue gas react with ammonia in the flue gas denitration device and are converted to nitrogen.

The low temperature combustion exhaust gas 506 is also guided to the waste heat recovery boiler 502. The steam turbine 500 is driven by the steam 504 generated in the waste heat recovery boiler 502. This steam turbine is also connected to the generator 400. The steam that has driven the steam turbine 500 is the condenser 5
It becomes water at 08 and is supplied again to the waste heat recovery boiler 502. Here, the positions of the waste heat recovery boiler and the flue gas denitration device may be reversed. The combustion exhaust gas passes through the waste heat recovery boiler, is mixed with the exhaust gas from other gas turbines at the chimney, and is discharged into the atmosphere.

FIG. 13 is a schematic diagram showing an embodiment of the control system configuration of a thermal power plant equipped with the automatic exposure fuel-air ratio evaluation apparatus of the present invention. The air temperature of the combustion condition is measured by the air temperature sensor 228, the air pressure is measured by the air pressure sensor 233, the air humidity is measured by the air humidity sensor 232, and the fuel heat generation amount is measured by the fuel heat generation sensor 260.
Taken in 8. Although it is preferable to capture the measurement results described in FIG. 10 for the air amount and the fuel amount, the air flow rate control signal 716 and the fuel flow rate control signal 718 may be captured as alternative values. A signal from the image processing device 808 is fetched for the combustion conditions of the combustor with respect to these combustion conditions, the air amount, and the fuel amount. In addition, it is measured by the exhaust gas sensor 280 or the fuel-air ratio sensor 281, and is captured in comparison with the combustion condition / combustion result map 708. It is known that the lower the fuel-air ratio, the lower the NOx, but the probability of misfire increases. Therefore, a command to increase / decrease the air amount and the fuel amount is given from the obtained fuel-air ratio. The fuel-air ratio, NOx, and the limit of stable combustion that does not cause misfire are sequentially stored for each combustion condition and can be used as a map for a control command of the actual combustor.

In this manner, the optimum command values of the fuel amount and the air amount peculiar to the combustor with respect to the combustion condition and the load demand are stored in the combustion condition / combustion result map 708. As described above, since the combustion conditions are innumerable depending on the combination of the respective conditions, the ranges having no significant difference in the combustion state are regarded as the same conditions and handled.

The host computer 700 outputs an operation command and a load command based on the load request and the basic control plan input in advance. MPU-1 (whole control) 701
Receives the operation command and the load command, determines the fuel flow rate and the air flow rate, and outputs the flow rate command value. Here, the air temperature, the humidity, etc. of the combustion conditions are appropriately measured by each sensor and serve as a pointer for map reference. When there is a change in the combustion condition, the pointer immediately refers to the map corresponding to the combustion condition and changes it to a flow rate control signal to appropriately change the fuel amount and the air amount. In the present embodiment, the sampling times of the combustion conditions are made different in consideration of the changing speed of the combustion conditions. That is, the change in temperature and humidity is gradual, so the sampling is slowed down and the sampling is speeded up in response to the load demand. By the way, the fuel calorific value usually changes slowly, but the fuel calorific value becomes high when the safety valve 252 of the fuel tank is activated. The NOx value occurs when nitrogen in the air is exposed to a high temperature. Therefore, in the case of a fuel gas having a high calorific value, it is generally preferable to set the fuel-air ratio low. This calorific value change has a time constant that depends on the length of the pipe from the safety valve to the combustor,
Reach the combustor. Since this time constant is unique to each device, the operation of the safety valve can be detected and interrupt control can be performed.
When the operation of the safety valve 252 is restored, it returns to the normal command value of the fuel-air ratio with a constant time constant. Here, although not shown, an interrupt can be generated based on the operation signal of the safety valve to output the fuel flow rate control signal 718 with the time constant adjusted.

As means for not using the operation signal of the safety valve,
It is also possible to deal with this by increasing the heating value sampling time.

Although the control for increasing / decreasing the fuel amount has been described with respect to the operation of the safety valve, the air amount may be controlled. It is also an effective means to let the gas from the safety valve escape to another pipe. Actually, it is sufficient to prepare a table or map of about 2 to 5 as a representative property of the change in the calorific value of the fuel when the safety valve operates or including the difference in the composition of liquefied natural gas (LNG). As a result, the fuel-air ratio corresponding to the heat value of the fuel can be output.

By the way, the control of the flow rate at the rated rotation has been described so far, but since the rotational speed of the compressor 100 sent to the combustor changes when the generator 400 is started, the air pressure of the compressor 100 changes. To do. For this reason, the flow rate control at the time of startup needs to have a pattern different from that at the time of rating.
Therefore, a startup pattern 710 is separately provided at the time of startup,
Performs flow rate control at startup. This start-up pattern also holds different start-up conditions such as differences in combustion conditions such as air temperature, temperature, humidity, pressure, and fuel calorific value.

Next, the default value 712 of the memory area is an area in which design values are input to the learning map 708 at the time of test operation. This is an area for inputting the optimum values of the same type combustor from the past combustor database before the test run. ROM is used for this area for backup, or if it is RAM, it is preferable to protect it so that it cannot be easily rewritten. At the beginning of the operation of the new combustor, this command value is used to control the flow rate according to the combustion conditions and load demand.

As described above, the fuel-air ratio is calculated from the image information from the camera, and the correlation between the fuel-air ratio and NOx can be obtained. Therefore, the camera information is fed back in real time to control the optimum fuel-air ratio. You can Other than this, for example, it is possible to feed back the value of NOx in real time to control to an optimum fuel-air ratio. However, in the present invention, it is practical to install it at the outlet of the turbine because of the heat resistance of the NOx sensor. Therefore, there is a time delay between the measured values of the fuel-air ratio and NOx. As described above, it is difficult to perform feedback control using only NOx, and it is also possible to learn past combustion conditions and combustion results and use the past data offline.

In addition, the spectroscopic camera of R, G, and B outputs of the present invention may be applied to process control in a plasma chemical process, for example. The plasma chemical process is a process for synthesizing a substance by using radicals that emit light in a reaction, and the distribution state of the radicals that emit light greatly affects the properties of the product. Therefore, it is necessary to control the internal pressure of the process chamber, the supply amount of raw materials, etc. while constantly monitoring the distribution state of the radicals. However, under the present circumstances, it is rare to monitor the radical emission intensity distribution, and normally, the finished product is simply inspected.
Therefore, in the present situation, the proportion of rejected properties is high. At present, the radical emission intensity distribution is scarcely monitored because the conventional camera complicates the apparatus. That is, in the conventional camera, a filter that allows only light in a specific wavelength range to pass must be arranged in front of the lens. Furthermore, if there are two or more types of radicals to be monitored, or if you also want to obtain a normal color image, install a mechanical drive mechanism for switching filters, or use multiple cameras. There must be. When a drive mechanism or the like is provided, there is a high possibility that a failure will occur and the handling will be troublesome. In the case of using a plurality of cameras, the plurality of cameras must always capture the same light emitting portion, but this is extremely difficult. The conventional camera referred to here is one in which the detection wavelength bands of R, G, and B are overlapped with each other and the entire visible wavelength band is set as the detection wavelength band. The spectroscopic system using the spectroscopic camera and the exposure control circuit of the present invention can be applied without such a problem. Therefore, the radical emission intensity distribution can be constantly monitored, and the quality can be improved.

Although the color image monitor and the spectroscopic analysis monitor are separately provided in the above description of the embodiment, one TV monitor may be provided. Even in this case, since switching of both functions is required only by changing the content of signal processing in the device (or selection of a signal to be output to the monitor), there is almost no possibility of failure. Also, the operation is easy.

In the description of the above embodiments, the description has been made on the premise that the camera uses a CCD, but the present invention is not limited to this. It goes without saying that any camera that can make the detection wavelength range different for each pixel on the image pickup surface can be applied to a camera that detects light according to another principle or another method.

[0090]

According to the spectroscopic system of the present invention, it is possible to measure the combustion state of the combustor whose emission intensity is remarkably different with one camera without causing halation. In addition, since it is possible to calculate the fuel-air ratio by extracting only a color image having a color image close to that of the human eye, it is advantageous in terms of cost. Further, since the filter or the like external to the camera is not used for the spectral analysis for each wavelength, there are few failures and the operation is the same as that of a normal camera. If the spectroscopic system of the present invention is applied to, for example, a combustion evaluation device, both a color image and observation based on an air ratio or the like can be performed. Further, the flame combustibility can be spatially evaluated in a short time by only simple optical adjustment such as focus adjustment. Therefore, flame diagnosis can be correctly performed, and the accuracy of combustion control is also improved. Further, by applying these devices or methods, it is possible to obtain a combustion system having excellent environmental performance and high combustion efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a combustion control system including a combustion diagnostic device for performing exposure control according to the present invention.

FIG. 2 is a diagram showing the image processing and display unit of the image diagnostic apparatus and combustion control system of the present invention.

FIG. 3 is a diagram showing relative detection sensitivity of the camera of this embodiment.

FIG. 4 is a diagram showing an emission spectrum of a flame.

FIG. 5 is a diagram showing a relationship between a fuel-air ratio and emission intensity.

FIG. 6 is a graph showing the relationship between the emission intensity ratio between radicals and the fuel-air ratio.

FIG. 7 is a diagram showing a relationship between a detection signal and a fuel-air ratio when exposure conditions are changed.

FIG. 8 is a diagram showing a relationship between a detection signal and a fuel-air ratio when exposure conditions are changed.

FIG. 9 is an overall flowchart for changing the exposure conditions of the present invention.

FIG. 10 is an example diagram showing a fuel-air ratio measurement result of the present invention.

FIG. 11 is an example diagram showing a fuel-air ratio measurement result of the present invention.

FIG. 12 is an overall view of a thermal power generation system to which the present invention is applied.

FIG. 13 is an overall diagram of a combustion control system to which combustion diagnosis is applied to the present invention.

[Explanation of symbols]

202 ... combustor, 241 ... flame, 272 ... F2 combustor,
284 ... F1 combustor, 802, 810 ... Monitor device, 8
04 ... Image capturing device, 806 ... Arithmetic device, 808 ...
Image processing device, 812 ... Storage device, 814 ... Comparison device,
816 ... Fuel amount control device, 818 ... Air amount control device, 8
20 ... camera.

Claims (6)

[Claims] 1. A combustor that forms a flame using air and fuel, a means for measuring the emission brightness of the radicals of the flame in the combustor, and the air introduced into the combustor from the emission brightness. In a combustor control device having means for calculating a fuel-air ratio with fuel, and means for controlling fuel and air introduced into the combustor from the fuel-air ratio, the means for measuring the emission brightness is A combustor control device comprising a quantity control device. 2. A combustor that forms a flame using air and fuel, a means for measuring the emission brightness of the radicals of the flame in the combustor, and the air introduced into the combustor from the emission brightness. In a combustor control device having means for calculating a fuel-air ratio with fuel and means for controlling fuel and air to be introduced into the combustor from the fuel-air ratio, a camera included in the means for measuring the emission brightness Combustor control device having means for controlling the shutter speed of the combustor. 3. A combustor that forms a flame using air and fuel, a means for measuring the emission brightness of the radicals of the flame in the combustor, and the air introduced into the combustor from the emission brightness. In a combustor control device having means for calculating a fuel-air ratio with fuel and means for controlling fuel and air to be introduced into the combustor from the fuel-air ratio, a camera included in the means for measuring the emission brightness A combustor control device comprising means for controlling the throttle diameter of the combustor. 4. The emission brightness of radicals in a flame in a combustor driving a gas turbine is measured by using a detection system, and the ratio of fuel and air introduced into the combustor is measured from the measured brightness. And controlling the amount of fuel and air introduced into the combustor from the ratio, the exposure amount of a camera included in the detection system before the detection system saturates. A method for controlling a combustor, comprising controlling a shutter speed and / or an aperture diameter. 5. Radiation emission intensity of radicals in a flame in a combustor driving a gas turbine is measured by image processing,
In a combustor control method, which comprises calculating a ratio of fuel and air introduced into the combustor from the measured emission brightness and controlling the amount of fuel and air introduced into the combustor from the ratio. A method for controlling a combustor, comprising: controlling an exposure amount, a shutter speed, and / or a diaphragm diameter of a means for deriving the image when the area to be subjected to the image processing exceeds a predetermined value. 6. A thermal power plant comprising the combustor control device according to claim 1.