JPH07269832A - Method and device to control temperature of fluidize bed incineration furnace - Google Patents

Abstract

PURPOSE:To prevent clinker from generating due to the melting of a low melting point compound, and continue a fluidized bed combustion of collected ash, etc., stably by a method wherein both control quantities of the feeding quantity of auxiliary fuel and feeding quantity of collected soot and dust are made to cooperate, to maintain a combustion temperature in a fluidized bed within a specified range. CONSTITUTION:When a temperature of a fluidized bed 2 changes, the flow rate of auxiliary fuel 19 is preferentially controlled. A fuel quantity setting apparatus for the auxiliary fuel 10 is provided, and a deviation between the quantity of the fuel 19 which is set by the quantity setting apparatus, and an actually fed quantity of the fuel 19 is detected, and the combustion is controlled so that the deviation may be eliminated, and the actually fed quantity and the set quantity may become equal. Also, at the same time, a feeding quantity of an unburned residue 20 such as collected dust ash, etc., is controlled by a deviation signals to the previously mentioned set fuel quantity and a control signal wherein a primary time delay element until the fed unburned residue 20 actually burns is incorporated. At the same time, the combustion is controlled so that the actual quantity of the fuel 19 may become the same as the set quantity. By this method, the temperature in the fluidized bed 2 is kept within the specified range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric dust collector and a fluidized bed incinerator for burning unburned residue such as dust ash containing unburned carbon collected by other dust collectors in a fluidized bed. In particular, the present invention relates to a method for controlling a temperature inside a fluidized bed in a fluidized bed incinerator, which is suitable for keeping the temperature inside the fluidized bed within a predetermined range and suppressing the formation of clinker due to melting of the low melting point compound.

[0002]

2. Description of the Related Art As a conventional method for controlling the combustion temperature in a fluidized bed of a fluidized bed incinerator for incinerating unburned residue such as dust collecting ash, there is, for example, JP-A-55-3513. This is a low melting point compound such as sodium compound contained in EP ash or vanadium pentoxide in a fluidized bed type EP ash incinerator that incinerates dust particles (called EP ash) in combustion exhaust gas collected by an electric dust collector or the like. It is a method of controlling the combustion temperature in the fluidized bed between about 600 ° C. and 750 ° C. so as to prevent the formation of heat. Further, it is a combustion control method that prevents the formation of lumpy clinker due to melting of the low-melting point compound in the fluidized bed, and enables stable fluidized bed combustion to be continued. The combustion control method of this fluidized bed type EP ash incinerator is as follows. As shown in FIG. 3, a fluidized air dispersion plate 13 is installed in the lower part of the incinerator body 1, and fluidized air is introduced from the lower part of this air dispersion plate 13. By flowing 15 and jet air 16, the fluidized bed 2 is formed by fluidizing a fluidized medium such as sand above the fluidized air dispersion plate 13. The EP ash is quantified by the EP ash feeder 4 attached to the lower part of the EP ash hopper 3, and is supplied into the fluidized bed 2 through the EP ash airflow transport pipe 6 and the EP ash layer supply nozzle 7 to be incinerated. To be done.
The auxiliary combustion oil 19 is supplied to the inside of the fluidized bed 2 through the oil supply pump 8, the oil amount control valve 11, and the auxiliary combustion burner 12, and combustion control is performed so that the combustion temperature in the fluidized bed is within a predetermined range. . For the combustion temperature control in the fluidized bed, the temperature of the fluidized bed is measured by the in-bed thermometer 17, and the oil quantity control valve 11 and the EP ash supply amount are adjusted from the control box 18 by a variable speed machine 5 of the EP ash feeder.
Is performed by controlling the amount of auxiliary combustion oil and the amount of EP ash supplied. When combustion of the auxiliary combustion oil 19 is required to maintain the temperature in the fluidized bed within a predetermined range, first, the auxiliary combustion oil 1
When the combustion is controlled only by 9, and the heat of combustion of EP ash increases,
The auxiliary combustion oil 19 is gradually reduced, and finally the oil amount control valve 11 is controlled to be fully closed so that the auxiliary combustion oil amount becomes zero.
Then, at this time, the temperature control in the fluidized bed is switched to the control of the EP ash supply amount. On the contrary, when the combustion heat of the EP ash decreases, the temperature control in the fluidized bed switches from the control of the EP ash supply amount to the control of the auxiliary combustion oil supply amount. That is, it is a method of controlling the combustion temperature in the fluidized bed by controlling either the amount of auxiliary combustion oil or the EP ash supply amount independently.
As a conventional technique, in addition to the above-mentioned publication, there is a method of controlling the unburned component storage level prior to the operation stop of the fluidized cell and controlling the auxiliary combustion amount in accordance with the fluidized bed temperature. It is proposed in Japanese Patent Publication No. 49-79068.

[0003]

In the above-mentioned prior art, there is no consideration for the time delay of the EP ash supply from the EP ash hopper to the fluidized bed incinerator, and the time delay of the combustion of the EP ash. Although it was possible to control the temperature in the fluidized bed within a predetermined range by controlling the supply amount of fuel oil, the control for maintaining the temperature in the fluidized bed within a predetermined range by the supply amount of EP ash is the above-mentioned EP. It was extremely difficult to control due to the time delay of ash supply and the time delay of combustion of EP ash. For this reason, in the actual operation of the EP ash incinerator, in order to keep the temperature in the fluidized bed within a predetermined range, the operator can manually control the EP ash so that the amount of auxiliary combustion oil can be constantly controlled. The operation to increase or decrease the supply amount was performed.

An object of the present invention is to provide an electric dust collector and a fluidized bed incinerator in which unburned residues such as dust ash containing unburned carbon collected by other dust collectors are burned in a fluidized bed. Coordinate the control amount of both the auxiliary fuel supply amount and the EP ash supply amount, maintain the combustion temperature in the fluidized bed within a predetermined range, prevent the formation of clinker due to melting of the low melting point compound, and stabilize the temperature. An object of the present invention is to provide a method for controlling the temperature inside the bed of a fluidized bed incinerator that can continue the fluidized bed combustion of unburned residue such as collected ash.

[0005]

In order to achieve the above object of the present invention, in the bed temperature control method for a fluidized bed incinerator of unburned residue such as dust ash, the temperature in the fluidized bed is changed. When doing, give priority to the flow rate of the auxiliary combustion oil (as the main control amount)
Control, on the other hand, by providing an oil amount setter for auxiliary combustion oil, detecting the deviation between the amount of auxiliary combustion oil set by this oil amount setter and the amount of auxiliary combustion oil actually supplied, Combustion control is performed so that this deviation is eliminated and the actual oil amount and the set oil amount become equal, and the supply amount of unburned residue such as dust ash is calculated from the deviation signal from the set oil amount and the unburned residue supplied. Is controlled by a control signal that incorporates a primary time delay element until the actual combustion, and combustion control is performed so that the actual amount of auxiliary combustion oil becomes the set amount of auxiliary combustion oil, and the temperature in the fluidized bed is within a predetermined range. Is a method of holding. The specific configuration of the bed temperature control method of the fluidized bed incinerator of the present invention, the unburned residue such as dust ash, the feed amount of the auxiliary fuel and the unburned residue are respectively controlled, the temperature in the fluidized bed. A method for controlling the in-bed temperature of a fluidized bed incinerator that maintains combustion within a set range, and sets the amount of supporting oil to bring the temperature in the fluidized bed to the set temperature. When there is a change, the temperature of the fluidized bed is controlled within the set range by giving priority to controlling the amount of auxiliary combustion oil supplied, while the amount of unburned residue supplied is set to the actual amount of auxiliary combustion oil set. The deviation signal from the flow rate and the control signal that incorporates a primary time delay element until the unburnt residue controlled for supply actually burns controls the supply amount of the unburnt residue, and the actual flow rate of the auxiliary combustion oil is A fluidized bed incinerator that controls the supply of unburned residue to return to the set flow rate. Is that the layer in the temperature control method. Further, the present invention relates to a bed temperature control device for a fluidized bed type incinerator, wherein unburned residue such as dust ash is controlled by controlling the supply amounts of auxiliary fuel and unburned residue, respectively. An in-bed temperature control device for a fluidized bed incinerator that holds a temperature in a set range for combustion, and an in-bed temperature setter that sets a combustion temperature in a fluidized bed to a set range, and the in-bed temperature setting Means for calculating the required amount of auxiliary combustion oil from the deviation signal between the reactor and the actual in-bed temperature, and controlling the oil amount control valve by the oil amount deviation between the required amount of auxiliary combustion oil and the actual amount of auxiliary combustion oil Means, the deviation signal between the set flow rate of the auxiliary combustion oil and the actual flow rate, and the control signal incorporating a primary time delay element until the unburnt residue controlled for supply actually burns Adjust the transmission to control the amount of unburned residue supplied, and set the actual flow rate of auxiliary combustion oil to the set flow rate. The feed rate of the unburned residue was controlled to return to a layer in the temperature control apparatus of at least provided with a fluidized bed incinerator means for controlling the fluidized bed to the temperature range of the set.

[0006]

In the method and apparatus for controlling the in-bed temperature of the fluidized bed incinerator according to the present invention, when the in-bed temperature changes, a deviation from the set temperature occurs, and the required oil amount is calculated by the function generator or the like. . A deviation occurs between the calculated required oil quantity and the actual oil flow rate, the oil quantity control valve operates in a direction to eliminate this deviation, and combustion is performed so that the temperature in the fluidized bed falls within a predetermined range. Controlled. Up to this point, the control method is normally performed. The present invention is further provided with an auxiliary combustion oil amount setting device,
The deviation signal between the set oil amount and the actual oil amount, and the control signal incorporating a primary delay element until the unburned residue such as dust ash to be actually burned is adjusted to adjust the unburned residue supply amount, Make sure that the actual amount of auxiliary fuel is the same as the set amount.
The amount of unburned residue supplied is controlled. Therefore, the amount of auxiliary combustion oil is always within the oil amount setting range of the oil amount control valve, eliminating the need for manual intervention by the operator and effectively controlling the inside of the fluidized bed within the set temperature range. Is possible,
There is no generation of clinker due to melting of low-melting-point compounds and the like, and it is possible to stably continue incineration of unburned residue such as dust collecting ash in the fluidized bed for a long period of time.

[0007]

Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG. 1 is a schematic view showing an example of the configuration of a fluidized bed type EP ash incinerator for controlling the temperature in the fluidized bed of the present invention. In the figure, as in the conventional fluidized bed type EP ash incinerator, the EP ash 20 is quantitatively cut out by an EP ash feeder 4 equipped with a variable speed machine 5 provided below the EP ash hopper 3. Then, the gas is supplied to the inside of the fluidized bed 2 through the EP ash airflow transport pipe 6 and the EP ash bed internal supply nozzle 7, and burns inside the bed. The oil supply pump 8, the oil flow meter 9, and the oil amount control valve 1 are used to maintain the temperature in the bed within a predetermined range.
1, the auxiliary combustion oil 19 is supplied to the inside of the fluidized bed 2 by the auxiliary combustion burner 12 and burned. The temperature inside the layer is measured by the layer thermometer 17 and transmitted to the control box 18. Further, the flow rate of the auxiliary combustion oil is also measured by the oil flow meter 9, and the control box 1
8 is sent. A signal from the control box 18 controls the oil amount control valve 11 and the variable speed machine 5 which is a drive unit of the EP ash feeder 4. FIG. 2 shows an example of the flow of temperature control in the fluidized bed of the present invention. The fluidized bed temperature to be controlled is set by the bed temperature setting device. The amount of auxiliary combustion oil is set by the auxiliary combustion oil amount setting device. The amount of auxiliary combustion oil is increased / decreased (controlled) by controlling the oil amount control valve 11 with a signal of an oil amount deviation between the required amount of oil required from the layer temperature and the actual amount of auxiliary combustion oil. The EP ash supply amount is increased / decreased by controlling the EP ash supply device 4 attached to the variable speed machine 5 by a signal in which a first-order lag element is added to the deviation signal between the set oil amount and the actual oil amount. During the stable operation of the fluidized bed EP ash incinerator with a set amount of oil and a constant bed temperature, for example, E
P When the ash calorific value changes to a higher direction, the heat input into the bed increases, and when the temperature inside the bed rises and there is a deviation from the set temperature, a signal that reduces the required oil quantity is sent to the oil quantity control valve. 11, the oil amount control valve 11 is throttled, and the amount of auxiliary combustion oil is reduced.
Further, when the EP ash calorific value continuously changes in the high direction, the above control is continuously repeated, and finally the oil amount control valve 11 is fully closed. This means that the temperature in the fluidized bed becomes higher than the set value, the low melting point compound in the EP ash melts in the fluidized bed to generate clinker, and the fluidized bed becomes hard to flow, making it impossible to incinerate the EP ash. Means that. In the present invention, in order to prevent the occurrence of the above trouble, an auxiliary combustion oil amount setting device is provided to set the oil amount. Therefore,
There will be a deviation between the set oil amount and the reduced actual oil amount. Due to this deviation of the oil amount, the EP ash feeder 4 attached to the variable speed machine 5 is controlled to reduce the EP ash supply amount, and the auxiliary combustion oil flow rate approaches the set oil amount. EP ash may be transported over a long distance of 100 m or more by air transportation,
Even if the EP ash supply amount is changed by the EP ash feeder 4 equipped with the variable speed machine 5, there is a considerable time delay until the EP ash is fed into the fluidized bed. In addition, the combustibles in EP ash are mainly fine carbon powders, and there is a considerable time delay before reaching the ignition temperature. Furthermore, although it is also a characteristic of the fluidized bed, since the fluid medium of the fluidized bed portion is the heat storage portion, these delay elements are synergistically changed, and after the EP ash supply amount is changed, the fluid flow corresponding to this change amount There will be a considerable time delay before the temperature change in the formation will appear. The controlled variable due to this time delay (internal temperature,
In order to prevent the ripple phenomenon of oil quantity and EP ash supply quantity),
A primary delay element is incorporated in the control of the supply amount of P ash. As a result, the temperature in the fluidized bed is mainly controlled by the amount of auxiliary fuel oil that has a quick response, and the EP ash supply amount is secondarily controlled so that the set amount of oil is always maintained, and stable automatic operation control is possible.

[0008]

As described in detail above, according to the fluidized bed type incinerator of the present invention, the amount of auxiliary combustion oil and the amount of dust collection can be increased without manually changing the supply amount of unburned residue such as dust ash. Since both the ash supply amount can be automatically controlled and the temperature in the fluidized bed can be stably maintained within a predetermined range, it is possible to prevent the formation of clinker due to the melting of the low-melting-point compound in advance. Enables long-term continuous operation of the layered incinerator.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a fluidized bed incinerator incorporating a fluidized bed temperature control system exemplified in an embodiment of the present invention.

FIG. 2 is a flowchart showing temperature control in a fluidized bed, which is exemplified in the embodiment of the present invention.

FIG. 3 is a schematic diagram showing an overall configuration of a fluidized bed incinerator incorporating a conventional fluidized bed temperature control system.

[Explanation of symbols]

 1 ... Incinerator main body 2 ... Fluidized bed 3 ... EP ash hopper 4 ... EP ash feeder 5 ... Variable speed machine 6 ... EP ash airflow transport pipe 7 ... EP ash layer supply nozzle 8 ... Oil supply pump 9 ... Oil flow meter DESCRIPTION OF SYMBOLS 10 ... Oil supply pipe 11 ... Oil amount control valve 12 ... Auxiliary burner 13 ... Fluidized air dispersion plate 14 ... Wind box 15 ... Fluidized air 16 ... Jet air 17 ... In-bed thermometer 18 ... Control box 19 ... Combustion oil 20 ... EP Ash

Claims (2)

[Claims] 1. A fluidized bed type incinerator that burns unburned residue such as dust ash by controlling the supply amount of auxiliary fuel oil and unburned residue respectively and keeping the temperature in the fluidized bed within a set range. A method for controlling the temperature inside a bed, in which the amount of auxiliary combustion oil for setting the temperature inside the fluidized bed to a set temperature is set, and when the temperature inside the fluidized bed changes, the supply amount of auxiliary combustion oil is preferentially controlled. This controls the temperature in the fluidized bed so that it is within the set range, while the unburned residue supply amount is controlled by the deviation signal between the set flow rate of the auxiliary fuel and the actual flow rate, and the unburned residue controlled by the supply. A control signal incorporating a primary time delay element until combustion is controlled to control the supply amount of the unburned residue, and to control the supply amount of the unburned residue so that the actual flow rate of the auxiliary combustion oil returns to the set flow rate. A method for controlling in-bed temperature in a fluidized bed incinerator, which is characterized by the above. 2. A fluidized bed incinerator that burns unburned residue such as collected ash by controlling the supply amounts of auxiliary fuel and unburned residue, keeping the temperature in the fluidized bed within a set range. An in-bed temperature control device, which comprises an in-bed temperature setter for setting a combustion temperature in a fluidized bed within a set range, and an auxiliary combustion oil required from a deviation signal between the in-bed temperature setter and an actual in-bed temperature. Means for calculating the amount, means for controlling the oil amount control valve by the oil amount deviation between the required auxiliary combustion oil amount and the actual auxiliary combustion oil amount, and a deviation signal between the set flow rate of the auxiliary combustion oil and the actual flow rate The control signal incorporating a primary time delay element until the unburnt slag to be controlled for supply is actually burned adjusts the variable speed machine of the unburnt slag feeder to control the supply amount of the unburnt slag. The amount of unburnt residue supplied is controlled so that the actual flow rate of fuel oil returns to the set flow rate, and the inside of the fluidized bed is installed. Intralayer temperature controller of the fluidized bed incinerator for that at least comprising means for controlling the temperature range of the features.