JPH08100916A - Combustion controller - Google Patents

Abstract

PURPOSE: To obtain a combustion controller which can always stably burn by obtaining the area of flame region from image data of imaging means, deciding the supply amount of burning air from the obtained flame area, and controlling the supply amount of the burning air based on the decided amount. CONSTITUTION: A stoker type refuse incinerating furnace comprises a burning zone M and an air supply mechanism 6 for supplying burning air to the zone M, imaging means 20 for inputting the burning state of the refuse in the zone M, and first calculating means C1 for extracting the flame region from the data by the means 20 to obtain the area. Second calculating means C2 calculates to lead the burning speed of the refuse based on predetermined correlation coefficient from the flame area obtained by the means C1, and decides the supply amount from the mechanism 6. Control means utilizing a computer regulates the supply amount of the burning air from the mechanism 6 based on the supply amount of the air decided by the means C2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device for an incinerator or the like, and more particularly to combustion in a stoker-type refuse incinerator having a combustion zone and an air supply mechanism for supplying combustion air to the combustion zone. The present invention relates to a combustion control device that adjusts the supply amount of commercial air.

[0002]

2. Description of the Related Art In a conventional combustion control device, a value obtained by multiplying a theoretical excess air amount required to burn a certain standard combustion product or standard waste in the case of a refuse incinerator by a predetermined excess ratio is set in advance. Set as a reference air supply amount to be supplied from the air supply mechanism, a thermocouple for monitoring the combustion state in the combustion zone is provided in the furnace, and the reference air is set so that the temperature detected by the thermocouple falls within the target temperature range. A control means using a control method such as PID for increasing / decreasing the supply amount is provided. That is, if the detected temperature is abnormally high, the control means adjusts the supply amount to be lower than the reference air supply amount to lower the combustion temperature, and if the detected temperature is low, the supply amount is higher than the reference air supply amount. Was adjusted to increase the combustion temperature to raise the combustion temperature so that the furnace temperature was maintained at the target temperature.

[0003]

However, in the above-mentioned conventional example, the temperature inside the furnace detected by the thermocouple is affected by the radiation inside the furnace, and not only in the combustion zone but also in the dry zones before and after the combustion zone. It is a value that also includes the effect of the after combustion zone, and it does not necessarily detect the combustion state in the combustion zone accurately, so it is not the optimum index for adjusting the air supply amount, and excessive supply or insufficient supply There was a problem that it may become.

In addition, the actual dust to be incinerated on the combustion zone may have a large difference in composition from the above-mentioned standard dust. In such a case, the reference air supply amount itself becomes a meaningless value. However, there is a problem in that it may lead to an extreme excess or shortage of air supply, which may cause inconveniences such as NOx generation in the former case and carbon monoxide generation in the latter case.

The object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to appropriately adjust the supply amount of combustion air to the combustion zone to constantly maintain the amount of combustion air regardless of the fluctuation of the waste components incinerated in the waste incinerator. The point is to provide a combustion control device capable of stable combustion.

[0006]

In order to achieve this object, the combustion control device according to the present invention is characterized by an image pickup means for inputting a combustion state of dust in a combustion zone, and a flame region based on image data obtained by the image pickup means. And a combustion speed of the dust from the air supply mechanism for calculating the combustion speed of the dust based on a predetermined correlation coefficient from the flame area obtained by the first calculation means. Second calculation means for determining the supply amount of air, and control means for adjusting the supply amount of combustion air from the air supply mechanism based on the supply amount of combustion air determined by the second calculation means It consists of

[0007]

As will be described later, according to combustion experiments, it has been found that the area S of the combustion flame on the combustion zone and the combustion velocity V have a certain correlation. That is,

[0008]

## EQU00001 ## (Flame area S) = k.multidot. (Combustion velocity V) -A where k is a proportional constant and A is a constant.

On the other hand, the excess air ratio Z, which is the ratio of the supply amount P of combustion air from the air supply mechanism to the air amount (theoretical air amount) P'necessary for combustion, is expressed by the following equation. It can be obtained by the ratio of P to the combustion speed V.

[0010]

[Equation 2] (Excess air ratio Z) = (Air supply amount P) /
(Theoretical air amount P ′) = (Air supply amount P) / B · (Combustion velocity V) Here, B is a constant.

Substituting (Equation 1) into (Equation 2),

[0012]

[Equation 3] (Air excess ratio Z) = C · (Air supply amount P)
/ ((Flame area S) + A)) where C is a constant.

That is, when the excess air ratio Z is set,
From (Equation 3), the air supply amount P is determined based on the value of the flame area S.

Therefore, based on the flame area obtained by the first computing means, the second computing means computes and derives the burning rate of dust from the image data obtained by the image pickup means based on a predetermined correlation coefficient. Determines the supply amount of combustion air from the air supply mechanism, and the control means determines the supply amount of combustion air from the air supply mechanism based on the supply amount of combustion air determined by the second calculation means. By adjusting, combustion is promoted in a state where the excess air ratio does not fluctuate significantly at all times.

Experimental examples will be described below. As shown in FIG. 4, the experimental apparatus is configured such that the experimental furnace 30 is loaded on the electronic balance 31, the soybean charcoal 32, which is a standard combustion product, is burned, and the burning state is photographed by the infrared camera 33. .
An exhaust gas analyzer 34 for detecting exhaust gas components generated in the experimental furnace 30 is provided and the exhaust gas components are recorded by the recorder 35, while the air pushed in by the compressor 36 is measured by the experimental furnace 3
Supply from below 0. The forced air is supplied to the valve 38.
The flow rate is freely adjustable and is monitored by the flow meter 39.

The burning rate can be obtained by detecting the weight change per unit time in the burning process of the bean charcoal 32 using the electronic balance 31. On the other hand, the image captured by the infrared camera 33 has a flame temperature of, for example, about 600 ° C. or more and 700 ° C. by an image processing means using a computer.
As described above, when the area of the flame region extracted by binarizing with a threshold value different from 800 ° C. or higher is obtained, as shown in FIG. 5, in any case, a positive correlation between the burning speed and the flame area is obtained. Turned out to be. Even if the flow rate is made variable by adjusting the valve 38, the area of the flame region extracted by binarizing the flame temperature by a constant threshold value, for example, 700 ° C. or higher by the image processing means is calculated. As shown in 6, the burning velocity and the flame area have a linear relationship shown in (Equation 1). Since the combustion speed and the amount of air required for combustion (theoretical air amount) have a linear relationship, the excess air ratio is determined as in (Equation 3).

[0017]

As described above, according to the present invention, the amount of combustion air supplied to the combustion zone can be appropriately adjusted to ensure stable combustion regardless of fluctuations in the waste components incinerated in the waste incinerator. A combustion control device can now be provided.

[0018]

EXAMPLES Examples of the combustion control device of the present invention will be described below. As shown in FIG. 1, the refuse incinerator is a hopper 3 that receives municipal refuse that is an object to be incinerated, a pusher 4 that puts the dust in the hopper 3 into the furnace from the lower end, and a pusher 4 that is put in by the pusher 4. A stoker-type incineration zone 5 for incinerating waste while stirring and transporting it is provided, and an air supply means 6 for supplying air for primary combustion from the bottom thereof is provided.

The incineration zone 5 is of a hydraulic drive type in which movable grate (not shown) that reciprocates obliquely upward with respect to a fixed grate (not shown) is arranged alternately along the transport direction. With the stoker mechanism, the drying zone L for transporting the dust while drying, the combustion zone M for transporting while burning the dust (composed of the front combustion zone M1 and the rear combustion zone M2), and the post combustion zone N for transporting the ashing treatment. And are arranged in a stepwise manner, and the reciprocating cycle of the movable grate is variable so that the speed of transporting dust can be adjusted.

The air supply means 6 is a blower fan 6a.
The air blown by the forced air by the air blower 6 to the air boxes 6c separately provided below the drying zone L, the combustion zone M, and the post combustion zone N, respectively.
It is configured to be supplied via b, and a damper mechanism 6d is provided on the outlet side of the air passage 6b to each air box 6c so that the air flow rate can be adjusted.

The upper part of the incineration zone 5 is constructed as a primary combustion zone 1 for directly incinerating dust, and a flue formed in the space above it is made a secondary combustion zone 2 for completely burning combustion gas. A nozzle 13a as a secondary combustion air supply mechanism 13 is provided on the flue inlet side of the flue so as to supply the induced air from the blower fan 13b to the flue.

A waste heat boiler 12 for recovering the thermal energy of combustion exhaust gas is provided in the space on the downstream side of the secondary combustion region 2 to supply the heat generated by combustion to the power generator 11 as steam, while the exhaust gas connected further downstream. Road 7 to chimney 1
An exhaust gas treatment device including a bag filter 8 and a smoke washing device 9 is provided in the middle of the flow path reaching 0.

A color CCD camera as an image pickup means 20 for photographing and inputting the combustion state in the combustion zone M is provided at the upper center of the side wall on the downstream side of the incineration zone 5, and the combustion is carried out from the image data inputted by the image pickup means 20. An image processing means 21 utilizing a microcomputer for judging the burning state of dust in the belt M is provided to constitute a burning state detecting device.

The image processing means 21 is shown in FIG.
As shown in (b), the image data input from the image pickup means 20 is decomposed into red (R) green (G) blue (B) color components, and a flame region is extracted from the green (G) component image data. The combustion speed of the dust is calculated and derived from the first calculation means C1 to be extracted and the flame area obtained by the first calculation means C1, and the combustion air is supplied from the air supply mechanism 6. It is composed of a second calculation means C2 for determining the quantity.

The computer-used control means 22 adjusts the supply amount of the combustion air from the air supply mechanism 6 based on the supply amount of the combustion air determined by the second calculating means C2.

Hereinafter, based on the flowchart shown in FIG.
It will be described in detail. The image data input from the image pickup means 20
When decomposed into red (R) green (G) blue (B) color components, FIG.
As shown in (a) and (b), red (R) green for each pixel
(G) Intensity data of blue (B) is obtained <# 1>. General
In addition, a flame with bright flame radiation emits a visible amount of visible light.
When the temperature rises, first red, then yellow,
Green, blue, and finally purple, the energy of light, the spectrum
A new color part is added to the tor. Combustion part,
For the combustion zone M in the incinerator, the imaging means 20
In addition to the flame part, the obtained image data includes side walls and dust.
Personal data is also included, and it depends on the temperature and reflected light of those parts.
The color components are mixed, so it is possible to accurately extract only the flame.
For reference, do not refer to the red (R) component, which indicates a relatively low temperature part.
Is preferred. On the other hand, the blue (B) component responds to the flame temperature.
As it fluctuates greatly, the area of
It is not preferable to specify Therefore, the first operator
In step C1, the intensity data of the green (G) component has a predetermined threshold value G. _Th
The larger pixel is the pixel corresponding to the flame area, that is, the area
(S_F<# 2>, <# 3>. here,
The threshold value is not particularly limited, and the furnace scale and operating conditions
It may be set as appropriate.

The second computing means C2 is the same as the above-mentioned (Equation 1).
According to the above, the combustion velocity V is calculated and derived from the flame area S obtained by the first calculation means C1, and based on (Equation 3),
Excess air ratio Z, which is the ratio of the supply amount P of combustion air from the air supply mechanism to the air amount (theoretical air amount) P ′ required for combustion
The air supply amount P is calculated and derived so as to fall within the range of about 0.8 to 1.2 <# 5>.

The control means 22 includes the second computing means C.
In order to supply the combustion air of the supply amount determined by 2,
The damper mechanism 6d of the air supply mechanism 6 is adjusted using an electromagnetic or hydraulic actuator <# 6>. In other words, when the combustion becomes more active and the combustion temperature rises as the area of the high-temperature region of the combustion flame becomes larger, the air supply amount is reduced to lower the combustion temperature and avoid the damage due to corrosive gas. When the value becomes smaller and the combustion temperature decreases, the air supply amount is increased to increase the combustion temperature and improve the combustion efficiency.

That is, the image pickup means 20, the image processing means 21, and the control means 22 constitute a combustion control device.

Another embodiment will be described below. In the above-described embodiment, the first computing means C1 extracts a pixel in which the intensity data of the green (G) component is larger than the predetermined threshold value G _{Th as} a pixel corresponding to the flame region, that is, the area (S _F ). However, the present invention is not limited to this.
Alternatively, the luminance data as a monotone image may be binarized at a predetermined threshold value to extract the flame region. Alternatively, the infrared camera may be used to configure the image pickup means 20, and the intensity data may be obtained at the predetermined threshold value. It may be binarized to extract the flame region.

In the case of an infrared camera, the flame temperature distribution is measured using a bandpass filter of about 4.5 μm capable of catching the CO ₂ radiation contained in the combustion gas. Therefore, as the image, if the threshold temperature is set, the flame area S above the temperature can be easily calculated. Therefore, the control means 22 only replaces the step <# 2> in FIG. 3 with the setting of the threshold temperature.

In the above embodiment, the case where the incineration zone is formed by arranging the dry zone L, the combustion zone M, and the post-combustion zone N in a stepwise manner has been described. The present invention is not limited to this, and can also be applied to a tilt furnace in which the incineration zone is linearly configured with a constant tilt angle.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

[Fig. 1] Schematic diagram of garbage incinerator

FIG. 2 is a characteristic diagram of input image data.

FIG. 3 Flow chart

[Fig. 4] Configuration diagram of the experimental apparatus

FIG. 5 Explanatory diagram of experimental data

FIG. 6 is an explanatory diagram of experimental data.

[Explanation of symbols]

 6 air supply mechanism 20 imaging means 22 control means C1 first calculation means C2 second calculation means M combustion zone

Claims (1)

[Claims] 1. A stoker-type refuse incinerator comprising a combustion zone (M) and an air supply mechanism (6) for supplying combustion air to the combustion zone (M), wherein the dust in the combustion zone (M) is An image pickup means (20) for inputting the combustion state of No. 1, a first calculation means (C1) for extracting a flame region from the image data obtained by the image pickup means (20) and obtaining the area thereof, the first calculation means (C1) Second calculation means (C2) for calculating and deriving the burning speed of dust from the flame area obtained by the above-mentioned calculation based on a predetermined correlation coefficient, and determining the supply amount of combustion air from the air supply mechanism (6); Combustion control comprising control means (22) for adjusting the supply amount of combustion air from the air supply mechanism (6) based on the supply amount of combustion air determined by the second calculation means (C2). apparatus.