JP2001033019A - Method for controlling combustion in refuse incinerator and refuse incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate quality of refuse in a refuse pit in a refuse incinerator and to improve the stability of a combustion state in the incinerator. SOLUTION: In a refuse incinerator 2, the position of refuse in a pit 5 is stored or by dividing the interior of the pit into sections, the position of refuse is stored. The refuse position is caused to correspond to information on refuse quality calculated by an automatic combustion control device 7. Further, by storing a dry air amount corresponding to refuse quality, stability of combustion is improved. Further, when refuse is charged, by selecting refuse in a position or at a partition near a preceding time for charging, or through charge of refuse after selecting refuse in a position at a section having quality near quality of preceding charged refuse based on information on refuse quality obtained by the automatic combustion control device 7 on and before a preceding time, the stability of combustion is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incinerator combustion control method and a waste incinerator for estimating the quality of waste in a waste pit and improving the stability of the combustion state in the furnace.

[0002]

2. Description of the Related Art Municipal solid waste incinerators play an important role in treating various wastes discharged in social life. In recent years, interest in the recovery of thermal energy generated by the incineration of refuse has increased, and the number of refuse incinerators equipped with boiler power generation equipment has increased, so that heat recovery in boilers can be performed efficiently. , Stable combustion is required.

[0003] On the other hand, as regulations on environmental pollutants released into the atmosphere become stricter, a combustion operation for reducing the emission of dioxins and nitrogen oxides is required.
As described above, since advanced combustion operation is desired for the refuse incinerator, an operation that satisfies the above requirements is performed by an automatic combustion control device. The automatic combustion control system stabilizes the amount of generated steam by controlling the operation amounts of the incinerator, such as the dust supply speed, the combustion grate speed, the amount of combustion air, and the amount of cooling air. It is operated so that the amount of unburned components in the ash is kept low by keeping the nitrogen and nitrogen oxides low.

[0004] However, since the quality of waste to be put in varies greatly depending on the collection area, collection time, weather and season, the calorific value of the waste greatly varies. Therefore, the garbage collected and collected in the garbage pit is agitated by a crane to achieve uniform garbage quality. Combustion is stabilized by introducing the uniformed waste into the furnace.

However, even if the garbage is stirred in the pit, the crane moves the garbage brought in from the garbage truck and puts it into the hopper at the same time, so that the quality of the garbage after the stirring is not necessarily uniform. Not. As a countermeasure, combustion management by automatic combustion control has been performed conventionally, but in order to further stabilize combustion, suppress fluctuations in the calorific value of the input waste or estimate the calorific value of the waste in advance, It is necessary to reflect the estimation result in the combustion control.

As one of the methods, there is a method of estimating the quality of the waste in the pit before the waste is introduced into the furnace and performing combustion control based on the estimation result, thereby maintaining stable combustion. Proposed.

As a method for maintaining stable combustion, for example, there is a technique described in Japanese Patent Application Laid-Open No. 5-215318. In this technology, the specific gravity of the garbage is measured by measuring the weight of the garbage with the weight detection device when the bucket of the crane grabs the garbage, and further measuring the pinch angle when the bucket grabs the garbage with the opening detection device. Is calculated. A method has been proposed in which the degree of wetness of the waste is obtained based on the waste quality estimated from the calculated specific gravity of the waste, and the transfer speed of the waste in the furnace is adjusted.

Another prior art is disclosed in Japanese Patent Laid-Open No. 9-17881.
Japanese Patent Laid-Open Publication No. 47-47 proposes that a pressure detection device is provided on the inner surface of the bucket, the quality of the waste is estimated from the pressure detection device and the opening degree of the bucket, and a combustion control method according to the quality of the waste is taken.

[0009]

According to the technology described in Japanese Patent Application Laid-Open No. 5-215318, the specific gravity of the refuse is calculated from the weight of the refuse and the angle at which the bucket is sandwiched. It is difficult to measure. This is because the bucket of the garbage crane does not always grip a fixed volume of garbage, but may grip an amount smaller than the volume of the bucket, or may grip the bucket out of the bucket.
In such a case, it is difficult to calculate an accurate specific gravity because the included angle and the volume do not correspond exactly.

Further, according to the technique described in Japanese Patent Application Laid-Open No. Hei 9-178147, in the case of the prior art in which the amount of generated heat is estimated from the amount of change and the degree of opening of the indicated value by the pressure detecting device on the inner surface of the bucket, the area where Since the quality and properties of the refuse vary depending on conditions such as temperature, season, and weather, even if the amount of change in pressure is high, depending on the properties of the refuse, the refuse is likely to burn, that is, the refuse may have a high calorific value. Further, since the refuse closer to the bottom of the pit is compressed, even if the refuse has the same refuse quality as the surface of the refuse layer, it may be assumed that the refuse quality is different.

Normally, the refuse carried into the refuse pit from the refuse collection vehicle is not directly introduced into the furnace, but is once stirred to make the refuse quality uniform. The homogenized refuse is piled up in a pit provided in the pit in the vicinity of the inlet to the hopper, and the refuse in the piled area is put into the furnace. However, since the agitation operation is agitated according to a predetermined procedure, if the dust quality in the charging zone is particularly non-uniform, it may not always be uniform.

The present invention solves the above problems,
An object of the present invention is to provide a combustion control method for a waste incinerator and a waste incinerator capable of estimating the quality of waste in a waste pit in the waste incinerator and improving the stability of a combustion state in the furnace.

[0013]

According to a first aspect of the present invention, in a refuse incinerator, the position of refuse introduced into the pit in the pit is stored, and information on the quality of the refuse is calculated by an automatic combustion control device. And storing the calculated information on the quality of the waste in association with a position in the waste pit.

According to the present invention, the position of the refuse charged into the furnace in the charging zone is stored in association with the refuse quality calculated by the automatic combustion control device. The next time the same position in the charging zone is injected, the change in the waste quality at the same position due to the agitation of the waste in the pit is expected to be small. By utilizing the information as advance information, it is possible to improve combustion stability.

According to a second aspect of the present invention, the waste pit in the first aspect of the present invention is divided into sections of a predetermined size, and each of the divided sections is stored with the position of the waste when storing the quality of the waste. It is a combustion control method of a refuse incinerator characterized by performing.

In the present invention, the position is stored as a section of a predetermined size, instead of simply storing the position of the dust. Here, it is convenient to match the predetermined size with the amount of refuse handling in the pit. Generally, when the crane bucket grabs the debris in the pit,
By being in a certain range depending on the size of the bucket,
A section corresponding to the size of the bucket can be managed as position information.

According to a third aspect of the present invention, in the first aspect or the second aspect of the invention, when the refuse of a certain section is inputted this time, the refuse quality when refuse of the same position is inputted in the past is provided. A method for controlling combustion in a refuse incinerator, characterized by supplying a dry air amount corresponding to the following.

In the present invention, the amount of dry air is determined by utilizing the fact that the refuse of the same position or section that was previously input and the refuse that is input this time are expected to have substantially the same quality.
Thus, by determining the current dry air amount with reference to the previously supplied dry air amount, an appropriate dry air amount can be supplied.

Changes in the combustion state in the furnace appear after the refuse starts burning. For this reason, if appropriate drying can be performed in the drying step of the refuse, the state after the refuse starts burning can be stably maintained. As a result, the deterioration of the furnace temperature caused by the deterioration of the combustion due to insufficient drying of the refuse, and the burning of the furnace at once due to the excessive drying, followed by the deterioration of the combustion leading to the generation of dioxins, such as the lowering of the furnace temperature due to the insufficient garbage. Can be prevented in advance.

According to a fourth aspect of the present invention, in the first aspect or the second aspect of the present invention, it is preferable that, when the current refuse is input, the trash in a position or a section close to the previous time is selected and input. This is a combustion control method for a refuse incinerator.

It is expected that the refuse adjacent to the previously introduced position or section is refuse-like refuse due to prior stirring. Also, when the garbage is grasped, the surrounding garbage collapses and agitates with the surrounding garbage, so that the bucket is closer to the position where the bucket is grasped or the garbage quality of the section. For this reason, it is possible to suppress a sudden change in the waste quality by introducing the waste adjacent to the position or section where the waste was previously injected. As a result, a sudden change in the combustion state of the refuse in the furnace can be avoided, so that the combustion state can be easily maintained in a stable state, the load on the combustion control can be reduced, and stable combustion of the refuse in the furnace can be maintained.

It should be noted that the invention of claim 3 and claim 4 described above.
By simultaneously implementing the present invention, the accuracy of combustion stability can be further improved.

According to a fifth aspect of the present invention, in the first aspect or the second aspect of the present invention, when the present waste is charged, the waste based on the waste quality information obtained by the automatic combustion control device up to the previous time. And selecting and introducing the waste in a location or a section close to the quality of the waste introduced last time.

The crane performs not only the work of putting waste from the waste pit to the hopper but also the movement and stirring of the waste in the pit. If the instruction to put garbage into the hopper is given during the movement of garbage or the agitation work, if the work area where the garbage is moved or agitation is separated from the section with the garbage for the garbage, the garbage will be added. Is delayed. If the introduction of the refuse is delayed, the amount of refuse in the hopper decreases, and the sealability in the furnace may be impaired.

For this reason, by storing the history of the relationship between the waste quality and the position or section that have been input up to the previous time, the position of the position or section that is close to the previously input waste quality and that is closest to the current position of the crane is stored. By selecting the refuse as the refuse for input, it is possible to input the refuse to the hopper in a short time.

As described above, by rapidly inputting the refuse close to the refuse introduced in the last time, it is possible to suppress a sudden change in the refuse quality. As a result, a rapid change in the combustion state of the refuse in the furnace can be avoided, the combustion state can be kept stable, the burden on the combustion control can be reduced, and the refuse in the furnace can be stably burned. The invention of 6 includes a refuse loading unit for temporarily loading refuse to be burned before charging the refuse into the combustion furnace main body, and a control device for controlling combustion of the refuse in the incinerator main body, The control device holds the combustion-related information of the refuse at each position corresponding to the loading position of the refuse in the refuse loading unit, and based on the combustion-related information, controls the refuse from the refuse loading unit to the incinerator main body. A refuse incinerator characterized by controlling input and / or combustion of refuse in a combustion furnace body.

[0027]

(Embodiment 1) FIG. 1 is a conceptual diagram of a refuse incinerator to which a combustion control method of the present invention is applied. The configuration shown in FIG. 1 is also applied to Embodiments 2 to 4 described later.

The collected waste 6 is temporarily stored in the waste pit 5. As shown in FIG. 1 and FIG.
Stir zone 5a where garbage is first introduced, and charging zone 5b
It is composed of The refuse stirred in the stirring zone 5a is loaded by the crane 3 in the charging zone 5b. That is, after the refuse 6 collected by the crane 3 and the crane bucket 4 is stirred and loaded in the input zone 5b,
It is carried into the incinerator 2 from the hopper 21. Note that the stirring zone 5a and the charging zone 5b do not indicate fixed locations in the refuse pit 5, and the areas are appropriately adjusted according to the refuse input state and the like.

The conveyed refuse is carried into the furnace by the dust supply device 8. While the refuse moves on the combustion grate 9, the combustion air sent from below the combustion grate by the combustion air fan 10 dries, ignites, burns, becomes ash and is carried out of the ash outlet 28 to the outside of the furnace. .

The exhaust gas generated by the combustion of the refuse passes through the furnace outlet 27, and the boiler 17 recovers waste heat. The harmful substances in the heat-recovered exhaust gas are removed by an exhaust gas treatment device 19. The exhaust gas from which the harmful substances have been removed is discharged from the chimney 20 into the atmosphere.

The combustion control device (b) 7 calculates from the measured values of the in-furnace thermometer 15, the furnace outlet thermometer 16, the steam flow meter 18 and the like, and the combustion control device (b) 7 from the heat balance in the furnace. Based on the estimated waste quality, the dust supply speed of the dust supply device 8, the combustion grate speed of the combustion grate device 9, the amount of combustion air by the combustion air fan 10 and the NO
1 Distribution damper 11, NO2 distribution damper 12, NO3 distribution damper 1
3. The combustion air distribution is adjusted by the NO4 distribution damper 14.

The quality of the waste put into the furnace is calculated from the heat balance in the furnace. Specifically, the amount of refuse supplied to the furnace, the amount of combustion air, the amount of cooling air, and the amount and temperature of exhaust gas generated by combustion, the amount of heat recovered by the boiler, the amount of heat dissipated from the furnace wall, the amount of ash taken out Can be calculated as the calorific value of the garbage from the balance calculation.

The amount of heat brought into the furnace is qi1: heat generation amount of waste (1), qi2: sensible heat of waste (2), qi3: heat amount of combustion air (3), qi4: cooling air Heat quantity to bring (4)
Equation, qi5: Consist of boiler feedwater sensible heat (5). The amount of heat taken out of the furnace is qo1: boiler evaporation (6), qo2:
Exhaust gas sensible heat (7), qo3: Heat dissipated from the furnace wall, and ash take-off heat (8). The calorific value of the refuse can be calculated from equation (9) using equations (1) to (8). qi1 = G × Hu… (1) qi2 = G × ir… (2) qi3 = L _FDF × ia (t _FDF )… (3) qi4 = L _CDF × ia (t _CDF )… (4) qi5 = Gs × iw (tb)… (5) qo1 = Gs × is… (6) qo2 = Ga × iga (tg)… (7) qo3 = Qc… (8) Hu = (qo1 + qo2 + qo3−qi2−qi3−qi4 −qi5) / G… (9) Hu: Waste heat kcal / ton G: Waste input ton / h (measured value) L _FDF : Combustion air amount Nm ³ / h (measured value), L _CDF : Cooling air Amount Nm ³ / h (measured value), t _FDF : Combustion air temperature ℃ (measured value), t _CDF : Cooling air temperature ℃ (measured value), Ga: Exhaust gas flow rate Nm ³ / h (measured value), Gs: Boiler Steam flow rate ton / h (measured value), tb: Boiler feedwater temperature ℃ (measured value), tg: Boiler outlet exhaust gas temperature ℃ (measured value) ir: Waste heat calorie kcal / ton, iw (・): Water holding Heat calorie kcal / ton, ia (・): Heat calorie of air kcal / Nm ³ , is: Heat calorie of steam kcal / ton, iga (・): Heat calorie of exhaust gas kcal / Nm ³ , Qc: Emission from furnace wall Calorie, calorie removal calorie kcal / h Combustion control unit (a) 1 The position of the pit entry zone 5b is stored using the position in the X and Y directions. The position of the crane in the X and Y directions and the calorific value of the refuse at the position of the input zone 5b calculated by the combustion control device (b) 7 are associated and stored. The next time garbage at the same position is thrown in, it is expected that garbage with the same heating value as the previous time will be thrown in, so the grate speed and dry air volume can be set in advance Becomes

(Embodiment 2) Another embodiment of the combustion control method according to the present invention will be described. The pit loading zone 5b is divided into small sections as shown in FIG. 2, and given in a two-dimensional array of positions (X, Y) so that it is possible to determine which section of the refuse has been introduced into the furnace. As in the first embodiment, the position (X, Y) of the two-dimensional array and the calorific value of the refuse at the position of the input zone 5b calculated by the combustion control device (b) 7 are associated and stored. The next time garbage at the same position is thrown in, it is expected that garbage with the same heating value as the previous time will be thrown in, so the grate speed and dry air volume can be set in advance Becomes

(Embodiment 3) With respect to a set value of a dry air amount calculated by the combustion control device (b) 7 based on a calorific value of refuse calculated at the time of injection, a refuse calorific value of the same position or section as the previous time. Is used to correct the set value of the dry air amount by the method shown in equation (10). If the calorific value Hu0 of the same position or section as the previous time is lower than the calorific value Hu calculated at the time of charging, the waste quality is expected to be poor and wet refuse, so the dry air amount is increased. Fdset = Fdset0 (Hu) × (1 + k (Hu−Hu0))… (10) Fdset0: Current dry air amount set value Fdset: Dry air amount set value after correction k: Correction parameter (k> 0) Hu : Calorific value of garbage calculated at loading Hu0: Calorific value of garbage when loaded from the same section last time

(Embodiment 4) The order of charging the refuse into the furnace from the charging zone 5b by the crane is as follows.
(Y), the position of the current loading zone 5b is (X, Y ±
a) Or select the garbage at different positions by a short distance a that satisfies (X ± a, Y) and put it into the furnace. In this way, if the selection is made, it is possible to constantly select the refuse at the position of the distance a in the section from the previous time to the current time.

When the input zone 5b is represented by a section, the current input zone (X, Y) is
In the section 5b, the refuse in the section satisfying (X, Y ± 1) or (X ± 1, Y) is selected and put into the furnace. in this way,
If you select this, you can always select the garbage of the adjacent section from the previous time to the current time.

For example, as shown in FIG. 3, when the refuse in the input zone 5b is thrown in from the section (1, 1), the trash in the section is selected in the order shown by the arrow in the figure.
It is possible to always select the garbage in the adjacent section.

If the waste is charged into the furnace in the above-described order of charging the waste, the quality of the waste is moderately changed, so that a sudden change in the combustion state in the furnace can be avoided and the combustion can be stabilized.

By performing the operations of Embodiments 3 and 4 at the same time, fluctuations in the quality of the waste introduced into the furnace are suppressed, and the amount of dry air is corrected. Can be improved.

(Embodiment 5) The relation between the position (X, Y) of the refuse introduced in the previous time in the charging zone 5b and the calorific value (Hu) of the refuse obtained by the calculation of the automatic combustion control is correlated. Remember.

When an input instruction is given to the crane 3, the current position of the crane 3 and the calorific value of the garbage input last time are
The position of the garbage located at the shortest position from the position of the crane 3 and close to the previous refuse calorific value is calculated.

Since the same waste quality as the previous time is not always at the shortest place, the difference between the previous heat generation value (Hu0) and the current heat generation value (Hu) is preset. If it is within the range, the waste may be selected as the current waste.

If the waste is introduced into the furnace by such a method of introducing the waste, the change in the waste quality becomes gentle, so that a rapid change in the combustion state in the furnace can be avoided and the combustion is stabilized.

In the first to fifth embodiments, the refuse loading section for temporarily loading refuse to be burned and the combustion of refuse in the incinerator main body are controlled before the refuse is injected into the combustion furnace main body. A control device, wherein the control device retains the combustion-related information of the refuse at each position corresponding to the garbage loading position in the refuse loading unit, and incinerates from the refuse loading unit based on the combustion-related information. This is achieved by a refuse incinerator that controls the introduction of refuse into the furnace body and / or the burning of refuse in the combustion furnace body.

The waste loading section has a waste pit 5
The whole or the input zone 5b in the garbage pit 5 corresponds. Further, a combustion control device (a) 1 and a combustion control device (b) 7 correspond to the control device.

[0047]

According to the present invention, since the position or section of the waste in the waste pit and the calculated value of the waste quality calculated by the automatic combustion control device are stored in association with each other, the waste put into the hopper is stored. Waste quality can be predicted. In this way, by performing combustion control by associating the position or section with the waste quality, it is possible to improve the stability of the combustion state in the furnace and reduce dioxins and nitrogen oxides in exhaust gas And

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a combustion control method in a refuse incinerator.

FIG. 2 is a diagram showing an embodiment of a section in a waste pit in a combustion control method for a waste incinerator.

FIG. 3 is a diagram showing one embodiment of selecting waste from a section of an input zone in a method of controlling combustion of a waste incinerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion control device (a) 2 Garbage incinerator 3 Crane 4 Crane bucket 5 Garbage pit 5a Stir zone 5b Input zone 6 Collected garbage 7 Combustion control device (b) 8 Dust supply device 9 Combustion grate 10 Combustion air fan 11 NO1 distribution damper 12 NO2 distribution damper 13 NO3 distribution damper 14 NO4 distribution damper 15 Furnace thermometer 16 Furnace outlet thermometer 17 Boiler 18 Steam flow meter 19 Exhaust gas treatment device 20 Chimney 21 Hopper 22 Cooling air fan 23 Combustion air thermometer 24 Cooling Air thermometer 25 Exhaust gas flow meter 26 Boiler feedwater thermometer 27 Furnace outlet 28 Ash fall

Continued on the front page F term (reference) 3K062 AA01 AB01 AC01 BA02 CB01 CB04 CB09 CB10 DA01 DA16 DA27 DA32 DA36 DB03 DB06 DB08 DB09

Claims (6)

[Claims] An automatic combustion control device calculates the information on the quality of the waste and stores the calculated information on the quality of the waste in correspondence with the position in the waste pit. A combustion control method for a refuse incinerator, characterized by storing and storing. 2. The method according to claim 1, wherein the inside of the refuse pit is divided into sections of a predetermined size, and each of the divided sections is used as a position of refuse when storing refuse quality. Combustion control method for garbage incinerator. 3. The invention of claim 1 or claim 2.
In the invention according to the invention, a method of controlling combustion in a refuse incinerator, characterized in that when refuse in a certain section is introduced this time, a dry air amount corresponding to the refuse quality when refuse of the same position was introduced in the past is supplied. . 4. The invention of claim 1 or claim 2.
In the invention according to the invention, when injecting garbage this time, the garbage in the incinerator in a refuse incinerator is characterized by selecting and injecting garbage in a position near or close to the previous time. 5. The invention of claim 1 or claim 2.
In the invention of the above, at the time of injecting the refuse this time, based on the information of the refuse quality obtained by the automatic combustion control device up to the previous time, the refuse of a position near or close to the refuse quality previously input is selected and supplied. A method for controlling combustion in a refuse incinerator. 6. A refuse loading section for temporarily loading refuse to be burned before charging refuse into the combustion furnace main body, and a control device for controlling combustion of refuse in the incinerator main body. The control device holds the combustion-related information of the refuse at each position corresponding to the loading position of the refuse in the refuse loading unit, and based on the combustion-related information, controls the refuse from the refuse loading unit to the incinerator main body. A refuse incinerator characterized by controlling the input and / or combustion of refuse in the combustion furnace body.