JP3106099B2 - Garbage incinerator combustion monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion monitoring device of a refuse incinerator for detecting a specific combustion gas component contained in a combustion flame of refuse to be incinerated and grasping a combustion state.

[0002]

2. Description of the Related Art As a conventional combustion monitoring device for a refuse incinerator, an infrared sensor for detecting infrared energy radiated from a combustion flame through band-pass filter means having a center wavelength of 3.4 .mu.m; And an arithmetic unit for detecting the presence or absence of hydrocarbon gas from the infrared energy detected by the computer.

[0003]

The above-mentioned conventional combustion monitoring apparatus for a refuse incinerator has a wavelength range where energy is absorbed by the hydrocarbon gas, that is, an infrared wavelength range radiated from the hydrocarbon gas is 3.4 μm. The infrared energy of the band is detected. If the infrared energy in the wavelength range is large, it can be determined that the combustion state is poor due to the lack of oxygen or the combustion temperature is low, and the infrared energy in the wavelength range is small. If so, the combustion state could be determined to be good. However, the detected infrared energy in the wavelength range is not due to only the hydrocarbon gas in the combustion flame,
There is a drawback that the state of the combustion flame is not always shown accurately because it also contains background components. Further, in order to monitor the combustion state, it is not sufficient to detect only the hydrocarbon gas in the combustion flame, and it is necessary to accurately detect other gas components.

[0004] The object of the present invention, in view of the problems described above,
It is an object of the present invention to provide a combustion monitoring device for a refuse incinerator that can accurately detect a specific gas component in a combustion flame to grasp the combustion state.

[0005]

In order to achieve this object, a combustion monitoring device for a refuse incinerator according to the present invention has the following features.
An infrared sensor for detecting infrared energy radiated from the combustion flame, filter means for selecting an energy band of infrared light incident on the infrared sensor, and a combustion state from infrared energy incident on the infrared sensor via the filter means. A combustion monitoring device for a refuse incinerator comprising a computing device that outputs data indicating the first and second bandpass filters that pass through a wavelength range in which there is no radiation from a combustion gas component of the combustion flame. A second band-pass filter that transmits a wavelength corresponding to the radiation wavelength of only the gas component to be detected in the combustion gas component, and the arithmetic device includes the infrared energy obtained by the first filter. A linear calculation is performed on the infrared energy obtained by the second filter and the infrared energy obtained by the second filter to obtain a gas component to be detected in the combustion flame. Lies in is arranged to detect the presence or absence of.

[0006]

[Function] The combustion flame of garbage incinerated in the incinerator is considered to be a mixture of nonflammable flame and bright flame due to the burning of both combustible gas generated by the decomposition of garbage and the carbon component contained in the garbage. , The radiant energy detected by the infrared sensor is
The radiant energy from the bright flame, the radiant energy from the non-flame flame and the radiant energy from the background object are superimposed. Therefore, by the first filter, a wavelength range where there is no heat radiation from the combustion gas component contained in the combustion flame, that is,
Transmit the infrared rays emitted from the bright flame and the background to detect the energy, and the detected gas component and the bright flame and the energy of the background in the combustion gas component by the second filter, that is,
The detected gas component, the bright flame and the infrared emitted from the background are transmitted to detect the energy, and further, by the arithmetic unit, the infrared energy obtained by the first filter and the infrared energy obtained by the second filter are obtained. If the infrared energy is linearly calculated, the infrared energy due to the bright flame and the background can be removed from the detected infrared energy. Here, the coefficient used in the linear operation is calculated by substituting the infrared energy value of only the bright flame detected via the second filter into the equation indicating Planck's law shown in (Equation 1), for example, the absolute temperature. May be determined so that the difference between the calculated value and the energy value in the wavelength region of the first filter with respect to the temperature becomes zero.

[0007]

(Equation 1)

[0008]

According to the present invention, the combustion of a refuse incinerator which can accurately detect a specific gas component in a combustion flame and grasp the combustion state for a combustion flame in which a non-flame flame and a bright flame are mixed. A monitoring device can now be provided.

[0009]

Embodiments will be described below. As shown in FIG. 1, the refuse incinerator has a trash hopper 4 having a pusher mechanism as an input mechanism 3 for pushing refuse to be incinerated into the furnace, and transports the refuse input by the pusher mechanism 3. An incineration treatment zone 5 in which a drying zone A for drying while drying, a combustion zone B for burning the dried debris, and a post-combustion zone C for completely ashes the combustion debris are cascaded through a step portion;
An air box 6 also serving as an ash chute installed below the incineration zone 5 is disposed in the furnace. Furthermore, an ash pit 7 for collecting the incineration residue incinerated in the incineration zone 5
And a waste heat boiler 10 is provided in a flue 9 formed in a space above the incineration zone 5, and the steam generated by the waste heat boiler 10 is supplied to a power generation device 11 to generate power, while heat recovery is performed. After the exhaust gas is purified by a gas purification device 12 including a bag filter and a smoke cleaning device, the exhaust gas is exhausted from a chimney 13. The air box 6 of the drying zone A, the combustion zone B, and the post-combustion zone C has an air ratio of about 1.7 (the theoretical air amount required for combustion is 1) from the blower 6a via the air passage 6b. Air for primary combustion is sent to be subjected to premix combustion, and the flue gas 9
The unburned gas generated in the furnace is completely burned by the air for secondary combustion ejected from the air supply mechanism 8 provided in the furnace. The incineration zone 5 is constituted by a stoker mechanism for extruding and transporting the garbage while stirring the garbage by alternately disposing a fixed grate and a movable grate in the direction of transporting the garbage and moving them relative to each other. The primary combustion air from 6 is supplied to the refuse from ventilation holes (not shown) formed in each grate.

A combustion monitoring device is provided for detecting the combustion flame on the combustion zone B and judging whether or not the combustion state of the refuse in the furnace is good. The combustion monitoring device includes an image sensor serving as an infrared sensor 1 that detects infrared energy radiated from a combustion flame;
Filter means 2 for selecting an energy band of infrared light incident on the infrared light, and data indicating a combustion state from infrared energy incident on the infrared sensor 1 via the filter means 2, for example, the presence or absence of a gas component to be detected in a combustion flame. And an arithmetic unit 15 that outputs a value indicating A first filter for transmitting all infrared rays in a wavelength range in which all the combustion gas components contained in the combustion flame do not have energy radiation; and a radiation of a gas component to be detected in the combustion gas component. A second filter 2b that transmits infrared light in a wavelength range corresponding to a wavelength; and a half mirror 2c that splits incident infrared light into the first and second filters 2a and 2b. It comprises a first infrared sensor 1a and a second infrared sensor 1b for separately detecting infrared rays transmitted through the first and second filters 2a and 2b. The first filter 2a is a band-pass filter having a center wavelength of 3.9 μm, and the second filter 2b is a band-pass filter having a center wavelength of 3.4 μm, which is a radiant energy band from hydrocarbon gas; The arithmetic device 15 derives the radiant energy intensity from the hydrocarbon gas by linearly calculating the outputs of the first infrared sensor 1a and the second infrared sensor 1b as follows. That is, (radiation energy intensity from hydrocarbon gas) = (output of second infrared sensor 1b) −K (first infrared sensor 1b)
Here, the coefficient K is an equation representing Planck's law (Equation 1) shown in the column of [Action] above, which indicates the infrared energy value of only the bright flame detected through the second filter. To obtain the absolute temperature, and calculate the energy value in the wavelength region of the first filter with respect to that temperature to set the difference between the calculated value and the value to be zero.

More specifically, when a combustion flame using a propane gas burner is measured by a spectrometer as an example of an inflammable flame, as shown in FIG. 2A, water vapor H ₂ O and carbon dioxide CO ₂ are shown in a completely burned state. Although the characteristic has a peak in the radiation intensity, in the incomplete combustion state, as shown in FIG.
In addition to steam H ₂ O and carbon dioxide CO ₂ , hydrocarbon HC
Has a peak also in the radiation intensity indicating 35-270 (Showa 44-2), 384. According to the figure, the combustion flame of garbage incinerated in the incinerator
As shown in the figure, it is considered that the flammable gas generated by the decomposition of dust and the carbon component contained in the dust are mixed flameless flames and bright flames that burn, and the radiant energy detected by the infrared sensor is The radiant energy from the background radiation and the luminous flame (equivalent to the black body radiation indicated by the broken line in the figure,
This is indicated by a dashed line. ) And radiant energy from the inflame flame are superimposed (indicated by solid lines in the figure). Therefore,
If the radiant energy of the bright flame is eliminated from the measured radiant energy of the combustion flame, the combustion gas component, that is, the radiant energy of the non-luminous flame, can be obtained. At that time, the characteristics of the second filter are specified. By setting the characteristics optimal for detecting the combustion gas component, the target combustion gas component can be accurately detected. In the above-described embodiment, an example has been described in which a hydrocarbon gas having a central wavelength of radiant energy of 3.4 μm is obtained as a specific combustion gas component. However, the present invention is not limited to this. By changing the characteristics, other gas components can be detected. For example, to detect NO _x , a band-pass filter having a center wavelength of 5 μm may be used. In addition, the elements constituting the infrared sensor 1 and the filter means 2 and the specific configuration thereof are not limited at all, and a known structure can be adopted as appropriate.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a garbage incinerator.

FIG. 2 is a characteristic diagram

FIG. 3 is a characteristic diagram

[Explanation of symbols]

 Reference Signs List 1 infrared sensor 2 filter means 2a first filter 2b second filter 2c half mirror 15 arithmetic unit

Claims (1)

(57) [Claims] 1. An infrared sensor (1) for detecting infrared energy radiated from a combustion flame, a filter means (2) for selecting an energy band of infrared light incident on the infrared sensor (1), and the filter means (1). An arithmetic unit (15) for outputting data indicating a combustion state from infrared energy incident on the infrared sensor (1) via 2)
A combustion monitoring device for a refuse incinerator comprising: a first band-pass filter (2a) that transmits light in a wavelength range where there is no radiation from a combustion gas component of the combustion flame; A second bandpass filter (2b) that transmits a wavelength corresponding to a radiation wavelength of only the gas component to be detected in the combustion gas component, wherein the arithmetic unit (15) is the first bandpass filter. The infrared energy obtained by (2a) and the infrared energy obtained by the second bandpass filter (2b) are linearly operated to detect the presence or absence of a gas component to be detected in the combustion flame. Monitoring system for garbage incinerators.