Method and device for controlling furnace

Abstract

To provide a method for controlling a furnace capable of suppressing production of nitrogen oxides in a combustion chamber.SOLUTION: At least one of a temperature distribution and an oxygen concentration distribution, the temperature distribution and a nitrogen oxide concentration distribution, and the oxygen concentration distribution and nitrogen oxide concentration distribution in a combustion chamber 11 of a furnace is measured. Then, at least one of an area A1 where a high temperature area and a high oxygen concentration area B1 in the combustion chamber 11 overlap, an area where the high temperature area and a high nitrogen oxide concentration area overlap, and an area where the high oxygen concentration area and the high nitrogen oxide concentration area overlap is acquired. Then, on the basis of the overlapping area A1, at least one of a combustion air distribution amount, an amount of stirring gas that stirs gas in the combustion chamber, a fuel supply device feed speed, and a fire grate feed speed is controlled.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for controlling a furnace, and more particularly to a method and apparatus for controlling a furnace capable of suppressing the generation of nitrogen oxides in a combustion chamber. [Background technology]

[0002] Stoker-type incinerators, fluidized-bed incinerators, ash melting furnaces, and other incinerators are equipped with a combustion chamber for burning fuel such as waste. Combustion air is blown into the combustion chamber to dry and burn the fuel.

[0003] As a method for controlling the amount of combustion air injected, Patent Document 1 discloses a method in which the oxygen concentration of the gas generated by post-combustion is measured with a laser measuring device, and the amount of combustion air injected into the combustion chamber is controlled so that the oxygen concentration of the gas generated by post-combustion becomes a target oxygen concentration.

[0004] Patent Document 2 discloses a method of measuring the oxygen concentration in each of multiple divided regions of a secondary combustion chamber using intersecting lasers, and controlling the amount of secondary combustion air injected into each of the multiple divided regions based on the results.

[0005] Patent Document 3 discloses a method of measuring the nitrogen oxide concentration distribution in a combustion chamber using a laser and controlling the amount of denitration agent injected based on the result. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-310416 A [Patent Document 2] JP 2018-105594 A [Patent Document 3] JP 2012-2463 A Summary of the Invention [Problem to be solved by the invention]

[0007] Measurement using a single laser path as described in Patent Document 1 cannot capture local differences in concentration, and is insufficient for measurement in a combustion chamber where the location and magnitude of combustion fluctuates over time.

[0008] As described in Patent Document 2, if the oxygen concentration is measured for each divided region, the amount of secondary combustion air injected into each divided region can be controlled. However, the amount of nitrogen oxides generated varies depending not only on the oxygen concentration but also on the combination of temperature and oxygen concentration.

[0009] As described in Patent Document 3, if the amount of denitration agent injected is controlled by measuring the concentration distribution of nitrogen oxides generated in the combustion chamber, it is not possible to suppress the generation of nitrogen oxides in the combustion chamber itself, and the effect of reducing the amount of denitration agent is limited.

[0010] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a furnace control method and device capable of suppressing the generation of nitrogen oxides in the combustion chamber. [Means for solving the problem]

[0011] In order to solve the above problems, one aspect of the present invention is a furnace control method which measures at least one of the temperature distribution and oxygen concentration distribution, the temperature distribution and nitrogen oxide concentration distribution, or the oxygen concentration distribution and nitrogen oxide concentration distribution in the combustion chamber of a furnace, determines at least one of the areas in the combustion chamber where a high temperature area and a high oxygen concentration area overlap, the areas where a high temperature area and a high nitrogen oxide concentration area overlap, or the areas where a high oxygen concentration area and a high nitrogen oxide concentration area overlap, and controls at least one of the amount of combustion air distribution, the amount of stirring gas that stirs the gas in the combustion chamber, the fuel supply device feed speed, and the grate feed speed based on the area of ​​overlap.

[0012] Another aspect of the present invention is a furnace control device that includes a distribution measuring device that measures at least one of the temperature distribution and oxygen concentration distribution, the temperature distribution and nitrogen oxide concentration distribution, or the oxygen concentration distribution and nitrogen oxide concentration distribution in the combustion chamber of a furnace, and a combustion control device that determines at least one of the overlapping areas in the combustion chamber where a high temperature area and a high oxygen concentration area overlap, the overlapping area where a high temperature area and a high nitrogen oxide concentration area overlap, or the overlapping area where a high oxygen concentration area and a high nitrogen oxide concentration area overlap, and controls at least one of the combustion air distribution amount, the stirring gas amount that stirs the gas in the combustion chamber, the fuel supply device feed rate, and the grate feed rate based on the overlapping area. Effect of the Invention

[0013] According to the present invention, since it is possible to predict the local generation of nitrogen oxides in the combustion chamber, it is possible to suppress the generation of nitrogen oxides in the combustion chamber. Furthermore, since the control index is not only the nitrogen oxide concentration distribution but also at least one of the temperature distribution and the oxygen concentration distribution, it is easy to control. [Brief description of the drawings]

[0014] [Figure 1] 1 is a vertical cross-sectional view of an incinerator to which a control device according to one embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a block diagram showing the configuration of a control device according to the present embodiment. [Diagram 3] 1 is a block diagram showing a configuration of a distribution measurement device of the present embodiment. [Figure 4] 1 is a schematic diagram showing a light path p and a grid q. [Diagram 5] FIG. 5(a) shows a two-dimensional image of the temperature distribution in the combustion chamber displayed on the display of the analysis device, and FIG. 5(b) is a schematic diagram showing the high-temperature and low-temperature regions determined by the combustion control device. [Figure 6] FIG. 2 is a schematic diagram showing a region where a high temperature region and a high oxygen concentration region overlap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a detailed description will be given of a method and apparatus for controlling a furnace according to an embodiment of the present invention with reference to the accompanying drawings. However, the method and apparatus for controlling a furnace according to the present invention can be embodied in various forms and is not limited to the embodiments described in the present specification. The present embodiment is provided with the intention of enabling a person skilled in the art to fully understand the invention by fully disclosing the specification. (Incinerator)

[0016] Fig. 1 shows a vertical cross-sectional view of an incinerator 1 to which a control device according to an embodiment of the present invention is applied. The incinerator 1 is a stoker-type incinerator having a fire grate, and burns waste as fuel. The incinerator 1 includes a hopper 3 into which waste is fed, a furnace body 4 in which the waste is combusted, and a boiler 5 disposed downstream of a furnace outlet 13.

[0017] The waste fed into the hopper 3 is sent to the grate 7, which also serves as an operating end, by a pusher of the fuel supply device 6, which also serves as an operating end. The grate 7 reciprocates, stirring and moving the waste by this reciprocating motion. The waste on the grate 7 is dried by blowing in combustion air from a blower 8, and then combusted, producing combustion exhaust gas and ash. The grate 7 comprises a drying grate 7a that dries and ignites the waste, a combustion grate 7b that burns the waste, and a post-combustion grate 7c that burns the unburned waste. The ash after the combustion falls from an ash drop port 9 and is discharged outside the furnace.

[0018] The total amount of combustion air supplied to the combustion chamber 11 from below the grate 7 is adjusted by a combustion air damper 10a, which is an operating terminal provided immediately adjacent to the blower 8. The amount of combustion air distributed to each wind box is adjusted by under-grate combustion air dampers 10b, 10c, and 10d, which are operating terminals provided on each pipe that supplies combustion air to each wind box. A number of wind boxes and a number of under-grate combustion air dampers are also provided in the furnace width direction, i.e., in the direction perpendicular to the paper surface of FIG. 1.

[0019] The combustible gas generated above the drying grate 7a and the combustion grate 7b and the combustion exhaust gas generated above the post-combustion grate 7c join and mix in the secondary combustion chamber 12 at the furnace outlet 13. Secondary combustion air is supplied to the secondary combustion chamber 12 by a blower 14, and secondary combustion is carried out. The total amount and distribution amount of secondary combustion air supplied to the secondary combustion chamber 12 are adjusted by secondary combustion air dampers 16a, 16b, and 16c as operating terminals provided on the piping that supplies secondary combustion air to the blowing nozzle 15. A boiler 5 is installed downstream of the secondary combustion chamber 12. Thermal energy is recovered from the combustion exhaust gas by the boiler 5, and the combustion exhaust gas is discharged to the outside through a chimney (not shown).

[0020] A stirring gas is supplied to the combustion chamber 11 of the furnace body 4 by a blower 17. The combustible gas and the combustion exhaust gas in the combustion chamber 11 are stirred by the stirring gas. The amount of the stirring gas supplied is adjusted by a stirring gas damper 19, which serves as an operating end provided on a pipe that supplies the stirring gas to the blowing nozzle 18. The type of the stirring gas is not particularly limited, and may be air or a circulating gas obtained by circulating the combustion exhaust gas discharged from the furnace body 4.

[0021] Thermometers for measuring the gas temperature in the furnace body 4 are provided at multiple positions within the furnace body 4. For example, a combustion chamber gas thermometer for measuring the temperature of the combustion chamber 11 is provided in the combustion chamber 11, a main flue gas thermometer is provided at a position below the furnace outlet 13, a furnace outlet lower thermometer is provided at a lower position of the furnace outlet 13, a furnace outlet middle gas thermometer is provided at a central position of the furnace outlet 13, and a furnace outlet gas thermometer is provided at a downstream position of the furnace outlet 13.

[0022] A boiler outlet oxygen concentration meter that measures the concentration of oxygen in the combustion exhaust gas is provided on the outlet side of the boiler 5. A gas concentration meter 31 that measures the concentration of nitrogen oxides (hereinafter referred to as NOx) and carbon monoxide in the combustion exhaust gas is provided in an exhaust gas duct 30 connected to the chimney. In addition, a gas flow meter that measures the flow rate of the combustion exhaust gas is provided in the exhaust gas duct 30.

[0023] The measurement values ​​of the gas temperature, concentration, and flow rate measured by the various thermometers, gas concentration meter 31, boiler outlet oxygen concentration meter, and gas flow meter are transmitted to the combustion control device 21 as combustion process data and stored in the memory unit of the combustion control device 21. (Control device)

[0024] The control device 2 includes a combustion control device 21, a distribution measuring device 22 that measures the temperature distribution and oxygen concentration distribution in the combustion chamber 11, and a nitrogen oxide concentration predicting device 23 (hereinafter referred to as NOx concentration predicting device 23). (Combustion control device)

[0025] First, the combustion control device 21 will be described. In this embodiment, the operation amounts of each operating end (combustion air amount (total combustion air amount and combustion air distribution amount), stirring gas amount, secondary combustion air amount, fuel supply device feed rate, and grate feed rate) are controlled by the combustion control device 21. The combustion control device 21 controls the operation amounts of each operating end based on a predetermined operation amount standard setting relational expression. The operation amount standard setting relational expression is a predetermined relational expression between the waste incineration amount set value (incineration amount target value) and the operation amount standard value of the operating end (operation amount target value). The operation amount standard setting relational expression is separately determined corresponding to each operating end, and is used to derive the operation amount standard value of the corresponding operating end based on the incineration amount set value.

[0026] As shown in FIG. 2, the combustion control device 21 includes a combustion process data acquisition unit 35, an operation quantity reference value calculation unit 32, an operation terminal control unit 33 such as a combustion air amount control unit 33a described later, and an evaluation unit 34.

[0027] The operation amount reference value calculation unit 32 of the combustion control device 21 prestores the operation amount reference setting relational expression, and calculates the operation amount reference value of each operation terminal based on the incineration amount setting value. The combustion process data acquisition unit 35 acquires combustion process measurement values ​​(e.g., measurements by each thermometer, each concentration meter, and exhaust gas flow meter) as combustion process data from the incinerator 1 in operation as combustion state quantities in the furnace. The operation amount reference value calculation unit 32 adjusts (corrects) the operation amount reference value based on a control algorithm prestored in advance, such as fuzzy inference, in response to fluctuations in the combustion process data acquired by the combustion process data acquisition unit 35. Furthermore, the operation amount reference value calculation unit 32 adjusts (corrects) the operation amount reference value based on a control algorithm prestored in advance, such as fuzzy inference, based on the evaluation result of the evaluation unit 34. The evaluation unit 34 will be described later.

[0028] The control element control unit 33 outputs the operation amount to the control element so that the operation amount (combustion air amount, stirring gas amount, secondary combustion air amount, fuel supply device feed rate, grate feed rate) follows the operation amount reference value (operation amount reference value calculated or adjusted by the operation amount reference value calculation unit 32) based on a control algorithm stored in advance such as PID control. That is, the combustion air amount control unit 33a outputs the operation amount to the combustion air damper 10a and the under-grate combustion air dampers 10b, 10c, and 10d (see FIG. 1) so that the combustion air amount (total amount and distribution amount) follows the operation amount reference value. The stirring gas control unit 33b outputs the operation amount to the stirring gas damper 19 (see FIG. 1) so that the stirring gas amount follows the operation amount reference value. The secondary combustion air amount control unit 33c outputs the operation amount to the secondary combustion air dampers 16a, 16b, and 16c (see FIG. 1) so that the secondary combustion air amount (total amount and distribution amount) follows the operation amount reference value. The fuel supply device feed speed control unit 33d outputs the operation amount to the fuel supply device 6 (see FIG. 1) so that the fuel supply device feed speed follows the operation amount reference value. The grate speed control unit 33e outputs the operation amount to the grate 7 (see FIG. 1) so that the grate feed speed follows the operation amount reference value.

[0029] The combustion control device 21 includes a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor), and a main storage unit such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The combustion control device 21 also includes a storage unit such as a volatile memory such as a RAM, a non-volatile memory such as a ROM, an EPROM (Erasable Programmable ROM), a hard disk drive, and a solid state drive. The above functions of the combustion control device 21 are realized by the processor executing various programs stored in the storage unit. The same applies to the analysis device 43 of the distribution measurement device 22 and the NOx concentration prediction device 23 described later. (Distribution Measuring Device)

[0030] The distribution measurement device 22 measures the temperature distribution and the oxygen concentration distribution of the combustion chamber 11 by using absorption spectroscopy using laser light and CT (Computed Tomography). Fig. 3 shows a horizontal cross-sectional view of the combustion chamber 11 and illustrates the configuration of the distribution measurement device 22. As shown in Fig. 3, the distribution measurement device 22 includes an irradiation device 41, a light receiving device 42, and an analysis device 43.

[0031] The irradiation device 41 irradiates the inside of the combustion chamber 11 with laser light. The light receiving device 42 receives the laser light that has passed through the combustion chamber 11. The analysis device 43 calculates the temperature distribution and the oxygen concentration distribution based on the electrical signal output by the light receiving device 42.

[0032] The irradiation device 41 includes a laser transmitter 44, a splitter 45, and a laser irradiator 46. The laser transmitter 44 is controlled by a laser control device (not shown) and outputs a laser beam in a wavelength region of the oxygen absorption band. The splitter 45 splits the laser beam from the laser transmitter 44 into a plurality of optical paths and outputs the split beam. The splitter 45 and the laser irradiator 46 are connected by an optical fiber. The laser irradiator 46 is a collimator (lens) or the like for adjusting the traveling direction of the laser beam, and irradiates the combustion chamber 11 with the laser beam.

[0033] The light receiving device 42 includes a receiver 47 disposed opposite the laser irradiator 46. The receiver 47 includes a light receiving element such as a photodiode or a phototransistor, receives the laser light transmitted through the combustion chamber 11, and outputs an electrical signal according to the intensity of the received laser light. The receiver 47 and the analysis device 43 are connected by wiring that transmits the electrical signal.

[0034] The analyzer 43 amplifies the electric signal from the receiver 47 by an amplifier, and analyzes the waveform (absorption spectrum) of the amplified signal by using absorption spectroscopy and CT to calculate the temperature distribution and the oxygen concentration distribution. The temperature distribution may be measured by using water vapor or carbon dioxide.

[0035] Absorption spectroscopy and CT are explained below. Absorption spectroscopy is a measurement method that utilizes the property that when a laser beam of a certain wavelength is irradiated onto the gas to be measured, certain gas molecules contained in the gas to be measured absorb the laser beam of a specific wavelength, and the property that the amount of absorption depends on the concentration and temperature. The intensity of the incident light (I λ0 ) and transmitted light intensity (I λ ) ratio (I λ / I λ0 ) can be used to measure the concentration and temperature of the target gas. λ / I λ0 is expressed by the following relational equation (1) according to the Lambert-Beer formula.

[0036]

number

[0037]

number

[0038] Here, A λ,p is the absorbance at the light path p, n q is the molecular number density at grid q, L p,q is the optical path length in the p direction through grid q, and α λ,q is the absorption coefficient at grid q. The optical path p and grid q are set as shown in Figure 4.

[0039] According to equation (2), the absorbance A for a certain wavelength is λ,p is the concentration n of the gas to be measured and the absorption coefficient α λ,q and the optical path length L. Since the optical path length L is known, the gas concentration n and absorption coefficient α λ,q If we know the absorbance A for each light path p, λ,p Here, the absorption coefficient α λ,q is a function of temperature. Therefore, if the gas concentration n and temperature T of each of the multiple grids q included in each optical path p are known, the absorbance A λ,p is required.

[0040] Assuming the initial concentration and temperature, the actual value ((A λ,q ) data , absorbance data) and theoretical values ​​((A λ,q ) theory The concentration and temperature at each grid are converged so that the error in is minimized. This makes it possible to calculate the gas concentration n and temperature T at each grid q, and to obtain the concentration distribution and temperature distribution of the gas to be measured.

[0041]

number

[0042] 5(a) shows a two-dimensional image of the temperature distribution in the combustion chamber 11 displayed on the display of the analysis device 43. The data of the temperature distribution and the oxygen concentration distribution obtained by the analysis device 43 are transmitted to the combustion control device 21 (see FIG. 2) via a communication line.

[0043] The evaluation unit 34 of the combustion control device 21 determines a high temperature region A1 where the temperature is equal to or higher than a predetermined threshold and a low temperature region A2 where the temperature is lower than a predetermined threshold, for example as shown in the schematic diagram of Fig. 5(b) based on the temperature distribution data input from the analysis device 43. The inside of the ellipse filled with black in Fig. 5(b) is the high temperature region A1, and the rest is the low temperature region A2. The evaluation unit 34 may divide the combustion chamber 11 into a plurality of regions in advance, calculate a representative value (maximum value, average value, etc.) of the temperature distribution of each region, and compare the representative values ​​to determine the high temperature region and the low temperature region.

[0044] Similarly, the evaluation unit 34 determines areas of high oxygen concentration and areas of low oxygen concentration based on the data of the oxygen concentration distribution input from the analysis device 43 .

[0045] Specifically, the evaluation unit 34 obtains the area of ​​the region A1 (region A1 of an ellipse filled with black in FIG. 6) where the high temperature region and the high oxygen concentration region B1 overlap, for example, as shown in the schematic diagram of FIG. 6. Then, the evaluation unit 34 evaluates the obtained area and sends the evaluation result to the manipulated variable reference value calculation unit 32. As the evaluation result, the evaluation unit 34 may send the area information as it is, may send information in which the area is weighted, or may send information on the necessity of adjusting the manipulated variable reference value determined based on the area information. Based on the evaluation result of the evaluation unit 34, the manipulated variable reference value calculation unit 32 adjusts (corrects) the manipulated variable reference value so that the area of ​​the overlapping region A1 becomes smaller or becomes zero, based on a control algorithm stored in advance, such as fuzzy inference.

[0046] For example, when a high temperature and high oxygen concentration area A1 exists in the combustion chamber 11 as shown in Fig. 6, the operation quantity reference value calculation unit 32 adjusts the distribution amount of combustion air so that the amount of combustion air is increased in the low oxygen concentration area B2 and decreased in the high oxygen concentration area B1. The operation quantity reference value calculation unit 32 also increases the amount of stirring gas so that the temperature distribution in the combustion chamber 11 becomes uniform, for example. Furthermore, the operation quantity reference value calculation unit 32 slows down the fuel supply device feed speed and the grate feed speed so that the combustion of waste in the combustion chamber 11 is accelerated, for example. By doing so, the area of ​​the overlapping area A1 becomes small or zero.

[0047] In the above embodiment, the distribution measurement device 22 measures the temperature distribution and oxygen concentration distribution in the combustion chamber 11, and the combustion control device 21 adjusts the reference value of the operation amount of the control end based on the region A1 where the high temperature region and the high oxygen concentration region B1 overlap; however, the distribution measurement device 22 may measure the NOx concentration distribution in addition to the temperature distribution and oxygen concentration distribution, and the combustion control device 21 may adjust the reference value of the operation amount of the control end based also on the NOx concentration distribution.

[0048] In addition, the distribution measuring device 22 may measure the temperature distribution and NOx concentration distribution in the combustion chamber 11, and the combustion control device 21 may determine the area where the high temperature area and the high NOx concentration area overlap, and adjust the reference value of the operation amount of the operating terminal based on this overlapping area.

[0049] Furthermore, the distribution measuring device 22 may measure the oxygen concentration distribution and the NOx concentration distribution in the combustion chamber 11, and the combustion control device 21 may determine the area where the high oxygen concentration area and the high NOx concentration area overlap, and adjust the reference value of the operation amount of the operating end based on this overlapping area. (NOx concentration prediction device)

[0050] Depending on the incinerator 1, there may be cases where the correlation between the temperature distribution and oxygen concentration distribution of the combustion chamber 11 and the NOx concentration generated in the combustion chamber 11 is unknown. In such cases, a NOx concentration prediction device 23 is provided to obtain the correlation between the temperature distribution and oxygen concentration distribution of the combustion chamber 11 and the NOx concentration downstream of the combustion chamber 11.

[0051] 2, data on temperature distribution and oxygen distribution measured by distribution measuring device 22 are input as learning input data to NOx concentration prediction device 23. NOx concentration data measured by gas concentration meter 31 (see FIG. 1) is also input as learning output data to NOx concentration prediction device 23. These data are stored as a database in memory unit 24 of NOx concentration prediction device 23.

[0052] The NOx concentration prediction device 23 uses the learning input data and the learning output data as teacher data to generate a NOx concentration prediction learning model 25 by machine learning such as deep learning using a neural network. If the data of the temperature distribution and oxygen concentration distribution measured by the distribution measurement device 22 is input to the generated NOx concentration prediction learning model 25, a predicted value of the NOx concentration is output. In this way, the NOx concentration prediction device 23 obtains a correlation between the temperature distribution and oxygen concentration distribution of the combustion chamber 11 and the NOx concentration downstream of the combustion chamber 11. The NOx concentration prediction device 23 may obtain this correlation by a fluid simulation. Alternatively, the distribution measurement device 22 may measure the NOx concentration distribution of the combustion chamber 11, and the NOx concentration prediction learning model 25 may obtain a correlation between the temperature distribution and oxygen concentration distribution of the combustion chamber 11 and the NOx concentration distribution of the combustion chamber 11.

[0053] Next, the NOx concentration prediction device 23 identifies the temperature distribution and oxygen concentration distribution of the combustion chamber 11 that can reduce the NOx concentration downstream of the combustion chamber 11. Then, as shown in Fig. 2, data on the identified temperature distribution and oxygen concentration distribution is transmitted to the operation amount reference value calculation unit 32 of the combustion control device 21. The operation amount reference value calculation unit 32 adjusts (corrects) the operation amount reference values ​​of each operation terminal based on the data on the temperature distribution and oxygen concentration distribution input from the NOx concentration prediction device 23. (Effects of the control device of this embodiment)

[0054] The effects of the control device 2 of this embodiment will be described below.

[0055] The NOx generated in the combustion chamber 11 includes thermal NOx generated by the oxidation of air, and fuel NOx generated by the oxidation of nitrogen contained in waste materials. Both types of NOx are generated locally in areas of high temperature and high oxygen concentration. According to the combustion control device 21 of this embodiment, the local generation of NOx in the combustion chamber 11 can be predicted, so that the generation of NOx in the combustion chamber 11 can be suppressed. In addition, since the control index is not only the NOx concentration distribution but also the temperature distribution and the oxygen concentration distribution, control is easy.

[0056] The area of ​​the region where the high temperature region and the high oxygen concentration region overlap is evaluated, and the reference values ​​of the manipulated variables of each control terminal are controlled based on the evaluation results, making control easy.

[0057] The NOx concentration downstream of the combustion chamber 11 is measured, and the correlation between the temperature distribution and oxygen concentration distribution of the combustion chamber 11 and the NOx concentration downstream of the combustion chamber 11 is determined, so that the temperature distribution and oxygen concentration distribution of the combustion chamber 11 can be used for control, which can lower the NOx concentration downstream of the combustion chamber 11.

[0058] It should be noted that the present invention is not limited to the above-described embodiment, and can be embodied in other embodiments without departing from the spirit and scope of the present invention.

[0059] For example, in the above embodiment, an example was described in which the incinerator was a stoker type incinerator, but the incinerator may also be a fluidized bed incinerator, an ash melting furnace, or the like.

[0060] In the above embodiment, the evaluation unit of the combustion control device evaluates the area of ​​the region where the high temperature region and the high oxygen concentration region overlap, and the operation amount reference value calculation unit adjusts the operation amount reference value of the operating end based on the evaluation result of the evaluation unit, but the operator may evaluate the area of ​​the region where the high temperature region and the high oxygen concentration region overlap, and adjust the operation amount reference value of the operating end based on the operator's evaluation result. [Explanation of symbols]

[0061] 1. Incinerator 2...Control device 6…Fuel supply device 7…Grate 10b~10d…Under-grate combustion air damper 11…Combustion chamber 19...Gas damper for mixing 21...Combustion control device 22...Distribution measurement device 23...Nitrogen oxide concentration prediction device 31...Gas concentration meter

Claims

1. measuring at least one of a temperature distribution and an oxygen concentration distribution, a temperature distribution and a nitrogen oxide concentration distribution, or an oxygen concentration distribution and a nitrogen oxide concentration distribution in a combustion chamber of a furnace; determining at least one of an overlapping region of a high temperature region and a high oxygen concentration region, an overlapping region of a high temperature region and a high nitrogen oxide concentration region, or an overlapping region of a high oxygen concentration region and a high nitrogen oxide concentration region in the combustion chamber; A furnace control method for controlling at least one of the combustion air distribution amount, the amount of stirring gas for stirring the gas in the combustion chamber, the fuel supply device feed rate, and the grate feed rate based on the overlapping area.

2. measuring the temperature distribution and the oxygen concentration distribution in the combustion chamber of the furnace; 2. The method of claim 1, further comprising determining an overlapping region of the high temperature region and the high oxygen concentration region in the combustion chamber.

3. A furnace control method as described in claim 1 or 2, characterized in that the area of ​​the overlapping region is evaluated, and at least one of the combustion air distribution amount, the stirring gas amount, the fuel supply device feed rate, and the grate feed rate is controlled based on the evaluation result.

4. measuring a nitrogen oxide concentration downstream of the combustion chamber; 3. The method for controlling a furnace according to claim 2, wherein a correlation is determined between the temperature distribution and oxygen concentration distribution in said combustion chamber and the nitrogen oxide concentration downstream of said combustion chamber.

5. measuring a nitrogen oxide concentration distribution in the combustion chamber; 3. The method of claim 2, further comprising determining a correlation between the temperature distribution and oxygen concentration distribution in the combustion chamber and the nitrogen oxide concentration distribution in the combustion chamber.

6. a distribution measuring device for measuring at least one of a temperature distribution and an oxygen concentration distribution, a temperature distribution and a nitrogen oxide concentration distribution, or an oxygen concentration distribution and a nitrogen oxide concentration distribution in a combustion chamber of a furnace; and a combustion control device that determines at least one of an overlapping area between a high temperature area and a high oxygen concentration area in the combustion chamber, an overlapping area between a high temperature area and a high nitrogen oxide concentration area, or an overlapping area between a high oxygen concentration area and a high nitrogen oxide concentration area, and controls at least one of the amount of combustion air distributed, the amount of stirring gas for stirring the gas in the combustion chamber, the fuel supply device feed rate, and the grate feed rate based on the overlapping area.

7. the distribution measurement device measures a temperature distribution and an oxygen concentration distribution in the combustion chamber of the furnace; 7. The furnace control system according to claim 6, wherein the combustion control system determines an overlapping region of a high temperature region and a high oxygen concentration region in the combustion chamber.

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