JP2019219094A - In-furnace situation determination method and combustion control method - Google Patents

Abstract

To provide a method for grasping a shape and movement of the waste of a dry part while exactly detecting a flame combustion start position and its moving direction.SOLUTION: An in-furnace situation determination method performs processing including an image acquisition process, a three-dimensional image creation process and a calculation process. In the image acquisition process, a plurality of images including contours of wastes deposited at least at a dry part 11 and flames and different in viewpoints are continuously acquired by using a plurality of imaging devices 95 different in viewpoints, from a window part arranged at a side wall formed at an end part of the dry part 11 in a furnace width direction. In the three-dimensional image creation process, a three-dimensional image is continuously created by applying image synthesizing processing to the plurality of images from the different viewpoints which are acquired in the image acquisition process. In the calculation process, a flame combustion start position is specified on the basis of the flames included in the three-dimensional image which is created in the three-dimensional image creation process, and calculates whether or not the flame combustion start position has moved to an upstream side in a conveyance direction, or moved to a downstream side in the conveyance direction.SELECTED DRAWING: Figure 1

Description

  The present invention mainly relates to a method for appropriately maintaining stable combustion in a grate-type waste incinerator in which waste is incinerated while being transported by a grate.

  2. Description of the Related Art Conventionally, various kinds of waste are put into a waste incinerator, and it is important that stable combustion can be appropriately maintained even when the properties of the put waste change. The grate-type waste incinerator is divided into a drying section for drying the waste, a combustion section for burning the waste by flame, and a post-combustion section for post-burning the waste (oki combustion). I have. In order to perform combustion control that appropriately maintains stable combustion, it is important to keep the position of the burn-off point, which is the end position of such flame combustion, within an appropriate range.

  (1) The main reason that the position of the burn-out point deviates from an appropriate range is that a difference occurs between the assumed drying time and the actual drying time due to the difference in the properties of the waste. Therefore, the position of the burn-off point should be controlled based on the information on the change of the burn-off point and the burn-off point where the state changes after a considerable time delay from the difference between the assumed drying time and the actual drying time. (3) The moving direction of the flame combustion start position is the tendency of the difference between the assumed drying time and the actual drying time (that is, the appropriateness of the progress of drying and burning of wastes). ), It can be treated as information necessary to keep the burn-out point within an appropriate range. Considering that the progress of drying of waste deposited on the grate in the drying section The information of the burnout point It can be handled as information for accommodating the location in the appropriate range.

  Patent Literature 1 discloses an incinerator in which one infrared camera is disposed further downstream in the transport direction than a post-combustion unit to acquire thermal image information in the furnace. In this incinerator, the thermal image information (thermographic information of the waste on the grate) obtained by the infrared camera is based on the fact that the wavelength of the infrared light emitted from the waste layer and the wavelength of the infrared light emitted from the flame are different. By performing the analysis, a thermal image of the waste in the drying section on the upstream side of the flame is obtained.

  Patent Literature 2 discloses an incinerator in which an infrared camera is arranged on a ceiling of a drying unit to acquire a thermal image of waste in the drying unit. Since the infrared camera is provided with a filter having a transmission wavelength of about 3.9 μm, a thermal image excluding infrared rays emitted by the flame is created. Note that Patent Document 2 discloses a configuration in which a thermal image is acquired using an infrared camera equipped with this filter and an infrared camera not equipped with this filter.

JP 2017-116252 A Japanese Patent No. 3315036

  However, in Patent Literature 1, since the infrared camera is disposed further downstream in the transport direction than the post-combustion section, the waste existing in the high-temperature combustion section, such as this, is located between the infrared camera and the flame combustion start position. There are radiated light (including infrared rays) from scattered waste materials, refractory materials and the like that have been heated to a high temperature by protecting the combustion part, and scattered light thereof. Therefore, even if infrared rays emitted from the flame are excluded based on the difference in wavelength, the shape and movement of the waste in the drying section on the upstream side of the flame cannot be sufficiently specified based on this image. .

  In Patent Literature 2, an infrared camera is arranged on the ceiling in the furnace. However, in the furnace, a large amount of pyrolysis gas generated by pyrolysis of waste and combustion gas generated by combustion are present. Has been blown up. Therefore, an infrared camera arranged on the ceiling is easily affected by this. Patent Literature 2 describes that a thermal image is acquired by a total of two infrared cameras: an infrared camera equipped with the above filter and an infrared camera not equipped with the filter. However, an infrared camera equipped with a filter mainly contains information about non-flames (that is, waste), while an infrared camera without a filter mainly contains information about flames. Therefore, even if the images acquired by these two infrared cameras are compared, the shape of the flame, the shape of the waste, and the movement thereof cannot be sufficiently specified.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to accurately detect a flame combustion start position and a moving direction thereof, and to grasp a shape of a waste in a drying section and a movement thereof. Is to provide.

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

  According to an aspect of the present invention, the following in-furnace state determination method is provided. That is, this method for judging the in-furnace state is composed of a grate divided into a drying section, a burning section, and a post-combustion section, and operates intermittently in a state where the waste is accumulated, thereby removing the waste. This is performed on a waste incinerator provided with a transport unit that transports and supplies primary combustion gas through the grate. The in-furnace situation determination method performs a process including an image acquisition step, a three-dimensional image creation step, and a calculation step. In the image acquisition step, at least the discarded material deposited on the drying unit is obtained by using a plurality of imaging devices having different viewpoints from a window provided on a side wall formed at an end of the drying unit in the furnace width direction. A plurality of images including the appearance of an object and a flame and having different viewpoints are continuously obtained. In the three-dimensional video creation step, a three-dimensional video is continuously created by performing image synthesis processing on a plurality of videos from different viewpoints acquired in the video acquisition step. In the calculation step, a flame combustion start position is specified based on the flame included in the three-dimensional image created in the three-dimensional image creation step, and whether the flame combustion start position is moving upstream in the transport direction is determined. It is calculated whether it is moving downstream in the direction.

  By providing the imaging device on the side wall of the drying unit, it is possible to directly obtain images of the flame and the waste of the drying unit without passing through the combustion unit and the post-combustion unit. Furthermore, the temperature of the side wall of the drying unit is lower than that of the side wall of the combustion unit, and the side wall of the drying unit is less affected by the pyrolysis gas and the combustion gas than the ceiling. In addition, by using the three-dimensional image, the moving direction of the combustion start position can be accurately calculated, and the shape and movement of the waste in the drying unit can be sufficiently detected.

  ADVANTAGE OF THE INVENTION According to this invention, the shape and movement of the waste of a drying part can be grasped | ascertained, detecting the flame combustion start position and its moving direction accurately.

The schematic block diagram of the waste incineration equipment containing the incinerator which performs the method of this invention. Functional block diagram of an incinerator. FIG. 2 is a three-dimensional schematic view of the incinerator showing an attachment position of the imaging device. 4 is a flowchart showing control performed by a control device to stabilize combustion. FIG. 4 is a schematic diagram illustrating a state in which waste is transported and values calculated by a control device. The schematic block diagram of the waste incineration equipment which shows a state when the flame combustion start position moves to the upstream side. The schematic block diagram of the waste incineration equipment which shows a state when the flame combustion start position moves to the downstream side.

  <Overall Configuration of Waste Incineration Facility> First, a waste incineration facility (waste incineration facility) 100 including an 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 to be subjected to the method of the present invention. In the following description, the terms “upstream” and “downstream” mean upstream and downstream in the direction in which waste, combustion gas, exhaust gas, primary air, secondary air, circulating exhaust gas, and the like flow.

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

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

  The steam turbine power generation equipment 35 is configured to include a turbine and a power generation device (not shown). The turbine is driven to rotate by steam supplied from the water pipe 31 and the superheater pipe 32. The power generation device generates power using the rotational driving force of the turbine.

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

  <Configuration of Incinerator 10> The incinerator 10 includes a dust supply device 40 for supplying waste into the incinerator. The dust feeding device 40 includes a waste input hopper 41 and a dust feeding device main body 42. The waste input hopper 41 is a portion into which waste is input from outside the furnace. The dust feeding 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 put in the waste input hopper 41 to the downstream side. The control device 90 controls the moving speed, the number of movements per unit time, the moving amount (stroke), and the position of the stroke end (moving range) of the dust feeding device main body 42. The dust feeding device may be of a type that moves at a certain 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 includes 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. I have. Therefore, the transport section 20 is composed of a plurality of stages of grate. Each grate is provided on the bottom surface of each part, and waste is placed thereon.

  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. The waste can be stirred while being transported to the downstream side. By increasing (decelerating) the operating speed of the movable grate, the transport speed of the waste can be increased (decelerated). In addition, the transport speed of the waste can be increased (decelerated) by shortening (extending) the stop time of the movable grate. The grate is arranged side by side with a gap large enough to allow gas to pass through.

  The drying unit 11 is a unit that dries the waste supplied to the incinerator 10. The waste in the drying unit 11 is dried by the primary air supplied from below the drying grate 21 and the radiant heat of combustion in the adjacent combustion unit 12. At this time, pyrolysis gas is generated from the waste in the drying unit 11 due to pyrolysis. The waste from the drying unit 11 is transported toward the combustion unit 12 by the drying grate 21.

  The combustion section 12 is a section for mainly burning the waste dried in the drying section 11. In the combustion section 12, the waste mainly causes flame combustion, and a flame is generated. The waste in the combustion unit 12, the ash generated by the combustion, and the unburned material that has not been 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 flow toward the post-combustion unit 13 through the throttle unit 17. 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 unit 13 is a unit that burns waste (unburned material) that has not been completely burned in the combustion unit 12. In the post-combustion unit 13, the radiant heat of the combustion gas and the primary air promote the combustion of the unburned substances that cannot be completely burned in the combustion unit 12. As a result, most of the unburned matter becomes ash, and the unburned matter decreases. The ash generated in the post-combustion unit 13 is transported toward the chute 24 by a post-combustion grate 23 provided on the bottom surface of the post-combustion unit 13. The ash conveyed to the chute 24 is discharged outside the waste incinerator 100. Although the post-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 section 11, the combustion section 12, and the post-combustion section 13 are different, the respective wall surfaces and the like are configured according to the reactions that occur. For example, a flame having a higher fire resistance level than that of the drying unit 11 is employed in the combustion unit 12 because flame combustion occurs.

  The reburning portion 14 is a portion for burning unburned gas contained in the combustion gas. The reburning section 14 extends upward from the drying section 11, the burning section 12, and the post-burning section 13, and secondary air is supplied along the way. Thereby, 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 section 14. The combustion that occurs in the combustion unit 12 and the post-combustion unit 13 is called primary combustion, and the combustion that occurs in the reburning unit 14 (that is, the combustion of unburned gas remaining in the primary combustion) is called 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 has a primary air supply unit 51, a secondary air supply unit 52, and an exhaust gas supply unit 53. Each supply unit is constituted by a blower for attracting or sending out gas.

  In this specification, the gas supplied for primary combustion is referred to as 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 a gas not used for combustion or the like (that is, excluding circulating exhaust gas). Therefore, the primary air includes a gas obtained by heating air taken in from the outside. Similarly, in this specification, a 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 primary air.

  The primary air supply unit 51 supplies 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. Note that a heater may be provided in the primary air supply path 71 so that the temperature of the primary air supplied to each unit can be adjusted.

  The first supply path 71 a is a path for supplying primary air to the drying step wind box 25 provided below the drying grate 21. The first supply path 71a is provided with a first damper 81, and can adjust the supply amount of the primary air supplied to the drying step wind box 25. 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 step wind box 26 provided below the combustion grate 22. A second damper 82 is provided in the second supply path 71b, and can adjust the supply amount of the primary air supplied to the combustion step box 26. 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 staircase 27 provided below the post-combustion grate 23. The third supply path 71c is provided with a third damper 83, so that the supply amount of the primary air supplied to the post-combustion step wind box 27 can be adjusted. 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 its upper part (the ceiling) via the secondary air supply path 72, and the combustion gas is supplied by the throttle unit 17. The secondary air is supplied to the portion that changes direction (near the throttle unit 17). In the secondary air supply path 72, a fourth damper 84 controlled by the control device 90 is provided, so that the supply amount of secondary air to each section can be adjusted.

  The exhaust gas supply unit 53 supplies (recirculates) the exhaust gas discharged from the waste incinerator 100 through the circulating exhaust gas supply path 73 into the furnace. Exhaust gas discharged from the waste incinerator 100 is purified by a filter-type dust collector 60, and a part of the exhaust gas is incinerated from both sides (a front side and a rear side of the paper) of the combustion unit 12 by an exhaust gas supply unit 53. It is supplied to the furnace 10. The position where the exhaust gas is supplied is not particularly limited. For example, the exhaust gas may be supplied from above the incinerator 10 (the ceiling) or may be supplied from only one side. By supplying the exhaust gas to the incinerator 10, the oxygen concentration in the incinerator 10 is reduced, and a local excessive rise in the combustion temperature can be suppressed. As a result, generation of NOx can be suppressed. A fifth damper 85 controlled by the control device 90 is provided in the circulation exhaust gas supply path 73, and the supply amount of the circulation 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 imaging device 95 are provided.

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

  In the present embodiment, two imaging devices 95 are provided. Each imaging device 95 has the same structure. Further, three or more imaging devices 95 may be provided. A plurality of imaging devices 95 are provided for the purpose of creating a three-dimensional video. Therefore, the relative positions of the plurality of imaging devices 95 are stored in advance. Note that the imaging device 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 a video (moving image). Is also good. Since image information obtained from continuously obtained still images is equivalent to video (moving image) information, any device has a function of obtaining a video.

  The purpose of each imaging device 95 is to acquire an image of the flame burning start position and an image of waste mainly conveyed through the dry grate 21. The imaging device 95 is not an infrared camera for detecting temperature or the like, but a camera for acquiring an image of the appearance (color, brightness, or the like) of the waste. Therefore, the image acquired by the imaging device 95 is an image showing the color, luminance, and the like in the furnace viewed from the viewpoint of the imaging device 95. Note that the viewpoint indicates a position where the imaging device 95 as a measuring device is arranged. In the incinerator 10, it is assumed that drying is completed at the downstream end of the drying unit 11 and flame combustion is started at the upstream end of the combustion unit 12. However, depending on the properties of the supplied waste (for example, the amount of water contained in the waste and the easiness of burning the waste), drying is completed in the middle of the drying unit 11 and flame combustion is started or combustion is started. The drying may not be completed and the flame combustion may not start even in the middle of the part 12.

  Therefore, in order to image the flame combustion start position, the imaging range of the two imaging devices 95 includes the image of the boundary between the drying unit 11 and the combustion unit 12 and the vicinity thereof. In the present embodiment, since the waste of the drying unit 11 is imaged, the imaging range of the two imaging devices 95 includes the surface of the waste of the drying unit 11. More specifically, the imaging range of the two imaging devices 95 of the present embodiment includes the area from the upstream end of the drying unit 11 to the center of the combustion unit 12 in the waste transport direction. Note that the imaging ranges of the two imaging devices 95 may be narrower or wider than in the present embodiment. Further, the imaging device 95 may have a configuration in which the imaging range of a video can be changed. In this case, the imaging device 95 may be able to change the imaging range without stopping the incinerator 10. The imaging device 95 is arranged at a position higher than the waste for the purpose of properly acquiring an image even when the amount of the waste accumulated becomes large. Therefore, the imaging device 95 is arranged to be inclined downward. Note that the imaging device 95 may be arranged without being inclined.

  As shown in FIG. 3, a direction perpendicular to the direction in which the waste is transported and the vertical direction (vertical direction) is referred to as a furnace width direction. The imaging device 95 acquires an image from a side wall 11a which is a wall formed at an end of the drying unit 11 in the furnace width direction. Specifically, two windows 11b are provided on the side wall 11a, and the two imaging devices 95 acquire images via the respective windows 11b. The window 11b is a part for observing the inside of the furnace. Specifically, the window 11b has a configuration in which a part of the side wall 11a is opened and the opening is closed with a transparent (including translucent) heat-resistant glass or the like. Part. Note that two imaging devices 95 may be arranged in one window 11b. In the present embodiment, the imaging devices 95 are arranged side by side in the transport direction. However, the imaging devices 95 may be arranged side by side in the vertical direction.

  In the present embodiment, two imaging devices 95 are arranged on only one of the left and right side walls 11a, but one or a plurality of imaging devices 95 may be arranged on both of the side walls 11a.

  <Process Performed by Control Device> The control device 90 includes 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 configured by a CPU, a RAM, a ROM, and the like, and can perform a process of creating a three-dimensional video based on the video acquired by the two imaging devices 95 (image synthesis process). 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 a three-dimensional image, will be described with reference to the flowchart of FIG. FIG. 4 is a flowchart showing control performed by control device 90 to stabilize combustion.

  First, the control device 90 stores a three-dimensional image created by the image processing device 96 based on images acquired by a plurality (two) of imaging devices 95 (S101). The process of creating a three-dimensional video (a plurality of temporally continuous three-dimensional images) from a plurality of videos (each image) will be briefly described because it is a known technique. Here, in order to distinguish the two imaging devices 95, the first and second imaging devices 95 are sometimes described. The image acquired by the first imaging device shows the color and shape of the surface of the flame and the waste as viewed from the position of the first imaging device. The same applies to the video acquired by the second imaging device. Then, the image processing device 96 specifies where the specific portion A on the surface of the flame or the waste is displayed in each of the two images. As described above, since the positional relationship between the first imaging device and the second imaging device is known, the distance from the first or second imaging device to the specific location A of the flame or waste can be calculated based on trigonometry or the like. . By performing this processing on other portions of the surface of the flame or the waste, the position (three-dimensional coordinates) of the surface of the flame or the waste can be specified.

  Next, the control device 90 calculates (1) a time change of the thickness, (2) a time change of the moving speed of the surface, and (3) a residence time of the drying unit for the waste of the drying unit 11 (S102). ). Since these values are used to correct the control values of the combustion control, these values are called correction data.

  Regarding the above (1), the thickness of the waste is a length along the vertical direction from the dry grate 21 to the surface of the waste, as shown in FIG. The position of the surface (upper surface) of the dry grate 21 is stored in the control device 90 or the like in advance. Further, the position of the surface of the waste can be specified based on the three-dimensional image. Therefore, the thickness of the waste can be calculated by comparing the two positions (coordinates). In addition, it is possible to calculate the thickness of the waste according to both the transport direction and the furnace width direction (although the processing may be actually performed), but in the present embodiment, in order to simplify the processing, Then, the thickness of the waste according to only the transport direction is calculated. If the thickness of the waste is different in the furnace width direction, the representative value is determined using the average in the furnace width direction.

  As described above, the distribution of the thickness of the waste in the drying unit 11 according to the transport direction can be calculated based on the three-dimensional image at a certain time. Since the three-dimensional images obtained by the image synthesizing process are sequentially created according to the time, the thickness of the waste is similarly calculated for the three-dimensional image at the next time. In this way, the control device 90 calculates the time change of the thickness of the waste according to the transport direction, and stores it in a predetermined storage unit.

  The significance of calculating the time change of the thickness of the waste is as follows. That is, the waste accumulated in the drying unit 11 is dried by evaporating water contained in the waste along with the drying operation (feeding operation) of the drying grate 21, and the mass is reduced and the volume is reduced. . That is, the temporal change in 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. Therefore, in the present embodiment, combustion control is performed based on a temporal change in the thickness of the waste.

  Regarding (2) above, the moving speed of the surface of the waste is a speed at which the surface of the waste moves in the transport direction, as shown in FIG. In FIG. 5, a thick line is drawn in a portion having a relatively large thickness for easy understanding, and a state in which this portion moves is shown. Since the three-dimensional image at each time shows the shape of the surface of the waste, how the surface of the waste moves can be obtained based on the three-dimensional image. Therefore, the moving speed of the specific part of the waste can be calculated based on the moving distance of the specific part on the surface of the waste and the time required for moving the moving distance. In addition, it is possible to calculate the moving speed of the waste according to both the transport direction and the furnace width direction (although the processing may be actually performed). Calculate the moving speed of waste. If the moving speed of the waste is different in the furnace width direction, the representative value is determined using the average in the furnace width direction.

  As described above, the distribution of the moving speed of the waste in the drying unit 11 according to the transport direction can be calculated. Since the three-dimensional images obtained by the image synthesis processing are sequentially created according to the time, a new moving speed of the waste is calculated using the three-dimensional image at the next time and the past three-dimensional image. Is done. In this way, the control device 90 calculates the time change of the moving speed of the waste according to the transport direction, and stores it in a predetermined storage unit.

  The significance of calculating the time change of the moving speed of the waste is as follows. That is, the time change of the moving speed of the waste is determined by the actual speed at which the waste accumulated in the drying unit 11 is sent in the transport direction while the volume is reduced by the drying operation (feeding operation) of the drying grate 21. It is an indicator of how waste has been "moved" by the drying operation. Therefore, in the present embodiment, the combustion control is performed based on the time change of the moving speed of the waste.

  Regarding the above (3), the drying section residence time is the time during which the waste accumulated in the drying section 11 is retained in the drying section 11. In other words, it is the time that has elapsed from when the respective wastes reached the drying unit 11 until the present time. As described above, the moving speed of the surface of the waste according to the transport direction and the time is calculated. Therefore, the residence time of the waste in the drying section can be calculated according to the transport direction. Since the three-dimensional images obtained by the image synthesizing process are sequentially created according to the time, the staying time of the waste in the drying section is similarly calculated using the moving speed based on the three-dimensional image at the next time ( Updated). In this manner, the control device 90 calculates the residence time of the waste in the drying unit according to the transport direction, and stores it in the predetermined storage unit.

  The significance of calculating the residence time of the waste in the drying section is as follows. That is, during the drying section residence time, the waste accumulated in the drying section 11 is dried by the drying operation (feeding operation) of the drying grate 21, and evaporation of water contained in the waste is stopped. This is information on the time (actual drying time to be described later) taken from the end to “start of combustion”. That is, the residence time according to the transport direction of the drying unit 11 is calculated and updated, and the residence time of the drying unit when the waste reaches the downstream end (or the flame combustion start position) of the drying unit 11 is actually dried. Equivalent to time. The actual drying time depends on how much the waste accumulated in the drying unit 11 was easy to dry (the amount of water contained in the waste was small) / whether it was difficult to dry (whether the amount of water contained in the waste was large) ). Therefore, in the present embodiment, combustion control is performed based on the residence time of the drying unit.

  Next, the control device 90 analyzes the three-dimensional image created by the image processing device 96 and specifies the flame combustion start position (S103). The flame combustion start position is a position in the transport direction at which flame combustion starts. Since the image acquired by the imaging device 95 includes the flame combustion, the flame is specified based on the color, the luminance, and the like, and the position of the upstream end of the flame is determined to obtain the flame combustion start position. Can be specified. As described above, the flame combustion start position can be specified only by the image acquired by the imaging device 95. However, since the three-dimensional position of the flame included in the image cannot be accurately specified by only the image acquired by one imaging device 95, the control device 90 starts the flame combustion using the three-dimensional image. Identify the location. Specifically, the position of the most upstream flame among the flames included in the three-dimensional image (specifically, the position of the portion of the flame that exists on the surface of the waste) is specified. Thus, the flame combustion start position can be specified more accurately. Although the flame combustion start position is not uniform in the furnace width direction, the flame combustion start position calculated by, for example, obtaining an average of the flame combustion start position in the furnace width direction is stored.

  Next, the control device 90 determines whether or not the flame combustion start position has moved upstream based on the time change of the flame combustion start position (S104). For example, when the amount of water contained in the waste supplied to the incinerator 10 is reduced or when flammable waste is supplied, the drying unit 11 dries the waste (and pyrolysis accompanying the drying). , The same applies hereinafter), the time actually required (actual drying time) is shortened. Therefore, the actual drying time is shorter than the assumed drying time of the waste that is assumed in advance (a difference occurs). In this case, as shown in FIG. 6, since drying is completed in the middle of the drying unit 11, flame combustion occurs in the middle of the drying unit 11 (the flame combustion start position moves to the upstream side). .

  If this state is left unchecked, flame combustion proceeds in the drying unit 11, so that the residence time required for flame combustion in the combustion unit 12 is shortened. The post-combustion, which is the stage, starts gradually. As a result, the respective positions of the drying, burning, and post-burning on the grate gradually move to the upstream side as a whole, and the burn-out point (the end position of the flame combustion) is out of an appropriate range. As a result, stable combustion cannot be maintained.

  In order to prevent this, the control device 90 basically determines that the flame combustion start position is moving to the upstream side (in the case of Yes in S104), and conveys the waste conveyance speed of the dry grate 21 ( Hereinafter, the transfer speed is simply increased (S105). As described above, in order to increase the transport speed, the operating speed of the movable grate of the dry grate 21 is increased, or alternatively or additionally, the stop time of the movable grate of the dry grate 21 is increased. Shorten. Thus, it is possible to prevent a situation where the combustion position of each part on the grate moves to the upstream side. Therefore, since the burn-off point can be set within an appropriate range, stable combustion can be maintained. The operating speed or the stop time of the movable grate is an example of a control value in controlling the transport speed.

  However, the flame combustion start position used for the determination when the transport speed of the dry grate 21 is increased is information on the waste that has already been burned (past information), and is actually the drying unit 11. By correcting the degree of increase in the transport speed on the basis of the above-mentioned correction data which is information relating to the properties of the waste, a more stable combustion can be maintained. In performing the correction based on the correction data in the processing of step S105 and other processing, the time change of the thickness of the waste, the time change of the moving speed of the surface of the waste, and the residence time of the drying section of the waste Is corrected using at least one of the above.

  Specifically, when the thickness reduction of the waste is accelerating (that is, when the thickness reduction per unit time (positive) is large), the actual drying time is shorter than the assumed drying time. Therefore, it may be preferable to further increase the transport speed. Further, since the moving speed of the surface of the waste and the dwell time of the drying section are information on the current transport speed of the waste, it is preferable to change the transport speed of the dry grate 21 in consideration of these values. .

  The drying and burning that occur in the incinerator 10 vary greatly depending on the shape and structure of the incinerator 10 and the waste that is charged. In addition, the target state greatly differs depending on the required processing amount, the durability of the incinerator 10, the regulations on exhaust gas, and the like. Therefore, even if the flame combustion start position moves to the upstream side, there may be a case where the control for increasing the transport speed is not performed. Similarly, with respect to the correction of the transport speed based on the correction data, a correction opposite to the above may be performed. Note that the control device 90 determines whether or not the transport speed of the dry grate 21 needs to be increased and the degree of the increase, in addition to whether or not the flame combustion start position has moved to the upstream side, and not only the correction data, but also other data. It is preferable to determine based on detection data (for example, detection data from the incinerator gas temperature sensor 91 to the NOx gas concentration sensor 94).

  When it is determined that the flame combustion start position has not moved to the upstream side (No in S104), the control device 90 moves the flame combustion start position to the downstream side based on the time change of the flame combustion start position. Is determined (S106).

  For example, when the amount of water contained in the waste supplied to the incinerator 10 increases or when non-flammable waste is supplied, the actual drying time for drying the waste in the drying unit 11 is reduced. become longer. Therefore, the actual drying time is longer than the assumed drying time of the waste that is assumed in advance (a difference occurs). In this case, as shown in FIG. 7, since the drying is not completed even at the downstream end of the drying unit 11, the flame combustion starts in the middle of the combustion unit 12 (the flame combustion start position moves to the downstream side). To do).

  If this state is left as it is, the required residence time for flame combustion in the combustion unit 12 is not ensured, so that flame combustion that should be completed in the combustion unit 12 is shifted to the post-combustion unit 13, Post-combustion will start in the middle of the combustion section 13. As a result, the respective positions of drying, burning, and post-burning on the grate gradually move to the downstream side as a whole, and the burn-out point falls out of an appropriate range. It cannot be maintained.

  To prevent this, the control device 90 basically reduces the transport speed of the dry grate 21 when it is determined that the flame combustion start position is moving to the downstream side (Yes in S106) ( S107). As described above, in order to reduce the transport speed, the operating speed of the movable grate of the dry grate 21 is reduced, or alternatively or additionally, the stopping time of the movable grate of the dry grate 21 is increased. I do. Thus, it is possible to prevent the situation where the combustion position of each part on the grate moves downstream. Therefore, the burn-off point can be set within an appropriate range, and stable combustion can be maintained.

  Even when the transport speed is reduced, it is preferable to perform correction based on the correction data for the same reason as described above. Specifically, when the thickness of the waste is rapidly decreasing, the actual drying time tends to be shorter than the expected drying time, and thus it may be preferable to reduce the degree to which the transport speed is reduced. Further, since the moving speed of the surface of the waste and the residence time of the drying section are information on the current transport speed of the waste as described above, the transport speed of the dry grate 21 is changed in consideration of these values. Is preferred. Note that, for the reason described in the correction at the time of increasing the transport speed, depending on circumstances such as the environment, the correction of the transport speed based on the correction data may be performed in a direction opposite to the above. In the control at the time of deceleration of the transport speed, it is preferable that the control value is determined based on still another detection data.

  In addition, assuming that a difference occurs between the actual drying time and the assumed drying time of the waste that is assumed in advance, changing the transport speed of the drying grate 21 can be achieved by actually supplying the drying grate 21 from the drying grate 21 to the combustion grate 22. This implies that the properties of the waste being used are already different from conventional assumptions. As a result, if the conveying speeds of the combustion grate 22 and the post-combustion grate 23 are made the same as in the prior art in that state, the time required for combustion and post-combustion has already changed, so that stable combustion cannot be maintained. .

  In order to prevent this, when the transport speed of the dry grate 21 is changed (Yes in S104 or S106), the control device 90 determines the property of the waste that is the cause of the change in the transport speed of the dry grate 21. The conveyance speed of the combustion grate 22 and the post-combustion grate 23 is changed according to the state of the change (S108). Note that the control device 90 determines whether or not the transport speed of the combustion grate 22 and the post-combustion grate 23 need to be changed and the amount to be changed. It is preferable to determine based on the following.

  Also, when changing the transport speed of the combustion grate 22 and the post-combustion grate 23, it is preferable to perform correction based on the correction data for the same reason as described above. Basically, it is preferable to change the transport speed of the combustion grate 22 and the post-combustion grate 23 as in the case of the dry grate 21. There is a correlation between the time lag until arrival (in other words, the difference in the nature of the waste in each part), the drying time in the drying unit 11, the burning time in the burning unit 12, and the after-burning time in the after-burning unit 13. It may be preferable to perform control different from the above for the reason that it cannot be stated.

  Next, the control device 90 adjusts at least one of the first damper 81 to the fifth damper 85 in accordance with the state of the change in the property of the waste that causes the change in the transport speed of the dry grate 21. Then, the supply amounts of the primary combustion gas and the secondary combustion gas are adjusted (S109). That is, the opening degree of the first damper 81 to the fifth damper 85 is an example of the control value. Conventionally, the supply amounts of the primary combustion gas and the secondary combustion gas are adjusted using, for example, detection data from the incinerator gas temperature sensor 91 to the NOx gas concentration sensor 94 and the like.

  On the other hand, in the present embodiment, in addition to the other detection data, the primary combustion gas and the primary combustion gas are determined based on the moving direction (moving upstream or downstream) of the flame combustion start position. Adjust the supply amount of secondary combustion gas. Here, when the flame combustion start position is moved to the upstream side and the transport speed of each grate is increased, the amount of generated pyrolysis gas is generally large, although it depends on the properties of the waste. At the same time, primary combustion gas (including unburned gas such as CO) generated by performing primary combustion increases. Therefore, it is necessary to increase the supply amounts of the primary combustion gas and the secondary combustion gas. On the other hand, when the flame combustion start position is moved to the downstream side and the transport speed of each grate is reduced, the amount of generated pyrolysis gas is generally reduced although it depends on the properties of the waste. At the same time, the amount of primary combustion gas generated by performing the primary combustion is reduced. Therefore, it is necessary to reduce the supply amounts of the primary combustion gas and the secondary combustion gas.

  Also, when changing the supply amounts of the primary combustion gas and the secondary combustion gas, it is preferable to perform correction based on the correction data for the same reason as described above. For example, since primary air, which is one of the primary combustion gases, is used not only for combustion in the combustion unit 12 but also for drying in the drying unit 11, it is preferable to shorten the actual drying time. In some cases, it is preferable to increase the supply amount of. However, since the primary air is also used for combustion in the combustion unit 12, such correction may not be performed in some cases.

  In addition, since there is a possibility that the property of the waste is constantly changed, the control device 90 performs the processing of step S101 and subsequent steps again after the processing of step S109. As a result, even if the properties of the waste change, the progress of the drying and combustion of the waste can be corrected so that the flame combustion start position is within an appropriate range, and the stability is maintained. Combustion can be maintained.

  As described above, the in-furnace condition determination method of the present embodiment is configured by the grate divided into the drying unit 11, the combustion unit 12, and the post-combustion unit 13, and is used in a state where waste is accumulated. The intermittent operation is performed on the incinerator 10 provided with the transport unit 20 that transports the waste and supplies the primary combustion gas via the grate. The in-furnace situation determination method performs a process including an image acquisition step, a three-dimensional image creation step, and a calculation step. In the image acquisition step, at least the drying unit 11 was deposited on the drying unit 11 from the window 11b provided on the side wall 11a formed at the end of the drying unit 11 in the furnace width direction using a plurality of imaging devices 95 having different viewpoints. A plurality of images including the appearance of the waste and the flame and having different viewpoints are continuously obtained. In the three-dimensional image creation step, a three-dimensional image is continuously created by performing image synthesis processing on a plurality of images from different viewpoints acquired in the image acquisition step. In the calculation step, the flame combustion start position is specified based on the flame included in the three-dimensional image created in the three-dimensional image creation step, and the flame combustion start position moves upstream in the transport direction or downstream in the transport direction. Calculate whether it is moving to the side.

  By providing the imaging device 95 on the side wall 11a of the drying unit 11, an image of the flame and the waste of the drying unit 11 can be directly acquired without passing through the combustion unit 12 and the post-combustion unit 13. Furthermore, since the side wall 11a of the drying unit 11 has a lower temperature than the side wall of the combustion unit 12 and is less susceptible to the pyrolysis gas and the combustion gas than the ceiling, the appropriate location of the imaging device 95 It is. In addition, by using the three-dimensional image, the moving direction of the combustion start position can be accurately calculated, and the shape and movement of the waste in the drying unit 11 can be sufficiently detected.

  In the in-furnace condition determination method of the present embodiment, the time change of the thickness of the waste on the dry grate 21 is calculated for the waste in the drying unit 11 based on the three-dimensional image.

  In the in-furnace situation determination method of the present embodiment, the time change of the moving speed of the surface of the waste in the drying unit 11 is calculated based on the three-dimensional image.

  In the in-furnace state determination method of the present embodiment, the drying unit, which is the time during which the waste of the drying unit 11 stays in the drying unit 11, based on the time change of the moving speed of the surface of the waste in the drying unit 11. Calculate the residence time.

  As described above, in the drying unit 11, it is possible to grasp the situation regarding how much the drying of the waste proceeds due to the change in the property of the waste.

  In the combustion control method according to the present embodiment, when it is specified that the flame combustion start position has moved to the upstream side in the transport direction, the transport speed of the waste by the dry grate 21 of the drying unit 11 is increased. Perform control. If it is determined that the flame combustion start position has moved to the downstream side in the transport direction, control is performed to reduce the transport speed of the waste by the dry grate 21 of the drying unit 11.

  Thereby, the difference between the assumed drying time and the actual drying time can be reduced, so that the progress of drying and burning of the waste can be made more appropriate. As a result, the burn-off point can be set within an appropriate range, and stable combustion can be maintained.

  In the combustion control method according to the present embodiment, a process of calculating a time change of the thickness of the waste on the drying grate 21, a process of calculating a time change of the moving speed of the surface of the waste in the drying unit 11, and a process of staying in the drying unit At least one of the processes for calculating the time is performed. The conveying speed of the drying grate 21 of the drying unit 11 is changed, and the combustion grate 22 and the post-combustion grate 23 are changed according to the state of change in the property of the waste obtained by at least one of the above-described processes. Change the transport speed.

  Thus, by changing not only the transport speed of the dry grate 21 but also the transport speeds of the combustion grate 22 and the post-combustion grate 23, it is possible to correct the overall fluctuation of the combustion state.

  In the combustion control method of the present embodiment, the drying unit 11, the combustion unit 12, and the post-combustion unit 13 are based on whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction. The supply amount of the primary combustion gas supplied to at least one of the above is adjusted.

  This makes it possible to correct the excess or deficiency of the primary combustion gas resulting from the change in the conveyance speed of the waste, so that drying, combustion, and post-combustion can be performed more appropriately.

  In the combustion control method of the present embodiment, in the incinerator 10, the primary combustion performed in the drying unit 11, the combustion unit 12, and the post-combustion unit 13, and the primary combustion gas including the unburned gas generated in the primary combustion is burned. Secondary combustion to be performed. The supply amount of the secondary combustion gas is adjusted based on whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction.

  This makes it possible to estimate the progress of primary combustion (ie, the amount of primary combustion gas generated) based on the direction of movement of the flame combustion start position, and accordingly adjusts the supply amount of the secondary combustion gas accordingly. Thus, the unburned gas contained in the primary combustion gas can be sufficiently burned in the secondary combustion.

  In the combustion control method of the present embodiment, at least the time change of the thickness of the waste on the drying grate 21, the time change of the moving speed of the surface of the waste in the drying unit 11, and the residence time of the drying unit. A control value for controlling the combustion state is determined based on either of them.

  Thereby, in addition to the flame combustion start position, the control value can be corrected by using the information on the property of the waste currently in the drying unit 11. Matched stable combustion can be maintained.

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

  In the above-described embodiment, the processing of creating a three-dimensional image of the entirety (from the upstream end to the downstream end) of the drying unit 11 in the transport direction has been described. Instead, the control device 90 creates a three-dimensional image of a part of the drying unit 11 in the transport direction (for example, a part excluding the upstream end and its vicinity, or a part downstream from the center in the transport direction). The configuration may be as follows.

  In the above embodiment, the transport speed from the dry grate 21 to the post-combustion grate 23 (particularly the dry grate 21) and the supply of the primary combustion gas and the secondary combustion gas are based on the moving direction of the flame combustion start position. Although the processing for changing the amount and the amount is performed, the processing for changing these values may be performed using the moving speed in addition to the moving direction of the flame combustion start position.

  In the above embodiment, the correction is performed based on the correction data in all of steps S105, S107, S108, and S109. However, the correction based on the correction data may be omitted in at least one of these processes. In step S108, the correction based on the correction data may be performed on only one of the combustion grate 22 and the post-combustion grate 23, but not both.

  In the above-described embodiment, the detection data used in the combustion control includes 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. The combustion control may be performed by omitting at least one detection data, or may be performed by adding detection data different from the above. As other detection data, for example, a boiler evaporation amount accompanying heat recovery from exhaust gas, or a water spray cooling water amount when cooling by water spray can be used.

10 incinerators (waste incinerators)
DESCRIPTION OF SYMBOLS 11 Drying part 11a Side wall 12 Burning part 13 Post-burning part 20 Conveying part 21 Dry grate 22 Burning grate 23 Post-burning grate 90 Control device 95 Imaging device 96 Image processing device

Claims (9)

It is composed of a grate divided into a drying section, a combustion section, and a post-combustion section, and operates intermittently in a state in which the waste is accumulated to transport the waste and primary through the grate. For waste incinerators equipped with a transport unit that supplies combustion gas,
From a window provided on a side wall formed at an end in the furnace width direction of the drying unit, using a plurality of imaging devices having different viewpoints, at least the appearance of the waste and the flame deposited on the drying unit at least. An image acquisition step of continuously acquiring a plurality of images including different viewpoints,
A three-dimensional video creation step of continuously creating a three-dimensional video by performing image synthesis processing on a plurality of videos from different viewpoints acquired in the video acquisition step;
The flame combustion start position is specified based on the flame included in the three-dimensional image created in the three-dimensional image creation step, and the flame combustion start position moves upstream in the transport direction or moves downstream in the transport direction. A calculating step of calculating whether or not
A method for judging an in-furnace situation, characterized by performing a process including: It is a furnace situation determination method according to claim 1,
A method according to claim 3, wherein a time change of the thickness of the waste on the grate is calculated with respect to the waste in the drying unit based on the three-dimensional image. It is a furnace situation determination method according to claim 1,
A method according to claim 3, wherein a time change of a moving speed of a surface of the waste in the drying unit is calculated based on the three-dimensional image. It is a furnace situation determination method according to claim 3,
Based on a time change of the moving speed of the surface of the waste in the drying section, a drying section stay time, which is a time during which the waste in the drying section stays in the drying section, is calculated. Method for determining the situation inside the furnace. A combustion control method for controlling a combustion state of a waste incinerator using the in-furnace state determination method according to claim 1,
If it is detected that the flame combustion start position is moving to the upstream side in the transport direction, perform control to increase the transport speed of the waste by the grate of the drying unit,
When it is detected that the flame combustion start position has moved to the downstream side in the transport direction, a control is performed to reduce the transport speed of the waste by the grate of the drying unit. . The combustion control method according to claim 5, wherein
Based on the three-dimensional image, for the waste of the drying unit, a process of calculating a temporal change in the thickness of the waste on the grate,
A process of calculating a temporal change in a moving speed of the surface of the waste in the drying unit,
At least one of a process of calculating a drying section residence time, which is a time during which the waste of the drying section stays in the drying section, based on a time change of a moving speed of the surface of the waste in the drying section. Do
While changing the transfer speed of the grate of the drying unit, which is a cause of the change of the transfer speed of the grate of the drying unit, the change in the property of the waste obtained by the in-furnace condition determination method. A combustion control method, wherein the conveying speed of the grate of the combustion part and the conveying speed of the grate of the post-combustion part are changed according to a state. The combustion control method according to claim 5 or 6, wherein
Based on whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction, for the primary combustion to be supplied to at least one of the drying section, the combustion section, and the post-combustion section. A combustion control method comprising adjusting a gas supply amount. The combustion control method according to any one of claims 5 to 7,
In the waste incinerator, the primary combustion performed in the drying section, the combustion section, and the post-combustion section, and secondary combustion for burning the primary combustion gas including unburned gas generated in the primary combustion, Done,
A combustion control method comprising: adjusting a supply amount of a secondary combustion gas based on whether a flame combustion start position is moving upstream in a transport direction or downstream in a transport direction. A combustion control method for controlling a combustion state of a waste incinerator using the in-furnace state determination method according to claim 1,
Time change of the thickness of the waste on the grate of the drying unit, calculated based on the three-dimensional image,
Time change of the moving speed of the surface of the waste of the drying unit calculated based on the three-dimensional image,
Calculated based on the time change of the moving speed of the surface of the waste of the drying unit, the drying unit residence time is the time that the waste of the drying unit stays in the drying unit,
Determining a control value for controlling the combustion state based on at least one of the following.

Images