JP7199235B2 - Combustion furnace and its starting method - Google Patents

Description

The present invention relates to a combustion furnace for burning refuse and the like and a method for starting the same.

In recent years, it has been proposed to use carbonized fuel as an alternative to fossil fuels. Carbonized fuel is obtained by drying biomass resources, heating and pyrolyzing the dried biomass resources in a low-oxygen atmosphere, and cooling the resulting carbide. The cooled char may be humidified to prevent self-heating. Carbonized fuel is powdery and granular, and has a calorific value comparable to that of low-grade coal. Patent Documents 1 and 2 disclose combustion furnaces using carbonized fuel.

The stoker-type waste incinerator of Patent Document 1 has a combustion chamber consisting of a dry zone, a main combustion zone and a post-combustion zone, and incinerates low-quality waste together with carbonized fuel supplied to the dry zone. By incinerating the carbonized fuel together with the low-quality garbage in this way, fluctuations in the properties of the low-quality garbage are absorbed, and the low-quality garbage is incinerated stably at a high temperature.

Further, in the sludge incinerator provided in the carbonization treatment facility of Patent Document 2, when the fossil fuel as the auxiliary fuel is insufficient, the carbonized fuel generated in the carbonization furnace provided in the facility is supplied. In this way, the use of carbonized fuel as part of the auxiliary fuel prevents an increase in the amount of fossil fuel used.

JP 2005-249262 A JP 2005-319374 A

FIG. 7 is a trend graph of fuel supply amount and in-furnace temperature during start-up operation of a conventional refuse incinerator. As shown in FIG. 7, conventionally, in general municipal waste incinerators, fossil fuels such as kerosene and heavy oil are supplied into the furnace as auxiliary fuels during start-up (at the time of start-up) to burn fossil fuels. After the furnace temperature is raised to a temperature T2 just before the combustion temperature T3 (about 850°C) of the waste, after the furnace temperature stabilizes at the combustion temperature T3, the waste is started to be fed and the steady operation is started. do. In addition, before the temperature inside the furnace reaches the combustion temperature T3 of the refuse, the temperature inside the furnace may be raised by burning plastics or dried wood having a high heat value.

As described in Patent Documents 1 and 2, carbonized fuel may be used as part of the combustion support fuel during steady-state operation of the furnace, but as described above, fossil fuel with a large calorific value is used during start-up operation of the furnace. It is conceivable to use carbonized fuel as an alternative fuel to fossil fuel even during startup operation of the furnace. There is a risk that the start-up time will be longer, and unburned components will calcine in the hearth, and incomplete combustion may include inappropriate components such as CO in the exhaust gas. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to propose a technique for properly starting a combustion furnace using carbonized fuel.

A method for starting a combustion furnace according to one aspect of the present invention comprises:
supplying fossil fuel into the furnace of a combustion furnace, and burning the fossil fuel to raise the furnace temperature to the ignition temperature of the carbonized fuel;
Reducing the supply amount of the fossil fuel and supplying the carbonized fuel to the furnace so as to be mixed with the fossil fuel, and increasing the furnace temperature above the ignition temperature by co-firing the fossil fuel and the carbonized fuel increasing to a predetermined switching temperature below the combustion temperature of the combustible material.

A combustion furnace according to one aspect of the present invention includes:
a fossil fuel burner for ejecting fossil fuel into the furnace together with the first combustion air;
a carbonized fuel burner for ejecting carbonized fuel together with secondary combustion air into the furnace to mix with the fossil fuel ejected from the fossil fuel burner;
a furnace temperature sensor that detects the temperature in the furnace;
A control device for controlling a fossil fuel supply amount from the fossil fuel burner and a carbonized fuel supply amount from the carbonized fuel burner based on the furnace temperature,
The control device increases the fossil fuel supply amount during startup operation, increases the furnace temperature to the ignition temperature of the carbonized fuel by burning the fossil fuel, and then reduces the fossil fuel supply amount. and increasing the supply amount of the carbonized fuel, and by co-firing the fossil fuel and the carbonized fuel, the furnace temperature is raised to a predetermined switching temperature that is higher than the ignition temperature and lower than the combustion temperature of the combustible material. There is.

In the above-described combustion furnace and its starting method, after the temperature in the furnace is raised to the ignition temperature of the carbonized fuel by the single combustion of the fossil fuel, the combustion is switched to the mixed combustion of the fossil fuel and the carbonized fuel. As a result, after the inside of the furnace reaches the ignition temperature of the carbonized fuel, the carbonized fuel supplied into the furnace quickly ignites and burns. Furthermore, since the carbonized fuel is supplied into the furnace so as to be mixed with the fossil fuel, the carbonized fuel is reliably and quickly ignited and burned even during start-up operation when the temperature in the furnace is unstable. Therefore, incomplete combustion of the carbonized fuel supplied into the furnace can be prevented. In addition, since the carbonized fuel supplied into the furnace burns quickly, by adjusting the supply amount of the carbonized fuel, the same calorific value as raising the combustion temperature in the furnace by single combustion of fossil fuel can be obtained. can be obtained in time. In this way, a reduction in the amount of fossil fuel used and good furnace start-up using carbonized fuel can be achieved.

ADVANTAGE OF THE INVENTION According to this invention, the technique of starting a combustion furnace satisfactorily using carbonized fuel can be provided.

FIG. 1 is a schematic diagram showing the overall configuration of a refuse incineration system including a combustion furnace according to one embodiment of the present invention. FIG. 2 is a diagram showing a start-up burner configuration including a fossil fuel burner and a carbonized fuel burner. FIG. 3 is a diagram showing a configuration of a modified starting burner including a fossil fuel burner and a carbonized fuel burner. FIG. 4 is a flow chart of control during start-up operation of the combustion furnace. FIG. 5 is a trend graph of the fuel supply amount and the furnace temperature during startup operation of the combustion furnace. FIG. 6 is a schematic diagram showing the configuration of a combustion furnace according to Modification 1. As shown in FIG. FIG. 7 is a trend graph of the fuel supply amount and the temperature inside the furnace at the start-up operation of the conventional refuse combustion furnace.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of a refuse incineration system 100 including a combustion furnace 1 according to one embodiment of the present invention.

A combustion furnace 1 shown in FIG. 1 is a stoker-type waste incinerator. A primary combustion chamber 21 and a secondary combustion chamber 22 provided downstream of the primary combustion chamber 21 are provided in the combustion furnace 1 . The combustion furnace 1 includes an input hopper 31 that supplies refuse into the furnace, a dust feeder 32 that feeds the refuse into the primary combustion chamber 21 in the furnace, and a stoker-type transfer device 33 that moves the refuse within the primary combustion chamber 21. Prepare. The stoker-type conveying device 33 has a dry stoker 33a, a combustion stoker 33b, and a post-combustion stoker 33c from the upstream side to the downstream side of the waste flow. An ash discharge port 34 is provided downstream of the post-combustion stoker 33c.

Primary air 51 is supplied to the primary combustion chamber 21 from below through stoker 33 a , 33 b , 33 c of a stoker-type transfer device 33 . Secondary air 52 is supplied into the primary combustion chamber 21 from the ceiling of the primary combustion chamber 21 . Further, a starting burner 4 and an auxiliary burner 35 are provided in the primary combustion chamber 21 . The secondary combustion chamber 22 is provided with an in-furnace temperature sensor 36 for detecting the in-furnace temperature.

In the combustion furnace 1 configured as described above, the dust introduced from the introduction hopper 31 into the entrance of the primary combustion chamber 21 is pushed out onto the drying stoker 33a by the dust feeder 32. As shown in FIG. The refuse is dried and heated to near the ignition point while being conveyed by the drying stoker 33a. The dried refuse is ignited while being conveyed by the combustion stoker 33b, and part of the ignited refuse is thermally decomposed to generate combustible thermal decomposition gas. This pyrolysis gas accompanies the primary air 51 and moves to the upper part of the primary combustion chamber 21 and is combusted together with the secondary air 52 . The rest of the ignited garbage is burned while being transported by the post-combustion stoker 33c, and the incineration ash remaining after combustion is discharged from the ash discharge port 34 and sent to an ash treatment facility (not shown). The combustion exhaust gas of the primary combustion chamber 21 is mixed with the secondary air 52 blown from the ceiling portion on the downstream side of the primary combustion chamber 21 and completely combusted in the secondary combustion chamber 22 .

A flue 23 connected to the secondary combustion chamber 22 is provided with a boiler 2 that recovers thermal energy from flue gas flowing through the flue 23 . Water pipes connected to the boiler drum 24 are stretched around the wall of the flue 23 . The boiler drum 24 is also connected to heat transfer tubes 25 and 26 installed in the flue 23 . The steam superheated by recovering the heat of the flue gas through the heat transfer tubes 25 and 26 is sent to power generation equipment (not shown) and used for power generation.

The flue gas that has passed through the boiler 2 is discharged to an exhaust line 8 connected to the flue 23 . The exhaust line 8 is provided with a dust collector 81, an induced draft fan 82, and the like. After dust is separated from the flue gas emitted from the boiler 2 by the dust collector 81, it is discharged to the atmosphere through the chimney 83.

An exhaust gas recirculation line (hereinafter referred to as “EGR line 9”) is connected to the exhaust line 8 downstream of the dust collector 81 and upstream of the induced draft fan 82 . The EGR line 9 is a flue gas flow path that returns part of the flue gas from the combustion furnace 1 to the inside of the combustion furnace 1 . In this embodiment, a burner supply line 92 for sending combustion exhaust gas to the starting burner 4 branches off from the EGR line 9 .

[Configuration of start burner 4]
FIG. 2 is a diagram showing the configuration of the starting burner 4 including the fossil fuel burner 41 and the carbonized fuel burner 42. As shown in FIG. The starting burners 4 shown in FIG. 2 include fossil fuel burners 41 and carbonized fuel burners 42 . It should be noted that the auxiliary burner 35 may also include the fossil fuel burner 41 and the carbonized fuel burner 42 in the same manner as the start burner 4 .

The fossil fuel burner 41 has a fossil fuel nozzle 41a for ejecting a fossil fuel F1 such as heavy oil or kerosene, and an air nozzle 41b for ejecting combustion air A1. In the fossil fuel burner 41 according to this embodiment, an air nozzle 41b is provided so as to surround the fossil fuel nozzle 41a. However, the configuration of the fossil fuel burner 41 is not limited to this.

The amount of fossil fuel F1 supplied from the fossil fuel burner 41 into the furnace (hereinafter referred to as "fossil fuel supply amount f1") can be adjusted by a fossil fuel supply amount adjustment valve 45 connected to the fossil fuel nozzle 41a. Also, the flow rate of the combustion air A1 can be adjusted by a combustion air control valve 46 connected to the air nozzle 41b. The flow rate of the combustion air A1 is adjusted so as to achieve a suitable air-fuel ratio with respect to the fossil fuel supply amount f1.

The carbonized fuel burner 42 has a carbonized fuel nozzle 42a that blows out a mixture of the carbonized fuel F2 and the combustion air A2 (that is, the carbonized fuel F2 airflow-conveyed by the combustion air A2). The combustion air A2 blown out from the carbonized fuel nozzle 42a may be air taken in from the outside, but is preferably flue gas supplied through the EGR line 9 and the burner supply line 92. The flue gas is hotter than the air taken in from the outside.

The amount of carbonized fuel F2 supplied from the carbonized fuel burner 42 into the furnace (hereinafter referred to as "carbonized fuel supply amount f2") can be adjusted by a carbonized fuel supply amount adjustment valve 47 connected to the carbonized fuel nozzle 42a. A damper 93 (see FIG. 1) provided in the burner supply line 92 may function as the carbonized fuel supply amount adjustment valve 47 when the combustion air A2 is combustion exhaust gas.

The fossil fuel burner 41 and the carbonized fuel burner 42 are arranged so that the carbonized fuel F2 supplied into the furnace from the carbonized fuel burner 42 can be mixed with the fossil fuel F1 supplied into the furnace from the fossil fuel burner 41. . For example, the fossil fuel burner 41 and the carbonized fuel burner 42 are arranged close to each other. Further, for example, fossil fuel burners 41 are arranged around the carbonized fuel burners 42 . Further, for example, the fossil fuel burner 41 and the carbonized fuel burner 42 are arranged so that the blowing direction of the fossil fuel F1 and the blowing direction of the carbonized fuel F2 intersect.

FIG. 3 is a diagram showing a configuration of a modification of the starting burner 4 including the fossil fuel burner 41 and the carbonized fuel burner 42. As shown in FIG. The starting burner 4 according to the modification of FIG. 3 is a mixed combustion burner in which a fossil fuel burner 41 and a carbonized fuel burner 42 are combined. A carbonized fuel burner 42 is provided in the center, and fossil fuel burners 41 are provided so as to surround the carbonized fuel burner 42 . More specifically, a plurality of fossil fuel nozzles 41a for blowing out the fossil fuel F1 are annularly arranged on the outer peripheral side of the carbonized fuel nozzles 42a for blowing out a mixture of the carbonized fuel F2 and the combustion air A2. An air nozzle 41b is arranged on the outer peripheral side of the annular row. The air nozzle 41b may be a plurality of nozzles arranged in an annular shape, or may be a single nozzle having an annular flow path.

The fossil fuel supply amount adjustment valve 45 , the combustion air adjustment valve 46 , the carbonized fuel supply amount adjustment valve 47 , and the in-furnace temperature sensor 36 are electrically connected to the control device 6 . The controller 6 changes the opening degrees of the fossil fuel supply adjustment valve 45, the combustion air adjustment valve 46, and the carbonized fuel supply adjustment valve 47 based on the furnace temperature detected by the furnace temperature sensor 36. Thus, the fossil fuel supply amount f1, the combustion air supply amount, and the carbonized fuel supply amount f2 are adjusted.

The controller 6 may be embodied as a kind of computer, such as a PLC (Programmable Controller). The control device 6 includes a processor configured by a CPU, MPU, GPU, etc., and volatile and non-volatile memories (all not shown). The processor reads and executes various programs stored in the memory, thereby performing processing for realizing the functions of the control device 6 .

[Startup operation of combustion furnace 1]
Here, the start-up operation (start-up) of the combustion furnace 1 will be described. FIG. 4 is a flow chart of the control during startup operation of the combustion furnace 1, and FIG. is a trend graph of

The control device 6 receives the start-up command (YES in step S1) and starts the start-up operation of the combustion furnace 1 . First, the control device 6 causes the activation burner 4 to burn the fossil fuel F1 (step S2). Specifically, the control device 6 increases the opening degree of the fossil fuel supply amount adjustment valve 45 to increase the fossil fuel supply amount f1 from the starting burner 4, and also increases the opening degree of the combustion air adjustment valve 46. Then, the combustion air A1 is supplied at a flow rate corresponding to the fossil fuel supply amount f1.

As shown in FIG. 5, when the fossil fuel F1 is supplied into the furnace and combustion of the fossil fuel F1 begins, the temperature inside the furnace rises. The control device 6 monitors the in-furnace temperature detected by the in-furnace temperature sensor 36 .

If the furnace temperature reaches the ignition temperature T1 of the carbonized fuel F2 or higher (YES in step S3), the starting burner 4 causes the fossil fuel F1 and the carbonized fuel F2 to co-combust (step S4). Specifically, the control device 6 reduces the opening degree of the fossil fuel supply amount adjustment valve 45 to reduce the fossil fuel supply amount f1 from the starting burner 4, and reduces the opening degree of the carbonized fuel supply amount adjustment valve 47. is increased to increase the carbonized fuel supply amount f2 from the starting burner 4. By adjusting the opening degree of the combustion air control valve 46, the flow rate of the combustion air A1 is adjusted so that the air-fuel ratio around the starting burner 4 becomes appropriate. The ignition temperature T1 of the carbonized fuel F2 varies depending on the components of the carbonized fuel F2, but is approximately 300 to 400.degree.

When the fossil fuel F1 and the carbonized fuel F2 are supplied into the furnace and the combustion of the fossil fuel F1 and the carbonized fuel F2 starts, the temperature in the furnace further rises. In order to make the in-furnace temperature trend during start-up operation shown in FIG. 5 correspond to the in-furnace temperature trend during conventional start-up operation shown in FIG. The carbonized fuel supply amount f2 may be determined so as to compensate. Further, the fossil fuel supply amount f1 is adjusted so that the calorific value of the fossil fuel F1 and the calorific value of the carbonized fuel F2 are approximately the same (that is, the calorific value of the fossil fuel F1: the calorific value of the carbonized fuel F2≈1:1). and carbonized fuel supply amount f2 may be determined.

When the furnace temperature reaches the predetermined switching temperature T2 (YES in step S5), the starting burner 4 is switched to the fossil fuel F1 (step S6). Specifically, the control device 6 reduces (or closes) the opening degree of the carbonized fuel supply amount adjustment valve 47 while maintaining the opening degree of the fossil fuel supply amount adjustment valve 45 to to decrease the carbonized fuel supply amount f2. Here, the amount of fossil fuel supply f1 should be a level that can absorb fluctuations in the quality of refuse in order to stabilize combustion. Further, although the carbonized fuel supply amount f2 is set to zero and the combustion is switched to the fossil fuel F1 alone, the carbonized fuel supply amount f2 may not be set to zero and the carbonized fuel F2 may be burned. The switching temperature T2 is higher than the ignition temperature T1 of the carbonized fuel F2 and lower than or equal to the combustion temperature T3 (about 850° C.) of the refuse. The switching temperature T2 may be, for example, about 600-700.degree.

As described above, the combustion furnace 1 of the present embodiment includes the fossil fuel burner 41 that ejects the fossil fuel F1 into the furnace together with the first combustion air A1, and the fossil fuel F1 that is ejected from the fossil fuel burner 41 and mixed with the fossil fuel F1. a carbonized fuel burner 42 for ejecting the carbonized fuel F2 into the furnace together with the second combustion air A2, a furnace temperature sensor 36 for detecting the temperature in the furnace, and the fuel from the fossil fuel burner 41 based on the temperature in the furnace. A control device 6 for controlling the fossil fuel supply amount f<b>1 and the carbonized fuel supply amount f<b>2 from the carbonized fuel burner 42 . During startup operation, the control device 6 increases the fossil fuel supply amount f1, increases the furnace temperature to the ignition temperature T1 of the carbonized fuel F2 by burning the fossil fuel F1, and then reduces the fossil fuel supply amount f1. In addition, the carbonized fuel supply amount f2 is increased to increase the furnace temperature to a predetermined switching temperature T2 that is higher than the ignition temperature T1 and lower than the combustion temperature T3 of the combustible material by co-firing the fossil fuel F1 and the carbonized fuel F2. It is

Similarly, in the method for starting the combustion furnace 1 according to the present embodiment, the fossil fuel F1 is supplied into the furnace of the combustion furnace 1, and the combustion of the fossil fuel F1 raises the furnace temperature to the ignition temperature T1 of the carbonized fuel F2. and reducing the supply amount of the fossil fuel F1 and supplying the carbonized fuel F2 into the furnace so as to be mixed with the fossil fuel F1, and by co-firing the fossil fuel F1 and the carbonized fuel F2, the furnace temperature is reduced to the ignition temperature increasing to a predetermined switching temperature T2 which is higher than T1 and lower than or equal to the combustion temperature T3 of the combustible material.

In the combustion furnace 1 and its startup method, the temperature in the furnace is raised to the ignition temperature T1 of the carbonized fuel F2 by mono-firing the fossil fuel F1, and then the combustion is switched to the co-firing of the fossil fuel F1 and the carbonized fuel F2. After the inside of the furnace reaches the ignition temperature T1 of the carbonized fuel F2, the carbonized fuel F2 supplied into the furnace quickly ignites and burns. Furthermore, since the carbonized fuel F2 is supplied into the furnace so as to be mixed with the fossil fuel F1, the carbonized fuel F2 is a low-quality carbide with high moisture content and high ash content even during startup operation when the temperature in the furnace is unstable. Even if there is, the carbonized fuel F2 is reliably and quickly ignited and burned. Therefore, incomplete combustion of the carbonized fuel F2 supplied into the furnace can be prevented. The carbonized fuel F2 is not limited to low-quality carbides, but according to the combustion furnace 1 and its starting method, it is possible to use low-quality carbides, which are cheaper than coal, as the carbonized fuel F2.

In addition, since the carbonized fuel F2 supplied into the furnace burns quickly, by adjusting the carbonized fuel supply amount f2, the calorific value equivalent to raising the inside of the furnace to the combustion temperature T3 by burning the fossil fuel F1 alone. can be obtained in the same amount of time. In this way, it is possible to realize a reduction in the amount of fossil fuel F1 used and a good start-up of the furnace using carbonized fuel F2.

Further, in the combustion furnace 1 according to the present embodiment, the second combustion air A2 is part of the combustion exhaust gas from the inside of the furnace. Similarly, in the method for starting the combustion furnace 1 according to the present embodiment, the carbonized fuel F2 is supplied into the combustion furnace 1 together with the flue gas.

The combustion exhaust gas of the combustion furnace 1 has a higher temperature than the air taken in from the outside. By supplying the carbonized fuel F2 into the furnace together with the high-temperature combustion air A2 in this way, the temperature in the furnace is suppressed from decreasing, and the ignition and combustion of the carbonized fuel F2 are promoted.

In the combustion furnace 1 , the fossil fuel burner 41 and the carbonized fuel burner 42 may be configured as a co-combustion burner in which the fossil fuel burner 41 is arranged around the carbonized fuel burner 42 .

As a result, the fossil fuel F1 supplied into the furnace from the fossil fuel burner 41 and the carbonized fuel F2 supplied into the furnace from the carbonized fuel burner 42 are reliably mixed. Since the carbonized fuel F2 is supplied to the place where the temperature is increased by the combustion of the fossil fuel F1, the ignition and combustion of the carbonized fuel F2 are promoted.

Although the preferred embodiments of the present invention have been described above, the present invention may include modifications of the details of the specific structures and/or functions of the above embodiments without departing from the spirit of the present invention. . For example, the above configuration can be modified as follows.

For example, in the above-described embodiment, the combustion furnace 1 is a stoker-type waste incinerator, but the material to be incinerated in the combustion furnace 1 is not limited to garbage.

Further, for example, in the above embodiment, the combustion furnace 1 is a stoker-type waste incinerator, but the combustion furnace 1 according to the present invention can be widely applied to combustion furnaces such as fluidized bed furnaces that use fossil fuels at startup. . Modification 1 in which the combustion furnace according to the present invention is applied to a fluidized bed furnace will be described below.

FIG. 6 is a schematic diagram showing the configuration of a combustion furnace 101 according to Modification 1. As shown in FIG. The combustion furnace 101 shown in FIG. 6 is a fluidized bed waste incinerator. A primary combustion chamber 121 and a secondary combustion chamber 122 are formed in the combustion furnace 101 . A fluidized bed 134 is provided at the bottom of the furnace. The combustion furnace 101 includes an input hopper 131 into which refuse is input, and a dust feeder 132 that feeds refuse into a primary combustion chamber 121 in the furnace. Fluidization air 151 is supplied from the lower part of the fluidized bed 134 . A starting burner 104 and an auxiliary burner 135 are provided in the primary combustion chamber 121 . Secondary air 152 is supplied to the vicinity of the boundary between the primary combustion chamber 121 and the secondary combustion chamber 122 in the furnace. The secondary combustion chamber 122 is provided with an in-furnace temperature sensor 136 that detects the in-furnace temperature.

Also in the combustion furnace 101 having the above configuration, the start-up burner 104 includes the fossil fuel burner 41 and the carbonized fuel burner 42 as in the above-described embodiment. Then, as in the above-described embodiment, during the startup operation of the furnace, the startup burner 104 (and/or the auxiliary combustion burner 135) fires only the fossil fuel F1 or mixedly fires the fossil fuel F1 and the carbonized fuel F2 based on the temperature in the furnace. , to the mono-firing of the fossil fuel F1.

Reference Signs List 1, 101: combustion furnace 2: boiler 4, 104: starting burner 6: control device 8: exhaust line 9: EGR line 21, 121: primary combustion chamber 22122, secondary combustion chamber 23: flue 24: boiler drum 25 , 26: heat transfer tubes 31, 131: feeding hoppers 32, 132: dust supply device 33: stoker-type transfer devices 33a, 33b, 33c: stoker 34: ash discharge ports 35, 135: auxiliary burners 36, 136: furnace temperature sensor 41: Fossil fuel burner 41a: Fossil fuel nozzle 41b: Air nozzle 42: Carbonized fuel burner 42a: Carbonized fuel nozzle 45: Fossil fuel supply adjustment valve 46: Combustion air adjustment valve 47: Carbonized fuel supply adjustment valve 81: Dust collector 82: Induced draft fan 83: Chimney 92: Burner supply line 93: Damper 100: Incineration system 134: Fluidized bed

Claims (7)

A method for starting a combustion furnace that burns a combustible material,
A step of supplying a fossil fuel into the furnace of the combustion furnace and increasing the temperature in the furnace to the ignition temperature of the carbonized fuel by burning the fossil fuel;
Reducing the supply amount of the fossil fuel and supplying the carbonized fuel to the furnace so as to be mixed with the fossil fuel, and increasing the furnace temperature above the ignition temperature by co-firing the fossil fuel and the carbonized fuel raising to a predetermined switching temperature below the combustion temperature of the combustible material,
How to start a combustion furnace. supplying the carbonized fuel into the furnace together with flue gas of the combustion furnace;
The method for starting a combustion furnace according to claim 1. A combustion furnace for burning a combustible material,
a fossil fuel burner for ejecting fossil fuel into the furnace together with the first combustion air;
a carbonized fuel burner for ejecting carbonized fuel together with secondary combustion air into the furnace to mix with the fossil fuel ejected from the fossil fuel burner;
a furnace temperature sensor that detects the temperature in the furnace;
A control device for controlling a fossil fuel supply amount from the fossil fuel burner and a carbonized fuel supply amount from the carbonized fuel burner based on the furnace temperature,
The control device increases the fossil fuel supply amount during startup operation, increases the furnace temperature to the ignition temperature of the carbonized fuel by burning the fossil fuel, and then reduces the fossil fuel supply amount. and increasing the supply amount of the carbonized fuel, and by co-firing the fossil fuel and the carbonized fuel, the furnace temperature is raised to a predetermined switching temperature that is higher than the ignition temperature and lower than the combustion temperature of the combustible material has been
combustion furnace. the second combustion air is part of flue gas from within the furnace;
Combustion furnace according to claim 3. The fossil fuel burner and the carbonized fuel burner are configured as a mixed combustion burner in which the fossil fuel burner is arranged around the carbonized fuel burner,
A combustion furnace according to claim 3 or 4. After the temperature in the furnace is raised to the switching temperature, the step of raising the temperature in the furnace to the combustion temperature of the combustible material by burning the fossil fuel or co-combusting the fossil fuel and the carbonized fuel. include,
3. The method for starting a combustion furnace according to claim 1 or 2. After the furnace temperature is raised to the switching temperature, the control device adjusts the furnace temperature to the combustion temperature of the combustible material by burning the fossil fuel or co-combusting the fossil fuel and the carbonized fuel. raise to
A combustion furnace according to claim 3 or 4.

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