Combustion device and control method

Abstract

Provided is a control method for a waste incineration facility that reduces NOx emissions. 【Solution means】The combustion device is a furnace body that includes a furnace hearth into which the gas after combustion flows, a drying stage, a combustion stage, and a post-combustion stage, and conveys the waste to be incinerated while burning it. When the upstream side in the conveyance direction of the waste to be incinerated is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, it has a primary combustion chamber having a front ceiling portion extending forward from the furnace hearth, a rear ceiling portion extending rearward from the furnace hearth, and a rear wall extending downward from the rear end portion of the rear ceiling portion, a secondary combustion chamber connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, an optical measurement device that detects an object in a specific wavelength band provided in the primary combustion chamber, a means for calculating a detection position of the object of the specific wavelength, and by activating the reaction of the unburned gas at the detection position to promote the generation of NOx, increasing the NOx concentration at an early stage to increase the reaction rate of reduction in the reduction region downstream.

Description

Technical Field

[0001] The present disclosure relates to a combustion device and a control method.

Background Art

[0002] There is a demand for reducing the emission amount of harmful gases discharged from waste incineration facilities. For example, Patent Document 1 discloses a technique for measuring the surface temperature of waste in an incinerator using infrared rays, measuring the temperature inside the furnace using a temperature sensor, and performing combustion control based on the measured waste surface temperature and furnace temperature, thereby reducing the emission amount of dioxins. Patent Document 1 does not disclose a control method for NOx reduction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a demand for a technique for reducing the emission amount of NOx.

[0005] The present disclosure provides a combustion device and a control method capable of solving the above problems.

Means for Solving the Problems

[0006] The combustion device of the present disclosure includes a furnace into which the gas after combustion flows, and a furnace body that includes a drying stage, a combustion stage, and a post-combustion stage and conveys the object to be incinerated while burning it. When the upstream side in the conveyance direction of the object to be incinerated is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, it has a primary combustion chamber having a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end portion of the rear ceiling portion, a secondary combustion chamber provided connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, an optical measurement device that detects an object in a specific wavelength band provided in the primary combustion chamber, and means for calculating the detection position of the object of the specific wavelength and activating the reaction of the unburned gas at the detection position to promote the generation of NOx. Regarding a plurality of wind boxes which are supply ports of primary air arranged along the conveying path below the conveying path for conveying the object to be incinerated, when the distance from the upstream end of the wind box arranged directly below the detection position to the detection position in the conveying direction is equal to or greater than a predetermined value, the primary air supplied from the wind box directly below is increased, and when the distance is less than the predetermined value, the primary air supplied from the wind box one upstream of the wind box directly below is increased. Alternatively, by increasing the primary air supplied to the detection position on the upstream side of the primary combustion chamber, the reaction of unburned gas at the detection position is activated to promote the generation of NOx, the NOx is reduced in the secondary combustion chamber from the downstream side of the primary combustion chamber, and the reduced substance is completely burned in the furnace after the secondary combustion chamber, thereby reducing the NOx discharged from the device.

[0007] The control method of the present disclosure is for a combustion device including a furnace into which the gas after combustion flows, and a furnace body that includes a drying stage, a combustion stage, and a post-combustion stage and conveys the object to be incinerated while burning it. When the upstream side in the conveyance direction of the object to be incinerated is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, it has a primary combustion chamber having a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end portion of the rear ceiling portion, a secondary combustion chamber provided connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, and an optical measurement device that detects an object in a specific wavelength band provided in the primary combustion chamber. A computer calculates the detection position of the object of the specific wavelength, Regarding a plurality of wind boxes which are supply ports of primary air arranged along the conveying path below the conveying path for conveying the object to be incinerated, when the distance from the upstream end of the wind box arranged directly below the detection position to the detection position in the conveying direction is equal to or greater than a predetermined value, the primary air supplied from the wind box directly below is increased, and when the distance is less than the predetermined value, the primary air supplied from the wind box one upstream of the wind box directly below is increased, thereby activates the reaction of the unburned gas at the detection position to promote the generation of NOx.

Advantages of the Invention

[0008] According to the combustion device and control method of the present disclosure, the emission amount of NOx can be reduced.

Brief Description of the Drawings

[0009]

Figure 1

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MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. And the overlapping descriptions of those configurations may be omitted. The following embodiments do not limit the invention according to the claims. Also, not all combinations of the features described in the embodiments are essential for the solution means of the invention.

[0011] In the present disclosure, "based on XX" means "based at least on XX", and may include cases where it is based on other elements in addition to XX. Also, "based on XX" is not limited to the case of directly using XX, and may include cases where it is based on something obtained by performing operations or processing on XX. In the present disclosure, "XX or YY" is not limited to either XX or YY, and may include both XX and YY. This is the same even when there are three or more selectable elements. "XX" and "YY" are arbitrary elements (for example, arbitrary information).

[0012] In this application, "acquire" is not limited to the case of actively acquiring by transmitting a transmission request, and may include cases of acquiring by passively receiving information transmitted from other devices. Also, "acquire" is not limited to the case of directly acquiring the target information (information to be acquired) from the outside, and may include cases of generating and acquiring the target information by performing operations or processing on the information obtained from the outside.

[0013] Also, in the embodiments described below, for the sake of convenience of explanation, the side where the furnace body 30 is located with respect to the hopper 21 described later is defined as "rear", and the opposite side is defined as "front". In the following, for the sake of convenience of explanation, the upstream side in the conveyance direction of the object to be incinerated may be referred to as "front", and the downstream side in the conveyance direction may be referred to as "rear". Also, the "front side" may be referred to as the "front side of the furnace", and the "rear side" may be referred to as the "rear side of the furnace". Also, "left" and "right" are defined based on the direction from the hopper 21 toward the furnace body 30.

[0014] <Embodiment> Hereinafter, the low NOx control of the garbage combustion equipment of the present disclosure will be described with reference to FIGS. 1 to 12. (Overall configuration of combustion equipment) FIG. 1 is a diagram showing an example of the configuration of a combustion facility according to an embodiment. For example, the combustion facility 1 is a stoker furnace that uses municipal waste, industrial waste, biomass, or the like as the waste S to be incinerated. Note that the combustion facility 1 is not limited to a stoker furnace, and may be another type of combustion facility. Hereinafter, for convenience of explanation, the "waste to be incinerated" may be referred to as "garbage" in some cases. For example, the combustion facility 1 includes a control device 2, an incinerator 3, a waste heat recovery boiler 4, a desuperheater 5, a dust collector 6, a flue 7, and a chimney 8.

[0015] The incinerator 3 is a furnace that burns the waste S to be incinerated while conveying the waste S introduced from a storage section (not shown) that temporarily stores the collected waste S to be incinerated. Exhaust gas is generated in the incinerator 3 due to the combustion of the waste S in the incinerator 3. The generated exhaust gas is sent to a waste heat recovery boiler 4 provided above the incinerator 3. The waste heat recovery boiler 4 heats water by performing heat exchange between the exhaust gas generated in the incinerator 3 and water to generate steam. The exhaust gas that has passed through the waste heat recovery boiler 4 is cooled in the desuperheater 5 and then sent to the dust collector 6. The exhaust gas is discharged into the atmosphere through the flue 7 and the chimney 8 after the soot and dust are removed by the dust collector 6.

[0016] The incinerator 3 has, for example, a supply mechanism 20, a furnace body 30, a stoker 40, a discharge chute 43, a plurality of wind boxes 50a to 50e, a firebox 60, a blower mechanism 70, a first EGR nozzle 91, and a second EGR nozzle 93.

[0017] The supply mechanism 20 is a mechanism that temporarily stores the waste S introduced from a storage section (not shown) and sequentially supplies it toward the processing space V of the furnace body 30 described later. The supply mechanism 20 has, for example, a hopper 21, a feeder 22, a moisture meter 23, and a watering device 24.

[0018] The hopper 21 is a storage section provided to supply the waste S into the furnace body 30. The hopper 21 has an inlet section into which the waste S is introduced and an outlet section that communicates with the processing space V of the furnace body 30 described later. The waste S carried by a crane is introduced into the hopper 21.

[0019] The feeder 22 is provided at the bottom of the hopper 21. The feeder 22 is formed, for example, in a plate shape along the bottom of the hopper 21. The feeder 22 is driven by the control device 2 and is reciprocally movable along the direction from the hopper 21 toward the processing space V of the furnace body 30. The feeder 22 pushes out the waste S deposited inside the hopper 21 toward the processing space V of the furnace body 30. The moisture meter 23 is a measuring instrument that detects information (for example, moisture content or moisture amount) regarding the moisture content of the waste S introduced into the hopper 21. The watering device 24 is a device that adjusts the moisture content of the waste S by watering the waste S.

[0020] The furnace body 30 is provided adjacent to the hopper 21 and is a facility for burning while conveying the waste S. Hereinafter, the conveying direction of the waste S in the combustion facility 1 is referred to as the "conveying direction D". The conveying direction D may also be referred to as the "depth direction".

[0021] The furnace body 30 has a drying stage 30a, a combustion stage 30b, and a post-combustion stage 30c in this order from the upstream side to the downstream side in the conveying direction D. The furnace body 30 conveys the waste S from the upstream side to the downstream side while burning it. The drying stage 30a is located upstream of the combustion stage 30b and the post-combustion stage 30c and is a region for drying the waste S supplied from the hopper 21 prior to combustion on the stoker 40. The combustion stage 30b and the post-combustion stage 30c are regions for burning the waste S in a dried state that has passed through the drying stage 30a on the stoker 40. In the combustion stage 30b, diffusion combustion occurs due to the pyrolysis gas generated from the waste S, and a flame F is generated. In the post-combustion stage 30c, fixed carbon combustion occurs after the diffusion combustion of the waste S, so no flame F is generated.

[0022] The furnace body 30 has, for example, a furnace internal temperature sensor 31 and a furnace internal pressure sensor 35. The furnace internal temperature sensor 31 is, for example, a thermocouple and detects the temperature inside the furnace body 30 (which may sometimes be referred to as "inside the furnace"). The furnace internal pressure sensor 35 detects the pressure inside the furnace body 30. A plurality of furnace internal temperature sensors 31 may be provided.

[0023] The furnace body 30 has, for example, a visible light camera 32 and an infrared camera 33. The visible light camera 32 and the infrared camera 33 photograph the inside of the furnace body 30. For example, the visible light camera 32 and the infrared camera 33 are provided at the downstream end of the furnace body 30 in the conveying direction D (hereinafter referred to as the "furnace bottom"), and photograph the upstream side in the conveying direction D from the furnace bottom.

[0024] The visible light camera 32 photographs, for example, the flame F. The infrared camera 33 photographs the gas in the furnace. The inside of the furnace is photographed by the infrared camera 33 equipped with a filter that transmits specific wavelengths (CO: 2125 - 2245 nm, CO2: 4160 - 4360 nm, H2O: 1375 - 1425 nm, NH3: 1500 - 1600 nm, background (flame transmission): 3800 - 4000 nm) according to the gas species present in the furnace. The imaging results of the visible light camera 32 and the infrared camera 33 are transmitted to the control device 2.

[0025] Note that the infrared camera 33 may be constituted by, for example, a plurality of infrared cameras arranged in a stereo manner. Also, instead of the furnace bottom of the furnace body 30, the visible light camera 32 and the infrared camera 33 may be provided at another position (such as the left side wall and / or the right side wall of the furnace body 30). Also, both or one of the visible light camera 32 and the infrared camera 33 may be omitted. Further, instead of / in addition to the infrared camera 33, a depth camera, a stereo camera, a multispectral camera, a laser, etc. may be provided.

[0026] The stoker 40 includes a plurality of fire grates 41. The plurality of fire grates 41 form a stoker surface 40a that is the bottom surface of the furnace body 30. The object to be incinerated S is supplied in layers to the stoker surface 40a by the supply mechanism 20. The stoker surface 40a is provided over the above-described drying stage 30a, combustion stage 30b, and afterburning stage 30c. The plurality of fire grates 41 include a fixed fire grate and a movable fire grate. The fixed fire grate is fixed to the upper surfaces of the air boxes 50a to 50e described later. The movable fire grate reciprocates along the conveyance direction D at a constant speed, and conveys the object to be incinerated S on the movable fire grate and the fixed fire grate (on the stoker surface 40a) downstream while stirring and mixing it.

[0027] The discharge chute 43 is a device that drops the object to be incinerated S that has finished burning and become ash to an ash extrusion device located below the furnace body 30. The discharge chute 43 is provided at the bottom of the furnace body 30.

[0028] The plurality of air boxes 50a to 50e are provided below the stoker 40 and supply primary air for combustion into the furnace body 30 through the stoker 40. In the present embodiment, the plurality of air boxes 50a to 50e are arranged side by side in the conveyance direction D corresponding to, for example, the plurality of fire grates 41. An air box pressure sensor 51a for detecting the pressure inside the air box 50a is provided in the air box 50a. The pressure inside the air box 50a corresponds to the pressure of the primary air supplied from the air box 50a into the furnace body 30. Similarly, air box pressure sensors 51b, 51c, 51d, and 51e are provided in the air boxes 50b, 50c, 50d, and 50e, respectively. The air boxes 50a to 50e may be collectively referred to as the air box 50, and the air box pressure sensors 51a to 51e may be collectively referred to as the air box pressure sensor 51.

[0029] The furnace 60 extends upward from the upper part of the furnace body 30. The furnace 60 is disposed above the grate 41 and the combustion gas after combustion flows in. That is, the exhaust gas generated by the combustion of the object to be incinerated S in the furnace body 30 flows into the exhaust heat recovery boiler 4 through the furnace 60. The furnace 60 includes a front wall 60a located on the front side of the space through which the exhaust gas flows and a rear wall 60b located on the rear side of the space through which the exhaust gas flows. The front wall 60a and the rear wall 60b extend in the vertical direction, for example. When the upstream side in the conveyance direction of the object to be incinerated S is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, the furnace 60 has a front ceiling part 55 extending forward from the furnace 60, a rear ceiling part 57 extending rearward from the furnace 60, and a rear wall 59 extending downward from the rear end part of the rear ceiling part 57. This space is called the primary combustion chamber. Also, the space that is connected to the outlet side of the primary combustion chamber and constitutes the lower part of the furnace 60 is called the secondary combustion chamber.

[0030] The blower mechanism 70 supplies combustion air to the inside of the furnace body 30 and the furnace 60. The blower mechanism 70 has, for example, a blower 71, a primary air line 72, an air preheater 73, a secondary air line 74, a damper 75, and an air flow sensor 76.

[0031] The blower 71 is a forced draft blower that pumps combustion air into the furnace body 30 and the furnace 60. The blower 71 includes, for example, a first blower 71A and a second blower 71B. The first blower 71A pumps primary combustion air into the inside of the furnace body 30 (for example, the processing space V, the primary combustion chamber) through the primary air line 72 and a plurality of wind boxes 50a to 50e. The second blower 71B pumps secondary combustion air into the inside of the furnace 60 (for example, the processing space V´, the secondary combustion chamber) through the secondary air line 74.

[0032] The primary air line 72 connects the first blower 71A and the plurality of wind boxes 50a to 50e. One or more (for example, a plurality of) primary air dampers 75A are provided in the middle of the primary air line 72. In the present embodiment, the plurality of primary air dampers 75a to 75e are provided in a one-to-one correspondence with the plurality of wind boxes 50a to 50e. The primary air damper 75a changes the flow rate of the primary air flowing into the wind box 50a corresponding to the primary air damper 75a from the primary air line 72 according to the opening degree of the primary air damper 75a. The same applies to the primary air dampers 75b to 75e. In other words, the distribution ratio of the primary air in the plurality of wind boxes 50a to 50e (which wind box 50a etc. supplies the primary air into the furnace body 30 preferentially) is changed by the opening degrees of the plurality of primary air dampers 75a to 75e.

[0033] The air preheater 73 is a heat exchanger that preheats the primary air pumped from the first blower 71A. For example, the air preheater 73 is provided in the middle of the primary air line 72. The air preheater 73 has a preheating temperature sensor 73a that detects the temperature of the preheated primary air.

[0034] The secondary air line 74 connects the second blower 71B and the furnace 60. In the present embodiment, the secondary air line 74 has a first supply port 74a and a second supply port 74b. The first supply port 74a opens to the front wall 60a of the furnace 60 and supplies secondary air from the front wall 60a of the furnace 60 into the space (exhaust gas flow path) in the furnace 60. On the other hand, the second supply port 74b opens to the rear wall 60b of the furnace 60 and supplies secondary air from the rear wall 60b of the furnace 60 into the space (exhaust gas flow path) in the furnace 60. One or more (for example, a plurality of) secondary air dampers 75B are provided in the middle of the secondary air line 74.

[0035] The air flow sensor 76 detects the flow rate of the combustion air supplied to the inside of the furnace body 30 and the hearth 60. The air flow sensor 76 includes, for example, a first air flow sensor 76A and a second air flow sensor 76B. The first air flow sensor 76A is provided in the middle of the primary air line 72 and detects the flow rate of the primary air supplied through the primary air line 72. The second air flow sensor 76B is provided in the middle of the secondary air line 74 and detects the flow rate of the secondary air supplied through the secondary air line 74. The first air pressure sensor 77 detects the pressure of the combustion air supplied to the inside of the furnace body 30. The first air pressure sensor 77 is provided in the middle of the primary air line 72 and detects the pressure of the primary air supplied through the primary air line 72.

[0036] The gas sensor 81 is a sensor that detects the components in the exhaust gas. The gas sensor 81 can detect, for example, the oxygen concentration (hereinafter referred to as "O2 concentration"), carbon monoxide concentration (hereinafter referred to as "CO concentration") (unburned components), carbon dioxide concentration (hereinafter referred to as "CO2 concentration"), or NOx concentration, and the air-fuel ratio in the primary combustion zone, etc. The gas sensor 81 is provided, for example, in the flue 7, but may be provided inside the chimney 8 or at another location (for example, a location where the gas after combustion can be detected).

[0037] The first EGR nozzle 91 is provided in a region behind the center of the rear ceiling portion 57 in the conveyance direction of the object to be incinerated S in the rear ceiling portion 57 or on the rear wall 59 extending downward from the rear end portion of the rear ceiling portion 57. The first EGR nozzle 91 discharges EGR, air, or EGR mixed with air forward.

[0038] The second EGR nozzle 93 is provided at a position in front of the first EGR nozzle 91 in the rear ceiling portion 57. The second EGR nozzle 93 discharges EGR, air, or EGR mixed with air (an example of the second combustion gas) from the rear ceiling portion 57 toward the drying stage 30a or the combustion stage 30b. The second EGR nozzle 93 is provided with an angle adjustment mechanism 97 capable of changing the direction of discharging the EGR.

[0039] (Control device) Next, the control device 2 will be described. FIG. 2 is a block diagram showing the functional configuration of the control device 2. The control device 2 controls the combustion equipment 1. For example, the control device 2 performs combustion control of the waste S in the furnace body 30. The control device 2 has various functions, but only the functions related to the low NOx control according to this embodiment will be described.

[0040] The control device 2 includes an acquisition unit 2a, a position identification unit 2b, a distribution determination unit 2c, and a control unit 2d. The acquisition unit 2a acquires the images captured by the visible light camera 32 and the infrared camera 33. In the low NOx control of this embodiment, the visible light camera 32 and the infrared camera 33 are used for the purpose of measuring the emission positions of various gases in the furnace. A plurality of infrared cameras 33 may be provided as illustrated in FIG. 3. FIG. 3 is a view of the furnace body 30 seen from above. A plurality of infrared cameras, such as infrared cameras 33-1 to 33-14, may be provided on the side surface of the furnace body 30 so as to photograph the front side obliquely across the drying stage 30a, the combustion stage 30b, and the post-combustion stage 30c. Alternatively, a plurality of infrared cameras, such as infrared cameras 33-15 to 33-16, may be provided near the ceiling side of the post-combustion stage 30c. By providing a plurality of infrared cameras 33-1 to 33-16, etc., and analyzing the images captured by each camera, the emission positions of various gases can be accurately detected.

[0041] The position identification unit 2b identifies the position where the primary air supplied into the furnace is increased to achieve low NOx. The distribution determination unit 2c determines the distribution ratio of the primary air supplied into the furnace from each of the wind boxes 50a to 50e. The control unit 2d controls the primary air dampers 75a to 75e to control the flow rate of the primary air supplied from the wind boxes 50a to 50e into the furnace so that the flow rate of the primary air becomes the distribution ratio determined by the distribution determination unit 2c.

[0042] (Low NOx control) Next, with reference to FIG. 4, the low NOx control of this embodiment will be described. In this embodiment, the position (depth direction position) where unburned gas (CO, NH3) and burned gas (CO2, H2O) exist is estimated from the image captured by the infrared camera 33. In order to actively generate NOx upstream of the stoker 40 (for example, upstream of the primary combustion chamber which is a reduction zone, for example, the first half of the drying stage 30a to the combustion stage 30b), primary air is preferentially fed into the combustion position. As a result, NOx is generated (partially oxidized) directly above the layer where the waste burns, reduced in the hearth space, and completely burned in the furnace 60. In the hearth space, the unburned components generated by char combustion serve as a reducing agent.

[0043] The arrows 1 to 4 shown in FIG. 4 indicate the gas flow in the furnace when the low NOx control of this embodiment is implemented. The gas of the volatile matter burned by the primary air introduced from below the stoker 40 is drawn into the hearth space as shown in the figure and flows toward the furnace 60 along the space in the furnace body 30. In the example of FIG. 4, relatively more primary air is supplied into the furnace from the windbox 50b where the flame F exists. By increasing the amount of primary air at the position of the flame F, the N contained in the fuel is oxidized and the generation of NOx is promoted. In arrow 1, the release and transportation of the volatile matter gas occur. For low NOx, it is important to promote combustion at the position where the volatile matter gas is released. In arrows 2 and 3, reduction combustion occurs. Next, compared with the conventional control shown in FIGS. 5 and 6, the region where reduction combustion occurs can be made wider. By widening the region of reduction combustion, the time required for NOx reduction can be ensured. In arrow 4, complete combustion occurs. By widening the reduction combustion region, at the position of arrow 4, N is reduced compared with the conventional control, the generation of NOx at the position of arrow 4 (secondary combustion chamber) is suppressed, and as a result, the NOx discharged from the combustion facility 1 can be reduced.

[0044] For comparison, FIG. 5 shows an example of the gas flow in the furnace when the low NOx control of the present embodiment is not applied. The gas flow path and the flow direction are the same as those in the case of FIG. 4. In the case of FIG. 5, relatively more primary air is supplied into the furnace from the wind box 50c on the downstream side of the flame F. At the position of arrow 1, due to the lack of O, the N of the fuel cannot be released from the aromatic ring. At the furnace bottom position of arrow 2, a region with a high O2 concentration is locally formed, and an oxidation combustion region is generated. Therefore, NOx is generated at the positions of arrows 3 to 4. In this example, NOx is not reduced.

[0045] FIG. 6 shows another example of the gas flow in the furnace when the low NOx control of the present embodiment is not applied. The gas flow path and the flow direction are the same as those in the case of FIG. 4. In the case of FIG. 6, primary air is supplied into the furnace from each of the wind boxes 50a to 50e in an equal distribution. At the position of arrow 1, volatile gas is released, at the position of arrow 2, gas transport is performed, at the position of arrow 3, reduction combustion occurs, and at the position of arrow 4, complete combustion occurs. When the mixing of air and volatiles is insufficient by the combustion stage 30b, N is not sufficiently released from the aromatic ring in the reduction region of arrow 3. Then, the residence time of NOx in the reduction region is insufficient, and it flows out to the outlet without sufficient reduction. Also, N remains in the complete combustion region of arrow 4, increasing the generation of NOx. Therefore, in this example, NOx is not reduced.

[0046] The N component in the material S to be incinerated exists in a state of being combined with hydrocarbons, and when this is oxidized, it becomes NOx. When suppressing NOx by a two-stage combustion method of reduction and oxidation, it is necessary to complete the chemical reaction of NOx with a reducing substance to N2 in the first-stage reduction zone, and to ensure that as little NOx as possible remains in the second-stage oxidation zone. The problem here is that when the N component is combined with hydrocarbons, it does not become N2 by the reduction reaction, and if the N component in the hydrocarbons remains until the oxidation zone, oxidation occurs in the oxidation zone and NOx is formed. Therefore, in the reduction zone, it is required to oxidize the N component in the hydrocarbons to NOx as early as possible. Thus, in the present embodiment, as shown in FIG. 4, the position where the volatile gas is released is specified, the primary air supplied to the specified position is increased, and the N component in the volatile matter is oxidized early to form NOx. By doing so, the reduction zone is widened, the residence time of NOx in the reduction zone is sufficiently taken, NOx is changed to N2, and the generation of NOx in the oxidation zone is suppressed. Also, by promoting the generation of NOx and increasing the NOx concentration early, the reaction rate of reduction in the subsequent reduction zone can be increased. Thereby, low NOx formation is realized. Generally, the control of the primary air is often performed to adjust the flame position, but in the present embodiment, the distribution control of the primary air is performed for the purpose of promoting the generation of NOx in the reduction zone.

[0047] (Specification of the release position of the volatile gas) Next, a method for specifying the release position of the volatile gas will be described. The position-specific part 2b acquires an image of the furnace interior captured by an infrared camera 33 equipped with a filter that transmits specific wavelengths corresponding to gas species (CO: 2125 - 2245 nm, CO2: 4160 - 4360 nm, H2O: 1375 - 1425 nm, NH3: 1500 - 1600 nm, for background imaging (flame transmission): 3800 - 4000 nm), and identifies the volatile emission position and the main combustion position. Note that the filter for transmitting the flame for background imaging is used to more accurately identify the emission positions of CO, NH3, H2O, and CO2 by taking the difference between the image captured with this filter and the images captured with filters of other wavelengths. The filter for transmitting the flame is not essential. The position identification can be in the simplest form by combining one camera (infrared camera 33) with monocular depth estimation technology. For example, for an image captured by the infrared camera 33 equipped with a filter that transmits the wavelengths of unburned components (CO, NH3), the position-specific part 2b identifies the maximum emission position and calculates the distance from the infrared camera 33 to the identified emission position by monocular depth estimation. Also, for example, for an image captured by the infrared camera 33 equipped with a filter that transmits the wavelengths of burned components (H2O, CO2), the position-specific part 2b identifies the maximum position of the luminance change and calculates the distance from the infrared camera 33 to the identified emission position by monocular depth estimation. An example of an image captured by the infrared camera 33 is shown in Fig. 7(a), and a schematic of monocular depth estimation is shown in Fig. 7(b). Fig. 7(a) is an image captured with a filter for CO. 71 and 72 are the emission positions (positions with high CO concentration).

[0048] Further, for example, the position specifying unit 2b may estimate the concentrations of CO, CO2, H2O, and NH3, and specify the active combustion position from the differential value of the concentration as the volatile gas emission position. For example, the position specifying unit 2b obtains an image in which the gas information is in a steady state and the instantaneous state of the object to be incinerated S is photographed by changing the filters for CO, CO2, H20, and NH3 respectively and photographing for several seconds each. Then, the position specifying unit 2b generates an average image or a standard deviation image of the images photographed in each wavelength band by image processing, and uses a function that defines the relationship between the temperature, density, and luminance ratio constructed based on theory to calculate the temperature obtained from the image (or the measured value of the in-furnace temperature sensor 31 may also be used.) and the density of each gas from the luminance and the function, and converts the density to the concentration. For example, the reaction progress can be calculated from the concentration ratio of CO and CO2. Also, for H2O, assuming the maximum value of the H2O concentration is 20% and the measured concentration is 10%, 10% / 20% = reaction progress 0.5 may be used. The gas concentration and the reaction progress are used when determining how much flow rate to supply to the specified position (described later). Further, the position specifying unit 2b may calculate the active combustion position from the differential value of the calculated concentration, and specify the calculated position as the volatile gas emission position. It can be considered that the closer the active combustion position is to the upstream side of the primary combustion chamber, the more the generation of NOx is promoted. Note that the measurement order of the concentrations of each gas species is performed in the order of first the post-combustion components (CO2, H2O), then the unburned components (NH3, CO), and then calculating the reaction progress. When there are differences in the evaluation results of the volatile matter emission amount for each of the estimated values of the CO and NH3 concentrations, the reaction progress evaluation value based on the H2O concentration, and the CO / CO2 ratio (for example, the evaluation from the CO concentration shows a high volatile matter amount, while the evaluation from the CO / CO2 ratio is low), the values are trusted with the priority of CO concentration estimated value > NH3 concentration estimated value > reaction progress evaluation value based on H2O concentration > CO / CO2 ratio (the priority of the CO concentration estimated value is the highest).

[0049] Note that the position specification by the above-described camera 33 is an example. As another embodiment, it may be as follows. (a) Instead of attaching filters for various gases, an image inside the furnace may be captured by a multispectral camera, and an image in the wavelength band corresponding to each gas type may be obtained through digital filter processing. (b) Prepare a plurality of infrared cameras equipped with the above filters, estimate the release positions of volatile gases from the respective images captured by the plurality of cameras, and combine these estimation results to specify the three-dimensional position of the release position of the volatile gases. Alternatively, two infrared cameras equipped with monocular depth estimation may be arranged at positions where they can complement each other's blind spots, estimate the release positions of volatile gases from the respective images captured by the two cameras, and combine these estimation results to specify the release position of the volatile gases. (c) Estimate the flame position (volatile release position) using a machine learning device that has learned the relationship between various plant data (for example, in-furnace temperature, pressure, flow rates of wind boxes 50a to 50e, etc.) and the flame position. (d) Calculate the distance from the position of the luminous flame (the position behind the flame) included in the image captured by the visible light camera 32 installed at the furnace bottom to the visible light camera 32. In this case, since it is not precisely known where the front side of the flame is, the position on the front side by a predetermined length from the position indicated by the calculated distance from the visible light camera 32 is estimated as the flame position (volatile gas release position). (e) Emit one or more laser lights into the furnace and identify the high-CO region through laser CT measurement. (f) Install temperature sensors in the longitudinal direction of the stoker 40, and estimate the position where the measured temperature is the highest or the position where the measured temperature is equal to or higher than a predetermined threshold as the flame position (volatile gas release position).

[0050] (Estimation of pressure loss, etc.) As described above, in this embodiment, NOx is actively generated in the drying stage 30a to the combustion stage 30b, and NOx is reduced in the hearth space. In order to promote the generation of NOx, the supply amount of the primary air is increased at the position where the volatile gas is released or slightly upstream thereof. In order to control the flow rate of the primary air supplied into the furnace to a desired value, it is necessary to consider the pressure loss of the primary air dampers 75a to 75e, the leakage between the wind boxes 50a to 50e (holes are opened in the wind boxes 50a to 50e, and when there is a pressure difference in the adjacent wind box 50, the primary air flows into the adjacent wind box 50), the pressure loss of the fire grate 41, etc. Therefore, a ventilation test is carried out before the waste is charged or during the furnace shutdown, and the relationship between the opening degree, pressure loss, and leakage of the primary air dampers 75a to 75e is calculated in advance.

[0051] FIGS. 8A to 8C show schematic diagrams of the primary air supply system. The fire grates 41a to 41 respectively represent the fire grates corresponding to the wind boxes 50a to 50e, and the objects to be incinerated Sa to Se respectively indicate the object to be incinerated S conveyed onto the fire grates 41a to 41. The leak 52ab represents the leak between the wind boxes 50a and 50b, 52bc represents the leak between the wind boxes 50b and 50c, 52cd represents the leak between the wind boxes 50c and 50d, and 52de represents the leak between the wind boxes 50d and 50e.

[0052] In the ventilation test, the pressure loss coefficient and leakage of each wind box damper alone are obtained. For example, as shown in FIG. 8B, with no waste layer, only one damper, for example, the primary air damper 75a, is operated, and the other primary air dampers 75b to 75e are closed. The opening degree of the primary air damper 75a is varied in various ways, and the relationship between the opening degree of the primary air damper 75a and the pressure loss is obtained from the difference between the measured value of the wind box pressure sensor 51a and the measured value of the first air pressure sensor 77. Also, the flow rate of the leak 50ab is calculated from the difference between the measured value of the wind box pressure sensor 51a and the measured value of the wind box pressure sensor 51b. For example, the average value of the leak flow rates when the opening degree of the primary air damper 75a is varied in various ways may be calculated. Similarly, for the primary air dampers 75b to 75e, the relationship between the damper opening degree and the damper pressure loss, and the leak flow rate between the adjacent wind boxes 50 are calculated.

[0053] Next, as shown in FIG. 8C, by equalizing the pressures measured by the bellow pressure sensors 51a to 51e, the leak between the bellows is eliminated, the fire grates 41a to 41e are opened and closed, and the pressure losses of the fire grates 41a to 41e are calculated from the pressures measured by the furnace pressure sensor 35, the first air pressure sensor 77, and the bellow pressure sensors 51a to 51e (it is assumed that the pressure losses of the fire grates 41a to 41e are the same value). During the operation of the combustion equipment 1, from the pressure measured by the first air pressure sensor 77, the pressures measured by the bellow pressure sensors 51a to 51e, the pressure measured by the furnace pressure sensor 35, the pressure losses of the primary air dampers 75a to 75e calculated in the previous ventilation test, and the pressure losses of the fire grates 41a to 41e, the pressure losses of the refuse layers Sa to Se from the refuse layers Sa to Se are estimated (it is assumed that the pressure losses of the refuse layers Sa to Se are the same value).

[0054] The distribution determination unit 2c calculates the distribution of the primary air supplied to the primary combustion chamber through the wind boxes 50a to 50e in consideration of the pressure losses of the primary air dampers 75a to 75e, the pressure loss of the fire grate 41, the pressure loss of the refuse layer, and the leakage between the wind boxes. For example, the total loss of the flow rate resulting from the pressure losses of the primary air dampers 75a to 75e, the pressure loss of the fire grate 41, and the pressure loss of the refuse layer is "5", the leakage between the wind boxes is all "1", and it is desired to send 60% of the total primary air into the furnace from the wind box 50a and 10% of the total primary air into the furnace from each of the wind boxes 50b to 50e. Also, let the flow rate of the primary air supplied from the wind box 50a into the furnace be Xa, the flow rate of the primary air supplied from the wind box 50b into the furnace be Xb, and so on. Considering the pressure losses and the leakage between the wind boxes, the flow rate of the primary air supplied from the wind box 50a into the furnace is Xa - 5 (pressure loss) - 1 (leakage to the wind box 50b), the flow rate of the primary air supplied from the wind box 50b into the furnace is Xb - 5 (pressure loss) - 1 (leakage to the wind box 50c) + 1 (leakage from the wind box 50a), and so on. The distribution determination unit 2c calculates Xa to Xe such that this result becomes 6:1:1:1:1. At this time, the distribution determination unit 2c sets the distribution ratio of each of the wind boxes 50a to 50e so that the total of the distribution ratios of the primary air supplied to the primary combustion chamber falls within the range of 0.9 to 1.05. Also, in this embodiment, by sending a large amount of primary air to the release position of the volatile gas, the generation of NOx is promoted, but it has been confirmed that the final NOx emission amount can be reduced by sending 5 to 80% of all the primary air to the wind box 50 corresponding to the release position of the volatile gas (described later).

[0055] (Operation) FIG. 9 is a flowchart showing an example of the low NOx control according to the embodiment. The acquisition unit 2a acquires an image of a specific wavelength (step S1). For example, the acquisition unit 2a acquires images of wavelengths corresponding to CO, CO2, NH3, and H2O respectively. Next, the position identification unit 2b estimates the distance in the depth direction of the light emission position by means of a monocular depth estimation technique (step S2). The position identification unit 2b identifies the light emission position based on the luminance of the image acquired in step S1. When there are a plurality of light emission positions, all the light emission positions are identified. Next, for all the identified light emission positions, the position identification unit 2b estimates the distance from the infrared camera 33 by means of a monocular depth estimation technique. After estimating the light emission position, the position identification unit 2b then estimates the unburned component position (the above-mentioned volatile component emission position) (step S3). For unburned gas such as CO2 and NH3, the position identification unit 2b estimates the position of the maximum light emission intensity as the unburned component position (the above-mentioned volatile component emission position). Also, for burned gas such as H2O and CO2, the position identification unit 2b estimates the position with a large change in luminance as the unburned component position (the above-mentioned volatile component emission position). Further, the position identification unit 2b calculates the CO and NH3 concentrations, the progress of the reaction of H2O, the CO / CO2 ratio, etc.

[0056] Next, the position identification unit 2b determines whether the estimated unburned component position is separated from the tip of the blast box directly below by a predetermined length or more (step S4). Referring to FIG. 10 here. FIG. 10(a) is an example when the unburned component position is separated from the tip (upstream end) of the blast box directly below by a predetermined length or more. FIG. 10(b) is an example when the unburned component position is close to the tip of the blast box directly below and is not separated by a predetermined length or more. When the unburned component position is separated from the tip of the blast box directly below by a predetermined length or more (step S4; Yes, the case of FIG. 10(a)), the position identification unit 2b sets the blast box 50b directly below as the control target (step S5). When the unburned component position is not separated from the tip of the blast box directly below by a predetermined length or more (step S4; No, the case of FIG. 10(b)), the position identification unit 2b sets the blast box 50a one before (upstream side) the blast box 50b directly below the unburned component position as the control target (step S6). The position identification unit 2b notifies the distribution determination unit 2c of the blast box specified as the control target. By steps S4 to S6, primary air can be appropriately fed into the unburned component position.

[0057] Next, the distribution determination unit 2c determines the distribution of the primary air supplied to the bellows 50a to 50e (step S7). The distribution determination unit 2c has a map or function with the estimated CO concentration, the estimated NH3 concentration, the reaction progress of H2O, the CO / CO2 ratio, etc. on the horizontal axis and the target primary air ratio of the bellows to be controlled (the target value of the distribution of the primary air supplied to the bellows 50 to be controlled) on the vertical axis (for example, FIG. 11). The distribution determination unit 2c refers to this map based on the estimated CO concentration, etc., and determines the target primary air ratio corresponding to the estimated CO concentration, etc. This map is created so that the target primary air ratio is determined in the range of 5 to 80%. For the bellows 50 to be controlled, the distribution determination unit 2c determines the distribution in this way, and for the remaining bellows 50, for example, it distributes the supply amount of the primary air so as to be equal. The distribution determination unit 2c calculates the distribution ratio of the primary air supplied from each of the bellows 50a to 50e into the furnace so that the supply amount of the primary air actually supplied from the bellows 50a to 50e becomes the determined distribution ratio of the primary air, taking into account the pressure loss of dampers, etc. calculated in the prior ventilation test and the leakage between the bellows 50, and outputs the calculated distribution ratio to the control unit 2d. The control unit 2d controls the primary air dampers 75a to 75e according to the distribution ratio. As a result, the supply amount of the primary air supplied from the bellows 50a to 50e into the furnace is controlled to be the distribution ratio of the primary air determined by the distribution determination unit 2c.

[0058] (Effect) As described above, according to the present embodiment, based on the image captured by the infrared camera 33 or the like, the position where the volatile gas is generated by the combustion of the garbage is estimated. Then, by supplying a large amount (5 to 80% of the whole) of primary air to the estimated position, the reaction of the unburned gas is activated and the generation of NOx is promoted. By promoting the generation of NOx at an early stage in the primary combustion chamber, which is the reduction zone, when the garbage burns, the remaining time staying in the primary combustion chamber can be allocated to the time for reduction. For example, the hearth space can be used as the reduction zone. Further, by promoting the generation of NOx at an early stage, the NOx concentration is increased at an early stage, and the reduction reaction rate in the subsequent reduction zone is increased. Thereby, the generation of NOx in the subsequent complete combustion can be suppressed, and the emission amount of NOx from the incineration facility 1 can be reduced.

[0059] FIG. 12 is a diagram showing an example of the hardware configuration of the control device. The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The above-described control device 2 is implemented in the computer 900. And each of the above-described functions is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903 and expands it in the main storage device 902, and executes the above processing according to the program. Further, the CPU 901 secures a storage area in the main storage device 902 according to the program. Further, the CPU 901 secures a storage area in the auxiliary storage device 903 for storing the data being processed according to the program.

[0060] Note that a program for realizing all or part of the functions of the control device 2 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform processing by each functional unit. The "computer system" referred to here shall include hardware such as an OS and peripheral devices. Also, the "computer system" shall include a homepage providing environment (or display environment) if the WWW system is used. Further, the "computer-readable recording medium" refers to a portable medium such as a CD, DVD, USB, or a storage device such as a hard disk built into a computer system. Also, when this program is distributed to the computer 900 via a communication line, the computer 900 that has received the distribution may expand the program in the main storage device 902 and execute the above processing. Also, the above program may be for realizing a part of the functions described above, and may further be capable of being realized in combination with a program already recorded in the computer system for realizing the functions described above.

[0061] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

[0062] <Supplementary Note> The combustion device and control method described in the embodiment can be understood as follows, for example.

[0063] (1) The combustion device according to the first aspect includes a furnace into which the gas after combustion flows, and a furnace body that includes a drying stage, a combustion stage, and a post-combustion stage and conveys the object to be incinerated while burning it. When the upstream side in the conveyance direction of the object to be incinerated is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, it has a primary combustion chamber having a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end portion of the rear ceiling portion; a secondary combustion chamber provided connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle; an optical measurement device that detects an object in a specific wavelength band provided in the primary combustion chamber; and means for calculating a detection position of the object of the specific wavelength and activating the reaction of the unburned gas at the detection position to promote the generation of NOx. Thereby, NOx can be generated early in the first half of the temporary combustion chamber, which is a reduction zone, the residence time of the NOx in the reduction zone can be extended, and the time for completing the reduction can be ensured. Further, by promoting the generation of NOx early, the NOx concentration can be increased early, and the reaction rate of reduction in the downstream reduction zone can be increased. Thereby, the emission amount of NOx can be reduced.

[0064] (2) The combustion device according to the second aspect is the combustion device of (1) to (2), and controls the opening degree of a damper provided in a flow path for supplying primary air to the primary combustion chamber to increase the flow rate of the primary air sent to the detection position to 5 to 80% of the total primary air supplied to the primary combustion chamber, thereby activating the reaction of the unburned gas. Thereby, NOx can be generated early and the residence time of the NOx in the reduction zone can be extended.

[0065] (3) The combustion device according to the third aspect is the combustion device of (1) to (2), and calculates the distribution of the primary air supplied to each of the plurality of wind boxes in consideration of the pressure loss of the damper provided for each of the plurality of wind boxes arranged along the conveyance path below the conveyance path for conveying the object to be incinerated and the leakage amount of the primary air between the adjacent wind boxes. By taking into account the pressure loss and the leakage between the wind boxes, it is possible to accurately realize the distribution ratio of the primary air supplied to the primary combustion chamber through each wind box.

[0066] (4) The combustion device according to the fourth aspect is the combustion device of (1) to (3), and for the plurality of the wind boxes which are the supply ports of the primary air arranged along the conveyance path below the conveyance path for conveying the object to be incinerated, when the distance from the upstream end in the conveyance direction of the wind box arranged directly below the detection position to the detection position is equal to or greater than a predetermined value, the primary air supplied from the directly below wind box is increased, and when the distance is less than the predetermined value, the primary air supplied from the wind box one upstream side from the directly below wind box is increased. Thereby, the primary air can be surely sent to the position where the unburned gas exists, and the generation of NOx can be activated.

[0067] (5) The control method according to the fifth aspect is for a combustion device including a hearth into which the gas after combustion flows, and a furnace body including a drying stage, a combustion stage, and a post-combustion stage and conveying the object to be incinerated while burning it. When the upstream side in the conveyance direction of the object to be incinerated is referred to as the front and the downstream side in the conveyance direction is referred to as the rear, a front ceiling portion extending forward from the hearth, a rear ceiling portion extending rearward from the hearth, and a rear wall extending downward from the rear end portion of the rear ceiling portion, a primary combustion chamber having the same, a secondary combustion chamber provided connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, and an optical measurement device for detecting an object in a specific wavelength band provided in the primary combustion chamber. A computer calculates the detection position of the object of the specific wavelength, and activates the reaction of the unburned gas at the detection position to promote the generation of NOx.

Explanation of Signs

[0068] 1... Combustion equipment, 2... Control device, 2a... Acquisition unit, 2b... Location determination unit, 2c... Allocation determination unit, 2d... Control unit, 3... Incinerator, 21... Hopper, 22... Feeder, 23... Moisture meter, 24... Sprinkler, 30... Furnace body, 31... In-furnace temperature sensor, 32... Visible light camera, 33... Infrared camera, 40... Stoker, 41... Fire grate, 50... Air box, 51... Air box pressure sensor, 55... Front ceiling part, 57... Rear ceiling part, 59... Rear wall, 60... Firebox, 60a... Front wall, 60b... Rear wall, 70... Blower mechanism, 71... Blower, 73... Air preheater, 75... Damper, 81... Gas sensor, 91... First EGR nozzle, 93... Second EGR nozzle, 900... Computer, 901... CPU, 902... Main memory device, 903... Auxiliary memory device, 904... Input / output interface, 905... Communication interface

Claims

1. a furnace into which the combustion gas flows; A furnace body that includes a drying stage, a combustion stage, and a post-combustion stage and transports the incineration material while burning it, and in which the upstream side of the transport direction of the incineration material is referred to as the front and the downstream side of the transport direction is referred to as the rear, the furnace has a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end of the rear ceiling portion; a secondary combustion chamber connected to an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle; An optical measurement device for detecting a target in a specific wavelength band provided in the primary combustion chamber; a means for calculating a detection position of the target of the specific wavelength and activating a reaction of unburned gas at the detection position to promote the generation of NOx; Equipped with For a plurality of wind boxes that are supply ports for primary air and are arranged along the conveying path below the conveying path that conveys the incineration materials, when the distance from the upstream end in the conveying direction of the wind box arranged directly below the detection position to the detection position is equal to or greater than a predetermined value, the amount of primary air supplied from the wind box directly below is increased, and when the distance is less than the predetermined value, the amount of primary air supplied from the wind box one position upstream of the wind box directly below is increased. Combustion device.

2. By controlling the opening degree of a damper provided in a flow path for supplying primary air to the primary combustion chamber, the flow rate of the primary air sent to the detection position is increased to 50 to 80% of the total amount of the primary air supplied to the primary combustion chamber, thereby activating the reaction of the unburned gas. The combustion device of claim 1 .

3. Calculating the distribution of the primary air to be supplied to each of the plurality of wind boxes, taking into consideration the pressure loss of the dampers provided for each of the plurality of wind boxes arranged along the conveying path below the conveying path for conveying the incineration materials, and the amount of leakage of the primary air between the adjacent wind boxes. The combustion device according to claim 2.

4. a furnace into which the combustion gas flows; A furnace body that includes a drying stage, a combustion stage, and a post-combustion stage and transports the incineration material while burning it, and in which the upstream side of the transport direction of the incineration material is referred to as the front and the downstream side of the transport direction is referred to as the rear, the furnace has a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end of the rear ceiling portion; a secondary combustion chamber connected to an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle; An optical measurement device for detecting a target in a specific wavelength band provided in the primary combustion chamber; a means for calculating a detection position of the target of the specific wavelength and activating a reaction of unburned gas at the detection position to promote the generation of NOx; Equipped with By increasing the amount of primary air supplied to the detection position upstream of the primary combustion chamber, the reaction of unburned gas at the detection position is activated to promote the generation of NOx, the NOx is reduced in the secondary combustion chamber downstream of the primary combustion chamber, and the reduced material is completely combusted in the furnace at the rear of the secondary combustion chamber, thereby reducing the NOx emitted from the device. Combustion device.

5. A combustion apparatus comprising: a furnace into which combustion gas flows; a furnace body including a drying stage, a combustion stage, and a post-combustion stage for transporting materials to be incinerated while burning them; a primary combustion chamber having a front ceiling portion extending forward from the furnace, a rear ceiling portion extending rearward from the furnace, and a rear wall extending downward from the rear end portion of the rear ceiling portion, where the upstream side of the transport direction of the materials to be incinerated is referred to as the front and the downstream side of the transport direction as the rear; a secondary combustion chamber connected to the outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle; and an optical measuring device for detecting targets in a specific wavelength band provided in the primary combustion chamber, The computer A detection position of the target of the specific wavelength is calculated, and for a plurality of wind boxes which are supply ports of primary air arranged along a transport path below the transport path which transports the incineration material, if the distance from the upstream end in the transport direction of the wind box arranged directly below the detection position to the detection position is equal to or greater than a predetermined value, the amount of primary air supplied from the wind box directly below is increased, and if the distance is less than the predetermined value, the amount of primary air supplied from the wind box one position upstream of the wind box directly below is increased, thereby activating the reaction of unburned gas at the detection position and promoting the generation of NOx. Control methods.

Images