JP2000088240A - Combustion controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confine the total quantity of carbon dioxide being discharged during a predetermined interval within a regulated value by specifying the mixing ratio of one fuel required for attaining a specified carbon emission when two kinds of fuel having different carbon content are supplied to a combustion furnace and combusted. SOLUTION: The fuel controller 1 comprises a section 3 for regulating the flow rate of fuel A based on the mixing ratio thereof determined at a fuel ratio regulating section 2 for calculating the ratio of fuel A and fuel B, and a section 4 for regulating the flow rate of fuel B based on the mixing ratio thereof determined at a fuel ratio regulating section 2. When these fuels A, B having different carbon content are supplied to a combustion furnace, mixing ratio ra of fuel A required for attaining a specified carbon emission Fc is controlled according to a formula; ra=(Fc/Fa+Fb)-Rbc)/(Rac-Rbc), where Rac, Rbc are weight ratios of carbon contained in unit weight flow rates Fa, Fb of fuel A and fuel B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device provided in a thermal power plant or the like, and in particular, controls the type and amount of fuel supplied to a boiler so that the amount of carbon dioxide emission falls within a specified value. The present invention relates to a combustion control device.

[0002]

2. Description of the Related Art Combustion equipment such as a boiler, which is provided in a thermal power plant or the like and generates steam necessary to drive a turbine of a generator, has a fuel flow rate detected by a fuel flow rate sensor and a fuel flow rate detected by an air flow rate sensor. Based on the measured air flow rate, the steam pressure value detected by the main steam pressure sensor, and the steam pressure set value (main steam pressure set value), the opening of the fuel valve and the opening of the air flow controller are adjusted. To obtain the specified amount of steam.

[0003] Further, as a combustion facility other than such a combustion facility, under normal conditions, fuel with low dynamic characteristics, but low-cost fuel is burned, and the setting of the power generation amount and the like is changed, so that it is necessary for power generation. When the amount of steam, etc. is changed, a high-cost but high-dynamic fuel fuel supply is started to generate the specified amount of steam while supplementing the lack of calories. Is being developed.

[0004]

Meanwhile, in recent years, carbon dioxide emission regulations are scheduled on a worldwide scale, and accordingly, carbon dioxide emitted from combustion equipment such as a boiler provided in a thermal power plant or the like is accompanied. It is anticipated that regulations will be imposed.

[0005] However, in the combustion equipment provided in such a thermal power plant or the like, since the amount of generated power must be adjusted according to the amount of power consumed by each consumer, the required amount of steam fluctuates. CO2 emissions may fluctuate depending on the conditions, and the total amount of carbon dioxide emissions per unit of time (accumulated emissions) from combustion equipment may not be lower than the specified value set from the viewpoint of environmental regulations There is.

In order to solve such a problem, it is conceivable to use a fuel that emits a small amount of carbon dioxide, for example, a fuel such as natural gas. However, since such a fuel is expensive, There is a problem that power generation costs increase.

For this reason, while keeping the power generation cost low,
There has been a strong demand for the development of a combustion control device capable of reducing the total amount of carbon dioxide emitted per unit time from combustion equipment to a specified value or less set from the viewpoint of environmental regulations.

[0008] In view of the above circumstances, according to the present invention, the total amount of carbon dioxide emitted from the combustion furnace within a certain period from the present time is kept within a specified total emission regulation value. It is an object of the present invention to provide a combustion control device that can perform the combustion control.

According to the second aspect of the present invention, the combustion control can reduce the total amount of carbon dioxide emitted from the combustion equipment per fixed time period to a specified value or less set from the viewpoint of environmental regulations while keeping the power generation cost low. It is intended to provide a device.

According to the third aspect, even if the mixing ratio of various fuels supplied to the combustion furnace is adjusted, the total amount of carbon dioxide discharged per unit time from the combustion furnace can be kept within the total carbon dioxide emission regulation value. When there is a risk of not being able to do so, the fuel supply is forcibly reduced to reduce the combustion load, thereby keeping the total carbon dioxide emissions per unit time from the combustion furnace within the total carbon dioxide emission regulation value. It is an object of the present invention to provide a combustion control device that can perform the combustion control.

[0011]

In order to achieve the above object, according to the present invention, when supplying A fuel and B fuel having different carbon contents to a combustion furnace for combustion, A
When the carbon weight ratios contained in the fuel unit weight flow rates F _a and F _{b of the} fuel and the B fuel are R _ac and R _bc , respectively,
Predetermined fuel mixing ratio r _a of A fuel for the emissions F _c of carbon content,

[Number 2] is set to _{r a = (F c / (} F a + F b) -R bc) / (R ac -R bc) , characterized in that the control ... (1).

According to a second aspect of the present invention, a fuel control section for supplying and burning several kinds of fuels having different carbon contents to the combustion furnace and a total carbon dioxide emission per unit time discharged from the combustion furnace are estimated. By this estimation process, when the total carbon dioxide emission per unit time is likely to exceed the total carbon dioxide emission regulation value, the fuel control unit is controlled to select or mix the fuel with a low carbon content. A fuel ratio adjustment unit that changes the supply ratio of the various fuels to keep the total carbon dioxide emission per unit time discharged from the combustion furnace within the total carbon dioxide emission regulation value. I have.

According to a third aspect of the present invention, in the combustion control apparatus according to the second aspect, even if the fuel ratio adjusting section controls the fuel adjusting section to change the supply ratio of the various fuels, the fuel ratio is controlled from the combustion furnace. When the total amount of carbon dioxide emitted per unit time cannot be kept within the total carbon dioxide emission regulation value, the fuel supply amount is reduced to suppress the combustion load.

According to the first aspect of the present invention, when the fuel A and the fuel B having different carbon contents are supplied to the combustion furnace and burned, the fuel unit weight flow rate F of the fuel A and fuel B is determined.
_a, the carbon weight percentage contained respectively F _b R _ac,
When the R _bc, a fuel mixing ratio r _a of A fuel for a predetermined emissions F _c of carbon content (1) controlled by formula. With this, when the total emission regulation value of carbon dioxide that can be emitted from the combustion furnace within a certain period from the present time is specified, the mixing ratio of various fuels is adjusted to adjust the carbon dioxide emission from the combustion furnace. Keep total carbon emissions within specified total emission limits.

According to a second aspect of the present invention, there is provided a combustion control device for supplying fuel to a combustion furnace and burning the fuel to obtain necessary calories.
The fuel control unit estimates the total amount of carbon dioxide emitted per unit time from the combustion furnace while the fuel ratio control unit supplies and burns several types of fuels having different carbon contents to the combustion furnace. , This estimation process
When the total carbon dioxide emission per unit time may exceed the total carbon dioxide emission regulation value, control the fuel control unit to change the supply ratio of various fuels, and Total carbon dioxide emissions within the total carbon dioxide emission regulations. As a result, the total amount of carbon dioxide emitted per unit time from the combustion equipment per unit time is kept below a specified value set from the viewpoint of environmental regulations, while keeping the power generation cost low.

According to a third aspect, the fuel ratio adjusting section provides
If the total amount of carbon dioxide emitted per unit time from the combustion furnace cannot be controlled within the total carbon dioxide emission regulation value even if the fuel control unit is controlled and the supply ratio of various fuels is changed, The combustion load is suppressed by reducing the fuel supply amount. When the total amount of carbon dioxide emitted from the combustion furnace per unit time may not be within the total carbon dioxide emission regulation value even if the mixing ratio of various fuels supplied to the combustion furnace is adjusted, In addition, the fuel supply is forcibly reduced to suppress the combustion load, thereby keeping the total amount of carbon dioxide emitted from the combustion furnace per unit time within the total carbon dioxide emission regulation value.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS << First Embodiment >> FIG. 1 is a block diagram showing a first embodiment of a combustion control device according to the present invention.

The combustion control device 1 shown in FIG.
The fuel ratio adjusting unit 2 for calculating the fuel ratio of the B fuel, and the A fuel flow rate based on the fuel mixture ratio of the A fuel determined by the fuel ratio adjusting unit 2 (also referred to as “mixed combustion rate”) r _a . includes an a fuel control unit 3 for adjusting, and B fuel control unit 4 for adjusting the B fuel flow rate based on the mixing ratio (混燃baked ratio) 1-r _a B-fuel determined by the fuel ratio adjusting section 2, During a certain period based on the present time, the combustion control is performed in which the total amount of carbon dioxide emitted from the boiler is suppressed to a certain value.

The fuel ratio adjusting section 2 controls the total emission (carbon content ratio) F required to regulate the total amount of carbon in the carbon dioxide emitted from the boiler during a certain period from the present time.
a setter _{5 c} is set, the carbon content of the A fuel used in the boiler (carbon weight ratio) and the setting device 6 which R _ac is set, the carbon content of B fuel used by the boiler R _bc , The carbon content ratio F _c , the carbon content R _{ac of} the A fuel, the carbon content R _{bc of} the B fuel, and the A fuel adjustment unit which are set in the setting devices 5, 6, 7. a fuel was measured at 3 flow F _a, based on B B fuel measured by the fuel control unit 4 a flow rate F _b, a fuel valve opening r _a ', B fuel valve opening 100-
and a fuel ratio calculator 8 for calculating r _a ′.

[0020] Then, the carbon content ratio F _c set in the setting device 5, the carbon content R _ac of A fuel being set in the setting unit 6, carbon in B fuel being set in the setting device 7 The content R _bc and the A fuel flow rate F measured by the A fuel control unit 3
_a and, based on the B fuel control unit was measured at 4 B fuel flow rate F _b, seek A fuel valve opening r _a 'by the fuel ratio calculator 8 supplies it to the A fuel control unit 3, Based on the A fuel valve opening r _a ′, a B fuel valve opening 100−r _a ′ is obtained and supplied to the B fuel adjusting section 4.

[0021] In this case, the fuel ratio calculator 8, A fuel flow rate F _a and B fuel control unit 4 which is output from the A fuel control unit 3
By adding the B fuel flow rate F _b outputted from the total adder 9 to obtain the total fuel flow rate F _a + F _{b, A} fuel flow rate in the total fuel flow rate F _a + F _b output from the total adder 9 dividing the F _a, seek a fuel flow ratio _{F a / (F a + F} b), a divider 10 to output as the process value PV, total fuel flow rate F _a + F _b outputted from the total adder 9 And each setting device 5,
Based on the carbon content ratio F _c set to 6, 7 and the carbon content R _{ac of} the fuel A and the carbon content R _{bc of the} fuel B, the calculation shown in the following equation (1) is performed to perform the fuel flow rate A. Ratio setting value r
_a, and a mixing ratio calculator 11 that outputs this as a set value SV, and an A fuel flow ratio F output from the divider 10
_a / (F _a + F _b ) and A output from the mixing ratio calculator 11
Based on the difference between the fuel flow rate ratio set value r _a, and generates an A fuel valve opening r _a ', and the fuel flow ratio adjusting meter 12 and supplies it to A fuel control unit 3, the fuel flow ratio adjusting meter 12 Is provided with a subtractor 13 that obtains the B fuel valve opening 100-r _a ′ based on the A fuel valve opening ra _a ′ output from the controller and outputs the obtained B fuel valve opening to the B fuel adjusting unit 4.

[0022]

R _a = (F _c / (F _a + F _b ) −R _bc ) / (R _ac −R _bc ) (1) Here, the above equation (1) is derived as follows.

[0023] Now, a carbon content ratio _{F c = F a × R ac} + F b × R bc ... (2) A fuel flow ratio _{r a = F a / (F} a + F b) ... (3), F a + F placing a _b = F _t, (3) from the _{equation, F a = r a × (} F a + F b) = r a × F t ... (4) F b = F t -F a = F t -r a × F _t (5) By substituting equations (4) and (5) into equation (2),

F _c = r _a × F _t × R _ac + (F _t −r _a × F _t ) × R _bc = r _a × (F _t × R _ac −F _t × R _bc ) + F _t × R _bc … (6)

R _a = (F _c −F _t × R _bc ) / (F _t × R _ac −F _t × R _bc ) = (F _c / F _t −R _bc ) / (R _ac −R _bc ) ... (7) When _Ft in equation (7) is restored, equation (1) is obtained.

[0024] The A fuel adjusting section 3 is provided for the A fuel supplied to the boiler.
The fuel flow rate is measured, A fuel flow rate sensor 1 supplies A fuel flow rate F _a obtained by this measuring operation in the fuel ratio adjusting section 2
4 and the A fuel valve opening r output from the fuel ratio adjuster 2
_a ′ based on _a ′, and an A fuel flow rate adjusting valve 15 that adjusts the valve opening degree to adjust the A fuel flow rate supplied to the first burner of the boiler. the fuel flow rate was measured, based on the a fuel flow rate F _a obtained by this measurement operation while supplying the fuel ratio adjusting section 2, the a fuel valve opening r _a 'output from the fuel ratio adjusting section 2,
By adjusting the opening of the valve, the flow rate of the A fuel supplied to the first burner of the boiler is adjusted.

Further, B fuel control unit 4 measures the B fuel flow supplied to the boiler, and B fuel flow rate sensor 16 supplies the B fuel flow F _b obtained by this measuring operation in the fuel ratio adjusting section 2 , Based on the B fuel valve opening 100-r _a ′ output from the fuel ratio adjusting unit 2, adjusting the valve opening to adjust the B fuel flow supplied to the second burner of the boiler.
And a fuel flow rate control valve 17, measure the B fuel flow rate supplied to the second burner of the boiler, while supplying B fuel flow F _b obtained by this measuring operation in the fuel ratio adjusting section 2, the fuel B fuel valve opening 1 output from ratio adjuster 2
Based on 00-r _a ′, the opening degree of the valve is adjusted to adjust the flow rate of B fuel supplied to the second burner of the boiler.

[0026] Thus, in this embodiment, the carbon content ratio F _c set in the setting device 5, the carbon content R _ac of A fuel being set in the setting unit 6, the setting device 7 The set carbon content _{Rbc of the} B fuel and the A fuel adjustment unit 3
And A fuel flow rate F _a THAT measured, based on the B fuel control unit measured at 4 B-fuel flow rate F _b, seek A fuel valve opening r _a 'by the fuel ratio calculator 8, which A fuel It is supplied to the adjusting unit 3, with adjusting the a fuel flow, 'based on, B fuel valve opening 100-r _a' a fuel valve opening r _a seek, and supplies it to the B fuel control unit 4 Thus, the B fuel flow rate was adjusted. For this reason, when the carbon content ratio _{Fc, which} is the total emission control value of carbon dioxide that can be emitted from the boiler within a certain period based on the present time, is specified, the mixing ratio of the fuel A and the fuel B is changed. By adjusting the total amount of carbon dioxide emitted from the boiler within a certain period from the present time, it is possible to keep the total amount of carbon dioxide within the specified total emission regulation value.

<< Second Embodiment >> FIG. 2 is a block diagram showing a second embodiment of the combustion control device according to the present invention.

The combustion control device 21 shown in this figure measures the pressure of steam generated by a boiler (not shown) and, based on the measurement result, a control output value required to adjust the pressure of steam. Main steam pressure adjusting unit 22 that generates
And an air flow control unit that measures the flow rate of air supplied to the boiler, and adjusts the flow rate of air supplied to the boiler based on the measurement result and the control output value output from the main steam pressure control unit 22. 23, a fuel ratio adjusting unit 24 for calculating a fuel ratio of A fuel and B fuel used in the boiler, an A fuel mixed combustion rate (set value) r _asv determined by the fuel ratio adjusting unit 24, and main steam. Based on the control output value output from the pressure adjusting unit 22, the A fuel adjusting unit 25 that adjusts the A fuel flow supplied to the boiler, and the B fuel mixed combustion rate (set value) determined by the fuel ratio adjusting unit 24 B) a B fuel adjusting unit 2 that adjusts a B fuel flow rate supplied to the boiler based on 1-r _asv and a control output value output from the main steam pressure adjusting unit 22.
6 is provided. The combustion control device 21 controls the pressure of steam generated by the boiler, the flow rate of air supplied to the boiler, the flow rate of A fuel supplied to the boiler, the flow rate of B fuel supplied to the boiler, Based on the carbon dioxide emission regulation value (carbon equivalent total regulation value F _ck ), the carbon content R _ac of fuel A, and the carbon content R _{bc of} fuel B,
By adjusting the ratio of fuel A and fuel B, the amount of steam required for power generation is secured while keeping the amount of carbon dioxide emitted from the boiler within a specified value.

The main steam pressure adjusting section 22 has a main steam pressure sensor 27 for measuring the pressure of the steam generated by the boiler.
And a main output that generates a control output value required to generate steam at a required pressure based on a difference between a measurement result (steam pressure value) of the main steam pressure sensor and a main steam pressure set value required for power generation. A steam pressure controller 28 for measuring the pressure of the steam generated by the boiler,
Based on the difference from the main steam pressure set value required for power generation, a control output value required to generate steam at a required pressure is generated, and this is output to the air amount adjusting unit 23, the A fuel adjusting unit 25, The fuel is supplied to the B fuel adjusting unit 26.

The air flow rate adjusting unit 23 measures the flow rate of air supplied to the boiler, the measurement result (air flow rate measured value) of the air flow rate sensor 29, and the output from the main steam pressure adjusting unit 22. Based on the control output value
An air flow controller 30 that generates an air flow set value necessary to adjust the flow rate of air supplied to the boiler, and an air flow controller that is supplied to the boiler based on the air flow set value output from the air flow controller 30 An air flow controller 31 that adjusts the flow rate of the air to be supplied to the boiler, and measures the flow rate of the air supplied to the boiler. , The flow rate of the air supplied to the boiler is adjusted.

The fuel ratio adjusting unit 24 operates for a predetermined time T
Specified total amount of carbon corresponding to the total amount of carbon dioxide that can be released into the furnace (regulated value of total amount of carbon equivalent) F _ck
Setter but the setter 32 is set, the setter 33 that the carbon content R _ac of A fuel used is set in the boiler, the carbon content R _bc of B fuel used in the boiler is set 34, the amount of carbon equivalent amount regulation value is set to each setting device 32, 33, 34 F _ck, the carbon content of the a fuel R _ac, B
Based on the carbon content R _{bc of} the fuel, the A fuel flow rate F _a measured by the A fuel adjustment unit 25, and the B fuel flow rate F _b measured by the B fuel adjustment unit 26, the remaining time T−
combustible carbon flow rate F _csv to t, A fuel混燃sintered rate r _asv,
Fuel ratio calculator 35 for _obtaining B fuel mixed combustion rate 1- _rasv
And

[0032] Then, a carbon content corresponding total amount controlling value F _ck set in the setter 32, and the total carbon flow rate F _c contained in A fuel, B fuel is burned in the boiler up to the present time, a predetermined time T A fuel that can be burned in the remaining time T−t in the fixed time T by performing a calculation represented by the following formula based on the elapsed time t up to the present time based on the start time of the fixed time T and B The carbon flow rate _Fcsv contained in the fuel is determined.

[0033]

F _csv = (F _ck −F _c ) / (T−t) (8) Thereafter, the carbon flow rate F _csv obtained by the equation (8) is set in the setting unit 33. A carbon content R _{ac of} fuel A,
Carbon content R of B fuel set in setter 34
_bc and the A fuel flow rate F measured by the A fuel adjustment unit 25
_a and, based on the B fuel control unit 26 B-fuel flow rate F _b measured at, by performing a calculation shown in the following equation, A fuel混燃sintered rate r
seeking _asv, which supplies to the A fuel control unit 25, B fuel混燃sintered rate corresponding to the A fuel混燃sintered rate r _a 1-
R _asv is obtained and supplied to the B fuel adjustment unit 26. However, when the A fuel mixed combustion rate r _asv becomes a negative value,
As load (fuel flow rate), (at that time, the maximum flow rate that can be supplied) maximum range of the A fuel flow rate F _a Set, thereby limiting the flow of steam boiler, avoiding uncontrollable.

[0034]

Equation 7] _{r asv = {F csv / (} F a + F b) -R bc} / (R ac -R bc) ... (9) A fuel control unit 25 measures the A fuel flow supplied to the boiler and, outputs a fuel flow rate F _a obtained by this measuring operation with a fuel flow sensor 36 supplied to the fuel ratio adjusting unit 24, the control output value output from the main steam pressure adjusting section 22 and the fuel ratio adjusting unit 24 A multiplier 37 for multiplying the A fuel mixed combustion rate r _asv to obtain an A fuel set flow value to be supplied to the boiler, and an A fuel set flow value output from the multiplier 37 and an A fuel based on the difference between a fuel flow rate F _a which is output from the flow sensor 36, an a fuel adjusting meter 38 which generates a valve opening degree value, based on the valve opening value outputted from the a fuel adjusting meter 38, the valve Of the A fuel to be supplied to the first burner of the boiler by adjusting the opening of the boiler That A
And a fuel flow rate control valve 39, to measure A fuel flow supplied to the boiler, while supplying A fuel flow rate F _a obtained by this measuring operation in the fuel ratio adjusting unit 24, a main steam pressure control unit The control output value output from the fuel ratio adjustment unit 24 is multiplied by the A fuel mixed combustion rate r _asv output from the fuel ratio adjustment unit 24 to obtain the A fuel set flow rate value that must be supplied to the boiler. a set flow rate value, based on a difference between a fuel flow rate F _a, by adjusting the degree of opening of the valve, to adjust the a fuel flow rate supplied to the first burner of the boiler.

The B fuel adjusting section 26 measures the flow rate of B fuel supplied to the boiler, and obtains the B fuel obtained by this measuring operation.
Fuel flow rate F _b of the B fuel flow sensor 40 supplied to the fuel ratio adjusting unit 24, a main steam pressure control unit controls an output value outputted from the 22 and the fuel ratio adjusting unit B fuel混燃sintered rate output from the 24 1- a multiplier 41 for multiplying by R _asv to obtain a B fuel set flow rate value to be supplied to the boiler;
Based on the difference between the B fuel flow rate F _b output from the B fuel set flow rate value and B the fuel flow sensor 40 which is output from the multiplier 41, the B fuel adjusting meter 42 which generates a valve opening degree value, the B Based on the valve opening value output from the fuel controller 42,
A B fuel flow control valve 43 for adjusting the valve opening to adjust the B fuel flow supplied to the second burner of the boiler, and measuring the B fuel flow supplied to the boiler; fuel ratio adjusting unit 24 to obtain B fuel flow rate F _b in
_Must be multiplied by the control output value output from the main steam pressure adjusting unit 2 and the B-fuel mixed combustion rate 1- _rasv output from the fuel ratio adjusting unit 24 and supplied to the boiler. The B set fuel flow value is determined, and this B
The fuel flow rate setting value, based on the difference between the B fuel flow rate F _b, by adjusting the degree of opening of the valve, to adjust the B fuel flow rate supplied to the boiler the second burner.

As a result, as shown in FIG. 3, the total carbon amount regulation value _Fck is set,
Is set, the fuel A and the fuel B are continuously supplied to the boiler at the current flow ratio at the time when the time t has elapsed with reference to the start time of the fixed time T, and the remaining time T when the -t has elapsed, when the emissions of carbon is expected to exceed the amount of carbon equivalent amount regulation value F _ck, by changing the a fuel flow rate F _a, the ratio of B fuel flow rate F _b In addition, the amount of carbon contained in the carbon dioxide discharged from the boiler is suppressed so that the amount does not exceed the total carbon amount regulation value _Fck .

Thus, in this embodiment,
Pressure of steam generated by the boiler, flow rate of air supplied to the boiler, flow rate of A fuel supplied to the boiler, flow rate of B fuel supplied to the boiler, and a regulated value of carbon dioxide emission within a certain period of time (Carbon equivalent total regulation value F _ck )
Based on the carbon content R _ac of the fuel and the carbon content R _bc of the B fuel, the ratio between the A fuel and the B fuel is adjusted so that the amount of carbon dioxide emitted from the boiler falls within a specified value. While keeping it, the amount of steam required for power generation was secured.
For this reason, preferentially use fuels with low carbon dioxide emissions (cheap fuels), such as coal, within the regulation value,
While lowering the power generation cost, the amount of carbon contained in the carbon dioxide emitted from the boiler can be _adjusted to the total carbon regulation value F _ck
Only when there is a risk of exceeding the limit, while using less fuel such as natural gas and other fuels (expensive fuels), reduce the amount of coal used, and reduce the amount of carbon dioxide emitted from the boiler. Can be prevented from _{exceeding the} carbon amount equivalent total amount regulation value _Fck (effect of claim 2).

Further, in this embodiment, (9) when A fuel混燃sintered rate r _asv that obtained is a negative value by type, as the load (fuel flow rate), the maximum range of the A fuel flow rate F _a (At this time, the maximum flow rate that can be supplied) is set, thereby limiting the steam flow rate of the boiler and avoiding uncontrollability.
Even if the mixing ratio between the fuel and the B fuel is adjusted, the remaining time T
At −t, when there is a possibility that the total amount of carbon dioxide emitted from the boiler cannot be kept within the total carbon dioxide emission regulation value, the supply amount of fuel is forcibly reduced,
The combustion load can be suppressed, whereby the total amount of carbon dioxide emitted from the boiler can be kept within the total carbon dioxide emission regulation value (effect of claim 3).

[0039]

As described above, according to the present invention, in the combustion control apparatus according to the first aspect, the total amount of carbon dioxide discharged from the combustion furnace within a certain period from the present time is specified. It can be kept within the total emission regulation value.

In the combustion control device according to the second aspect, the total amount of carbon dioxide emitted from the combustion equipment per fixed time is kept to a specified value or less from the viewpoint of environmental regulations while keeping the power generation cost low. Can be.

According to the third aspect of the present invention, the total amount of carbon dioxide discharged per unit time from the combustion furnace does not exceed the total carbon dioxide emission regulation value even when the mixing ratio of various fuels supplied to the combustion furnace is adjusted. When it may not be possible to control the total amount of carbon dioxide per unit time, the amount of fuel supply is forcibly reduced to reduce the combustion load, thereby reducing the total amount of carbon dioxide emitted from the combustion furnace per unit time. It can be within the value.

[Brief description of the drawings]

FIG. 1 is a partial block diagram illustrating an embodiment of a combustion control device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the combustion control device according to the present invention.

FIG. 3 is an explanatory diagram showing an operation example of the combustion control device shown in FIG. 2;

[Explanation of symbols]

 1, 21: Combustion control device 2, 24: Fuel ratio adjustment unit 3, 25: A fuel adjustment unit 4, 26 ... B fuel adjustment unit 5, 6, 7, 32, 33, 34: Setting device 8, 35: Fuel Ratio calculator 9 Total adder 10 Divider 11 Mixing ratio calculator 12 Fuel flow ratio controller 13 Subtractor 14, 36 A fuel flow sensor 15, 39 A fuel flow control valve 16, 40 B fuel flow sensor 17, 43 B fuel flow control valve 22 main steam pressure control unit 23 air volume control unit 27 main steam pressure sensor 28 main steam pressure controller 29 air flow sensor 30 air flow controller 31 ... Air flow controller 37, 41 ... Multiplier 38 ... A fuel controller 42 ... B fuel controller

Claims (3)

[Claims] 1. When supplying an A fuel and a B fuel having different carbon contents to a combustion furnace and burning them, the fuel unit weight flow rates F _a and F _{b of the} A fuel and the B fuel are respectively specified. carbon weight ratio R _ac included, when the R _bc, a fuel mixing ratio r _a of the a fuel for a predetermined emissions F _c of carbon content, Equation 1] r _a = (F _c / (F _a + F _b ) −R _bc ) / (R _ac −R _bc ) (1) 2. A fuel control unit for supplying and burning several types of fuels having different carbon contents to a combustion furnace, and estimating a total carbon dioxide emission per unit time emitted from the combustion furnace, and When there is a possibility that the total carbon dioxide emission per unit time exceeds the total carbon dioxide emission regulation value by the processing, the fuel control unit is controlled to select or mix the fuel having a low carbon content. A fuel ratio adjusting unit that changes a fuel supply ratio and keeps a total carbon dioxide emission per unit time discharged from the combustion furnace within a total carbon dioxide emission regulation value. Control device. 3. The combustion control device according to claim 2, wherein the fuel ratio adjustment unit is discharged from the combustion furnace even when the fuel ratio adjustment unit controls the fuel adjustment unit to change the supply ratio of the various fuels. A combustion control device characterized in that when the total carbon dioxide emission per unit time cannot be within the total carbon dioxide emission regulation value, the fuel supply is reduced to suppress the combustion load.