JP7231406B2 - Garbage incinerator and its control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refuse incinerator equipped with a stoker-type conveying device and a method of controlling the same, and more specifically to technology for predicting the withering of refuse.

2. Description of the Related Art A waste incinerator equipped with a stoker-type conveying device that conveys waste from upstream to downstream in the order of a drying stage, a combustion stage, and a post-combustion stage is conventionally known. The refuse incinerator is equipped with a dust feeder that supplies refuse to the drying stage. The dust feeder has a reciprocally driven pusher, and the amount of dust fed to the drying stage varies depending on the stroke and operation cycle of the pusher. The refuse conveying speed of each stage of the drying stage, the combustion stage and the post-combustion stage varies according to the operating speed of the grate of each stage.

Exhaust heat from the incinerator is recovered by an exhaust heat recovery boiler and used for power generation. In order to maintain stable power generation, it is known to detect the thickness of the waste in the drying stage and adjust the amount of dust supplied to the drying stage of the waste incinerator and the waste conveying speed by the stoker based on this.

In Patent Document 1, the dust thicknesses in the drying stage and the combustion stage are detected by an infrared detecting means, and based on the detected dust thickness, the dust conveying speed in the drying stage and the dust conveying speed in the combustion stage are set independently. It is described to adjust by

Further, Patent Document 2 describes detecting the thickness of the dust in the drying stage from the pressure difference between the pressure in the wind box for sending the combustion air to the drying stage and the pressure in the furnace. The detected dust thickness of the drying stage is used to adjust the dust conveying speed of the drying stage.

Further, Patent Document 3 describes that the dust thickness (dust height) in the drying stage is detected by oscillating radio waves from above the dust in the drying stage and receiving the reflected waves. . The detected dust thickness of the drying stage is used to adjust the amount of dust supplied to the drying stage.

JP-A-7-004629 Japanese Patent Publication No. 7-9288 JP 2017-145980 A

In such a refuse incinerator, the refuse quality of the refuse in the drying stage may fluctuate. As the waste quality changes, the appropriate amount of waste staying in the furnace also changes. For example, even if the same volume of refuse is brought into the combustion stage, if the density of the refuse is low, the amount of refuse to be burned may be insufficient, and if the density of the refuse is high, the amount of refuse to be burned may be excessive. When there is a significant shortage of combustible waste (hereinafter referred to as "waste dryness"), the amount of waste heat recovered from the combustion of waste decreases, resulting in a decrease in power generation. When the dust quality fluctuates in this way, maintaining the dust thickness in the drying stage at a predetermined value does not necessarily stabilize the power generation amount.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to propose a technology for predicting waste withering in consideration of fluctuations in waste quality in a waste incinerator equipped with a stoker-type conveying device. It is in.

A control method for a refuse incinerator according to an aspect of the present invention comprises:
A control method for a garbage incinerator equipped with a stoker-type conveying device that conveys garbage in order of a drying stage for drying garbage, a combustion stage for burning the dried garbage, and a post-combustion stage for incinerating the burned garbage, comprising: ,
Detecting the thickness or volume of dust in the drying stage as the amount of dust remaining in the furnace;
extracting a fluctuation component from a standard value of the amount of accumulated waste in a predetermined evaluation period from the time-series data of the amount of accumulated waste;
extracting a decreasing component from the fluctuating component;
obtaining a correction gain that monotonically decreases or remains constant with respect to the amount of staying dust;
correcting the decrease component by multiplying the decrease component by the correction gain; and
Using the corrected reduction component as a dust reduction index, and performing a predetermined dust withering countermeasure process based on the dust reduction index.

Further, the refuse incinerator according to one aspect of the present invention is
a combustion chamber having a stoker-type conveying device for conveying garbage in order of a drying stage for drying garbage, a combustion stage for burning the dried garbage, and a post-combustion stage for incinerating the burned garbage;
a dust supply device that supplies dust to the drying stage;
a dust amount detector for detecting the thickness or volume of dust in the drying stage as the amount of dust remaining in the furnace;
A fluctuation component from a standard value of the amount of accumulated waste in a predetermined evaluation period is extracted from the time series data of the amount of accumulated garbage, a decrease component is extracted from the fluctuation component, and monotonously decreases with respect to the amount of accumulated waste. Alternatively, a constant correction gain is obtained, the reduction component is corrected by multiplying the reduction component by the correction gain, the corrected reduction component is used as a dust reduction index, and a predetermined dust withering is performed based on the dust reduction index. and a control device that performs a corresponding process.

In the above refuse incinerator and its control method, the decreasing component of the fluctuating component of the amount of remaining refuse is obtained from the measured amount of refuse remaining in the furnace, that is, the amount of refuse in the drying stage, and the decreasing component is a sign of refuse withering. catch. In other words, unlike Patent Documents 1 to 3, it is not based on whether the thickness of dust in the drying stage is equal to or greater than a predetermined amount, but it is possible that dust withering may occur based on a decrease in the thickness of dust in the drying stage. Evaluate gender. Therefore, even if the appropriate amount of waste in the furnace changes due to changes in the quality of waste, it is possible to predict waste withering without being affected by it, and perform appropriate processing for the predicted waste withering. be able to.

Further, in the garbage incinerator and its control method, the garbage reduction index is obtained by correcting the obtained reduction component with a correction gain corresponding to the amount of garbage staying in the furnace. Therefore, based on the garbage reduction index, it is possible to evaluate the possibility of garbage withering actually occurring, and also to evaluate the degree of shortage of garbage fuel (garbage withering) that will occur.

ADVANTAGE OF THE INVENTION According to this invention, in the waste incinerator provided with the stoker-type conveying apparatus, the technique which considers the fluctuation|variation of a waste quality and predicts waste withering can be proposed.

FIG. 1 is a schematic diagram showing an example of a waste incineration plant including a waste incinerator according to one embodiment of the invention. FIG. 2 is a block diagram showing the configuration of the staying dust amount adjusting device. FIG. 3 is a data flow diagram of the staying dust amount adjustment process. FIG. 4 is a graph 1 showing an example of chronological changes in the amount of refuse retained in the furnace during the evaluation period. FIG. 5 is a graph 2 showing fluctuation components extracted from the time-series data of the amount of in-furnace waste in graph 1. FIG. FIG. 6 is graph 3 showing the decrease component extracted from the fluctuation component of graph 2. FIG. FIG. 7 is a diagram showing an example of correction gain-remaining dust amount information. FIG. 8 is a diagram showing an example of dust reduction index-control correction amount information.

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a waste incineration plant 100 including a waste incinerator 1 according to one embodiment of the invention.

The waste incineration plant 100 shown in FIG. and a power generation facility 8 that generates power using exhaust heat. The refuse storage facility 3 and power generation facility 8 may be provided adjacent to the incineration plant 100 .

[Garbage storage facility 3]
The refuse storage facility 3 is provided with a pit 60 adjacent to the refuse incinerator 1 for temporarily storing refuse to be treated by the refuse incinerator 1 . A crane 6 is provided above the pit 60 for throwing the garbage in the pit 60 into the garbage incinerator 1 . The crane 6 grabs the garbage in the pit 60 with a bucket and throws the garbage into the throw-in hopper 12 of the garbage incinerator 1, which will be described later. Although a conveyor is interposed between the crane 6 and the charging hopper 12 in FIG. 1, the conveyor may be omitted.

[Waste incinerator 1]
The refuse incinerator 1 is a stoker-type incinerator. The refuse incinerator 1 is provided with a main combustion chamber 14 (primary combustion chamber) and a secondary combustion chamber 19 . The floor of the main combustion chamber 14 is provided with a stoker-type conveying device S including a drying stoker 15, a combustion stoker 16, and a post-combustion stoker 17 arranged stepwise from top to bottom. The drying stoker 15 forms the drying stage _S1 , the combustion stoker 16 forms the combustion stage _S2 and the post-combustion stoker 17 forms the post-combustion stage _S3 . A discharge chute 18 for discharging incinerated ash from the main combustion chamber 14 is provided downstream of the post-combustion stoker 17 .

The stokers 15, 16, 17 of each stage are driven by hydraulic cylinders 15c, 16c, 17c. By changing the reciprocating driving speed of the stokers 15, 16, 17 by the hydraulic cylinders 15c, 16c, 17c, the speed of transporting the refuse by the stokers 15, 16, 17 of each stage can be changed independently.

Wind boxes 15a, 16a, 17a are provided below the stoker 15, 16, 17 of each stage. Primary combustion air 51 is supplied to the wind boxes 15a, 16a, 17a, and is introduced into the main combustion chamber 14 through the stokers 15, 16, 17 from below. The flow rate of primary combustion air supplied to each wind box 15a, 16a, 17a is adjusted by dampers 15b, 16b, 17b provided for each wind box 15a, 16a, 17a. Secondary combustion air 52 is also supplied from the ceiling of the main combustion chamber 14 into the main combustion chamber 14 .

An input hopper 12 is connected to the inlet of the main combustion chamber 14 via a chute 13 . Garbage in the pit 60 is thrown into the throw-in hopper 12 by the crane 6 . Also, at the entrance of the main combustion chamber 14, a dust feeder 41 is provided for feeding dust to the drying stage _S1 . The dust supply device 41 includes a pusher 41a that pushes out dust, and a drive device 41b that horizontally reciprocates the pusher 41a.

In the refuse incinerator 1 constructed as described above, the refuse thrown into the inlet of the main combustion chamber 14 from the throw-in hopper 12 through the chute 13 falls onto the step 41c provided immediately upstream of the drying stage _S1 . Dust on the step 41c is pushed out by the dust feeder 41 to the drying stage _S1 . The refuse is dried in the drying stage _S1 , heated to near the ignition point, and sent to the combustion stage _S2 . The dried refuse is ignited while being transported to the combustion stage _S2 , and part of the ignited refuse is pyrolyzed to generate combustible pyrolysis gas. This pyrolysis gas rides on the primary combustion air 51 and moves to the upper part of the main combustion chamber 14 and is flame-burned together with the secondary combustion air 52 . The rest of the ignited refuse is burned in the post-combustion stage _S3 , and the incineration ash remaining after combustion is discharged from the discharge chute 18 and sent to an ash disposal facility (not shown). The flue gas of the main combustion chamber 14 is mixed with the secondary combustion air 52 blown from the ceiling portion on the downstream side of the main combustion chamber 14 and completely combusted in the secondary combustion chamber 19 .

[Boiler 2]
The flues 20, 21, 22 connected to the secondary combustion chamber 19 of the refuse incinerator 1 are provided with a boiler 2 for recovering thermal energy from flue gas flowing through the flues 20, 21, 22. A water pipe 23 connected to a boiler drum 24 is stretched around the walls of the first flue 20 and the second flue 21 . Also, the boiler drum 24 is connected to the superheater pipe 27 of the superheater 25 . The superheating pipe 27 is installed inside the third flue 22 , and the steam passing through the superheating pipe 27 recovers the heat of the exhaust gas passing through the third flue 22 . A steam flow meter 39 measures the amount of steam sent from the superheater 25 to the power generation equipment 8 . The power generation equipment 8 includes a generator 85 and a steam turbine 84 that drives it, and the steam sent from the boiler 2 rotates the steam turbine 84 .

The flue gas that has passed through the boiler 2 is discharged to an exhaust passage 28 connected to the third flue 22 . The exhaust path 28 is provided with a bag filter 81, an induced draft fan 82, and the like, and the exhaust gas from the boiler 2 is discharged to the atmosphere through a stack 83 after dust is separated by the bag filter 81.

The operation of the refuse incineration plant 100 configured as described above is controlled by the combustion control device 10 . The combustion control device 10 adjusts the amount of dust fed by the dust feeder 41 so that the flow rate of the main steam detected by the steam flowmeter 39 becomes a predetermined value (and/or satisfies a predetermined waste incineration amount). Also, so-called automatic combustion control is performed to adjust the flow rates of the primary combustion air 51 and the secondary combustion air 52 required to burn the waste.

[Remaining dust amount adjusting device 7]
Even if the incineration plant 100 is under automatic combustion control as described above, a significant shortage of waste (waste dryness) in the combustion stage _S2 may occur due to changes in the quality of waste, generation of bridges, and the like. When the waste dries up, the amount of energy generated by burning the waste is reduced, so the main steam flow rate of the boiler 2 is reduced, and the amount of power generated by the power generation equipment 8 becomes unstable. Therefore, the incineration plant 100 according to the present embodiment is provided with the retained waste amount adjusting device 7, and by increasing the dust supply amount in response to the predicted waste withering, the main steam flow rate of the boiler 2 caused by the waste withering , thereby stabilizing the amount of power generated by the power generation equipment 8 .

FIG. 2 is a block diagram showing the configuration of the staying dust amount adjusting device 7. As shown in FIG. The staying dust amount adjusting device 7 shown in FIG. 2 includes a dust amount detecting device 79 (see FIG. 1) for detecting the amount of staying dust in the furnace, and a dust amount detector 79 (see FIG. 1) for detecting the amount of dust staying in the furnace, and a device for preventing the dust from withering based on the detected amount of dust staying in the furnace. is provided with a control device 70 (remaining waste amount control device) for controlling the amount of waste remaining in the furnace. In this embodiment, the accumulated dust amount adjusting device 7 is described independently from the combustion control device 10 , but the accumulated dust amount adjusting device 7 may be configured as a functional part of the combustion control device 10 .

The control device 70 includes functional units including a staying dust amount measuring unit 71 , a fluctuation component extracting unit 72 , a decreasing component extracting unit 73 , a gain calculating unit 74 , and a dust withering processing unit 75 . The controller 70 may be embodied as a kind of computer, such as a PLC (Programmable Controller). The control device 70 includes a processor 70a including a CPU, MPU, GPU, etc., and a volatile and nonvolatile memory 70b. The processor 70a reads and executes various programs stored in the memory 70b, thereby performing processing for realizing each functional unit of the control device 70. FIG.

FIG. 3 is a data flow diagram of the staying dust amount adjustment process. The function of each functional unit of the control device 70 of the staying dust amount adjusting device 7 will be described with reference to FIGS. 2 and 3. FIG.

The control device 70 is electrically connected to a dust amount detection device 79 . The dust amount detector 79 is provided in the refuse incinerator 1 and periodically detects the amount of refuse in the drying stage _S1 . The amount of dust detected by the dust amount detector 79 is output to the control device 70 as the amount R of residual dust in the furnace. The staying dust amount measuring unit 71 stores the obtained staying dust amount R in the memory 70b in association with the detection time. In this manner, time-series data of the amount of waste R in the furnace is accumulated in the memory 70b.

The amount of dust detected by the dust amount detection device 79 may be the thickness of the dust on the dry stoker 15 or the volume of dust on the dry stoker 15 that can be obtained from the thickness of the dust. The dust amount detection device 79 may be of any type as long as it can detect the thickness of the dust on the drying stoker 15 . For example, the dust amount detection device 79 is composed of an infrared camera (or a visible light camera) and an image processing device. good. Further, for example, the dust amount detection device 79 is composed of an ultrasonic wave or radio wave transmitting/receiving device and a processing device. A wave may be received and the processing device may determine the dust layer based on the time from oscillation to reception. Also, the dust thickness may be a value detected at a single position on the drying stoker 15 or an average value of values detected at a plurality of positions on the drying stoker 15 .

The fluctuation component extraction unit 72 extracts short-term fluctuation components of the amount R of staying dust. The short-term fluctuation component of the amount of residual dust R represents the fluctuation component of the amount of residual dust in the furnace due to the intermittent dust supply operation of the dust supply device 41 . Here, the fluctuation component extraction unit 72 filters the amount of staying dust R when extracting the fluctuation component. The filters used here may be, for example, high-pass filters, band-pass filters, and the like. Filters to be used are not particularly limited, but filters with a large delay should be excluded for the purpose of detecting dust withering in advance. Moreover, it is desirable that the cutoff frequency of the filter is longer than the time from the timing of dust supply until the energy appears in the main steam flow rate of the boiler 2 . The short-term fluctuation component of the amount of staying dust R extracted by filtering as described above is obtained by removing the long-term fluctuation component from the time-series change of the amount of staying dust R. FIG. The long-term fluctuation component removed by the filter can be regarded as the standard value of the amount R of retained dust. In other words, it can be said that the short-term fluctuation component of the amount R of staying dust is the fluctuation component from the standard value of the amount R of staying dust. In this way, by performing filtering for extracting the short-term fluctuation component for the amount of residual waste R, the fluctuation component from the standard value of the amount of residual waste R can be extracted without calculating the standard value (that is, the long-term fluctuation). can be extracted.

However, the fluctuation component from the standard value of the amount of retained refuse R may be the fluctuation component from the calculated standard value of the amount of retained refuse in the furnace (hereinafter referred to as “standard value R _S ”). In this case, the fluctuation component extractor 72 reads out the time-series data of the amount of accumulated dust R for a predetermined evaluation period from the memory 70b, and extracts the fluctuation component from the standard value _RS of the amount of accumulated garbage R. The standard value R _S may be a median value, an average value, or a moving average value for the most recent predetermined period of the time-series data of the amount of retained waste R. Alternatively, the standard value _RS may be a value appropriately input by the operator and stored in the memory 70b.

FIG. 4 is a graph 1 showing an example of chronological changes in the amount of refuse remaining in the furnace during the evaluation period, where the vertical axis represents the amount of refuse remaining in the furnace and the horizontal axis represents time. FIG. 5 is a graph 2 showing fluctuation components extracted from the time-series data of the in-furnace waste amount R of the graph 1. FIG. The vertical axis of graph 2 represents the fluctuation component, and the horizontal axis represents time. The horizontal axes (time) of graphs 1 and 2 correspond to each other.

As shown in Graph 2, the fluctuation component of the amount of retained refuse R includes an increasing component greater than zero and a decreasing component less than zero. The decrease component extraction unit 73 extracts only the decrease component from the fluctuation components. Here, the decrease component extracting unit 73 extracts the decrease component by, for example, converting the plus of the fluctuation component of the amount of staying dust R into minus, converting the minus into plus, and excluding numbers of 0 or less with the lower limiter. may The decrease component extracted in this way is the absolute value of the decrease component of the fluctuation component of the amount R of staying dust.

FIG. 6 is graph 3 showing the decrease component extracted from the fluctuation component of graph 2. FIG. The vertical axis of the graph 3 represents the decrease component of the fluctuation component of the amount of staying dust R, and the horizontal axis represents time. The horizontal axes (time) of graphs 1 to 3 correspond.

The gain calculator 74 calculates a correction gain G corresponding to the amount R of staying dust. More specifically, the gain calculation unit 74 obtains the amount of staying dust R, and calculates the correction gain G from this amount of staying dust R by using "correction gain - amount of staying dust information". The correction gain-remaining dust amount information is information representing the relationship between the correction gain G and the staying dust amount R, and is stored in advance in the memory 70b. The amount of staying dust R used by the gain calculator 74 is the current amount of staying dust R detected by the dust amount detection device 79 .

FIG. 7 shows an example of correction gain-remaining dust amount information. In this correction gain-remaining dust amount information, the correction gain G is the maximum value GH when the amount of staying dust R is in the range of 0 to α1, and the correction gain G is the maximum value when the amount of staying dust R is in the range of α1 to α2. The correction gain G is the minimum value GL in the range where the amount R of staying dust decreases from GH as the amount R of staying dust increases, and the amount R of staying dust is equal to or greater than α2. The correction gain G monotonically decreases with respect to the amount of staying dust R in the range from α1 to α2. Both the maximum value GH and the minimum value GL are numbers greater than zero. However, the correction gain G is not limited to the above, and may be a constant value regardless of the value of the amount R of staying dust.

The withered dust processing unit 75 obtains a dust reduction index I by multiplying the reduction component by the correction gain G. FIG. When the thickness of the dust in the drying stage _S1 is sufficiently large, that is, when the value of the correction gain G is small, even if the decrease component is large, there is a low possibility that the dust will dry up. On the other hand, when the thickness of the dust in the drying stage _S1 is small, that is, when the value of the correction gain G is large, the increase in the decrease component increases the possibility that the dust will dry up. In this way, the dust reduction index I is an evaluation index of the possibility that dust withering actually occurs by correcting the reduction component with the correction gain G. FIG.

Further, based on the dust reduction index I, the withered dust handling unit 75 performs a predetermined dust withered handling process. In the present embodiment, in the dust withering process, a correction amount for the dust supply operation amount (or dust supply amount) is obtained based on the dust reduction index I, and the dust supply operation amount corrected by the correction amount is applied to the combustion control device. 10 (or dust supply device 41). Here, the correspondence processing unit 75 obtains the control correction amount C of the operating terminal corresponding to the dust reduction index I. The operating end may be, for example, at least one of the stroke of the pusher 41a of the dust feeder 41 and the operation cycle of the pusher 41a. The dust withering processing unit 75 uses the "dust reduction index-control correction amount information" stored in advance in the memory 70b when obtaining the control correction amount C of the operating terminal. The dust reduction index-control correction amount information is information representing the relationship between the dust reduction index and the control correction amount of the operating terminal.

FIG. 8 shows an example of dust reduction index-control correction amount information. In the dust reduction index-control correction amount information, the control correction amount C gradually increases from 0 to the maximum correction amount CH when the dust reduction index I is in the range of 0 to β1, and when the dust reduction index I is β1 or more, the control correction amount is C is the maximum correction amount CH. All of the control correction amounts C are numbers greater than zero. Although the control correction amount C illustrated in FIG. 8 is a variable, the control correction amount C may be a constant. Further, when there are a plurality of operating terminals, by providing the dust reduction index-control correction amount information for each operating terminal, it is possible to determine the superiority of the control correction amount C for each operating terminal.

The calculated control correction amount C is output to the combustion control device 10 . The combustion control device 10 corrects the control amount of the dust supply device 41 based on the control correction amount C obtained. In other words, the control correction amount C corresponds to the correction amount of the dust supply amount by the dust supply device 41 . As a result, when the dust withering is predicted, the amount of dust supplied to the drying stage _S1 is increased, and the dust withering can be avoided.

As described above, the refuse incinerator 1 according to the present embodiment includes the drying stage S ₁ for drying refuse, the combustion stage S ₂ for burning the dried refuse, and the post-combustion stage for incinerating the burned refuse. A combustion chamber (main combustion chamber 14) having a stoker-type conveying device S that conveys waste in order of _S3 , a dust feeder 41 that supplies waste to the drying stage _S1 , and a drying stage as the amount of residual waste R in the furnace A dust amount detector 79 for detecting the dust thickness or volume of _S1 and a controller 70 are provided. The control device 70 extracts the fluctuation component from the standard value of the amount of staying dust R in a predetermined evaluation period from the time-series data of the amount of staying dust, extracts the decrease component from the fluctuation components, and A correction gain G that monotonically decreases or is constant is obtained by multiplying the decrease component by the correction gain G, the decrease component is corrected, the corrected decrease component is taken as a dust reduction index I, and based on the dust reduction index I Predetermined dust withering countermeasure processing is performed.

In addition, the control method of the refuse incinerator 1 according to the present embodiment is to detect the refuse thickness or refuse volume of the drying stage _S1 as the refuse amount R retained in the furnace, and from the time-series data of the refuse amount R, Extracting the fluctuation component from the standard value of the amount of staying dust R in a predetermined evaluation period, extracting the decreasing component from the fluctuation component, and obtaining the correction gain G that monotonously decreases or is constant with respect to the amount of staying dust R correcting the reduced component by multiplying the reduced component by a correction gain G; and using the corrected reduced component as a dust reduction index I, and performing predetermined dust withering processing based on the dust reduction index I. including.

In the refuse incinerator 1 and its control method, the decrease component of the fluctuation component of the amount of retained refuse R is obtained from the measured amount of refuse R in the furnace, that is, the amount of refuse in the drying stage _S1 . Recognize the signs of dying litter. In this way, since the decrease component extracted from the measured value of the amount of remaining waste R is used for prediction of waste withering, even if the appropriate amount of waste staying in the furnace changes with changes in the quality of waste, it will not be affected. It is possible to predict the shortage of garbage fuel (waste dryness) without having to deal with it, and to perform appropriate processing for the predicted waste dryness.

In the refuse incinerator 1 and its control method, the refuse reduction index I is obtained by correcting the determined reduction component with the correction gain G corresponding to the amount of refuse staying in the furnace. Therefore, by using the garbage reduction index I, it is possible to evaluate the possibility of garbage withering actually occurring, and also to evaluate the degree of shortage of garbage fuel (garbage withering) that will occur.

Further, in the refuse incinerator 1 according to the present embodiment, the refuse withering handling process obtains a correction amount of the dust supply operation amount based on the refuse reduction index I, and determines the dust supply operation amount corrected by the correction amount. to the dust feeding device 41. Similarly, in the control method of the refuse incinerator 1 according to the present embodiment, the above-described process for dealing with withered refuse determines the correction amount of the amount of dust supplied to the drying stage _S1 based on the refuse reduction index I. include.

In this manner, the amount of dust supplied to the drying stage _S1 is automatically corrected based on the dust reduction index I, so that a good amount of dust staying in the furnace can be automatically maintained. Further, the correction amount of the dust supply operation amount (correction amount of the dust supply amount) is based on the reduction component (that is, the dust reduction index I) corrected by the correction gain G corresponding to the amount R of dust remaining in the furnace. . As a result, when the amount R of dust remaining in the furnace is sufficiently large, the correction amount of the dust supply amount is suppressed, and when the amount R of dust staying in the furnace is small, the amount of correction of the dust amount is increased. In this way, the in-furnace waste amount R can be set to an appropriate value.

Although the preferred embodiments of the present invention have been described above, the present invention may include modifications of the details of the specific structures and/or functions of the above embodiments without departing from the spirit of the present invention. . The refuse incinerator 1 and its control method described above can be modified, for example, as follows.

In the refuse incinerator 1 and the control method thereof according to the above-described embodiment, the refuse withering process is correction of the dust supply amount (or dust supply operation amount) to the drying stage _S1 . However, the processing for dealing with withered dust is not limited to this, and may include two or more types of processing. For example, in the above-described dust withering process, the presence or absence of dust withering is predicted based on the dust reduction index I, and when dust withering is predicted, output to the notification device 77 so as to notify it. may include In this case, the staying dust amount adjustment device 7 may further include a notification device 77 (see FIG. 2) such as a notification device using sound or light, or a display monitor.

In this way, by notifying the predicted dust withering, the operator can adjust the amount of dust to be fed in response to the dust withering, and the conveying speed of each stage of the stoker-type conveying apparatus S and the primary It is possible to adjust the flow rate of the combustion air 51 and adjust the amount of refuse thrown into the throw-in hopper 12 .

In addition, in the refuse incinerator 1 and the control method thereof according to the above-described embodiment, the refuse withering response process is performed based on the refuse reduction index I, but before that, the necessity of the refuse withering response process may be determined. . For example, the withered garbage handling unit 75 of the staying garbage amount adjustment device 7 compares the garbage reduction index I with a predetermined threshold value to determine whether or not there is a sign of garbage withering (prediction of garbage withering). If I is equal to or less than the threshold value, it may be assumed that dust withering is not predicted, and the dust withering handling process may be omitted. In addition, when determining whether or not there is a sign of dust withering, the dust withering processing unit 75 may compare the dust reduction index I with a predetermined threshold value, or the integrated value of the dust reduction index I (the graph in FIG. 6). 3) may be compared with a predetermined threshold.

1: Garbage incinerator 2: Boiler 3: Garbage storage equipment 6: Crane 7: Stagnant garbage amount adjustment device 70a: Processor 70b: Memory 8: Power generation equipment 10: Combustion control device 12: Input hopper 13: Chute 14: Main combustion chamber 15: Drying stoker 16: Combustion stoker 17: Post-combustion stoker 15a, 16a, 17a: Wind box 15b, 16b, 17b: Damper 15c, 16c, 17c: Hydraulic cylinder 18: Discharge chute 20, 21, 22: Flue 24: Boiler drum 25 : Superheater 28 : Exhaust passage 39 : Steam flow meter 41 : Dust supply device 51, 52 : Combustion air 60 : Pit 70 : Control device 71 : Remaining dust amount measurement unit 72 : Fluctuation component extraction unit 73 : Reduction component Extraction unit 74 : Gain calculation unit 75 : Waste withering processing unit 77 : Notification device 79 : Waste amount detection device 84 : Steam turbine 85 : Generator 100 : Incineration plant S : Stoker type conveying device S ₁ : Drying stage S ₂ : Combustion stage S ₃ : post-combustion stage

Claims (6)

A control method for a garbage incinerator equipped with a stoker-type conveying device that conveys garbage in order of a drying stage for drying garbage, a combustion stage for burning the dried garbage, and a post-combustion stage for incinerating the burned garbage, comprising: ,
Detecting the thickness or volume of dust in the drying stage as the amount of dust remaining in the furnace;
extracting a fluctuation component from a standard value of the amount of accumulated waste in a predetermined evaluation period from the time-series data of the amount of accumulated waste;
extracting a decreasing component from the fluctuating component;
obtaining a correction gain that monotonically decreases or remains constant with respect to the amount of staying dust;
correcting the decrease component by multiplying the decrease component by the correction gain; and
using the corrected reduction component as a garbage reduction index, and performing a predetermined garbage withering countermeasure process based on the garbage reduction index;
Control method of garbage incinerator. The dust withering countermeasure process includes obtaining a correction amount for the amount of dust supplied to the drying stage based on the dust reduction index.
A control method for a refuse incinerator according to claim 1. The garbage withering response process predicts whether or not garbage withering will occur based on the garbage reduction index, and when garbage withering is predicted, notifying it,
A control method for a refuse incinerator according to claim 1 or 2. a combustion chamber having a stoker-type conveying device for conveying garbage in order of a drying stage for drying garbage, a combustion stage for burning the dried garbage, and a post-combustion stage for incinerating the burned garbage;
a dust supply device that supplies dust to the drying stage;
a dust amount detector for detecting the thickness or volume of dust in the drying stage as the amount of dust remaining in the furnace;
A fluctuation component from a standard value of the amount of accumulated waste in a predetermined evaluation period is extracted from the time series data of the amount of accumulated garbage, a decrease component is extracted from the fluctuation component, and monotonously decreases with respect to the amount of accumulated waste. Alternatively, a constant correction gain is obtained, the reduction component is corrected by multiplying the reduction component by the correction gain, the corrected reduction component is used as a dust reduction index, and a predetermined dust withering is performed based on the dust reduction index. A control device that performs corresponding processing,
Garbage incinerator. The dust withering handling process includes obtaining a correction amount of the dust supply operation amount based on the dust reduction index, and outputting the dust supply operation amount corrected by the correction amount to the dust supply device.
A refuse incinerator according to claim 4. Further comprising a notification device,
The garbage withering response process predicts whether or not garbage withering will occur based on the garbage reduction index, and when garbage withering is predicted, outputting to the notification device so as to notify it,
The refuse incinerator according to claim 4 or 5.

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