JP6880145B2 - Combustion status evaluation method and combustion control method - Google Patents

Description

The present invention mainly relates to a method for evaluating a combustion state in order to appropriately maintain stable combustion in a grate-type incinerator that incinerates waste while transporting it by a grate.

Since a wide variety of wastes are put into the incinerator, it is important to be able to properly maintain stable combustion even if the properties of the put wastes change. In addition, the grate-type waste incinerator is divided into a drying section for drying the waste, a combustion section for burning the waste with flame, and a post-combustion section for post-combusting the waste (Oki combustion). There is. In order to perform combustion control to properly maintain stable combustion, for example, it is important to obtain sufficient information on the waste deposited on the grate. Patent Documents 1 to 9 disclose methods for acquiring and controlling information on waste.

In the method of Patent Document 1, a visible image of a flame and an infrared image (thermal image) of waste on a grate are acquired by two imaging means provided on the wall of an incinerator, and the visible image and the thermal image are obtained. And are used for combustion control. In the method of Patent Document 2, the inside of the incinerator is photographed by using two TV cameras to acquire a visible image, a stereoscopic image is created based on these images, and this stereoscopic image is used for combustion control. .. In the methods of Patent Documents 3 to 5, one or a plurality of thermal image capturing units capture a thermal image of waste on a grate, and the one or a plurality of thermal images are used for combustion control. In particular, Patent Documents 3 and 4 describe that a thermal image imaging unit that detects infrared rays having a specific wavelength is used in order to exclude the influence of flame. In the method of Patent Document 6, a radar device is used to acquire the three-dimensional distribution of fuel on the grate, and an infrared camera is used to acquire the temperature distribution of fuel on the grate, and this information is used for combustion control. Used for. In the method of Patent Document 7, the height of waste on the grate is obtained by using a stereo camera having an optical filter for removing the wavelength of the flame, the burnout position is estimated, and the burnout position is burned. Used for control. In the method of Patent Document 8, the thermal image of the waste moving in the furnace is continuously imaged through the flame, and the boundary line with the inner wall surface of both sides of the furnace body of the waste is detected from the thermal image data. The estimated volume of waste in the region is calculated and the estimated volume of waste is used for combustion control.

Japanese Unexamined Patent Publication No. 10-54532 Japanese Unexamined Patent Publication No. 5-118524 Tokuseki 2017-187228 Japanese Unexamined Patent Publication No. 2018-21686 JP-A-2017-116252 Japanese Unexamined Patent Publication No. 8-355630 JP-A-2018-155411 Japanese Patent No. 6472035

When a visible image is used as in Patent Documents 1 and 2, the flame generated in the combustion part becomes an obstacle, and the shape and movement of the waste on the grate cannot be sufficiently obtained. In the first place, Patent Document 2 acquires an image to detect the position of abnormal combustion and creates a stereoscopic image, and does not target waste on the grate. In Patent Documents 3 to 5, since the thermal images of one or more wastes are used as they are, the detailed shape and movement of the wastes cannot be sufficiently obtained. Further, when the fuel on the grate is detected by the radar as in Patent Document 6, it is necessary to detect the electromagnetic wave reflected by the waste in a high temperature environment and in the presence of flame, so that the cost of the radar itself is high. It gets higher. Further, in Patent Document 6, the infrared camera is used to acquire the temperature distribution instead of the shape of the fuel. In Patent Document 7, the burnout position is estimated using the waste height information, but since not only the height of the waste but also the feed rate of the waste changes depending on the properties of the waste, the waste It may not be possible to calculate an appropriate burnout position in order to control the combustion state from the height alone. In Patent Document 8, since only the boundary line with the inner wall surface of both sides of the furnace body of the waste is used as the information used for calculating the estimated volume of the waste, the difference in the height of the waste in the furnace width direction is not considered. As a result, the accuracy of the estimated volume of waste becomes low, and the error may be too large to be used as an index of combustion control.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a method for calculating appropriate information for using as an index of combustion control.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

From the viewpoint of the present invention, the following combustion condition evaluation method is provided. That is, this combustion condition evaluation method is divided into a dry part, a combustion part, and a post-combustion part, and incinerator provided with a grate for transporting the waste by operating intermittently in a state where the waste is accumulated. Performed on the incinerator. This combustion state evaluation method includes a preparation step, a division step, a first calculation step, a second calculation step, a third calculation step, a volume calculation step, and a volume prediction step. In the preparation step, a plurality of infrared cameras are used to observe at least the waste accumulated in the dry portion and the combustion portion through a filter that selectively transmits light having a wavelength not emitted by the flame. A plurality of thermal images having different viewpoints are acquired, and a three-dimensional thermal image is created based on the plurality of thermal images. In the division step, the waste of the three-dimensional thermal image is mesh-divided into a plurality of elements. In the first calculation step, the thickness of the waste and the surface moving speed of the waste are calculated for each of the elements based on the three-dimensional thermal image. In the second calculation step, based on the calculation result of the first calculation step, the thickness elapsed indicating how the thickness of the waste located in the element changed in time series until it was located in the element. Information is calculated for each of the elements. In the third calculation step, based on the calculation results of the first calculation step and the second calculation step, how the volume flow rate before the waste located in the element is located in the element is in chronological order. Volumetric flow rate progress information indicating whether or not the change has occurred is calculated for each of the above elements. In the volume calculation step, the volume of the waste during combustion at the present time is calculated. In the volume prediction step, the volume of the waste during combustion after the lapse of the first time is predicted. Further, in the volume calculation step, the current volume flow rate progress information is analyzed to identify an intermediate combustion element, which is the element after the combustion startable state is reached and before the combustion burnout state is reached. The volume of the waste located in the mid-combustion element is calculated. The volume prediction step is based on the volume flow rate progress information for each element and the time change of the control value including at least a value used for combustion control for setting the transport speed of the grate. Based on the tendency of the volume flow rate obtained after the lapse of time, the change in the volume flow rate after the lapse of the first time is predicted for each of the elements, and based on the prediction result, the element in the middle of combustion after the lapse of the first time is determined. It identifies and predicts the volume of the waste located in the mid-burning element after the lapse of the first hour.

Since pyrolysis gas is generated from the waste during combustion, the volume of the waste during combustion is a value that is an index of the amount of pyrolysis gas generated per hour (the amount of heat generated). In particular, the volume of waste in the middle of combustion in the future is an index of the amount of heat generated in the incinerator in the future. In this way, useful information can be obtained as an index of combustion control.

According to the present invention, it is possible to calculate appropriate information for using it as an index of combustion control.

The schematic block diagram of the waste incinerator including the incinerator which performs the method of this invention. Functional block diagram of the incinerator. A three-dimensional schematic view of an incinerator showing the mounting position of an infrared camera. A flowchart showing a part of the control performed by the control device to stabilize combustion. A flowchart showing the rest of the control performed by the controller to stabilize combustion. Perspective view showing waste thickness, surface moving speed, and mesh division. The figure explaining the thickness progress information. The figure explaining the volume flow rate progress information and its prediction. Schematic diagram for explaining the specific results of current and future combustion mid-combustion elements.

<Overall Configuration of Waste Incinerator> First, the waste incinerator (waste incinerator) 100 including the incinerator (waste incinerator) 10 of the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a waste incinerator 100 including an incinerator 10 for performing the method of the present invention. In the following description, when the terms "upstream" and "downstream" are used, they mean upstream and downstream in the direction in which waste, combustion gas, exhaust gas, primary air, secondary air, circulating exhaust gas, etc. flow.

As shown in FIG. 1, the waste incinerator 100 includes an incinerator 10, a boiler 30, and a steam turbine power generation facility 35. The incinerator 10 incinerates the supplied waste. The detailed configuration of the incinerator 10 will be described later.

The boiler 30 uses the heat generated by the combustion of waste to generate steam. The boiler 30 generates steam (superheated steam) by exchanging heat between high-temperature combustion gas generated in the furnace and water in a large number of water pipes 31 and superheater pipes 32 provided on the flow path wall. The steam generated in the water pipe 31 and the superheater pipe 32 is supplied to the steam turbine power generation facility 35.

The steam turbine power generation facility 35 includes a turbine and a power generation device (not shown). The turbine is rotationally driven by steam supplied from the water pipe 31 and the superheater pipe 32. The power generation device uses the rotational driving force of the turbine to generate electricity.

Here, in order to generate stable power generation, it is necessary to stabilize the amount of steam (superheated steam) produced in the boiler 30. In order to stabilize the amount of steam (superheated steam) generated in the boiler 30, it is necessary to stabilize the heat input to the boiler 30. That is, in order to keep the amount of power generation constant, it is necessary to stabilize the amount of heat possessed by the combustion gas supplied from the incinerator 10 to the boiler 30 and keep the heat input to the boiler 30 stable.

<Structure of Incinerator 10> The incinerator 10 includes a dust supply device 40 for supplying waste into the furnace. The dust supply device 40 includes a waste input hopper 41 and a dust supply device main body 42. The waste input hopper 41 is a portion where waste is input from outside the furnace. The dust supply device main body 42 is located at the bottom of the waste input hopper 41 and is configured to be movable in the horizontal direction. The dust supply device main body 42 supplies the waste charged into the waste input hopper 41 to the downstream side. The movement speed of the dust supply device main body 42, the number of movements per unit time, the movement amount (stroke), and the position of the stroke end (movement range) are controlled by the control device 90. The dust supply device may be of a type that moves at a slight angle with respect to the horizontal direction.

The waste supplied into the furnace by the dust supply device 40 is supplied by the transport unit 20 in the order of the drying unit 11, the combustion unit 12, and the post-combustion unit 13. The transport unit 20 is composed of a dry grate 21 provided in the drying unit 11, a combustion grate 22 provided in the combustion unit 12, and a post-combustion grate 23 provided in the post-combustion unit 13. There is. Therefore, the transport unit 20 is composed of a plurality of stages of grate. Each grate is provided on the bottom of each part, and waste is placed on it.

The grate is composed of a movable grate and a fixed grate arranged side by side in the waste transport direction, and the movable grate operates in the order of forward, stop, reverse, stop, etc. to dispose of waste. The waste can be agitated while being transported to the downstream side. By increasing (decelerating) the operating speed of the movable grate, it is possible to increase (decelerate) the transport speed of waste. Further, by shortening (longening) the stop time of the movable grate, it is possible to increase (decelerate) the transport speed of waste. In addition, the grate is arranged side by side with a gap large enough for gas to pass through.

The drying unit 11 is a portion for drying the waste supplied to the incinerator 10. The waste of the drying unit 11 is dried by the primary air supplied from under the drying grate 21 and the radiant heat of combustion in the adjacent combustion unit 12. At that time, thermal decomposition gas is generated from the waste of the drying portion 11 by thermal decomposition. Further, the waste of the drying unit 11 is conveyed toward the combustion unit 12 by the drying grate 21.

The combustion unit 12 is a portion that mainly burns the waste dried by the drying unit 11. In the combustion unit 12, the waste mainly causes flame combustion to generate a flame. The waste in the combustion unit 12, the ash generated by combustion, and the unburned material that cannot be completely burned are conveyed toward the post-combustion unit 13 by the combustion grate 22. Further, the combustion gas and the flame generated in the combustion unit 12 pass through the throttle unit 17 and flow toward the post-combustion unit 13. The combustion grate 22 is provided at the same height as the dry grate 21, but may be provided at a position lower than the dry grate 21.

The post-combustion section 13 is a section that burns waste (unburned matter) that could not be completely burned by the combustion section 12. In the post-combustion unit 13, the radiant heat of the combustion gas and the primary air promote the combustion of the unburned material that could not be completely burned in the combustion unit 12. As a result, most of the unburned material becomes ash, and the unburned material decreases. The ash generated in the post-combustion unit 13 is conveyed toward the chute 24 by the post-combustion grate 23 provided on the bottom surface of the post-combustion unit 13. The ash conveyed to the chute 24 is discharged to the outside of the waste incineration facility 100. Although the rear combustion grate 23 of the present embodiment is provided at a position lower than the combustion grate 22, it may be provided at the same height as the combustion grate 22.

As described above, since the reactions that occur in the drying unit 11, the combustion unit 12, and the post-combustion unit 13 are different, the wall surfaces and the like are configured according to the reactions that occur. For example, since flame combustion occurs in the combustion unit 12, a structure having a higher refractory level than the drying unit 11 is adopted.

The reburning unit 14 is a part that burns the unburned gas contained in the combustion gas. The re-combustion unit 14 extends upward from the drying unit 11, the combustion unit 12, and the post-combustion unit 13, and secondary air is supplied in the middle thereof. As a result, the combustion gas is mixed and agitated with the secondary air, and the unburned gas contained in the combustion gas is burned in the reburning unit 14. The combustion generated in the combustion unit 12 and the post-combustion unit 13 is referred to as primary combustion, and the combustion generated in the recombustion unit 14 (that is, the combustion of the unburned gas remaining in the primary combustion) is referred to as secondary combustion.

The gas supply device 50 is a device that supplies gas into the furnace. The gas supply device 50 of the present embodiment includes a primary air supply unit 51, a secondary air supply unit 52, and an exhaust gas supply unit 53. Each supply unit is composed of a blower for attracting or sending out gas.

In the present specification, the gas supplied for primary combustion is referred to as a primary combustion gas. The primary combustion gas includes primary air, circulating exhaust gas, and a mixed gas thereof. The primary air is air taken in from the outside and is not used for combustion or the like (that is, excluding circulating exhaust gas). Therefore, the primary air also includes a gas obtained by heating the air taken in from the outside. Similarly, in the present specification, the gas supplied for secondary combustion is referred to as a secondary combustion gas. The secondary combustion gas includes secondary air, circulating exhaust gas, and a mixed gas thereof. The definition of secondary air is similar to that of primary air.

The primary air supply unit 51 supplies the primary air into the furnace via the primary air supply path 71. The primary air supply path 71 is branched into a first supply path 71a, a second supply path 71b, and a third supply path 71c. A heater may be provided in the primary air supply path 71 so that the temperature of the primary air supplied to each part can be adjusted.

The first supply path 71a is a path for supplying primary air to the drying step air box 25 provided below the drying grate 21. A first damper 81 is provided in the first supply path 71a, and the amount of primary air supplied to the drying stage air box 25 can be adjusted. Further, the first damper 81 is controlled by the control device 90.

The second supply path 71b is a path for supplying primary air to the combustion stage air box 26 provided below the combustion grate 22. A second damper 82 is provided in the second supply path 71b, and the amount of primary air supplied to the combustion stage air box 26 can be adjusted. Further, the second damper 82 is controlled by the control device 90.

The third supply path 71c is a path for supplying primary air to the post-combustion stage air box 27 provided below the post-combustion grate 23. A third damper 83 is provided in the third supply path 71c, and the amount of primary air supplied to the post-combustion stage air box 27 can be adjusted. Further, the third damper 83 is controlled by the control device 90.

The secondary air supply unit 52 supplies the secondary air to the air gas holding space 16 of the incinerator 10 from the upper part (ceiling part) via the secondary air supply path 72, and the combustion gas is generated by the throttle unit 17. Secondary air is supplied to the portion that changes direction (near the throttle portion 17). Further, the secondary air supply path 72 is provided with a fourth damper 84 controlled by the control device 90, and the amount of secondary air supplied to each part can be adjusted.

The exhaust gas supply unit 53 supplies (recirculates) the exhaust gas discharged from the waste incineration facility 100 into the furnace via the circulating exhaust gas supply path 73. The exhaust gas discharged from the waste incinerator 100 is purified by the filtration type dust collector 60, and a part of the exhaust gas is incinerated by the exhaust gas supply unit 53 from both side surfaces (front side of the paper surface and the back side of the paper surface) of the combustion unit 12. It is supplied to the incinerator 10. The position where the exhaust gas is supplied is not particularly limited. For example, the exhaust gas may be supplied from above (ceiling portion) of the incinerator 10, or may be supplied from only one side surface. By supplying the exhaust gas to the incinerator 10, the oxygen concentration in the incinerator 10 is lowered, and the local excessive rise in the combustion temperature can be suppressed. As a result, the generation of NOx can be suppressed. The circulating exhaust gas supply path 73 is provided with a fifth damper 85 controlled by the control device 90, and the supply amount of the circulating exhaust gas can be adjusted.

As shown in FIGS. 1 and 2, the incinerator 10 is provided with a plurality of sensors for grasping a combustion state and the like. Specifically, an incinerator gas temperature sensor 91, an incinerator outlet gas temperature sensor 92, a CO gas concentration sensor 93, a NOx gas concentration sensor 94, and an infrared camera 95 are provided.

The gas temperature sensor 91 in the incinerator is arranged in the incinerator 10 (for example, downstream of the air gas holding space 16 and upstream of the post-combustion unit 13), detects the gas temperature in the incinerator, and controls the control device 90. Output to. The incinerator outlet gas temperature sensor 92 is arranged near the outlet of the incinerator 10 (for example, downstream of the reburning unit 14 and upstream of the boiler 30), detects the incinerator outlet gas temperature, and sends it to the control device 90. Output. The CO gas concentration sensor 93 is arranged downstream of the dust collector 60, detects the CO gas concentration contained in the exhaust gas (CO gas concentration discharged from the incinerator), and outputs the CO gas concentration sensor 93 to the control device 90. The NOx gas concentration sensor 94 is arranged downstream of the dust collector 60, detects the NOx gas concentration contained in the exhaust gas (NOx gas concentration discharged from the incinerator), and outputs the NOx gas concentration sensor 94 to the control device 90.

The infrared cameras 95 are provided in pairs. Each infrared camera 95 has the same structure. Further, the infrared camera 95 may be provided as a set of three or more. Since the purpose of the infrared camera 95 is to create a three-dimensional thermal image (an image showing the temperature distribution in three dimensions), a plurality of infrared cameras 95 form a set. Therefore, the relative positions of the plurality of infrared cameras 95 of the same set are stored in advance. The infrared camera 95 may be a device whose main purpose is to continuously capture still images at appropriate intervals, or a device whose main purpose is to capture moving images. Since a moving image is a plurality of continuous still images, the function of acquiring a thermal image is the same regardless of the device.

The infrared camera 95 acquires a thermal image in the furnace by detecting infrared rays radiated from an object in the furnace. The thermal image acquired by each infrared camera 95 is an image showing the temperature distribution in the furnace as seen from the viewpoint of the infrared camera 95. The viewpoint indicates a position where the infrared camera 95, which is a measuring instrument, is arranged. Further, the infrared camera 95 of the present embodiment acquires a thermal image in the furnace via a selective transmission filter (filter) 95a. The selective transmission filter 95a is a filter that selectively transmits light having a wavelength (for example, 3.9 μm band) that the flame does not emit. The phrase "flame does not radiate" here means that the light intensity is significantly lower (almost no irradiation) than the light of other wavelengths emitted by the flame, and the flame does not radiate at all. Does not indicate. By acquiring the thermal image in the furnace through the selective transmission filter 95a, it is possible to acquire a thermal image of an object other than the flame. In other words, it can penetrate the flame and obtain a thermal image of the object behind it. In the present embodiment, the selective transmission filter 95a is integrally configured with the infrared camera 95, but may be a separate body. That is, the selective transmission filter 95a may be arranged on the path through which the light in the furnace passes, and the transmitted light transmitted through the selective transmission filter 95a may be processed by a normal infrared camera.

The purpose of the infrared camera 95 is to acquire a thermal image of the waste transported mainly through the dry grate 21 and the combustion grate 22. Specifically, in the present embodiment, two sets of infrared cameras 95 are provided, and the first set of infrared cameras 95 mainly carries the waste grate 21 (more specifically, the combustion start position is included). The purpose is to acquire the waste in the range), and the second set of infrared cameras 95 mainly acquires the waste carried through the combustion grate 22 (more specifically, the waste in the range including the burnout position). The purpose is to do.

Further, the flame combustion start position and the burnout position change depending on the properties of the supplied waste and the control of the incinerator 10. Therefore, the imaging range of the first set of infrared cameras 95 may include waste to be conveyed by the combustion grate 22, or the post-combustion grate 23 is conveyed to the imaging range of the second set of infrared cameras 95. Waste may be included. Further, in order to observe the waste without omission, it is preferable that the imaging ranges of the first and second sets of the infrared cameras 95 partially overlap.

Further, the infrared camera 95 may have a configuration in which the imaging range of the image can be changed. In this case, the infrared camera 95 may be able to change the imaging range without stopping the incinerator 10. The infrared camera 95 is arranged at a position higher than the grate and the waste for the purpose of appropriately acquiring an image even when the amount of accumulated waste is large. Therefore, the infrared camera 95 is arranged so as to be inclined downward. The infrared camera 95 may be arranged without being tilted.

As shown in FIG. 3, the direction perpendicular to the waste transport direction and the vertical direction (vertical direction) is referred to as the furnace width direction. The first set of infrared cameras 95 is provided on the side wall 11a, which is a wall portion formed at the end portion of the drying portion 11 in the furnace width direction. The two infrared cameras 95 acquire a thermal image (infrared ray) of the surface of the waste through the window portion 11b formed on the side wall 11a. In the present embodiment, two infrared cameras 95 are arranged only on one side wall 11a of the left and right side walls 11a, but one or a plurality of infrared cameras 95 may be arranged on both side walls 11a, respectively.

The second set of infrared cameras 95 is provided on the back wall 13a, which is a wall on the downstream side in the transport direction with respect to the rear combustion unit 13. The two infrared cameras 95 acquire a thermal image (infrared ray) of the surface of the waste through the window portion 13b formed on the back wall 13a.

Further, the positions where the first and second sets of infrared cameras 95 are provided are examples, and for example, the infrared cameras 95 may be provided on a wall or ceiling different from the above.

<Processing performed by the control device> The control device 90 is composed of a CPU, a RAM, a ROM, and the like, performs various calculations, and controls the entire waste incineration facility 100. Similarly, the image processing device 96 is also composed of a CPU, RAM, ROM, etc., and performs a process (image composition process) of creating a three-dimensional thermal image based on the thermal images acquired by the two infrared cameras 95 of each set. It can be carried out. In the present embodiment, the control device 90 and the image processing device 96 are separate hardware, but one piece of hardware may have the functions of both the control device 90 and the image processing device 96. Hereinafter, the combustion control performed by the control device 90, particularly the control performed by analyzing the three-dimensional thermal image, will be described with reference to the flowcharts of FIGS. 4 and 5. 4 and 5 are flowcharts showing the control performed by the control device 90 to stabilize the combustion.

<S101> First, the control device 90 stores a three-dimensional thermal image created by the image processing device 96 based on the thermal image acquired by the infrared camera 95 (S101). In the present embodiment, the first three-dimensional thermal image is created based on the thermal image acquired by the first set of infrared cameras 95, and the second is based on the thermal image acquired by the second set of infrared cameras 95. A three-dimensional thermal image of is created. The position range (waste range, imaging range) where the first 3D thermal image is created is called the first range, and the position range (waste range, imaging range) where the second 3D thermal image is created is called the first range. ) Is referred to as the second range.

Since the process of creating a three-dimensional thermal image from a plurality of thermal images is a known technique, it will be briefly described. Here, α and β may be added in order to distinguish between the two infrared cameras 95 of each set. Since the thermal image acquired by the infrared camera 95 of the present embodiment does not include a flame, the thermal image acquired by the infrared camera α shows the temperature distribution of the surface of the waste as seen from the position of the infrared camera α. ing. The same applies to the infrared camera β. Then, the specific location A on the surface of the waste is specified where each of the two thermal images is displayed. Since the positional relationship between the infrared camera α and the infrared camera β is known as described above, the distance from the infrared camera α and the infrared camera β to the specific location A of the waste can be calculated based on the triangular method or the like. By performing this treatment on other parts of the waste surface, the position (three-dimensional coordinates) of the waste surface can be specified.

<S102> Next, the control device 90 mesh-divides the surface of the waste of the three-dimensional thermal image into a plurality of elements (division units), and (1) the thickness of the waste and (2) the surface for each element. The movement speed is calculated and stored in association with the control value (S102). This process is performed individually for each of the first three-dimensional thermal image (first range) and the second three-dimensional thermal image (second range). The mesh division is to divide the waste of the three-dimensional thermal image into a plurality of regions under predetermined conditions. In the present embodiment, as shown in FIG. 6, the waste is divided into a grid pattern by drawing a plurality of parallel lines in the transport direction and a plurality of parallel lines in the furnace width direction. In the present embodiment, the mesh-divided elements are quadrangular, but may have different shapes. The shapes and areas of the plurality of elements may be the same or different. For example, only the parts considered to be important may be finely divided into meshes.

Regarding (1) above, the thickness of the waste is the length along the vertical direction from the grate to the surface of the waste, as shown in FIG. The position of the surface (upper surface) of the grate is stored in advance in the control device 90 or the like. In addition, the position of the surface of the waste can be specified based on the three-dimensional thermal image. Therefore, by comparing these two positions (coordinates), the thickness of the waste can be calculated for each element. As described above, the distribution of the thickness of waste for each element at a certain time can be calculated based on one three-dimensional thermal image. Since the three-dimensional thermal images are sequentially created, the thickness of the waste is calculated in the same manner for the newly created three-dimensional thermal images. In this way, the control device 90 calculates the thickness of the waste for each element and stores it in a predetermined storage unit in chronological order.

The significance of calculating the thickness of waste is as follows. That is, the waste accumulated in the drying portion 11 is dried by evaporating the water contained in the waste as the drying operation (feeding operation) of the drying grate 21 is performed, and the mass is reduced and the volume is also reduced. .. That is, the time change of the thickness of the waste indicates the progress of the drying of the waste, and is a kind of index of the progress of the drying operation. Further, the waste accumulated in the combustion unit 12 is thermally decomposed by the combustion operation (feeding operation) of the combustion grate 22, and the thermal decomposition gas is discharged, so that the mass and volume are reduced. That is, the time change of the thickness of the waste indicates the process of thermal decomposition of the waste, and is a kind of index of the progress of the combustion operation.

Regarding (2) above, the surface moving speed of the waste is the speed at which the surface of the waste moves in the transport direction, as shown in FIG. In FIG. 6, a thick line is drawn on a relatively thick portion for easy understanding, and a state in which this portion moves is shown. Since the shape of the surface of the waste is shown in the three-dimensional thermal image, it is possible to obtain how the surface of the waste is moving based on the three-dimensional thermal image created in time series. Therefore, the surface moving speed of each mesh-divided element can be calculated based on the moving distance of a specific portion of the surface of the waste, the time interval at which the three-dimensional thermal image is acquired, and the like. As described above, the distribution of the surface moving speed of waste for each element can be calculated. Since the three-dimensional thermal images are sequentially created, a new surface movement speed of the waste is calculated using the newly created three-dimensional thermal image and the past three-dimensional thermal image. In this way, the control device 90 calculates the surface moving speed of the waste and stores it in a predetermined storage unit in chronological order.

The significance of calculating the surface moving speed of waste is as follows. That is, the time change of the moving speed of the waste in the drying unit 11 is such that the waste accumulated in the drying unit 11 is sent in the transport direction while reducing the volume by the drying operation (feeding operation) of the drying grate 21. It shows the actual speed, and is an index of how the waste has been "moved" by the drying operation. Further, the surface moving speed of the waste in the combustion unit 12 is such that the waste accumulated in the combustion unit 12 is sent in the feed direction while reducing the volume by the combustion operation (feed operation) of the combustion grate 22. It is an indicator of velocity and an indicator of how waste has been "moved" by the combustion operation. Since it is not possible to calculate how the surface other than the surface of the waste moves from the three-dimensional thermal image, in the present embodiment, the "surface movement speed of the waste" indicates the "movement speed of the entire waste". Assuming that, the following calculations are performed.

The control value is a value changed to control the combustion state of the incinerator 10, and is, for example, the transfer speed of each grate, the supply amount of the primary combustion gas, the supply amount of the secondary combustion gas, and the like. It is a value for determining. The thickness of the waste, the surface moving speed, and the volumetric flow rate described later are affected by this control value. Therefore, in order to evaluate and control in consideration of the influence of the control value, the control device 90 stores the thickness of the waste and the surface movement speed in association with the control value set in the incinerator 10. Further, when the control value is different depending on the mesh-divided elements (for example, the element on the dry grate 21, the element on the combustion grate 22, and the element on the post-combustion grate 23, the grate is conveyed. The control device 90 stores the thickness of the waste and the surface movement speed in association with the control values corresponding to the corresponding elements.

<S103> Next, the control device 90 calculates the thickness progress information for each element based on the thickness of the waste for each element and the surface moving speed, and stores the information in association with the control value (S103). This process is performed separately for the information in the first range and the second range. As shown in FIG. 7, the thickness progress information is information indicating how the thickness changes in time series until the waste located in the element is located in the element. In FIG. 7, the thickness progress information of each element is schematically shown graphically. As shown in this graph, the thickness progress information is information in which "thickness" and "position in the transport direction with the passage of time" are associated with each other. That is, the thickness progress information is information indicating, for example, the thickness of the waste in the element A at the present time when the waste in the element A was present at the upstream position in the past when the element A is focused on. .. The thickness progress information may be information in which the thickness and the time are associated with each other.

The thickness progress information can be calculated as follows, for example. For example, when focusing on a certain element A, the progress of transporting the waste at the position of the element A at the present time (that is, which element was located at which time) is the current state of the element A and the element on the upstream side thereof. It can be calculated based on the past surface movement speed. Further, the thickness of the waste for each element and each time is calculated and stored in step S102. Therefore, the thickness progress information can be calculated by associating the time and the element indicated by the transportation progress of the waste with the thickness of the waste. In this way, the control device 90 calculates the thickness progress information based on the thickness of the waste and the surface moving speed. Since the three-dimensional thermal images are sequentially created, new thickness progress information of the waste is calculated by performing the same calculation using the newly created three-dimensional thermal images. The control device 90 stores the calculated thickness progress information in a predetermined storage unit in chronological order. The process and the reason for associating the thickness progress information with the control value are the same as in step S102.

The significance of obtaining thickness progress information is as follows. That is, how the thickness progress information of the drying portion 11 is obtained while the waste accumulated in the drying portion 11 is deposited and passed on the grate by the drying operation (feeding operation) of the drying grate 21. It shows the process of being sent in the feeding direction while reducing the volume, and is an index of how the volume of waste has been reduced by the drying operation. Further, the thickness progress information of the combustion unit 12 can be obtained as to how the waste accumulated in the combustion unit 12 is accumulated and passed on the grate by the combustion operation (feed operation) of the combustion grate 22. It shows the process of being sent in the feeding direction while reducing the volume, and is an index of how the volume of waste has been reduced by the combustion operation.

<S104> Next, the control device 90 calculates the volume flow rate progress information for each element based on the surface movement speed and the thickness progress information of the waste for each element, and the volume flow rate progress in the first range and the second range. The information is also stored in association with the control value (S104). First, a process of calculating the volume flow rate progress information is performed for each of the first range and the second range.

As shown in FIG. 8, the volumetric flow rate progress information is information indicating how the volumetric flow rate has changed in time series until the waste located in the element is located in the element. In the upper figure of FIG. 8, the volumetric flow rate progress information of each element is schematically shown graphically. As shown in this graph, the volume flow rate progress information is information in which the “volume flow rate” and the “transportation direction position with the passage of time” are associated with each other. That is, the volumetric flow rate progress information is information indicating what kind of volumetric flow rate the waste in the element A at the present time had when it was present at the upstream position in the past, for example, when focusing on the element A. Is. The volume flow rate progress information may be information indicating the correspondence between the volume flow rate and the time.

Volumetric flow rate is the volume of waste that moves per unit time. Therefore, the volumetric flow rate can be calculated by multiplying the "waste thickness", "waste surface moving speed", and "furnace width length", respectively. Further, the furnace width length when calculating the volume flow rate for each element is the furnace width length of each element. Therefore, the volume flow rate progress information is the value obtained by multiplying the "thickness of waste indicated by the thickness progress information" and the "surface movement speed of waste" by combining the elements (position) and the time, and "the furnace width of each element". It can be calculated by multiplying by "length". In this way, the control device 90 calculates the volume flow rate progress information for each element.

Next, the control device 90 combines the volume flow rate progress information of the first range and the second range to generate one volume flow rate progress information. In addition, the first range and the second range partially overlap. Therefore, for the overlapping range, the value is determined by taking an average or using one of the volume flow rate progress information. Thereby, the volume flow rate progress information including the first range and the second range (that is, including the range from the drying section 11 to a part of the post-combustion section 13) can be calculated.

The control device 90 stores this volumetric flow rate progress information in a predetermined storage unit. Since the three-dimensional thermal images are sequentially created, new volume flow rate progress information of the waste is calculated by performing the same calculation using the newly created three-dimensional thermal images. The control device 90 stores the calculated volumetric flow rate progress information in a predetermined storage unit in time series in association with the control value. The process and the reason for associating the volume flow rate progress information with the control value are the same as in step S102. Moreover, since the furnace width and length are constant, the volumetric flow rate progress information is a function of only the waste thickness and the surface moving speed. In other words, the volumetric flow rate progress information is conceptual information that includes not only the thickness of waste but also the moving speed.

If the furnace width length of each grate is constant and the furnace width length of each element is constant, the process of multiplying the furnace width length is omitted when calculating the volume flow rate progress information. May be good. This is because what is required for combustion control is not a specific value of the volumetric flow rate, but a variation mode thereof. In other words, the vertical axis of the graph in the upper figure of FIG. 8 is not limited to a specific volume flow rate, and may be a value proportional (correlated) to the volume flow rate.

The significance of acquiring volumetric flow rate progress information is as follows. That is, the waste accumulated in the drying portion 11 is compressed by the evaporation of water as the drying operation (feeding operation) of the drying grate 21 is performed, and the mass and volume are reduced. That is, the volumetric flow rate progress information indicates the progress of the waste drying, and is a direct index of the degree of progress of the drying operation. Here, as the drying of the waste progresses and the moisture from the waste evaporates (dry state), the amount of evaporation of the moisture decreases and the internal temperature of the waste layer rises, so that the waste heats up. It shifts to the state where decomposition gas is generated (thermal decomposition state). Further, since combustion can be started when the pyrolysis state is reached, the state after the transition to the pyrolysis state is referred to as a "combustion startable state". Further, by shifting to the state where combustion can be started, the degree of change in the volume of waste becomes smaller. Therefore, the volumetric flow rate progress information is the most suitable index for evaluating the degree of the state in which combustion can be started.

Further, the waste accumulated in the combustion unit 12 is thermally decomposed by the combustion operation (feeding operation) of the combustion grate 22, and the thermal decomposition gas is discharged, so that the mass and volume are reduced. That is, the volumetric flow rate progress information indicates the progress of thermal decomposition of waste, and is a direct index of the degree of progress of the combustion operation. In particular, as the waste combustion reaction progresses, the pyrolysis gasification reaction of waste (reaction with a large degree of change in the volume of waste) decreases, and the residual unburned carbon post-combustion reaction (waste) The reaction shifts to a reaction in which the degree of volume change is small). Therefore, the volumetric flow rate progress information is the most suitable index for evaluating the degree of "burnout state".

<S105> Next, the control device 90 creates trend data showing the tendency of the volume flow rate to change with time based on the volume flow rate progress information for each element and the time change of the control value associated therewith (S105). .. Waste is a mixture of substances with various properties in various proportions, and the properties and mixing proportions are unknown. The change in the volume of waste also depends on the configuration and control of the incinerator 10. Therefore, in general, it is difficult to grasp the tendency of changes in the volumetric flow rate of waste. However, in the present embodiment, since the waste is divided into meshes and the volume flow rate progress information for each element is calculated, it is difficult to average the change in the volume flow rate. Further, by dividing the mesh, detailed and a large amount of information regarding the volumetric flow rate can be obtained. Then, the control value that affects the volume flow rate progress information is stored in association with the volume flow rate progress information. From the above, in the present embodiment, it is possible to create trend data capable of specifying the change tendency of the volume flow rate and the influence of the control value on the volume flow rate to some extent.

The tendency data created here may be a database of volume flow rate progress information and control values stored in the storage unit. Alternatively, it may be a model constructed by machine learning the volume flow rate progress information and the control value stored in the storage unit. In order to predict the volume flow rate, it is preferable that this model outputs the change of the volume flow rate in the future by inputting the volume flow rate up to the present and the control value, for example.

<S106> Next, the control device 90 predicts the future change of the volume flow rate for each element based on the trend data (S106). As shown in FIG. 8, for example, when focusing on the element A, it is predicted how the volumetric flow rate of the waste located in the element A will change in the future.

Specifically, the control device 90 first reads out the change in the volumetric flow rate and the change in the control value of the element of interest up to the present. In addition, since the above-mentioned trend data includes the change tendency of the volume flow rate and the influence of the control value on the volume flow rate, the tendency data can be used to determine the future volume flow rate of the waste located in this element. Change can be predicted. By making this prediction for a plurality of elements, it is possible to predict the overall movement of the waste in the incinerator 10. In addition, by predicting future changes in volume flow rate, it is possible to calculate volume flow rate progress information for the period from the past to the future.

When the tendency data is a database of volume flow rate progress information, the control device 90 searches for past data similar to, for example, the "change in volume flow rate and control value up to the present" of the element of interest. Then, the control device 90 extracts one or a plurality of similar past data, and predicts the change in the volume flow rate of the data of interest based on how the volume flow rate changes in the extracted data. .. In addition, when the trend data is a model constructed by machine learning, by inputting the "change in volume flow rate up to the present and control value" of the element of interest, the future change in volume flow rate of the data of interest is output. Will be done.

<S107> Next, the control device 90 identifies the elements that are in the combustible startable state and the burnout state for the waste at the present time and at a plurality of time points in the future (S107). As described above, the degree of change in the volumetric flow rate of waste is greatly reduced at the timing of transition to the combustible startable state. After that, at the timing of transition to the burnout state, the degree of change in the volumetric flow rate of the waste is greatly reduced again. Therefore, it is possible to identify the elements that are in the combustion startable state and the burnout state based on the degree of change in the volumetric flow rate. Since the degree of change in the volumetric flow rate differs depending on the control value of the incinerator 10, it is preferable to specify it using a condition (for example, a threshold value) according to the control value.

The control device 90 performs this process on the volume flow rate progress information (information calculated in step S104) up to the present time. As a result, it is possible to identify the elements that are in the state where combustion can be started and the state where combustion is burned out for the current waste. Further, the control device 90 performs this process on the volume flow rate progress information (information predicted in step S106) after the lapse of the first time and after the lapse of the second time. As a result, it is possible to identify the elements that are in the combustible startable state and the burnout state for the waste at a plurality of time points in the future.

<S108> Next, the control device 90 identifies an in-combustion element for waste at a plurality of time points at present and in the future (S108). The mid-combustion element is an element after the state in which combustion can be started and before the state in which combustion is completely burned out. Therefore, the control device 90 can identify the combustion intermediate element based on the identification result of the combustion startable state and the burnout state. FIG. 9 shows a specific result of whether or not the combustion is in progress. FIG. 9 is a schematic view of the transport unit 20 viewed in the vertical direction, and each of the squares shown in FIG. 9 is a mesh-divided element. In FIG. 9, diagonal lines are drawn for the elements identified as the in-combustion state.

<S109> Next, the control device 90 calculates and stores the mid-combustion volume of the waste at a plurality of time points at the present time and in the future (S109). The mid-combustion volume is the sum of the volumes of all the mid-combustion waste (that is, the waste located in the mid-combustion element). The waste in the middle of combustion is, in other words, the waste in which pyrolysis gas is generated. In addition, there is a correlation between the volume of waste during combustion and the amount of pyrolysis gas generated per hour. Therefore, the volume during combustion is a value that is an index of the amount of pyrolysis gas generated per hour (in other words, the amount of heat generated per hour).

The control device 90 pays attention to a predetermined combustion intermediate element at the present time, and multiplies the area of the combustion intermediate element (the area of one predetermined element) by the thickness of the waste located in the combustion intermediate element. Calculate the volume of waste located in the mid-combustion element of interest. By performing this process for all the mid-combustion elements, the current mid-combustion volume is calculated. Moreover, how the volumetric flow rate changes in the future can be predicted for each element as described above. Therefore, it is possible to predict how the volume of waste will change from the present time at multiple points in the future. Therefore, the control device 90 can calculate the volume in the middle of combustion at a plurality of time points in the future.

<S110> Next, the control device 90 increases or decreases the transfer speed of (a) the combustion grate 22 based on the comparison result between the current combustion intermediate volume and the combustion intermediate volume after the lapse of the first time. , (B) Increase or decrease the transport speed of the dry grate 21, post-combustion grate 23, (c) Adjust the supply amount of primary combustion gas, (d) Adjust the supply amount of secondary combustion gas, The control value for controlling the above is calculated (S110). As described above, the transport speed of the grate can be changed by changing the operating speed and the stop time of the grate. Therefore, the values related to the operation speed and the stop time are the control values. Further, by adjusting the first damper 81 to the fifth damper 85, the supply amounts of the primary combustion gas and the secondary combustion gas can be adjusted. Therefore, the value related to the opening degree of the first damper 81 to the fifth damper 85 is the control value.

For example, when the volume during combustion after the lapse of the first time is larger than the volume during combustion at the present time, the properties of the waste are changed and the amount of components that are pyrolyzed and gasified is increasing. Can be inferred. In this case, the transport speed of the combustion grate 22 is reduced in accordance with the increase in the amount of the thermally decomposed gas generated per hour, and the transport speed of the dry grate 21 and the post-combustion grate 23 is also reduced accordingly. Therefore, it is preferable to reduce the supply amount of the primary combustion gas supplied to the drying unit 11, increase the supply amount of the primary combustion gas supplied to the combustion unit 12, and increase the supply amount of the secondary combustion gas. .. As a result, stable combustion can be appropriately maintained. Further, when the volume during combustion becomes smaller in the future, it is preferable to control to change each value in the direction opposite to the above.

Further, since the prediction accuracy of the mid-combustion volume is limited, if the mid-combustion volume changes slightly in the future, it is less necessary to perform control based on it. Therefore, it is preferable to change the control values of (a) to (d) when the degree of change in the volume during combustion is equal to or greater than the threshold value.

Further, the combustion generated in the incinerator 10 greatly differs depending on the shape and structure of the incinerator 10 and the waste to be charged. In addition, the target combustion state greatly differs depending on the required processing amount, the durability of the incinerator 10, the laws and regulations regarding exhaust gas, and the like. Therefore, even if it is predicted that the volume will change during combustion, it may be desirable not to change the control values from (a) to (d). In order to determine this, the control device 90 further uses various detection data (for example, detection data from the incinerator gas temperature sensor 91 to the NOx gas concentration sensor 94, etc.) to control the values (a) to (d). It is preferable to calculate.

Further, even if the volume during combustion is predicted to change, there is a possibility that only the volume during combustion changes and the amount of pyrolysis gas generated per hour does not change. In this case, it is not necessary to change the control values from (a) to (d). Here, from the above-mentioned various detection data, for example, an index of the amount of heat and the component generated by combustion can be obtained. Therefore, more appropriate control values can be calculated by calculating the control values of (a) to (d) by further using various detection data.

<S111> Next, the control device 90 corrects the control values (a) to (d) based on the comparison result between the current combustion intermediate volume and the future combustion intermediate volume at a plurality of time points (S111). ). By calculating and comparing the mid-combustion volume at multiple points in the future (for example, after the lapse of the first time, after the lapse of the second time, ...), it is possible to further understand how the mid-combustion volume increases or decreases in the future. Can be grasped. In other words, it is only possible to predict whether the volume in the middle of combustion will increase or decrease only by comparing the current time point and the future time point point. On the other hand, by comparing the current and future multiple time points, it is possible to obtain information such as, for example, the volume during combustion continues to increase, decreases slightly after increasing, and returns to the current volume during combustion after increasing. be able to.

For example, when the volume during combustion is expected to increase and then decrease, the amount of change of each control value from (a) to (d) may be smaller than that when the volume is expected to continue to increase. In this way, by correcting the control value according to the future change tendency of the volume during combustion, stable combustion can be maintained more appropriately.

Further, in steps S110 and S111, the control value is calculated or corrected based on the magnitude relationship of the volume during combustion, but in addition to this, the control value is calculated or corrected based on the magnitude of the increase or decrease in the volume during combustion. You may. For example, as the amount of increase / decrease in the volume during combustion increases at the present time and after the lapse of the first time, the amount of change in the control value increases. Further, the larger the increase / decrease in the volume during combustion after the lapse of the first time and the second time, the larger the correction amount.

<S112> Next, the control device 90 corrects the control values (a) to (d) based on the comparison result between the volume in the middle of combustion at a plurality of time points in the past and the volume in the middle of combustion at the present time (S112). ). Steps S110 and S111 are processes for calculating and correcting the control value based on the future change in the volume during combustion. On the other hand, step S112 is a process of correcting the control value based on the change in the volume during combustion from the past to the present. The past mid-combustion volume used here is the one stored in step S109.

For example, when the volume during combustion increases over a long period from the past to the present, it is considered that the properties of the entire waste change and the amount of heat generated increases. Therefore, in such a case, it is preferable to change the control value. On the other hand, if the volume is frequently increased or decreased during combustion between the past and the present, it is considered that the properties of the waste have changed temporarily, so the control value is not changed (change amount). (Reduce) is preferable. In this way, the control device 90 corrects the control values of (a) to (d) based on the change in the volume during combustion from the past to the present.

While future changes in the volume during combustion are useful because they are directly linked to the future combustion state, the prediction accuracy is limited. On the other hand, the change in volume during combustion from the past to the present is highly reliable because it is based on the fact that it has already ended. In the present embodiment, since the control values of (a) to (d) are corrected based on the changes in the volume during combustion both from the present to the future and from the past to the present, more appropriate control can be performed. ..

In this embodiment, the calculation and correction of the control value based on the predicted change in the volume during combustion from the present to the future and the correction of the control value based on the change in the volume during combustion from the past to the present are performed stepwise. Is. Instead of this, the change in the volume during combustion from the past to the future may be obtained, and the control value may be calculated based on this change.

<S113> Next, the control device 90 executes the control of (a) to (d) with the control values calculated and corrected in steps S110 to S112 (S113).

Further, since the properties of the waste may change at all times, the control device 90 performs the processing in step S101 and subsequent steps again after the processing in step S113. As a result, even if the properties of the waste change, it is possible to revise the future prediction for the progress of drying and combustion of the waste to be appropriate, so that the volume of the incinerator as a whole during combustion can be adjusted. Since it is continuously stabilized, stable combustion can be maintained.

As described above, the combustion condition evaluation method of the present embodiment is divided into a drying unit 11, a combustion unit 12, and a post-combustion unit 13, and operates intermittently in a state where waste is accumulated. This is done for the incinerator 10 provided with a grate for transporting the waste. This combustion state evaluation method includes a preparation step, a division step, a first calculation step, a second calculation step, a third calculation step, a volume calculation step, and a volume prediction step. In the preparation process, a plurality of infrared cameras 95 are used to observe at least the waste accumulated in the drying section 11 and the burning section 12 through the selective transmission filter 95a that selectively transmits light having a wavelength not emitted by the flame. Therefore, a plurality of thermal images having different viewpoints are acquired, and a three-dimensional thermal image is created based on the plurality of thermal images. In the dividing step, the waste of the three-dimensional thermal image is mesh-divided into a plurality of elements. In the first calculation step, the thickness of the waste and the surface movement speed of the waste are calculated for each element based on the three-dimensional thermal image. In the second calculation step, based on the calculation result of the first calculation step, the element includes thickness progress information indicating how the thickness of the waste located in the element changes in time series until it is located in the element. Calculated for each. In the third calculation step, based on the calculation results of the first calculation step and the second calculation step, it is shown how the volume flow rate changes in time series until the waste located in the element is located in the element. Volumetric flow rate progress information is calculated for each element. In the volume calculation step, the volume of waste in the middle of combustion at the present time is calculated. In the volume prediction step, the volume of waste during combustion after the lapse of the first time is predicted. Further, in the volume calculation process, the current volume flow rate progress information is analyzed to identify the intermediate combustion element, which is an element after the combustion startable state is reached and before the burnout state is reached, and the combustion intermediate element is identified. Calculate the volume of waste located in. In the volume prediction step, the volume obtained based on the volume flow rate progress information for each element and the time change of the control value including at least the value used for combustion control for setting the transport speed of the grate. Based on the tendency of the flow rate over time, the change in the volumetric flow rate after the lapse of the first time is predicted for each element, and based on the prediction result, the element in the middle of combustion after the lapse of the first time is specified, and the first time Predict the volume of waste located in the mid-burning element after the lapse.

Since pyrolysis gas is generated from the waste during combustion, the volume of the waste during combustion is a value that is an index of the amount of pyrolysis gas generated per hour (the amount of heat generated). In particular, the volume of waste in the middle of combustion in the future is an index of the amount of heat generated in the incinerator in the future. In this way, useful information can be obtained as an index of combustion control.

Further, in the combustion control method of the present embodiment, the volume of the waste of the combustion intermediate element at the present time and the volume of the waste of the combustion intermediate element after the lapse of the first time are compared with each other.
(A) Acceleration or deceleration of the transport speed of the combustion grate 22 (b) Acceleration or deceleration of the transport speed of the dry grate 21 and the post-combustion grate 23 (c) Adjustment of the supply amount of the primary combustion gas (d) ) A control step of performing at least one of four controls for adjusting the supply amount of the secondary combustion gas used in the secondary combustion for burning the primary combustion gas including the unburned gas generated in the primary combustion is included.

As a result, combustion control can be performed using an appropriate control value according to the amount of heat generated in the incinerator in the future. As a result, stable combustion can be appropriately maintained.

Further, in the combustion control method of the present embodiment, in the volume prediction step, the volume of waste located in the combustion intermediate element after the lapse of the second time is further predicted. In the control step, at least at present, it is used in the four controls (a) to (d) based on the comparison result of the volume of the waste located in the intermediate combustion element after the lapse of the first time and the lapse of the second time. Determine the control value.

As a result, combustion control can be performed using an appropriate control value according to the amount of heat generated in the incinerator 10 in the future and its change. As a result, stable combustion can be maintained more appropriately.

Further, in the combustion control method of the present embodiment, in the control step, further, based on the comparison result between the volume of the waste of the combustion intermediate element in the past and the volume of the waste of the current combustion intermediate element, (a). It is preferable to determine the control values used in the four controls from) to (d).

As a result, since the change in the volume during combustion from the past to the present is used, combustion control can be performed using a control value that more reliably captures the amount of heat generated in the future. As a result, stable combustion can be maintained more appropriately.

Although the preferred embodiment of the present invention has been described above, the above configuration can be changed as follows, for example.

In the above embodiment, two sets of infrared cameras 95 are used to observe the wastes from the drying section 11 to the post-burning section 13, but one set or three or more sets of infrared cameras 95 are used to observe these wastes. It may be.

The flowchart shown in the above embodiment is an example, and some processes may be omitted, the contents of some processes may be changed, or new processes may be added.

For example, at least one of the processes of steps S111 and S112 may be omitted. Further, in step S112, the volume during combustion at one time point may be used instead of the past plurality. Further, in the above embodiment, all the controls from (a) to (d) are performed, but only a part of (a) to (d) may be performed, or the control among (a) to (d) may be performed. A process of selecting an object to be performed may be performed.

Further, in the above embodiment, the first and second three-dimensional thermal images are created, and the processes of steps S102 to S104 are performed on the respective three-dimensional thermal images, respectively. Instead of this, one three-dimensional thermal image (a thermal image showing the three-dimensional position of the waste from the drying portion 11 to the post-combustion portion 13) is created based on the thermal images acquired by the two sets of infrared cameras 95. You may. In this case, the processes of steps S102 to S104 are performed on one three-dimensional thermal image.

Further, in the above embodiment, the volume flow rate progress information is calculated for each of the first range and the second range, and then the two are combined. Instead, for the first range and the second range, the thickness and the surface movement speed ( Alternatively, after calculating the thickness progress information), both may be combined.

In the above embodiment, as the detection data used in the combustion control, the detection data of the incinerator gas temperature sensor 91, the incinerator outlet gas temperature sensor 92, the CO gas concentration sensor 93, and the NOx gas concentration sensor 94 have been described. , Combustion control may be performed by omitting at least one detection data, or combustion control may be performed by adding detection data other than the above. As another detection data, for example, the amount of boiler evaporation associated with the recovery of heat from the exhaust gas, or the amount of water for water spray cooling when cooling by water spray can be used.

10 Incinerator 11 Drying part 12 Combustion part 13 Post-combustion part 21 Dry grate 22 Combustion grate 23 Post-combustion grate 90 Control device 95 Infrared camera 96 Image processing device

Claims (4)

For incinerators equipped with a grate that is divided into a drying section, a combustion section, and a post-combustion section and that transports the waste by operating intermittently in a state where the waste is accumulated.
A plurality of infrared cameras are used to observe at least the waste accumulated in the dry portion and the combustion portion through a filter that selectively transmits light having a wavelength not emitted by the flame, and a plurality of viewpoints are different. A creation process of acquiring a thermal image and creating a three-dimensional thermal image based on the plurality of thermal images,
A division step of mesh-dividing the waste of the three-dimensional thermal image into a plurality of elements, and
A first calculation step of calculating the thickness of the waste and the surface moving speed of the waste for each element based on the three-dimensional thermal image, and
Based on the calculation result of the first calculation step, thickness progress information indicating how the thickness of the waste located in the element changes in time series until it is located in the element is provided for each element. The second calculation process to calculate and
Based on the calculation results of the first calculation step and the second calculation step, the volume flow rate showing how the volume flow rate changed in time series until the waste located in the element was located in the element. The third calculation step of calculating the progress information for each of the elements, and
A volume calculation process for calculating the volume of the waste during combustion at the present time, and
A volume prediction step for predicting the volume of the waste in the middle of combustion after the lapse of the first time, and
Perform processing including
In the volume calculation step,
By analyzing the current volumetric flow rate progress information, the mid-combustion element, which is the element after the combustion startable state and before the burnout state is reached, is identified.
Calculate the volume of the waste located in the mid-combustion element,
In the volume prediction step,
The volumetric flow rate obtained based on the volumetric flow rate progress information for each element and the time change of the control value including at least a value used for combustion control for setting the transport speed of the grate. Based on the tendency of the passage of time, the change in the volumetric flow rate after the passage of the first time is predicted for each of the above factors.
Based on the prediction result, the mid-combustion element after the lapse of the first time is identified, and
A method for evaluating a combustion state, which comprises predicting the volume of the waste located in the mid-combustion element after the lapse of the first time. A combustion control method for controlling combustion in the incinerator by using the combustion condition evaluation method according to claim 1.
Based on the comparison result between the current volume of the waste of the intermediate combustion element and the volume of the waste of the intermediate combustion element after the lapse of the first time,
(A) Accelerating or decelerating the transport speed of the waste by the grate of the combustion unit (b) Accelerating or decelerating the transport speed of the waste by the grate of the drying portion and the post-combustion portion (b) c) Adjustment of the supply amount of the primary combustion gas (d) Four controls of adjustment of the supply amount of the secondary combustion gas used in the secondary combustion for burning the primary combustion gas including the unburned gas generated in the primary combustion. A combustion control method comprising a control step of performing at least one of the above. The combustion control method according to claim 2.
In the volume prediction step, the volume of waste located in the combustion intermediate element after the lapse of the second time is further predicted.
In the control step, at least at present, the control values used in the four controls are determined based on the comparison result of the volumes of wastes located in the combustion intermediate elements after the lapse of the first time and the lapse of the second time. Combustion control method characterized by that. The combustion control method according to claim 2 or 3.
In the control step, the control values used in the four controls are further determined based on the comparison result between the past volume of the waste of the intermediate combustion element and the current volume of the waste of the intermediate combustion element. Combustion control method characterized by

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