JP2023108773A - Boiler controller, boiler control method and program - Google Patents

Abstract

To prevent an advance control signal based on a previous load change from being a disturbance to realize stable operation when performing next load change after a changing load reaches a target load value.SOLUTION: A boiler controller comprises an advance control signal generation unit, and an advance control signal adjustment unit. The advance control signal generation unit generates an advance control signal for a boiler based on change of a load of the boiler. The advance control signal adjustment unit adjusts the advance control signal so that the advance control signal becomes zero when the load reaches a target load value.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a boiler control device, a boiler control method, and a program.

A thermal power plant uses a boiler that burns fuel to generate steam for driving a generator. Boilers in thermal power plants are basically operated at the rated output in the conventional base operation. For example, during times of low power demand such as nighttime, the operating state is changed to reduce the load. This adjusts the output.

The load change in such conventional boiler control is unidirectional toward the target load. A prior control signal (BIR: Boiler Input Ratio) may be input to control parameters such as the amount of fuel input and the amount of superheater spray in response to load changes that are occurring (for example, Patent Document 1).

Japanese Patent No. 5970368

The input amount of the advance control signal is determined, for example, by a load change test performed during trial operation of the boiler. The advance control signal is input, for example, at the start of the boiler load change, reaches a target value at a predetermined change rate, and is adjusted to gradually decrease to zero after the load change is completed. However, for example, after the load change is completed, if the next load change is performed before the advance control signal decreases to zero, the remaining advance control signal acts as a disturbance, and the boiler operating state becomes unstable. It may become stable.

In recent years, thermal power plants equipped with boilers are expected to play a role in adjusting fluctuations in the amount of power generated from renewable energy, which tends to fluctuate in the power supply system. In such applications, load changes increase in the boiler, so it is thought that the chances of the above-described problems occurring will also increase.

At least one embodiment of the present disclosure has been made in view of the above circumstances, and when performing the next load change after the changing load reaches the target load value, the preceding control signal based on the previous load change is It is an object of the present invention to provide a boiler control device, a boiler control method, and a program capable of realizing stable operation by preventing disturbance.

A boiler control device according to at least one embodiment of the present disclosure, in order to solve the above problems,
an advance control signal generator for generating an advance control signal for the boiler based on changes in boiler load;
an advance control signal adjuster for adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value.

In order to solve the above problems, the boiler control method according to at least one embodiment of the present disclosure includes:
generating an advance control signal for the boiler based on changes in boiler load;
and adjusting the advance control signal such that the advance control signal becomes zero when the load reaches a target load value.

A program according to at least one embodiment of the present disclosure, in order to solve the above problems,
using a computer
generating an advance control signal for the boiler based on changes in boiler load;
and adjusting the advance control signal such that the advance control signal is zero when the load reaches a target load value.

According to at least one embodiment of the present disclosure, when the next load change is performed after the changing load reaches the target load value, the preceding control signal based on the previous load change is prevented from becoming a disturbance. By doing so, it is possible to provide a boiler control device, a boiler control method, and a program capable of realizing stable operation.

1 is a schematic configuration diagram of a boiler according to one embodiment; FIG. It is a block diagram which shows the hardware constitutions of the boiler control apparatus which concerns on one Embodiment. It is a block diagram which shows the functional structure of the boiler control apparatus which concerns on one Embodiment. FIG. 4 is a control flow diagram of the preceding control signal generator in FIG. 3; FIG. 4 is a control flow diagram of the preceding control signal adjustment unit in FIG. 3; FIG. 10 is a diagram showing a typical advance control signal transition in a load change when the boiler load increases. 5 is a graph showing transition of a preceding control signal accompanying load change in the embodiment.

Several embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiment or shown in the drawings are not meant to limit the scope of the present disclosure, but are merely illustrative examples. do not have.

First, a boiler to be controlled by a boiler control device according to some embodiments of the present disclosure will be described. FIG. 1 is a schematic configuration diagram of a boiler 10 according to one embodiment.

The boiler 10 is a boiler that can generate superheated steam by burning pulverized fuel obtained by pulverizing solid fuel, which is the main fuel, with a burner and exchanging heat generated by this combustion with feed water or steam. Biomass fuel, coal, or the like is used as the solid fuel.

The boiler 10 has a furnace 11 , a combustion device 20 and a combustion gas passage 12 . The furnace 11 has a hollow rectangular shape and is installed along the vertical direction. The furnace wall 101, which constitutes the inner wall surface of the furnace 11, is composed of a plurality of heat transfer tubes and fins connecting the heat transfer tubes. While exchanging heat with steam and recovering it, the temperature rise of the furnace wall 101 is suppressed.

Combustion device 20 is installed in the lower region of furnace 11 . In this embodiment, the combustion device 20 has a plurality of burners 21A, 21B, 21C, 21D, 21E, and 21F (hereinafter collectively referred to as "burners 21") attached to the furnace wall 101. The burners 21 are arranged at regular intervals along the circumferential direction of the furnace 11 (for example, four burners installed at each corner of the rectangular furnace 11) as one set, and a plurality of stages are arranged along the vertical direction. are placed.

In FIG. 1, for convenience of illustration, only two burners out of one set are shown, and each set is denoted by 21A, 21B, 21C, 21D, 21E, and 21F. The shape of the furnace, the number of stages of burners, the number of burners in one stage, the arrangement of burners, etc. are not limited to this embodiment.

The burners 21A, 21B, 21C, 21D, 21E, and 21F are supplied via a plurality of finely divided fuel supply pipes 22A, 22B, 22C, 22D, 22E, and 22F (hereinafter collectively referred to as “finely divided fuel supply pipes 22”), respectively. are connected to a plurality of mills (pulverizers) 31A, 31B, 31C, 31D, 31E, and 31F (hereinafter collectively referred to as "mills 31"). The mill 31 has, for example, a crushing table (not shown) supported therein so as to be driven and rotatable, and a plurality of crushing rollers (not shown) above the crushing table so as to be rotatable in conjunction with the rotation of the crushing table. It is a configured vertical roller mill. The solid fuel pulverized by the cooperation of the pulverizing roller and the pulverizing table is conveyed to a classifier (not shown) provided in the mill 31 by primary air (carrier gas, oxidizing gas) supplied to the mill 31. . In the classifier, the fuel is classified into fine powder fuel having a particle size smaller than that suitable for combustion in the burner 21 and coarse powder fuel having a particle size larger than the particle size. The pulverized fuel passes through a classifier and is supplied to the burner 21 through the pulverized fuel supply pipe 22 together with primary air. Coarse fuel that has not passed through the classifier falls on the grinding table by its own weight inside the mill 31 and is ground again.

An air box (air register) 23 is provided outside the furnace 11 at the mounting position of the burner 21 , and one end of an air duct (air duct) 24 is connected to the air box 23 . A forced draft fan (FDF) 32 is connected to the other end of the air duct 24 . The air supplied from the forced draft fan 32 is heated by an air preheater 42 installed in the wind duct 24 and supplied to the burner 21 via the wind box 23 as secondary air (combustion air, oxidizing gas). , is thrown into the furnace 11 .

The combustion gas passage 12 is connected to the upper portion of the furnace 11 in the vertical direction. The combustion gas passage 12 includes superheaters 102A, 102B, and 102C (hereinafter collectively referred to as "superheaters 102"), reheaters 103A, 103B (hereinafter, heat exchangers for recovering the heat of the combustion gas). , appropriately collectively referred to as "reheater 103") and economizer 104 are provided, and heat exchange is performed between the combustion gas generated in the furnace 11 and the feedwater or steam flowing inside each heat exchanger. done.
The arrangement and shape of each heat exchanger are not limited to the form shown in FIG.

A flue 13 is connected to the downstream side of the combustion gas passage 12, through which the combustion gas whose heat is recovered by the heat exchanger is discharged. An air preheater (air heater) 42 is provided between the flue 13 and the flue 24, and heat exchange is performed between the air flowing through the flue 24 and the combustion gas flowing through the flue 13, By heating the primary air supplied to the mill 31 and the secondary air supplied to the burner 21, further heat is recovered from the combustion gas after heat exchange with water or steam.

A denitrification device 43 may be provided in the flue 13 at a position upstream of the air preheater 42 . The denitrification device 43 supplies a reducing agent, such as ammonia and urea water, which has the action of reducing nitrogen oxides, to the combustion gas flowing through the flue 13, and removes nitrogen oxides in the combustion gas supplied with the reducing agent. By promoting the reaction between (NOx) and the reducing agent by the catalytic action of the denitration catalyst installed in the denitration device 43, nitrogen oxides in the combustion gas are removed and reduced.

A gas duct 41 is connected to the downstream side of the air preheater 42 in the flue 13 . The gas duct 41 is provided with environmental equipment such as a dust collector 44 such as an electric dust collector for removing ash and the like in the combustion gas, a desulfurizer 46 for removing sulfur oxides, etc., and for guiding the exhaust gas to these environmental equipment. An induced draft fan (IDF: Induced Draft Fan) 45 is provided. The downstream end of the gas duct 41 is connected to a chimney 47, and the combustion gas treated by the environmental device is discharged out of the system as exhaust gas.

In the boiler 10 , when the plurality of mills 31 are driven, pulverized and classified pulverized fuel is supplied to the burner 21 through the pulverized fuel supply pipe 22 together with primary air. Also, the secondary air heated by the air preheater 42 is supplied to the burner 21 from the wind duct 24 via the wind box 23 . The burner 21 blows into the furnace 11 a pulverized fuel mixture in which pulverized fuel and primary air are mixed, and also blows secondary air into the furnace 11 . The pulverized fuel mixture blown into the furnace 11 is ignited and reacts with secondary air to form a flame. A flame is formed in the lower region within the furnace 11 , and hot combustion gases rise within the furnace 11 and flow into the combustion gas passage 12 .
In this embodiment, air is used as the oxidizing gas (primary air, secondary air). Stable combustion is achieved in the furnace 11 by adjusting the ratio of the amounts to within an appropriate range.

The combustion gas flowing into the combustion gas passage 12 exchanges heat with water and steam in the superheater 102, the reheater 103, and the economizer 104 arranged inside the combustion gas passage 12, and then is discharged to the flue 13. , Nitrogen oxides are removed by the denitrification device 43, heat exchanged with primary air and secondary air by the air preheater 42, and then discharged to the gas duct 41, ash etc. are removed by the dust collector 44, and desulfurization device 46 After the sulfur oxides are removed at , they are discharged from the stack 47 to the outside of the system.
The arrangement of each heat exchanger in the combustion gas passage 12 and each device in the flue 13 to the gas duct 41 does not necessarily have to be arranged in the order described above with respect to the combustion gas flow.

Next, the boiler control device 100 that controls the boiler 10 having the above configuration will be described. FIG. 2 is a block diagram showing the hardware configuration of the boiler control device 100 according to one embodiment.

The boiler control device 100 is configured as an arithmetic processing device such as a computer, for example. The hardware configuration of the boiler control device 100 includes an input section 110, a storage section 120, a calculation section 130, and an output section 140, as illustrated in FIG.

The input unit 110 is configured to input various information necessary for arithmetic processing performed in the boiler control device 100 . The input unit 110 may be a human interface such as a mouse, keyboard, and touch panel that can be operated by an operator, or an interface device for acquiring various information from other devices including the boiler 10 to be controlled. .

The storage unit 120 is configured to store various information necessary for arithmetic processing performed in the boiler control device 100 . The storage unit 120 is composed of a computer-readable storage medium including at least one of RAM (Random Access Memory) and ROM (Read Only Memory). The various information stored in the storage unit 120 includes programs for these hardware configurations to function as the boiler control device 100 .

The computation unit 130 is a component for performing various computations of the boiler control device 100, and includes, for example, a CPU (Central Processing Unit). The calculation unit 130 reads out the program stored in the storage unit 120 to a RAM or the like and executes information processing/calculation processing, thereby realizing various functions of the boiler control device 100 .

The program executed by the computing unit 130 may be stored in the storage unit 120 as described above, may be installed in advance in a ROM or other storage medium, or may be stored in a computer-readable storage medium. may be provided in a state of being stored in a storage medium, or may be distributed via wired or wireless communication means. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, and the like.

The output unit 140 is configured to output based on the calculation result of the calculation unit 130 . In this embodiment, the output unit 140 outputs a control signal for the boiler 10 to be controlled as the output of the boiler control device 100 . By receiving the control signal, the boiler 10 is controlled based on the control signal.

In addition to outputting a control signal to the boiler 10 to be controlled, the output unit 140 also displays, for example, a display for the operator to recognize the calculation result, and a display for notifying an alarm according to the calculation result. A human interface such as notification means may be included.

Next, a functional configuration of the boiler control device 100 will be described. FIG. 3 is a block diagram showing the functional configuration of the boiler control device 100 according to one embodiment. The boiler control device 100 includes a control section 150 , a preceding control signal generating section 160 and a preceding control signal adjusting section 170 .
Note that the block diagram shown in FIG. 3 is an example showing the functional configuration of the boiler control device 100 so as to correspond to the following description, and each block may be integrated with each other or further subdivided. may

The control unit 150 is configured to control the boiler 10 by generating control signals corresponding to control parameters to be controlled based on input parameters relating to the operating state of the boiler 10 .

The preceding control signal generation unit 160 is a configuration for generating a preceding control signal (BIR: Boiler Input Ratio) for the control signal handled by the control unit 150 . The advance control signal BIR is generated based on information about changes in the load on the boiler, which is known in advance, so that the operating state of the boiler changes due to excessive or insufficient transient boiler input (fuel supply amount, etc.) toward the target load. This is to prevent instability. In this embodiment, as an example, the preceding control signal BIR is generated based on a load index corresponding to the load of the boiler, a load change rate, and a load change width.

The preceding control signal adjustment unit 170 is configured to adjust the preceding control signal so that it gradually becomes zero when the load of the boiler 10 changes and reaches a target load value. In this embodiment, as will be described later in detail, the advance control signal adjuster 170 adjusts the advance control signal so that the advance control signal becomes zero when the load of the boiler 10 reaches the target load value.

Next, details of the control performed by the preceding control signal generating section 160 and the preceding control signal adjusting section 170 will be described with reference to FIGS. 4 and 5. FIG. 4 is a control flow chart of the preceding control signal generator 160 of FIG. 3, and FIG. 5 is a control flow chart of the preceding control signal adjusting section 170 of FIG.

First, as shown in FIG. 4, in the preceding control signal generation unit 160, as input parameters, a load index indicating the load of the boiler, a load change rate indicating the speed of load change, and a difference in the boiler load before and after the load change. Precedence control signal BIR is generated by inputting each load change width. The behavior of the advance control signal BIR is specified by the target value BIRt corresponding to the boiler load change and the BIR change rate.

Referring now to FIG. 6, the behavior of a typical advance control signal BIR will be described. FIG. 6 is a diagram showing a typical transition of the preceding control signal BIR in load changes when the load of the boiler 10 increases.

FIG. 6 shows a case where the boiler load, which is the initial value L1, starts increasing at time t1 and increases to reach the target value L2 at time t2. At this time, the preceding control signal BIR starts increasing at time t1 according to a first change rate R1 (constant value) preset as a change rate at the time of increase, and changes so as to reach the target value BIRt at time t3. . Typically, time t3 is before time t2, and the preceding control signal BIR, which reaches target value BIRt at time t3, is maintained constant until time t2 when the boiler load change ends. When the boiler load change ends at time t2, the preceding control signal BIR is gradually decreased from the target value BIRt to zero according to a second change rate R2 (constant value) preset as a change rate at the time of decrease. As a result, the preceding control signal BIR becomes zero (initial value) at time t4.

Returning to FIG. 4, in the preceding control signal generator 160, the load index, load change rate, and load change width, which are input parameters, are input to functions fx1, fx2, and fx3, respectively, and the respective outputs are multiplied. , the target value BIRt of the preceding control signal BIR is obtained.

Further, in the preceding control signal generator 160, the load index, which is an input parameter, is input to the functions fx4 and fx5, respectively, and the first change rate R1 and the second change rate R2 are obtained based on the respective calculation results. Based on the target value BIRt, the first change rate R1, and the second change rate R2 of the preceding control signal BIR thus calculated, the preceding control signal generation unit 160 is exemplarily described with reference to FIG. The preceding control signal BIR is generated such that the behavior of the preceding control signal BIR is realized.

In the present embodiment, when receiving the adjustment signal output from the advance control signal adjuster 170, the advance control signal generator 160 starts adjusting the value of the advance control signal BIR to zero at the second change rate R2. do.

Further, the preceding control signal generation unit 160 includes a switch 162 for outputting either the calculation result of the functions fx1, fx2, fx3 or the default value (zero) as the target value BIRt of the preceding control signal. Accordingly, when the adjustment signal is output from the preceding control signal adjusting section 170 as described later, the switching section 162 fixes the target value BIRt of the preceding control signal to the default value (zero). Further, when the adjustment signal is output from the preceding control signal adjusting section 170, the switching section 166 outputs the preceding control signal BIR amount immediately before the adjustment is started (before the start of adjustment). This BIR amount (before the start of adjustment) is used to calculate the required adjustment time, as will be described later.

The preceding control signal generation unit 160 fixes the preceding control signal adjusted by the preceding control signal adjusting unit 170 to zero until the load reaches the target load or changes to the next. As a result, the advance control signal corresponding to the previous load change does not more accurately disturb the boiler control for the next load change, and stable operation can be realized.

Subsequently, as shown in FIG. 5 , the preceding control signal adjuster 170 includes an adjustment required time calculator 172 , a load change amount calculator 174 , an adjustment start load value calculator 176 , and an adjustment start timing determiner 178 .

Based on the magnitude (current value) of the preceding control signal BIR and the BIR change rate, the adjustment required time calculation unit 172 calculates the time (adjustment required time Tn) required to change the preceding control signal BIR from the current value to zero. It is a configuration for calculating Specifically, the adjustment required time calculation unit 172 divides the BIR amount (before adjustment start), which is the magnitude of the preceding control signal BIR at the present time, by the adjustment rate, which is the change rate of the BIR, so that the preceding control signal A necessary adjustment time Tn for changing the BIR amount to zero is calculated.

The change rate (adjustment rate) of the preceding control signal BIR during adjustment is selected from the above-described first change rate R1 or second change rate R2 based on the state of load change corresponding to the preceding control signal BIR. . For example, as shown in FIG. 6, when it is desired to increase the preceding control signal BIR such as when the load is to be increased, the first change rate R1 corresponding to the increasing direction is selected as the change rate (adjustment rate) during adjustment. be done. On the other hand, when it is desired to decrease the preceding control signal BIR, such as after reaching the target load value or about to reach the target load value described later, the second change rate R2 corresponding to the decreasing direction is the change rate during adjustment (adjustment rate ).

The load change amount calculator 174 is configured to calculate the load change amount Ln of the boiler 10 during adjustment of the preceding control signal BIR based on the adjustment required time Tn and the boiler load change rate. The load change amount calculation unit 174 acquires the load change rate during the load change of the boiler 10, and determines how much the load of the boiler 10 changes during the required adjustment time Tn calculated by the required adjustment time calculation unit 172. is calculated. For example, when the load change rate is constant, the load change amount calculator 174 calculates the load change amount Ln by multiplying the load change rate by the adjustment required time Tn.

The adjustment start load value calculator 176 is configured to calculate an adjustment start load value Lm at which adjustment of the preceding control signal BIR should be started. Specifically, the adjustment start load value calculation unit 176 acquires the target load value L2 of the boiler 10, and subtracts the load change amount Ln calculated by the load change amount calculation unit 174 from the target load value L2. , to calculate the adjustment start load value Lm.

The adjustment start timing determining section 178 is a component for determining the timing for starting adjustment control with respect to the advance control signal. Specifically, the adjustment start timing determination unit 178 monitors the load of the boiler 10, and sets the time when the load reaches the adjustment start load value Lm calculated by the adjustment start load value calculation unit 176 as the adjustment start timing. decide. At the adjustment start timing determined by the adjustment start timing determination unit 178, the advance control signal adjustment unit 170 starts adjustment control of the advance control signal generation unit 160 on condition that the load change width is equal to or greater than a predetermined value. do. As a result, the advance control signal BIR is adjusted to zero at the timing when the load of the boiler 10 reaches the target load value L2.

Here, with reference to FIGS. 6 and 7, the adjustment control of the preceding control signal in the preceding control signal adjusting section 170 will be specifically described. FIG. 6 is a graph showing the transition of the preceding control signal accompanying load changes in a typical example. FIG. 7 is a graph showing the transition of the preceding control signal accompanying the load change in this embodiment.

In the typical example shown in FIG. 6, input of the preceding control signal BIR is started at time t1 when the load of the boiler 10 starts to change, and the preceding control signal BIR changes at a preset first change rate as the load increases. Increase with R1. When the advance control signal BIR reaches the preset target value BIRt at time t3, it is kept constant while the boiler load is changing. Thereafter, when the load of the boiler 10 reaches the target load value L2 at time t2, the preceding control signal BIR decreases at the second rate of change R2 and is adjusted to reach zero at time t4.

Thus, in the typical example shown in FIG. 6, after the time t2 when the load change of the boiler 10 is completed, the preceding control signal BIR remains not a little until the time t4. Therefore, when the next load change is performed before the preceding control signal BIR becomes zero (that is, between times t2 and t4), the remaining preceding control signal BIR affects as a disturbance, and the operating state of the boiler 10 changes. It may become unstable.

In FIG. 7, similarly to FIG. 6 described above, the load of the boiler 10 at the initial load value L1 starts to change at time t1, increases at a constant rate of change, and then reaches the target load value L2 at time t2. Behavior of the preceding control signal is shown. As shown in FIG. 7, this embodiment is similar to the typical example of FIG. 6 in that when the load change starts at time t1, the preceding control signal BIR also increases as the load rises. The adjustment of the preceding control signal BIR is started at the adjustment rate (second change rate R2) from the adjustment start timing t5 before the time t2. As a result, since the preceding control signal BIR reaches zero at the time t2 when the load change is completed, even when the next load change is performed after the time t2, there is no remaining preceding control signal BIR, which affects it as a disturbance. Therefore, a stable operating state of the boiler 10 can be realized.

As described above, according to the above embodiment, the preceding control signal BIR generated when the load of the boiler 10 changes toward the target load value L2 becomes zero when the load reaches the target load value L2. adjusted to be As a result, even when the next load change is performed after the load reaches the target load value L2, since the preceding control signal BIR corresponding to the previous load change is zero, the boiler control for the next load change is performed. Therefore, stable operation can be realized.

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the scope of the present disclosure, and the above-described embodiments may be combined as appropriate.

The contents described in each of the above embodiments are understood as follows, for example.

(1) A boiler control device (100) according to one aspect,
a forward control signal generator (160) for generating a forward control signal (BIR) for the boiler based on changes in the load of the boiler (10);
an advance control signal adjuster (170) for adjusting the advance control signal such that the advance control signal becomes zero when the load reaches a target load value.

According to the aspect (1) above, the advance control signal generated in response to the load change of the boiler is adjusted so as to become zero when the load reaches the target load value. As a result, even when the next load change occurs after the load reaches the target load value, the preceding control signal corresponding to the previous load change is zero, so the boiler control for the next load change is Stable operation can be realized without disturbance.
Note that the boiler load change broadly means information related to the boiler load change, and is a concept including, for example, a load index, a load change rate, and a load change width.

(2) In another aspect, in the aspect of (1) above,
The advance control signal adjuster is configured to adjust the advance control signal at a substantially constant adjustment rate from an adjustment start timing before the target load value is reached.

According to the above aspect (2), by setting the adjustment start timing of the advance control signal before the load change of the boiler reaches the target load value, the advance control signal is adjusted to a certain degree from the adjustment start timing. By being adjusted at the rate, the advance control signal can be adjusted to zero exactly at the timing when the load reaches the target load value.

(3) In another aspect, in the aspect of (2) above,
an adjustment required time calculation unit (172) for calculating an adjustment required time (Tn) for adjusting the preceding control signal to zero;
a load change amount calculator (174) that calculates the load change amount (Ln) during adjustment of the preceding control signal;
an adjustment start load value calculator (176) that calculates an adjustment start load value (Lm) at which adjustment of the preceding control signal should be started;
an adjustment start timing determination unit (178) that determines when the load reaches the adjustment start load value as the adjustment start timing;
Prepare.

According to the above aspect (3), by determining the adjustment start timing, it is possible to suitably adjust the advance control signal so that the advance control signal becomes zero when the load reaches the target load value.

(4) In another aspect, in the aspect of (3) above,
The adjustment required time calculation unit calculates the adjustment required time based on the magnitude of the preceding control signal and the adjustment rate.

According to the aspect (4) above, it is possible to calculate the necessary adjustment time required to adjust the advance control signal to zero based on the magnitude and adjustment rate of the advance control signal.

(5) In another aspect, in the above (3) or (4) aspect,
The load change amount calculation unit calculates the load change amount based on the adjustment required time and the load change rate.

According to the aspect (5) above, it is possible to calculate the amount of change in load while the load is being adjusted, based on the time required for adjustment and the load change rate of the boiler.

(6) In another aspect, in any one aspect of (3) to (5) above,
The adjustment start load value calculation unit calculates the adjustment start load value based on the target load value and the load change amount.

According to the above aspect (6), it is possible to calculate the adjustment start load value at which adjustment should be started based on the target load value and the amount of load change in the load change of the boiler.

(7) In another aspect, in any one aspect of (1) to (6) above,
The preceding control signal adjustment unit fixes the preceding control signal after adjustment to zero until the load reaches a target load or changes to the next.

According to aspect (7) above, the advance control signal is maintained at zero until the target load is reached or the next load change occurs. As a result, the advance control signal corresponding to the previous load change does not more accurately disturb the boiler control for the next load change, and stable operation can be realized.

(8) A boiler control method according to one aspect includes:
generating an advance control signal (BIR) for a control parameter of the boiler based on changes in the load of the boiler (10);
adjusting the advance control signal so that the advance control signal is zero when the load reaches a target load value;
Prepare.

According to the aspect (8) above, the advance control signal generated in response to the boiler load change is adjusted so as to become zero when the load reaches the target load value. As a result, even when the next load change occurs after the load reaches the target load value, the advance control signal corresponding to the previous load change is zero, so the boiler control for the next load change is Stable operation can be realized without disturbance.

(9) A program according to one aspect comprises:
using a computer
generating an advance control signal (BIR) for a control parameter of the boiler based on changes in the load of the boiler (10);
adjusting the advance control signal such that the advance control signal is zero when the load reaches the target load value;
is executable.

According to the aspect (9) above, the advance control signal generated in response to the boiler load change is adjusted to be zero when the load reaches the target load value. As a result, even when the next load change occurs after the load reaches the target load value, the preceding control signal corresponding to the previous load change is zero, so the boiler control for the next load change is Stable operation can be realized without disturbance.

10 Boiler 11 Furnace 12 Combustion gas passage 13 Flue 20 Combustion device 21 Burner 22 Pulverized fuel supply pipe 23 Wind box 24 Air duct 31 Mill 32 Forced draft fan 41 Gas duct 42 Air preheater 43 Denitration device 44 Dust collector 46 Desulfurization device 47 Chimney 100 Boiler control device 101 Furnace wall 102 Superheater 103 Reheater 104 Economizer 110 Input unit 120 Storage unit 130 Calculation unit 140 Output unit 150 Control unit 160 Advance control signal generation units 162, 166 Switch 170 Advance control signal adjustment Section 172 Adjustment Required Time Calculation Section 174 Load Change Amount Calculation Section 176 Adjustment Start Load Value Calculation Section 178 Adjustment Start Timing Determination Section

Claims (9)

an advance control signal generator for generating an advance control signal for the boiler based on changes in boiler load;
A boiler control device, comprising: a pre-control signal adjuster for adjusting the pre-control signal so that the pre-control signal becomes zero when the load reaches a target load value. 2. The boiler control apparatus according to claim 1, wherein said advance control signal adjuster is configured to adjust said advance control signal at a substantially constant adjustment rate from an adjustment start timing before said target load value is reached. an adjustment required time calculation unit that calculates an adjustment required time for adjusting the preceding control signal to zero;
a load change amount calculation unit that calculates a load change amount during adjustment of the preceding control signal;
an adjustment start load value calculation unit for calculating an adjustment start load value at which adjustment of the preceding control signal should be started;
an adjustment start timing determination unit that determines when the load reaches the adjustment start load value as the adjustment start timing;
3. The boiler control system of claim 2, comprising: 4. The boiler control device according to claim 3, wherein said required adjustment time calculation unit calculates said required adjustment time based on the magnitude of said preceding control signal and said adjustment rate. The boiler control device according to claim 3 or 4, wherein the load change amount calculation unit calculates the load change amount based on the adjustment required time and the load change rate. The boiler control device according to any one of claims 3 to 5, wherein the adjustment start load value calculation unit calculates the adjustment start load value based on the target load value and the load change amount. The boiler control according to any one of claims 1 to 6, wherein the advanced control signal adjustment unit fixes the adjusted advanced control signal to zero until the load reaches a target load or changes next. Device. generating an advance control signal for the boiler based on changes in boiler load;
and adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value. using a computer
generating an advance control signal for the boiler based on changes in boiler load;
and adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value.

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