JP2019178848A - Waste incinerator and waste incineration method - Google Patents

Abstract

To provide a waste incinerator and a waste incineration method capable of properly keeping a stable combustion state by promptly controlling combustion according to a change even when a property of the waste changes.SOLUTION: Combustion control means includes a target incineration amount calculation portion 26 for calculating a heat generation amount reference value in combustion of waste charged this time, and calculating a target incineration amount of the waste on the basis of the heat generation amount reference value and a predetermined target evaporation amount in a boiler, a controlled variable reference value calculation portion 27 for calculating a controlled variable reference value on the basis of the target incineration amount, a manipulated variable calculation portion 29 for calculating a manipulated variable of an operation end, and a quality change detection portion 23 for calculating the amount of change of a moisture content of the waste charged in this time from a moisture content of waste charged in the last time, and detecting the change of the quality of the waste when the amount of change is over a prescribed threshold value. The target incineration amount calculation portion 26 corrects the heat generation amount reference value on the basis of the calculated amount of change of moisture content when the change of quality of the waste is detected in the waste quality change detection portion 23.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a waste incinerator that burns waste introduced into a hopper in a combustion chamber and generates steam in a boiler by combustion heat, and a waste incineration method using the waste incinerator, and more particularly, properties of the waste. The present invention relates to a waste incinerator and an incineration method for measuring the moisture content and incinerating waste according to the measured value.

  In recent years, interest in the recovery of thermal energy generated by incineration of waste in waste incinerators has increased, and the number of waste incinerators equipped with boiler power generation equipment driven by this thermal energy has increased. There is a demand for combustion operation that can achieve efficient heat recovery. On the other hand, as the regulation of environmental pollutants released from the waste incinerator into the atmosphere becomes stricter, there is a need for a combustion operation that reduces emission of harmful substances derived from combustion such as dioxins and nitrogen oxides.

  Thus, since advanced combustion operation control is desired for a waste incinerator, operation control that satisfies the above-described requirements is performed by an automatic combustion control device. In the automatic combustion control device, when the incinerator is a stoker-type incinerator, for example, the dust generation rate, grate feed rate, combustion air amount, cooling air amount, etc., which are the manipulated variables, are controlled to stabilize the amount of steam generated. In order to achieve the purpose of reducing the concentration of dioxins and nitrogen oxides in the exhaust gas and reducing the unburned components in the ash, the waste is operated to burn stably.

  However, such combustion control does not monitor the properties of the waste at the time of the introduction of the waste, and in any case, the temperature of the combustion gas generated as a result of combustion, the oxygen concentration in the combustion gas, the monoxide in the combustion gas These factors can be used to detect the carbon concentration, etc., or calculate the calorific value of the waste put into the incinerator based on the calorific value of the exhaust gas after combustion and the evaporation amount data in the boiler. Alternatively, each operation amount is feedback-controlled in accordance with the (calculated) calorific value. Therefore, such combustion control is a follow-up type control, and when the property of waste to be put into the incinerator suddenly fluctuates, the operation amount cannot be controlled immediately without delay, and stable operation control is possible. May not be able to do.

  Combustion control using such a feedback control system is difficult to cope with sudden changes in properties of supplied waste.For example, when waste with a high moisture content and a very low calorific value is thrown into the furnace. However, it is not possible to quickly cope with this variation, and there arises a problem that the combustion temperature in the furnace is rapidly lowered and the amount of evaporation of the boiler is lowered.

  A major factor that disturbs the stability of the combustion operation of a waste incinerator is that the amount of heat generated by the waste fluctuates because the properties of the waste that is input are not constant. Since the properties of the waste that is put into the incinerator vary greatly depending on the area where the waste is collected, the time of collection, the weather, and the season, the calorific value of the waste varies greatly. Therefore, Patent Document 1 proposes a control method for a waste incinerator that obtains the properties of the waste to be introduced into the combustion chamber before the introduction and performs combustion control according to the obtained properties of the waste. Among the properties of waste, the factor that greatly affects the calorific value is the moisture content of the waste. In Patent Document 1, the moisture content in the waste is calculated from the measured capacitance value of the waste before combustion. A method is disclosed. Place a capacitance meter as a moisture meter in the middle of the chute hanging from the waste incinerator inlet to the combustion chamber, and measure the waste capacitance between a pair of electrodes. In order to get the moisture content of waste. The capacitance meter is connected to a moisture content calculator that has a correspondence relationship between the capacitance value and the moisture content, and the above correspondence relationship is obtained from the measured value measured by the capacitance meter. Based on this, the moisture content can be calculated.

JP2010-216990

  In Patent Document 1, the amount of heat generated from waste is estimated from the calculated water content of the waste, and each operation amount such as the dust feed rate, combustion grate feed rate, and combustion air amount is controlled accordingly. It is described that a stable combustion state can be obtained. However, although a method for measuring the moisture content is described, it is not clarified how combustion control is performed based on the obtained moisture content. Therefore, it is possible to accurately grasp the calorific value from the calculated moisture content of the waste, appropriately control the combustion of the waste incinerator against fluctuations in the calorific value, and operate the waste incinerator stably. It is not always possible.

  In view of such circumstances, the present invention is capable of promptly performing combustion control according to the fluctuation even if the properties of the waste supplied to the waste incinerator fluctuate, and maintain a stable combustion state well. To provide a waste incinerator and a waste incineration method that can be used, and more specifically, grasp the heat generation amount of waste immediately before being supplied to the combustion chamber of the incinerator and deal with the heat generation amount of the waste Thus, an object of the present invention is to provide a waste incinerator and a waste incineration method that enable stable operation of a waste incinerator by controlling each operation amount under appropriate operating conditions.

  According to the present invention, the above-mentioned problems are solved by the following first to fourth inventions with respect to the waste incinerator and the following fifth to eighth inventions with respect to the waste incineration method.

<First invention>
A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit that calculates a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculator that calculates an operation amount of the operation end based on the calculated control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection unit that detects that the quality of the material has changed,
The target incineration amount calculation unit corrects the calorific value reference value based on the calculated amount of change in moisture content when the waste quality change detection unit detects a change in waste quality. Characteristic waste incinerator.

<Second invention>
A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculator that calculates an operation amount of the operation end based on the calculated control amount reference value;
Calculates the amount of change in the moisture content of the waste that has been input this time, measured by the moisture content measurement means, from the moisture content of the waste that has been input last time, and also inputs the height of the waste surface in the hopper and the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection unit that detects that the quality of the waste has changed when the amount of change in the rate exceeds a predetermined threshold and the amount of change in the bulk density of the waste exceeds the predetermined threshold And
The target incineration amount calculation unit is based on the calculated moisture content change amount and the calculated bulk density change amount when the waste quality change detection unit detects the waste quality change. Waste incinerator characterized by correcting the calorific value reference value.

<Third invention>
A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment unit that adjusts the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition unit during combustion of the waste that has been input this time;
An operation amount calculator that calculates an operation amount of the operation end based on the adjusted control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection unit that detects that the quality of the material has changed,
The target incineration amount calculation unit corrects the calorific value reference value based on the calculated amount of change in moisture content when the waste quality change detection unit detects a change in waste quality. Characteristic waste incinerator.

<Fourth Invention>
A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment unit that adjusts the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition unit during combustion of the waste that has been input this time;
An operation amount calculator that calculates an operation amount of the operation end based on the adjusted control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection unit that detects that the quality of the waste has changed when the amount of change in the rate exceeds a predetermined threshold and the amount of change in the bulk density of the waste exceeds the predetermined threshold And
The target incineration amount calculation unit is based on the calculated moisture content change amount and the calculated bulk density change amount when the waste quality change detection unit detects the waste quality change. Waste incinerator characterized by correcting the calorific value reference value.

  In the waste incinerator according to the present invention, when the change in the waste quality is detected by the waste quality change detection unit, the calorific value reference value is corrected in advance based on the calculated change in the moisture content. In other words, so-called feed-forward control is performed, so that combustion control according to the amount of change in waste quality can be quickly performed. Therefore, sudden changes in the quality of the waste may cause the supply air amount to become insufficient and combustion become inactive, increasing CO emissions, or the supply air amount becoming excessive and combustion becoming overactive to increase NOx emissions. Can be suppressed without causing a time delay, and a stable combustion state can be favorably maintained.

  In the first invention to the fourth invention, the waste incinerator includes an extruder as an operation end for supplying waste into the combustion chamber, a grate as an operation end for moving the waste in the combustion chamber, and the combustion chamber. And a damper as an operation end for adjusting the supply amount of combustion air, and the combustion control means uses the moving speed of the extruder as the operation amount and sets the waste supply amount to the combustion chamber as the control amount. Controlling the grate feed rate as the manipulated variable, controlling the waste supply quantity to the grate as the controlled quantity, and controlling the air supply quantity as the controlled quantity using the damper opening as the manipulated variable It is good also as performing at least one of doing.

  In the first invention to the fourth invention, the control amount reference value adjusting unit is the amount of evaporation obtained in the boiler, the temperature in the combustion chamber, the oxygen concentration in the exhaust gas during the current combustion acquired by the incineration process information acquiring unit, The control amount reference value may be adjusted using at least one of the carbon monoxide concentration in the exhaust gas and the nitrogen oxide concentration in the exhaust gas as incineration status monitoring information.

<Fifth invention>
A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculation step of calculating an operation amount of the operation end based on the calculated control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection step for detecting that the quality of the material has changed,
The target incineration amount calculation step corrects the calorific value reference value based on the calculated amount of change in moisture content when a change in waste quality is detected in the waste quality change detection step. Characterized waste incineration method.

<Sixth Invention>
A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculation step of calculating an operation amount of the operation end based on the calculated control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection step for detecting that the quality of the waste has changed when the rate of change exceeds a predetermined threshold and the change in the bulk density of the waste exceeds a predetermined threshold. And
The target incineration amount calculating step is based on the calculated amount of change in moisture content and the calculated amount of change in bulk density when a change in waste quality is detected in the waste quality change detecting step. A waste incineration method characterized by correcting a calorific value reference value.

<Seventh invention>
A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment step for adjusting the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition step during combustion of the waste input this time;
An operation amount calculation step of calculating an operation amount of the operation end based on the adjusted control amount reference value;
Calculate the amount of change from the moisture rate of the waste that was input last time for the moisture rate of the waste that has been input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, discard A waste quality change detection step for detecting that the quality of the material has changed,
The target incineration amount calculation step corrects the calorific value reference value based on the calculated amount of change in moisture content when a change in waste quality is detected in the waste quality change detection step. Characterized waste incineration method.

<Eighth invention>
A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment step for adjusting the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition step during combustion of the waste input this time;
An operation amount calculation step of calculating an operation amount of the operation end based on the adjusted control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection step for detecting that the quality of the waste has changed when the rate of change exceeds a predetermined threshold and the change in the bulk density of the waste exceeds a predetermined threshold. And
The target incineration amount calculating step is based on the calculated amount of change in moisture content and the calculated amount of change in bulk density when a change in waste quality is detected in the waste quality change detecting step. A waste incineration method characterized by correcting a calorific value reference value.

  As described above, in the present invention, the moisture content of the waste thrown into the hopper is calculated, and the change in the moisture content of the waste thrown this time from the moisture content of the waste thrown in the previous time is calculated. When the amount of change exceeds a predetermined threshold, it is detected that the quality of the waste has changed, and when the change in the quality of the waste is detected, the calculated amount of change in the moisture content is The calorific value reference value was corrected based on this. Since the moisture content of the waste is measured at the waste layer in the chute just before the waste is sent into the combustion chamber, the fluctuation of the moisture content is accurately measured before the waste is actually incinerated. It is possible to grasp and correct the calorific value reference value in advance. As a result, the combustion control according to the amount of change in the quality of the waste can be promptly performed, so that a stable combustion state can be favorably maintained.

It is a schematic block diagram which shows the waste combustion furnace which concerns on 1st embodiment of this invention. It is a block diagram which shows the flow of the combustion control in 1st embodiment. It is a block diagram which shows the flow of the combustion control in 2nd embodiment. It is a block diagram which shows the flow of the combustion control in 3rd embodiment. It is a flowchart of the combustion control in 3rd embodiment. It is a graph which shows the time-dependent fluctuation | variation of a moisture voltage, a calorific value reference value, and a correction | amendment calorific value reference value.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is a schematic configuration diagram illustrating a waste combustion furnace according to an embodiment of the present invention. The waste combustion furnace according to this embodiment is a grate-type waste incinerator having a grate having a continuous structure (24 hours continuous operation), and a hopper 1 into which waste is intermittently charged from the outside, A chute 2 hanging from the hopper 1, a combustion chamber 3 for burning waste supplied via the chute 2, and primary combustion air for supplying primary combustion air into the combustion chamber 3 from below Air supply means 4, secondary combustion air supply means 5 for supplying secondary combustion air to the secondary combustion region on the downstream side of the combustion chamber 3, and heat from the exhaust gas received from the combustion chamber 3 A boiler 6 that generates steam by replacement and a combustion control means 7 that controls the operation amount of each operation end based on incineration process information described later as a combustion state amount of waste in the combustion chamber 3 are provided. A secondary combustion region is formed in the vicinity of the inlet of the boiler 6.

  The hopper 1 receives waste thrown by a crane (not shown). At the lower part of the chute 2 connected to the hopper 1, there is provided a reciprocating extruder 8 that extrudes waste and supplies it into the combustion chamber 3. In the present embodiment, the waste supply amount into the combustion chamber 3 is adjusted by the moving speed of the extruder 8.

  A moisture content measuring device 9 as a moisture content measuring means for measuring the moisture content of waste in the chute 2 is provided on the side wall of the chute 2. Various methods can be adopted as the moisture content measuring device 9, for example, a transmission microwave intensity method, a contact microwave intensity method, a contact capacitance method, a transmission capacitance method, an infrared intensity. The method etc. are mentioned.

  For example, the transmission-type microwave intensity method is a method in which the transmitted microwave is transmitted through the waste, and the moisture content of the waste is measured from the attenuation rate of the received microwave, and the range of waste that can be measured is widened. Since it can be ensured, it is suitable for the measurement when the moisture content is unevenly distributed like the waste in the chute.

  In the transmission-type microwave intensity method, a transmission-type microwave intensity moisture meter as the moisture content measuring device 9 includes a microwave transmission unit, a reception unit, and a moisture content calculator connected to the reception unit. Have. The transmitting unit is installed on one wall surface of the chute 2, and the receiving unit is installed on the other wall surface of the chute 2. Since the microwave has a characteristic of being absorbed by moisture, the microwave emitted from the transmitter is attenuated by moisture in the waste and reaches the receiver when passing through the waste. In the transmission type microwave intensity moisture meter, the moisture content contained in the waste can be calculated based on the attenuation rate of the microwave.

  Specifically, the transmission microwave intensity moisture meter is a voltage ratio of the transmission microwave intensity of the transmission unit to the reception microwave intensity at the reception unit, that is, the output voltage at the reception unit with respect to the input voltage at the transmission unit. The voltage ratio is determined as the attenuation rate when the microwave passes through the waste. The transmission-type microwave intensity moisture content meter previously stores the correlation between the attenuation rate of microwaves and the moisture content of waste as a relational database. By referring to the relational database, the voltage ratio measured above is measured. The moisture content of the waste is calculated from the attenuation rate obtained as follows. The moisture content calculator is connected to a waste quality change detector 23 described later of the combustion control means 7, and the waste moisture content calculated by the moisture content calculator is the waste quality change detector 23. Is transmitted to.

  Further, when the contact-type capacitance method is adopted as the moisture content measuring device 9, the contact-type capacitance moisture meter as the moisture content measuring device 9 includes a contact-type capacitance-type capacitance meter, And a moisture content calculator connected to the capacitance meter. The capacitance meter measures the capacitance of the waste in the chute 2, and the moisture content calculator calculates the capacitance meter from the correlation between the waste capacitance and the moisture content held in advance. It is possible to calculate a moisture content value corresponding to the measured capacitance value of the. Specifically, the moisture content calculator maintains a relational database in which the correlation between the capacitance of waste and the moisture content of waste is measured and clarified in advance, and is sent from the capacitance meter. The measured moisture content of the waste is collated with the relationship between the capacitance and moisture content in the relational database, and the measured moisture content of the waste is calculated. The moisture content calculator is connected to a waste quality change detector 23 described later of the combustion control means 7, and the waste moisture content calculated by the moisture content calculator is the waste quality change detector 23. Is transmitted to.

  Further, a waste level meter 10 for measuring the height (level) of the surface of the waste in the hopper 1 is provided at the upper part of the hopper 1. In the first embodiment, as described later with reference to FIG. 2, the measurement value of the height of the waste surface by the waste level meter 10 is not used for the combustion control by the combustion control means 7. It is not essential to provide 10.

  Below the combustion chamber 3, there are provided grates 11a, 11b, 11c, and 11d that move the waste in the combustion chamber 3 to the downstream side. The grate 11a-11d reciprocates to move the waste and also stir the waste. Hereinafter, for convenience of explanation, the grate 11a to 11d will be collectively referred to as “grate 11” as necessary. In the present embodiment, the amount of waste supplied to the grate is adjusted by the feed rate of the grate 11. The combustion chamber 3 is provided with an in-furnace thermometer 12 for measuring the temperature in the combustion chamber 3 at a substantially central position of the side wall of the combustion chamber 3.

  The primary combustion air supply means 4 has wind boxes 13a, 13b, 13c, and 13d below the grate 11a, 11b, 11c, and 11d, respectively, and supplies primary combustion air into the combustion chamber 3 from below. To do. The waste on the grate 11 moves on the grate 11 and becomes ash after being dried, burned, and post-combusted by the primary combustion air, and discharged to the outside from the ash drop opening 18. The primary combustion air is supplied into the combustion chamber 3 by the primary combustion air blower 14 from below the grate 11a to 11d via the wind boxes 13a to 13d. Further, the amount of primary combustion air is adjusted by a damper 15 provided in a pipe that supplies the primary combustion air. The amount of primary combustion air supplied to each of the wind boxes 13a to 13d is the amount of damper 15a, 15b provided in each pipe that supplies the primary combustion air to each of the wind boxes 13a, 13b, 13c, 13d. , 15c, 15d.

  The secondary combustion air supply means 5 supplies the secondary combustion air to the secondary combustion region in the vicinity of the inlet of the boiler 6 on the downstream side of the combustion chamber 3. The secondary combustion air is supplied to the secondary combustion region by the combustion secondary air blower 16. The amount of secondary combustion air is adjusted by a damper 17 provided in a pipe that supplies the secondary combustion air to the secondary combustion region. By supplying the secondary combustion air to the secondary combustion region, the combustible gas in the combustion gas that could not be combusted in the combustion chamber 3 is completely burned.

The exhaust gas after the secondary combustion is recovered by heat exchange in the boiler 6 on the downstream side, further subjected to exhaust gas treatment, and then discharged to the outside through the chimney 19. The waste combustion furnace of this embodiment is provided with a flow meter 20 for measuring the amount of steam generated in the boiler 6. A concentration meter 21 is provided at the outlet of the boiler 6 for measuring the concentrations of oxygen (O ₂ ), carbon monoxide (CO), and nitrogen oxides (NO _x ) contained in the exhaust gas. .

  The combustion control means 7 controls the operation amount of each operation end based on the incineration process information, for example, by PID control. In the combustion control in the present embodiment, the amount of waste supplied into the combustion chamber, the amount of waste supplied to the grate (generally referred to as waste supply amount), and the amount of air supply are set as control amounts. The operation ends corresponding to the waste supply amount are the extruder 8 and the grate 11a to 11d, and the operation ends corresponding to the air supply amount are the dampers 15. That is, the operation amount of the operation end corresponding to the waste supply amount is the moving speed of the extruder 8 and the feed rate of the grate 11a to 11d, and the operation amount of the operation end corresponding to the air supply amount is the amount of the damper 15. Opening degree. As shown in FIG. 1, the extruder 8, the grate 11 a to 11 d, and the damper 15 as operation ends are controlled by a control unit 25 described later of the combustion control means 7.

  The combustion control means 7 includes an incineration process information acquisition unit 22 that acquires incineration process information, which will be described later, a waste quality change detection unit 23 that detects a change in the quality of the waste charged into the hopper 1, and incineration process information. Calculation for calculating the operation amount of the operation end based on the incineration process information acquired by the acquisition unit 22 and the waste water content change amount and / or the waste bulk density change amount calculated by the waste quality change detection unit 23 And a control unit 25 that controls each operation end based on the operation amount calculated by the calculation unit 24.

  The calculation unit 24 calculates a reference value of the calorific value (Hu) for the combustion of waste and further calculates a target incineration amount for calculating the target incineration amount of the waste. A control amount reference value calculation unit 27 for calculating the control amount reference value, a control amount reference value adjustment unit 28 for adjusting the control amount reference value, and an operation amount at each operation end based on the adjusted control amount reference value. And an operation amount calculation unit 29 for calculating. In the first embodiment, as will be described later with reference to FIG. 2, the control amount reference value calculated by the control amount reference value calculation unit 27 is not adjusted, and the operation amount calculation unit 29 directly adjusts each operation end. Since it is used for calculation of the operation amount, it is not essential to provide the control amount reference value adjustment unit 28.

  The incineration process information acquisition unit 22 acquires incineration process information as a combustion state quantity of waste in the combustion chamber 3. Examples of the incineration process information include input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber 3.

The heat input / output information includes heat input information related to heat energy brought into or generated in the furnace, and heat output information related to heat energy taken out of the furnace. Examples of the heat input information include calorific value due to combustion of waste, sensible heat of waste, sensible heat of combustion air, sensible heat of air for adjusting the temperature in the furnace, sensible heat of spray water in the furnace, and the like. . The heat output information includes, for example, sensible heat of theoretical combustion gas, sensible heat of excess air, heat loss due to ash, heat loss due to unburned content, amount of heat dissipated in combustion chamber 3 and boiler 6, sensible heat of boiler steam Etc. The incineration status monitoring information includes, for example, the amount of evaporation in the boiler, the temperature in the combustion chamber 3 (furnace temperature), the exhaust gas O ₂ concentration, the exhaust gas CO concentration, the exhaust gas NO _X concentration, and the like. The evaporation amount, the furnace temperature, the exhaust gas O ₂ concentration, the exhaust gas CO concentration, and the exhaust gas NO _X concentration are obtained as measured values by the flow meter 20, the furnace thermometer 12, and the concentration meter 21, respectively.

  Hereinafter, the flow of combustion control by the combustion control means 7 in the present embodiment will be described with reference to FIG. The waste quality change detection unit 23 calculates the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that has been input this time, that is, the moisture content that the moisture content measuring device 9 has calculated this time. When the amount of change exceeds a predetermined threshold, it is detected that the quality of the waste has changed.

  First, the target incineration amount calculation unit 26 determines the amount of waste input this time based on the input / output heat information acquired by the incineration process information acquisition unit 22 and the incineration amount of the waste for the combustion of the waste input last time. Calculate a calorific value reference value for combustion. Specifically, the target incineration amount calculation unit 26 performs heat balance calculation in the combustion chamber 3 and the boiler 6 using the input / output heat information acquired by the incineration process information acquisition unit 22 during the previous combustion. In other words, because the heat balance that the total heat input and total heat output in the incinerator and boiler are equal is established, the amount of heat generated by the combustion of waste is calculated from the sum of the heat output information acquired. Calculated as the amount of heat minus other heat input information excluding the amount. Furthermore, the calorific value reference value for the combustion of the waste input this time is obtained by dividing the calculated calorific value due to the combustion of the waste by the actual incineration amount of the waste at the previous combustion. calculate. Next, when the waste quality change detection unit 23 detects that the waste quality has changed, the target incineration amount calculation unit 26 determines that the waste quality change detection unit 23 The calorific value reference value is corrected based on the calculated amount of change in moisture content. Further, the target incineration amount calculation unit 26 determines the target evaporation amount for the combustion of the waste that has been input this time based on the calculated or corrected calorific value reference value and the target evaporation amount in the boiler preset by the operator. Calculate the target incineration amount of waste necessary to achieve

  Normally, the moisture content of waste often fluctuates greatly every time it is introduced, and thus the moisture content measurement value tends to vary. Such variation causes the waste quality change in the waste quality change detection unit 23 to change. It becomes a factor which causes the false detection of the presence or absence of. A method for more reliably preventing such erroneous detection will be described later with reference to FIG.

  The control amount reference value calculation unit 27 uses the waste supply amount and the primary combustion air supply amount into the combustion chamber, which are derived based on the target incineration amount calculated by the target incineration amount calculation unit 26, as control amounts. Calculate the reference value of the control amount to achieve.

  The operation amount calculation unit 29 is based on the control amount reference value calculated by the control amount reference value calculation unit 27, that is, the waste supply amount reference value and the air amount reference value. , The feed rate of the grate 11 and the opening of the damper 15 are calculated. The control unit 25 controls the operation amount at each operation end based on the operation amount calculated by the operation amount calculation unit 29. The control of the operating end is preferably started when the waste supplied to the combustion chamber 3 reaches the main combustion region. Here, the “main combustion region” means that the waste is thermally decomposed and partially oxidized to generate a combustible gas, and the combustible gas is combusted with a flame and the solid content of the waste is combusted. Refers to the combustion area. In this way, the control of the operation end is started more accurately when the waste reaches the main combustion region, that is, at the timing when the waste reaches combustion, so that the combustion control according to the quality of the waste is performed more accurately. Can do. In addition, low air ratio combustion can be realized by reducing the amount of surplus oxygen that does not contribute to combustion in the primary combustion air supplied to the combustion chamber 3.

  When the combustion control means 7 controls each operation end by PID control, when the amount of change in the moisture content of the waste exceeds a predetermined threshold value, the combustion control means 7 performs proportional gain according to the amount of change. It is good also as adjusting. By adjusting the proportional gain in this way, the influence of the instantaneous value of the waste heat generation amount can be temporarily increased to better follow a sudden change in the quality of the waste.

<Second embodiment>
In the first embodiment, the waste quality change detection unit 23 detects the change in the waste quality based only on the amount of change in the moisture content of the input waste. The difference from the first embodiment is that the change in the quality of the waste is detected in consideration of the change in the bulk density of the waste in addition to the change in the moisture content of the waste. To do. In addition, the waste combustion furnace which concerns on 2nd embodiment has the same structure as the waste combustion furnace demonstrated in FIG. 1 in 1st embodiment. In the second embodiment, it is essential to provide the waste level meter 10.

  Hereinafter, the flow of combustion control by the combustion control means 7 in the present embodiment will be described with reference to FIG. In this embodiment, the flow of combustion control is the first implementation except that not only the amount of change in the moisture content of the waste but also the amount of change in the bulk density of the waste is considered when detecting the change in the quality of the waste. Common with form. Therefore, here, it demonstrates centering on difference with 1st embodiment, and abbreviate | omits description about a common point.

  In the present embodiment, as shown in FIG. 3, the waste quality change detection unit 23 detects the measured value in the waste level meter 10, that is, in the hopper 1 when the waste is put into the hopper 1. The volume of the waste thrown into the hopper 1 is calculated by obtaining the height of the surface of the waste and multiplying the increase in the height by the cross-sectional area (horizontal shape area) of the hopper 1. . Next, the bulk density of the waste is calculated by dividing the waste input amount (weight) by the waste volume. Here, the amount of waste input is measured by, for example, a weight meter (not shown) provided in the crane when the waste is input to the hopper 1. Next, the amount of change from the bulk density of the waste thrown in last time is calculated about the bulk density of the waste thrown in this time. The waste quality change detection unit 23 determines the quality of the waste when the amount of change in the moisture content of the waste exceeds a predetermined threshold and the amount of change in the bulk density of the waste exceeds a predetermined threshold. Detect that has changed.

  Then, the target incineration amount calculation unit 26 calculates the change in the moisture content and the calculated change in the bulk density when the change in the waste quality is detected by the waste quality change detection unit 23. The calorific value reference value is corrected based on this.

<Third embodiment>
In the first embodiment and the second embodiment, the control amount reference value calculated by the control amount reference value calculation unit 27 is not adjusted, and the operation amount calculation unit 29 directly calculates the operation amount at each operation end. It was decided to be used. On the other hand, in the third embodiment, the control amount reference value calculated by the control amount reference value calculation unit 27 is adjusted based on the incineration process information acquired by the incineration process information acquisition unit 22, and the adjusted control amount reference is adjusted. The value is used for calculation of the operation amount at each operation end by the operation amount calculation unit 29, and this is different from the first embodiment and the second embodiment.

  Hereinafter, the flow of combustion control by the combustion control means 7 in the present embodiment will be described with reference to FIG. Here, it demonstrates centering on difference with 2nd embodiment, and abbreviate | omits description about a common point.

In this embodiment, as shown in FIG. 4, the control amount reference value adjusting unit 28 is the incineration status monitoring information (evaporation amount, acquired by the incineration process information acquiring unit 22 during the combustion of the waste that has been input this time. The control amount reference value calculated by the control amount reference value calculation unit 27 based on the furnace temperature, the exhaust gas O ₂ concentration, the exhaust gas CO concentration, and the exhaust gas NO _X concentration), that is, the waste supply amount reference value and the air amount reference Adjust each value. The adjustment of the control amount reference value is performed every short time (for example, every 10 seconds) during the combustion of the waste that has been input this time. In this way, by adjusting the control amount reference value in real time according to the actual incineration situation, combustion control based on the accurately adjusted control amount reference value becomes possible.

  The operation amount calculation unit 29 then operates the operation amount at each operation end based on the control amount reference value adjusted by the control amount reference value adjustment unit 28, that is, the adjusted waste supply amount reference value and the adjusted air amount reference value. The moving speed of the extruder 8, the feed speed of the grate 11, and the opening degree of the damper 15 are calculated. The control unit 25 controls the operation amount at each operation end based on the operation amount calculated by the operation amount calculation unit 29.

  Next, based on FIG. 5, the point of the combustion control in 3rd embodiment is demonstrated. First, the operator sets a target evaporation amount (S1). Further, the target incineration amount calculation unit 26 calculates a heat generation amount reference value for the combustion of the waste that has been input this time (S2). At this time, if a change in waste quality is detected by the waste quality change detection unit 23 and a correction value for the calorific value reference value is calculated, the calorific value reference value is corrected based on the correction value. (S3).

  Next, the target incineration amount calculation unit 26 performs the target incineration for the waste thrown in this time based on the target evaporation amount set in S1 and the calorific value reference value calculated in S2 or corrected in S3. The amount is calculated (S4). Next, the control amount reference value calculation unit 27 calculates a control amount reference value for achieving the target incineration amount calculated in S4 (S5). Then, during the combustion of the waste input this time, the control amount reference value adjustment unit 28 adjusts the control amount reference value based on the incineration status monitoring information (S6).

  Next, the operation amount calculation unit 29 calculates the operation amount at each operation end based on the control amount reference value adjusted in S6, and transmits the operation amount to the control unit 25 (S7). The operation amount at each operation end is controlled based on the operation amount. Next, when new waste is introduced into the hopper 1 (Y in S8), the moisture content measuring device 9 measures the moisture content of the newly introduced waste (S9), The quality change detection unit 23 calculates the amount of change in the waste water content based on the measured value of the water content in S9 (S10). Further, the waste quality change detection unit 23 calculates the waste bulk density based on the measurement value of the height of the waste surface by the waste level meter 10 (S11), and the waste bulk calculated in S11. The amount of change in the waste bulk density is calculated based on the density (S12). On the other hand, when no new waste is put into the hopper 1 (N in S8), the process returns to S6 and the adjustment of the control amount reference value is continued. It should be noted that either the calculation of the change in the waste water content by S9 and S10 and the calculation of the change in the waste bulk density by S11 and S12 may be performed first or simultaneously. Also good.

  When the amount of change in the waste water content exceeds a predetermined threshold and the amount of change in the waste bulk density exceeds the predetermined threshold, that is, when a change in the quality of the waste is detected ( (Y in S13), the target incineration amount calculation unit 26 calculates a correction value of the heat generation amount reference value according to the change amount (S14), returns to S2, and with respect to the heat generation amount reference value calculated in S2 In step S3, the heat generation amount reference value is corrected based on the correction value. On the other hand, when at least one of the change amount of the waste water content and the change amount of the waste bulk density is equal to or less than a predetermined threshold, that is, when no change in the quality of the waste is detected (N in S13), Returning to S2, the target incineration amount calculation unit 26 does not calculate a correction value for the heat generation amount reference value. That is, the heat generation amount reference value calculated in S2 is not corrected.

  In the third embodiment, the change in the waste quality is detected based on the change in the waste water content and the change in the waste bulk density. A change in the quality of the waste may be detected based only on the amount of change. In this case, as the operation of the combustion control, S11 and S12 in FIG. 5 are omitted, and the determination of the size of the waste bulk density and the threshold is omitted in S13.

  In addition, here, the operation of the combustion control in the third embodiment has been described based on FIG. 5, but the operation of the combustion control in the first embodiment and the second embodiment is substantially the same as that of the third embodiment. Specifically, for the combustion control in the first embodiment, S6, S11, and S12 in FIG. 5 are omitted, and the determination of the size of the waste bulk density and the threshold is omitted in S13. In the combustion control operation in the second embodiment, S6 in FIG. 5 is omitted.

  In the first embodiment to the third embodiment, as described above, before supplying the waste into the combustion chamber 3, the amount of change in the water content from the previous time is calculated for the water content of the waste, It is detected that the quality of the waste has changed due to the magnitude of the change amount, and the calorific value reference value is corrected based on the change amount. By correcting the heat generation amount reference value in this way, even if the moisture content of the waste and thus the heat generation fluctuate, the operation end corresponding to the fluctuation of the heat generation before the waste is supplied to the combustion chamber. It is possible to perform feedforward control for controlling the operation amount. For example, when waste having a higher moisture content than the previous time, in other words, waste having a low calorific value, is supplied, the operation amount at the operating end is set so that the temperature of the combustion chamber is raised before the waste is supplied into the combustion chamber. By controlling, it is possible to perform feedforward control so that stable operation is performed even if the waste whose calorific value is reduced burns.

  The waste is intermittently thrown from the pit to the chute by a bucket crane, and the moisture content of the thrown waste in the chute is measured. Variations in moisture content measurements occur during a single waste feed. Therefore, in the feedforward control described above, it is important to prevent erroneous determination due to variation in the measured value of the moisture content, determine an accurate variation in the moisture content, and appropriately correct the heat generation amount reference value.

  The moisture content measuring device 9 provided in the chute 2 is, for example, a microwave transmission moisture meter, and measures the moisture content by measuring attenuation due to moisture when microwaves pass through the waste in the chute. It is. The microwave intensity transmitted and received by the receiver is measured, the difference between the transmitted intensity corresponding to attenuation and the received intensity is measured as the moisture voltage value, and the predetermined correspondence between the moisture voltage value and the moisture content is measured. The moisture content is obtained from the relationship. The greater the moisture voltage value, the higher the moisture content, that is, the smaller the amount of heat generated, and the smaller the moisture voltage value, the lower the moisture content, that is, the greater the amount of heat generated.

  Hereinafter, based on FIG. 6, when measuring the moisture content of the waste thrown into the chute with a microwave transmission moisture meter, misjudgment due to variations in the measured moisture content is prevented, and A procedure for determining an accurate variation and correcting the heat generation amount reference value will be described. FIG. 6 is a graph showing the temporal change of the moisture voltage value, the initial calorific value reference value, and the corrected calorific value reference value. In FIG. 6, times T <b> 1 to T <b> 7 are times when waste is thrown into the hopper 1. For example, the time T1 is the first waste input time, and the time T2 is the second waste input time. In addition, intervals between the input times are indicated as input intervals A1, A2,.

  The measured moisture voltage values vary as shown by the alternate long and short dash line in FIG. 6, and the range of change is large. The time average value of the moisture voltage value (average moisture voltage value B1, B2,...) At each input interval A1, A2,. In the graph of FIG. 6, average moisture voltage values B1, B2,... Are plotted at times T2, T3,.

  Next, one section obtained by combining three consecutive insertion intervals is set as a determination section. For example, a section extending from the insertion intervals A1 to A3 is set as a determination section C1, a section extending from the input intervals A2 to A4 is set as a determination section C2, a section extending from the input intervals A3 to A5 is set as a determination section C3, and a section extending from the input intervals A4 to A6 is set as a determination section C4. Set.

  Next, in each determination section, when the average moisture voltage value at each of the three input intervals included in the determination section is continuously increasing, it is assumed that the moisture content is increasing, and the heat generation amount of the waste is When it is determined that the average moisture voltage value is continuously decreasing, it is determined that the moisture content is decreasing and the heat generation amount of the waste is increasing. When it is determined that the moisture content is increasing and the waste heat generation amount is decreasing, the heat generation amount reference value is corrected with a correction amount corresponding to the degree of increase in the moisture content. If it is determined that the moisture content is decreasing and the heat generation amount of the waste is increasing, the heat generation amount reference value is corrected with a correction amount corresponding to the degree of decrease in the moisture content.

  For example, in the determination section C4, the average moisture voltage values B4 to B6 of the input intervals A4 to A6 continuously increase. In this case, it is determined that the moisture content is increased, and the heat generation amount of the waste is decreased, and the heat generation amount reference value is corrected with a correction amount corresponding to the degree of decrease in the heat generation amount in the determination section C4. In FIG. 6, at time T7, which is the end of the determination section C4, the initial calorific value reference value is indicated by a solid line, and the corrected corrected calorific value reference value is indicated by a broken line. In this way, based on the continuous increase / decrease tendency of the average moisture voltage value in the judgment section, the increase / decrease in the heat generation amount of the waste is determined by grasping the increase / decrease in the moisture content, and the correction amount according to the degree of increase / decrease in the moisture content The correction of the calorific value reference value is repeated in sequence. By correcting the calorific value reference value as described above, it is possible to prevent misjudgment due to variations in the moisture content measurement value, to determine the exact fluctuation of the moisture content, to grasp changes in the calorific value, and to feed forward Control can be performed.

  In addition, here, one interval that is a combination of three consecutive charging intervals is set as a determination interval, and moisture content is determined based on a continuous increase / decrease tendency of each average moisture voltage value at the three charging intervals included in the determination interval. Although it was decided to determine the increase or decrease in the amount of heat generated from the waste by grasping the increase and decrease in the rate, as another method, the average moisture voltage value (average moisture voltage value in the determination interval) within the above determination interval, For a plurality of continuous determination sections (for example, determination sections C2, C3, and C4 in FIG. 6), grasp the increase / decrease in the moisture content based on the continuous increase / decrease tendency of the average moisture voltage value in the determination section, May be determined. In addition, although the time average value of the moisture voltage value is used for the determination of the increase / decrease tendency of the moisture content, the median value of the moisture voltage value at each charging interval may be used instead.

  In the second embodiment and the third embodiment described above, the moisture content data of the waste passing through the chute 2 obtained by the moisture content measuring device 9 and the bulk density that can be grasped when the waste is put into the hopper. The feedforward control may be performed by appropriately combining the data. For example, only when the trend of increase / decrease in the measured moisture content and the calculated bulk density coincides, that is, only when both the measured moisture content and the calculated bulk density increase or decrease, It is also possible to determine that the quality has changed and perform feedforward control.

  Calculate the calorific value of the waste thrown into the incinerator from the data of the calorific value of the exhaust gas after combustion, the evaporation amount in the boiler, etc., and the amount of each operation corresponding to these monitoring factors or (calculated) calorific value In the control method that performs feedback control, it becomes follow-up control, and when the properties of the waste thrown into the incinerator suddenly fluctuate, the operation amount cannot be controlled immediately without delay, and stable operation control is achieved. There are things that cannot be done.

  On the other hand, in the first embodiment to the third embodiment and these modified examples, by grasping the fluctuation of the calorific value obtained from the moisture content measurement value and the bulk density calculation value, the fluctuating calorific value is immediately obtained. The feedforward control corresponding to can be performed. In addition, as described above, by using the data of both the moisture content measurement value and the bulk density calculation value, it is possible to prevent misjudgment by predicting the amount of waste heat generated with accuracy that cannot be obtained independently, and to provide a more accurate feedforward. Control, that is, stable combustion control can be realized.

  In the first embodiment to the third embodiment and the modifications thereof, when the change in the waste quality is detected by the waste quality change detection unit, the calculated change amount of the waste water content and / or The so-called feed-forward control is performed in which the calorific value reference value is corrected based on the calculated change amount of the bulk density before the waste is actually incinerated, so that it corresponds to the change amount of the waste quality. Combustion control can be performed quickly. Therefore, sudden changes in the quality of the waste may cause the supply air amount to become insufficient and combustion become inactive, increasing CO emissions, or the supply air amount becoming excessive and combustion becoming overactive to increase NOx emissions. Can be suppressed without causing a time delay, and a stable combustion state can be favorably maintained.

  In the present embodiment, each reference value or target value is a predetermined value, but instead, it may be set as a reference range or target range having a predetermined width.

  In the first embodiment to the third embodiment, both the waste supply amount and the primary combustion air supply amount are controlled amounts. Instead of this, either the waste supply amount or the primary combustion air supply amount is used. One may be used as a control amount.

  In the first embodiment to the third embodiment, the operation amount controlled by the control unit 25 is the moving speed of the extruder 8, the feed speed of the grate 11, and the opening degree of the damper 15. It is not essential that is an operation amount, and only a part of them may be set as the operation amount. In the present embodiment, the opening degree of the damper 15 is controlled with respect to the air supply amount which is one of the control amounts. However, instead of or in addition to this, the opening of the dampers 15a, 15b, 15c, 15d is controlled. The degree may be controlled.

In the first embodiment to the third embodiment, the incineration status monitoring information is the amount of evaporation in the boiler, the temperature in the combustion chamber 3 (furnace temperature), the exhaust gas O ₂ concentration, the exhaust gas CO concentration, and the exhaust gas NO _X concentration. However, it is not essential that all of these are acquired as incineration status monitoring information, and only some of them may be acquired.

DESCRIPTION OF SYMBOLS 1 Hopper 2 Chute 3 Combustion chamber 4 Primary combustion air supply means 5 Secondary combustion air supply means 6 Boiler 7 Combustion control means 8 Extruder 11a, 11b, 11c, 11d Grate 15 Damper 22 Incineration process information acquisition part 23 Discard Object quality change detector

Claims (10)

A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculator that calculates an operation amount of the operation end based on the calculated control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection unit that detects that the quality of the material has changed,
The target incineration amount calculation unit corrects the calorific value reference value based on the calculated amount of change in moisture content when the waste quality change detection unit detects a change in waste quality. Characteristic waste incinerator. A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculator that calculates an operation amount of the operation end based on the calculated control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection unit that detects that the quality of the waste has changed when the amount of change in the rate exceeds a predetermined threshold and the amount of change in the bulk density of the waste exceeds the predetermined threshold And
The target incineration amount calculation unit is based on the calculated moisture content change amount and the calculated bulk density change amount when the waste quality change detection unit detects the waste quality change. Waste incinerator characterized by correcting the calorific value reference value. A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment unit that adjusts the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition unit during combustion of the waste that has been input this time;
An operation amount calculator that calculates an operation amount of the operation end based on the adjusted control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection unit that detects that the quality of the material has changed,
The target incineration amount calculation unit corrects the calorific value reference value based on the calculated amount of change in moisture content when the waste quality change detection unit detects a change in waste quality. Characteristic waste incinerator. A hopper that intermittently throws in waste,
A combustion chamber for burning the waste supplied from the hopper via the chute,
A moisture content measuring means for measuring the moisture content of the waste in the chute,
Air supply means for supplying combustion air into the combustion chamber;
A boiler that receives exhaust gas from the combustion chamber and generates steam by heat exchange with the exhaust gas;
In a waste incinerator comprising combustion control means for controlling an operation amount at an operation end based on incineration process information as a combustion state quantity of waste in a combustion chamber,
The combustion control means includes
An incineration process information acquisition unit for acquiring input / output heat information about input / output heat in the waste incinerator and incineration status monitoring information for monitoring the incineration status of waste in the combustion chamber as the incineration process information;
Based on the above input / output heat information acquired by the incineration process information acquisition unit and the incineration amount of the waste, the calorific value reference value for the combustion of the currently input waste is calculated. A target incineration amount calculation unit for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculation unit that calculates a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment unit that adjusts the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition unit during combustion of the waste that has been input this time;
An operation amount calculator that calculates an operation amount of the operation end based on the adjusted control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection unit that detects that the quality of the waste has changed when the amount of change in the rate exceeds a predetermined threshold and the amount of change in the bulk density of the waste exceeds the predetermined threshold And
The target incineration amount calculation unit is based on the calculated moisture content change amount and the calculated bulk density change amount when the waste quality change detection unit detects the waste quality change. Waste incinerator characterized by correcting the calorific value reference value. The waste incinerator adjusts the supply amount of combustion air into the combustion chamber, the extruder as the operation end for supplying waste into the combustion chamber, the grate as the operation end for moving waste in the combustion chamber And a damper as an operating end to
The combustion control means uses the moving speed of the extruder as an operation amount, controls the waste supply amount to the combustion chamber as a control amount, and uses the grate feed rate as the operation amount, 5. The method according to claim 1, wherein at least one of controlling a waste supply amount and controlling an air supply amount as a control amount using an opening of a damper as an operation amount is performed. The waste incinerator according to any one of the above.   The control amount reference value adjustment unit is the amount of evaporation obtained in the boiler, the temperature in the combustion chamber, the oxygen concentration in the exhaust gas, the carbon monoxide concentration in the exhaust gas, and the exhaust gas during the current combustion acquired by the incineration process information acquisition unit The waste incinerator according to any one of claims 1 to 5, wherein the control amount reference value is adjusted by using at least one of the nitrogen oxide concentration in the incineration status monitoring information. A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculation step of calculating an operation amount of the operation end based on the calculated control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection step for detecting that the quality of the material has changed,
The target incineration amount calculation step corrects the calorific value reference value based on the calculated amount of change in moisture content when a change in waste quality is detected in the waste quality change detection step. Characterized waste incineration method. A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
An operation amount calculation step of calculating an operation amount of the operation end based on the calculated control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection step for detecting that the quality of the waste has changed when the rate of change exceeds a predetermined threshold and the change in the bulk density of the waste exceeds a predetermined threshold. And
The target incineration amount calculating step is based on the calculated amount of change in moisture content and the calculated amount of change in bulk density when a change in waste quality is detected in the waste quality change detecting step. A waste incineration method characterized by correcting a calorific value reference value. A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment step for adjusting the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition step during combustion of the waste input this time;
An operation amount calculation step of calculating an operation amount of the operation end based on the adjusted control amount reference value;
Calculate the amount of change from the moisture content of the waste that was input last time for the moisture content of the waste that was input this time measured by the moisture content measuring means, and when the amount of change exceeds a predetermined threshold, A waste quality change detection step for detecting that the quality of the material has changed,
The target incineration amount calculation step corrects the calorific value reference value based on the calculated amount of change in moisture content when a change in waste quality is detected in the waste quality change detection step. Characterized waste incineration method. A waste incineration method using a waste incinerator that burns waste supplied to a hopper via a chute in a combustion chamber and generates steam in a boiler,
A waste input process that intermittently inputs waste from outside into the hopper;
A moisture content measuring step for measuring the moisture content of the waste in the chute;
A waste combustion step of supplying waste to the combustion chamber, supplying combustion air to the combustion chamber, and burning the waste in the combustion chamber;
A steam generation process for generating steam in the boiler by heat exchange with the exhaust gas from the combustion chamber;
In a waste incineration method comprising a combustion control step for controlling an operation amount of an operation end based on incineration process information as a combustion state amount of waste in a combustion chamber,
The combustion control process
An incineration process information acquisition step for acquiring the incineration status monitoring information for monitoring the incineration status of the waste in the combustion chamber and the input / output heat information about the input / output heat in the waste incinerator;
Based on the above input / output heat information acquired in the incineration process information acquisition step and the incineration amount of the waste, the calorific value reference value for the combustion of the input waste is calculated. A target incineration amount calculating step for calculating a target incineration amount of waste based on the heat generation amount reference value and a target evaporation amount in a preset boiler;
A control amount reference value calculating step of calculating a control amount reference value based on the target incineration amount, with at least one of a waste supply amount and an air supply amount into the combustion chamber as a control amount;
A control amount reference value adjustment step for adjusting the control amount reference value based on the incineration status monitoring information acquired by the incineration process information acquisition step during combustion of the waste input this time;
An operation amount calculation step of calculating an operation amount of the operation end based on the adjusted control amount reference value;
Calculates the amount of change in the moisture content of the waste that was input this time, measured by the moisture content measurement means, from the moisture content of the waste that was input last time, as well as the height of the waste surface in the hopper and input to the hopper The volume density of the waste is calculated based on the amount of waste input, and the amount of change from the volume density of the previously input waste is calculated for the volume density of the currently input waste. Waste quality change detection step for detecting that the quality of the waste has changed when the rate of change exceeds a predetermined threshold and the change in the bulk density of the waste exceeds a predetermined threshold. And
The target incineration amount calculating step is based on the calculated amount of change in moisture content and the calculated amount of change in bulk density when a change in waste quality is detected in the waste quality change detecting step. A waste incineration method characterized by correcting a calorific value reference value.

Images