Boiler control device, boiler control method, and program

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

[Technical Field]

[0001] The present disclosure relates to a boiler control device, a boiler control method, and a program. [Background technology]

[0002] Thermal power plants use boilers to burn fuel to generate steam to drive generators. In conventional base operation, boilers in thermal power plants are basically operated at rated output, and during times of reduced power demand, such as at night, the operating state is changed to reduce the load, thereby adjusting the output.

[0003] In such conventional boiler control, load changes are unidirectional toward the target load, but in order to prevent the boiler's operating state from becoming unstable due to a transient excess or deficiency of boiler input, a pre-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 a load change that is known in advance (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5970368 Summary of the Invention [Problem to be solved by the invention]

[0005] The amount of the advance control signal to be input is determined, for example, by a load change test performed during a trial run of the boiler. The advance control signal is input, for example, when a load change on the boiler begins, and is adjusted so that it reaches a target value at a predetermined change rate and then gradually decreases to zero after the load change is completed. However, for example, if a next load change is performed after the load change is completed but before the advance control signal decreases to zero, the remaining advance control signal may act as a disturbance, causing the boiler's operating state to become unstable.

[0006] In recent years, thermal power plants equipped with boilers are expected to play a role in adjusting fluctuations in power generation from renewable energy sources, which tend to fluctuate in power generation. In such applications, the load changes on the boiler increase, and it is thought that the opportunities for the above-mentioned problems to occur will also increase.

[0007] At least one embodiment of the present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a boiler control device, a boiler control method, and a program that can achieve stable operation by preventing a preceding control signal based on a previous load change from becoming a disturbance when the next load change is made after the changing load reaches a target load value. [Means for solving the problem]

[0008] In order to solve the above problem, a boiler control device according to at least one embodiment of the present disclosure includes: an advance control signal generator for generating an advance control signal for the boiler based on a change in the load of the boiler; an advance control signal adjusting unit for adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; Equipped with.

[0009] In order to solve the above problem, a boiler control method according to at least one embodiment of the present disclosure includes: generating an advance control signal for the boiler based on a change in load on the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; Equipped with.

[0010] In order to solve the above problem, a program according to at least one embodiment of the present disclosure includes: Using a computer, generating an advance control signal for the boiler based on a change in load on the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; is possible. [Effects of the Invention]

[0011] According to at least one embodiment of the present disclosure, a boiler control device, a boiler control method, and a program can be provided that can achieve stable operation by preventing a preceding control signal based on a previous load change from becoming a disturbance when the next load change is made after the changing load has reached a target load value. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram of a boiler according to an embodiment. [Figure 2] 1 is a block diagram showing a hardware configuration of a boiler control device according to an embodiment. [Figure 3] 1 is a block diagram showing a functional configuration of a boiler control device according to one embodiment. [Figure 4] FIG. 4 is a control flow diagram of the advance control signal generating unit of FIG. 3. [Figure 5] FIG. 4 is a control flow diagram of the advance control signal adjuster of FIG. 3. [Figure 6] FIG. 10 is a diagram showing a typical progression of an advance control signal during a load change when the load on the boiler increases. [Figure 7] 6 is a graph showing a transition of an advance control signal in accordance with a change in load in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0014] First, a boiler that is a control target of 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.

[0015] The boiler 10 is a boiler that uses a burner to burn pulverized solid fuel, which is the main fuel, and exchanges the heat generated by this combustion with feedwater or steam to generate superheated steam. Biomass fuel, coal, etc. are used as the solid fuel.

[0016] The boiler 10 has a furnace 11, a combustion device 20, and a combustion gas passage 12. The furnace 11 has a hollow rectangular cylindrical shape and is installed vertically. The furnace wall 101 that forms the inner wall surface of the furnace 11 is composed of multiple heat transfer tubes and fins that connect the heat transfer tubes together, and recovers the heat generated by the combustion of pulverized fuel by heat exchange with water and steam circulating inside the heat transfer tubes, while suppressing the temperature rise of the furnace wall 101.

[0017] The combustion device 20 is installed in the lower region of the 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" where appropriate) attached to the furnace wall 101. The burners 21 are arranged at equal 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 are arranged in multiple stages along the vertical direction.

[0018] 1, for convenience of illustration, only two of one set of burners are shown, and each set is denoted by the reference numerals 21A, 21B, 21C, 21D, 21E, and 21F. The shape of the furnace, the number of burner stages, the number of burners per stage, the arrangement of the burners, etc. are not limited to this embodiment.

[0019] Burners 21A, 21B, 21C, 21D, 21E, and 21F are connected to a plurality of mills (pulverizers) 31A, 31B, 31C, 31D, 31E, and 31F (hereinafter, collectively referred to as "mills 31") via a plurality of pulverized fuel supply pipes 22A, 22B, 22C, 22D, 22E, and 22F (hereinafter, collectively referred to as "pulverized fuel supply pipes 22"), respectively. Mill 31 is, for example, a vertical roller mill having a pulverizing table (not shown) supported therein so as to be rotatable, and a plurality of pulverizing rollers (not shown) supported above the pulverizing table so as to be rotatable in conjunction with the rotation of the pulverizing table. The solid fuel pulverized by the cooperation of the pulverizing rollers and the pulverizing table is transported to a classifier (not shown) provided in mill 31 by primary air (carrier gas, oxidizing gas) supplied to mill 31. The classifier separates the pulverized fuel into pulverized fuel having a particle size smaller than that suitable for combustion in the burner 21 and coarse pulverized fuel having a particle size larger than that. The pulverized fuel passes through the classifier and is supplied to the burner 21 together with primary air via the pulverized fuel supply pipe 22. The coarse pulverized fuel that does not pass through the classifier falls onto the grinding table inside the mill 31 under its own weight and is re-ground.

[0020] An air register 23 is provided outside the furnace 11 at the installation position of the burner 21, and one end of an air duct 24 is connected to the air register 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 air duct 24 and is supplied to the burner 21 via the air register 23 as secondary air (combustion air, oxidizing gas) and introduced into the furnace 11.

[0021] The combustion gas passage 12 is connected to the vertical upper part of the furnace 11. The combustion gas passage 12 is provided with superheaters 102A, 102B, and 102C (hereinafter collectively referred to as "superheaters 102" as appropriate), reheaters 103A and 103B (hereinafter collectively referred to as "reheaters 103" as appropriate), and a coal economizer 104 as heat exchangers for recovering heat from the combustion gas, and heat is exchanged between the combustion gas generated in the furnace 11 and the feedwater or steam flowing inside each heat exchanger. The arrangement and shape of each heat exchanger are not limited to the form shown in FIG.

[0022] A flue 13 is connected to the downstream side of the combustion gas passage 12, and discharges the combustion gas whose heat has been recovered by the heat exchanger. An air preheater (air heater) 42 is provided between the flue 13 and the air duct 24, and heat is exchanged between the air flowing through the air duct 24 and the combustion gas flowing through the flue 13, heating the primary air supplied to the mill 31 and the secondary air supplied to the burner 21, thereby recovering further heat from the combustion gas after heat exchange with water and steam.

[0023] Furthermore, a denitration device 43 may be provided in the flue 13 at a position upstream of the air preheater 42. The denitration device 43 supplies a reducing agent, such as ammonia or urea water, which has the effect of reducing nitrogen oxides, to the combustion gas flowing through the flue 13, and promotes the reaction between the nitrogen oxides (NOx) in the combustion gas to which the reducing agent has been supplied and the reducing agent by the catalytic action of a denitration catalyst provided in the denitration device 43, thereby removing and reducing the nitrogen oxides in the combustion gas.

[0024] A gas duct 41 is connected to the flue 13 downstream of the air preheater 42. The gas duct 41 is provided with environmental equipment such as a dust collector 44, such as an electrostatic precipitator, that removes ash and the like from the combustion gas, and a desulfurization equipment 46 that removes sulfur oxides, as well as an induced draft fan (IDF) 45 that guides the exhaust gas to these environmental equipment. The downstream end of the gas duct 41 is connected to a chimney 47, and the combustion gas that has been treated in the environmental equipment is discharged to the outside of the system as exhaust gas.

[0025] In the boiler 10, when the multiple mills 31 are driven, pulverized and classified pulverized fuel is supplied to the burner 21 together with primary air via the pulverized fuel supply pipe 22. In addition, secondary air heated by the air preheater 42 is supplied to the burner 21 from the air duct 24 via the wind box 23. The burner 21 blows a pulverized fuel mixture, which is a mixture of pulverized fuel and primary air, into the furnace 11, and also blows secondary air into the furnace 11. The pulverized fuel mixture blown into the furnace 11 ignites and reacts with the secondary air to form a flame. A flame is formed in the lower region of the furnace 11, and high-temperature combustion gas rises within the furnace 11 and flows into the combustion gas passage 12. In this embodiment, air is used as the oxidizing gas (primary air, secondary air), but the oxidizing gas may have a higher or lower oxygen content than air, and stable combustion can be achieved in the furnace 11 by adjusting the ratio of the amount of oxygen to the amount of fuel supplied within an appropriate range.

[0026] The combustion gas that has flowed into the combustion gas passage 12 exchanges heat with water and steam in a superheater 102, a reheater 103, and a coal economizer 104, which are arranged inside the combustion gas passage 12, and is then discharged into the flue 13, where nitrogen oxides are removed in the denitration device 43, the combustion gas exchanges heat with primary air and secondary air in the air preheater 42, and is then discharged into the gas duct 41, where ash and the like are removed in the dust collector 44, and sulfur oxides are removed in the desulfurization device 46, and the combustion gas is then discharged to the outside of the system through a chimney 47. The arrangement of the heat exchangers in the combustion gas passage 12 and the devices from the flue 13 to the gas duct 41 does not necessarily have to be in the order described above with respect to the flow of combustion gas.

[0027] Next, a description will be given of a boiler control device 100 that controls the boiler 10 having the above configuration. Fig. 2 is a block diagram showing the hardware configuration of the boiler control device 100 according to one embodiment.

[0028] The boiler control device 100 is configured as an arithmetic processing device such as a computer. The hardware configuration of the boiler control device 100 includes an input unit 110, a storage unit 120, a calculation unit 130, and an output unit 140, as shown in FIG.

[0029] The input unit 110 is configured to input various information necessary for the calculation processing performed in the boiler control device 100. The input unit 110 may be a human interface such as a mouse, keyboard, or touch panel that can be operated by an operator, or an interface device for acquiring various information from other devices including the boiler 10 that is the object of control.

[0030] The storage unit 120 is configured to store various types of information necessary for the arithmetic processing performed in the boiler control device 100. The storage unit 120 is configured from a computer-readable storage medium including at least one of RAM (Random Access Memory) and ROM (Read Only Memory). The various types of information stored in the storage unit 120 include programs that enable these hardware configurations to function as the boiler control device 100.

[0031] The calculation unit 130 is configured to perform various calculations of the boiler control device 100, and includes, for example, a CPU (Central Processing Unit). The calculation unit 130 reads out the programs stored in the storage unit 120 into a RAM or the like and executes information processing and calculation processing, thereby realizing various functions of the boiler control device 100.

[0032] The program executed by the calculation unit 130 may be stored in the storage unit 120 as described above, or may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means, etc. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0033] The output unit 140 is configured to perform output based on the calculation result in the calculation unit 130. In this embodiment, the output unit 140 outputs a control signal to the boiler 10, which is the object of control, as the output of the boiler control device 100. By receiving the control signal, the boiler 10 is controlled based on the control signal.

[0034] In addition to outputting a control signal to the boiler 10 that is the object of control, the output unit 140 may also include a human interface such as a display for an operator to recognize the calculation results, or a notification means for issuing an alarm in accordance with the calculation results.

[0035] 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 unit 150, an advance control signal generation unit 160, and an advance control signal adjustment unit 170. The block diagram shown in FIG. 3 is an example showing the functional configuration of the boiler control device 100 in accordance with the following description, and each block may be integrated with another block or may be further subdivided.

[0036] The control unit 150 is configured to control the boiler 10 by generating a control signal corresponding to a control parameter of a control target based on an input parameter relating to the operating state of the boiler 10.

[0037] The advance control signal generating unit 160 is configured to generate an advance 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 regarding a known load change of the boiler, and is intended to prevent the boiler operating state from becoming unstable due to a transient excess or deficiency of boiler input (fuel supply amount, etc.) toward the target load. In this embodiment, as an example, the advance control signal BIR is generated based on a load index corresponding to the boiler load, a load change rate, and a load change width.

[0038] The advance control signal adjuster 170 is configured to adjust the advance control signal so that it gradually becomes zero when the load reaches a target load value during a load change in the boiler 10. In this embodiment, as will be described in detail later, the advance control signal adjuster 170 adjusts the advance control signal so that the advance control signal becomes zero when the load on the boiler 10 reaches a target load value.

[0039] Next, the control contents by the advance control signal generator 160 and the advance control signal adjuster 170 will be described in detail with reference to Fig. 4 and Fig. 5. Fig. 4 is a control flow diagram of the advance control signal generator 160 in Fig. 3, and Fig. 5 is a control flow diagram of the advance control signal adjuster 170 in Fig. 3.

[0040] 4, the advance control signal generator 160 receives as input parameters a load index indicating the boiler load, a load change rate indicating the speed of the load change, and a load change width indicating the difference in boiler load before and after the load change, and generates an advance control signal BIR. The behavior of the advance control signal BIR is determined by a target value BIRt corresponding to the boiler load change and the BIR change rate.

[0041] The behavior of a typical advance control signal BIR will now be described with reference to Fig. 6. Fig. 6 is a diagram showing the transition of a typical advance control signal BIR with a load change when the load on the boiler 10 increases.

[0042] FIG. 6 shows a case in which the boiler load, which has an initial value L1, begins to increase at time t1 and reaches a target value L2 at time t2. At this time, the advance control signal BIR begins to increase from time t1 according to a first rate of change R1 (constant value) preset as the rate of change during the increase, and changes to reach the target value BIRt at time t3. Typically, time t3 is before time t2, and the advance control signal BIR, which reaches the target value BIRt at time t3, remains constant until time t2, when the boiler load change ends. Then, when the boiler load change ends at time t2, the advance control signal BIR gradually decreases from the target value BIRt to zero according to a second rate of change R2 (constant value) preset as the rate of change during the decrease. As a result, the advance control signal BIR becomes zero (initial value) at time t4.

[0043] Returning to Figure 4, in the advance control signal generating unit 160, the input parameters of the load index, load change rate, and load change width are input to functions fx1, fx2, and fx3, respectively, and the respective outputs are multiplied to obtain the target value BIRt of the advance control signal BIR.

[0044] In the advance control signal generator 160, the load indexes, which are input parameters, are input to functions fx4 and fx5, and a first change rate R1 and a second change rate R2 are calculated based on the respective calculation results. Based on the target value BIRt of the advance control signal BIR, the first change rate R1, and the second change rate R2 calculated in this way, the advance control signal generator 160 generates the advance control signal BIR so as to realize the behavior of the advance control signal BIR exemplarily described with reference to FIG.

[0045] In this embodiment, upon 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.

[0046] The advance control signal generator 160 also includes a switch 162 for outputting either the calculation results of the functions fx1, fx2, and fx3 or a default value (zero) as the target value BIRt of the advance control signal. As a result, when an adjustment signal is output from the advance control signal adjuster 170 as described below, the switch 162 fixes the target value BIRt of the advance control signal to the default value (zero). When an adjustment signal is output from the advance control signal adjuster 170, the switch 166 outputs the advance control signal BIR amount (before the start of adjustment) immediately before the start of adjustment. This BIR amount (before the start of adjustment) is used to calculate the required adjustment time, as described below.

[0047] The advance control signal generator 160 fixes the advance control signal adjusted by the advance control signal adjuster 170 to zero until the load reaches the target load or changes next. This allows the advance control signal corresponding to the previous load change to more accurately prevent disturbance to boiler control for the next load change, thereby realizing stable operation.

[0048] 5, the advance control signal adjuster 170 includes a required adjustment time calculator 172, a load change amount calculator 174, an adjustment start load value calculator 176, and an adjustment start timing determiner 178.

[0049] The required adjustment time calculation unit 172 is configured to calculate the time (required adjustment time Tn) required to change the advance control signal BIR from its current value to zero based on the magnitude (current value) of the advance control signal BIR and the BIR change rate. Specifically, the required adjustment time calculation unit 172 calculates the required adjustment time Tn for changing the advance control signal BIR amount to zero by dividing the BIR amount (before adjustment starts), which is the magnitude of the advance control signal BIR at the current time, by the adjustment rate, which is the change rate of the BIR.

[0050] The rate of change (adjustment rate) of the advance control signal BIR during adjustment is selected from the first rate of change R1 or the second rate of change R2 described above based on the load change situation corresponding to the advance control signal BIR. For example, as shown in Fig. 6, when it is desired to increase the advance control signal BIR, such as when it is desired to increase the load, the first rate of change R1 corresponding to the increasing direction is selected as the rate of change (adjustment rate) during adjustment. On the other hand, when it is desired to decrease the advance control signal BIR, such as after reaching a target load value or when the target load value described below is about to be reached, the second rate of change R2 corresponding to the decreasing direction is selected as the rate of change (adjustment rate) during adjustment.

[0051] The load change amount calculation unit 174 is configured to calculate the load change amount Ln of the boiler 10 during adjustment of the advance control signal BIR based on the required adjustment time Tn and the load change rate of the boiler. The load change amount calculation unit 174 acquires the load change rate during the load change of the boiler 10, and calculates the load change amount Ln indicating how much the load of the boiler 10 changes during the required adjustment time Tn calculated by the required adjustment time calculation unit 172. For example, when the load change rate is constant, the load change amount calculation unit 174 calculates the load change amount Ln by multiplying the load change rate by the required adjustment time Tn.

[0052] The adjustment start load value calculation unit 176 is configured to calculate an adjustment start load value Lm at which adjustment of the advance control signal BIR should be started. Specifically, the adjustment start load value calculation unit 176 acquires a target load value L2 of the boiler 10 and calculates the adjustment start load value Lm by subtracting the load change amount Ln calculated by the load change amount calculation unit 174 from the target load value L2.

[0053] The adjustment start timing determination unit 178 is configured to determine the timing at which adjustment control should be started for the advance control signal. Specifically, the adjustment start timing determination unit 178 monitors the load of the boiler 10 and determines the point in time at which the load reaches the adjustment start load value Lm calculated by the adjustment start load value calculation unit 176 as the adjustment start timing. When the adjustment start timing determined by the adjustment start timing determination unit 178 arrives, the advance control signal adjustment unit 170 starts adjustment control for the advance control signal generation unit 160, on the condition that the load change width is equal to or greater than a predetermined value. As a result, the advance control signal BIR is adjusted to zero at the timing at which the load of the boiler 10 reaches the target load value L2.

[0054] 6 and 7, the adjustment control of the advance control signal in the advance control signal adjuster 170 will be specifically described. Fig. 6 is a graph showing the transition of the advance control signal with a load change in a typical example. Fig. 7 is a graph showing the transition of the advance control signal with a load change in this embodiment.

[0055] In the typical example shown in Figure 6, the advance control signal BIR begins to be input at time t1 when the load on the boiler 10 starts to change, and increases at a preset first change rate R1 as the load increases. When the advance control signal BIR reaches a preset target value BIRt at time t3, it is maintained constant while the boiler load is changing. Thereafter, when the load on the boiler 10 reaches a target load value L2 at time t2, the advance control signal BIR decreases at a second change rate R2 and is adjusted to reach zero at time t4.

[0056] 6, after the load change of the boiler 10 is completed at time t2, a considerable amount of the advance control signal BIR remains until time t4. Therefore, if the next load change is performed before the advance control signal BIR becomes zero (i.e., between times t2 and t4), the remaining advance control signal BIR may act as a disturbance, causing the operating state of the boiler 10 to become unstable.

[0057] 7, similar to the aforementioned FIG. 6, illustrates the behavior of the advance control signal when the load of the boiler 10, which is at an initial load value L1, starts to change at time t1, increases at a constant change rate, and then reaches the target load value L2 at time t2. In this embodiment, as shown in FIG. 7, when the load change starts at time t1, the advance control signal BIR also increases as the load increases, which is similar to the typical example of FIG. 6. However, adjustment of the advance control signal BIR begins at an adjustment rate (second change rate R2) from adjustment start timing t5, which is before time t2 when the load change is completed. As a result, the advance control signal BIR reaches zero at time t2 when the load change is completed. Therefore, even when the next load change is performed after time t2, there is no remaining advance control signal BIR, so there is no disturbance and no influence occurs, thereby achieving a stable operating state of the boiler 10.

[0058] As described above, according to the above embodiment, the advance control signal BIR, which is generated when the load of the boiler 10 changes toward the target load value L2, is adjusted to zero when the load reaches the target load value L2. As a result, even when the next load change is made after the load reaches the target load value L2, the advance control signal BIR corresponding to the previous load change is zero, so that the next load change does not become a disturbance to the boiler control, and stable operation can be achieved.

[0059] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0060] The contents described in each of the above embodiments can be understood, for example, as follows.

[0061] (1) A boiler control device (100) according to one aspect of the present invention comprises: an advance control signal generator (160) for generating an advance control signal (BIR) for the boiler (10) based on a change in the load of the boiler; an advance control signal adjusting unit (170) for adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; Equipped with.

[0062] According to the above aspect (1), the advance control signal generated in response to a load change on the boiler is adjusted to zero when the load reaches the target load value. As a result, even when the next load change is made after the load reaches the target load value, the advance control signal corresponding to the previous load change is zero, so that the next load change does not become a disturbance to the boiler control, and stable operation can be achieved. The change in the boiler load broadly means information relating to the change in the boiler load, and is a concept that includes, for example, a load index, a load change rate, and a load change width.

[0063] (2) In another embodiment, in the above embodiment (1), 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.

[0064] According to the above aspect (2), the timing for starting adjustment of the advance control signal is set before the load change of the boiler reaches the target load value, and the advance control signal is adjusted at a constant adjustment rate from the adjustment start timing, so that the advance control signal can be accurately adjusted to zero at the timing when the load reaches the target load value.

[0065] (3) In another embodiment, in the above embodiment (2), a required adjustment time calculation unit (172) that calculates a required adjustment time (Tn) for adjusting the advance control signal to zero; a load change amount calculation unit (174) that calculates a load change amount (Ln) during adjustment of the advance control signal; an adjustment start load value calculation unit (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 the time when the load reaches the adjustment start load value as the adjustment start timing; Equipped with.

[0066] According to the above aspect (3), by determining the adjustment start timing, the advance control signal can be suitably adjusted so that the advance control signal becomes zero when the load reaches the target load value.

[0067] (4) In another embodiment, in the above embodiment (3), The required adjustment time calculation unit calculates the required adjustment time based on the magnitude of the advance control signal and the adjustment rate.

[0068] According to the above aspect (4), 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.

[0069] (5) In another aspect, in the above aspect (3) or (4), The load change amount calculation unit calculates the load change amount based on the required adjustment time and the rate of change of the load.

[0070] According to the above aspect (5), the load change amount during the load adjustment can be calculated based on the required adjustment time and the boiler load change rate.

[0071] (6) In another embodiment, in any one of the above (3) to (5), The adjustment start load value calculation unit calculates the adjustment start load value based on the target load value and the load change amount.

[0072] 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 load target value and the load change amount in the load change of the boiler.

[0073] (7) In another embodiment, in any one of the above (1) to (6), The advance control signal adjusting unit fixes the adjusted advance control signal to zero until the load reaches a target load or changes next time.

[0074] According to the above aspect (7), the advance control signal is maintained at zero until the target load is reached or the next load change occurs. This allows the advance control signal corresponding to the previous load change to more accurately prevent disturbance to boiler control for the next load change, thereby realizing stable operation.

[0075] (8) A boiler control method according to one aspect includes: generating an advance control signal (BIR) for a control parameter of the boiler (10) based on a change in the load of the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; Equipped with.

[0076] According to the above aspect (8), the advance control signal generated in response to a load change on the boiler is adjusted to zero when the load reaches the target load value. As a result, even when the next load change is made after the load reaches the target load value, the advance control signal corresponding to the previous load change is zero, so that the next load change does not become a disturbance to the boiler control, and stable operation can be achieved.

[0077] (9) A program according to one aspect includes: Using a computer, generating an advance control signal (BIR) for a control parameter of the boiler (10) based on a change in the load of the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches the target load value; is possible.

[0078] According to the above aspect (9), the advance control signal generated in response to a load change on the boiler is adjusted to zero when the load reaches the target load value. As a result, even when the next load change is made after the load reaches the target load value, the advance control signal corresponding to the previous load change is zero, so that the next load change does not become a disturbance to the boiler control, and stable operation can be achieved. [Explanation of symbols]

[0079] 10. Boiler 11 Furnace 12 Combustion gas passage 13 Flue 20 Combustion equipment 21 Burner 22 Fine fuel supply pipe 23 Wind Box 24 Wind road 31 mil 32 Forced draft fan 41 Gas duct 42 Air preheater 43 Denitration equipment 44 Dust collection device 46 Desulfurization equipment 47 Chimney 100 Boiler control device 101 Furnace wall 102 Superheater 103 Reheater 104 Economizer 110 Input section 120 Storage section 130 Arithmetic section 140 Output section 150 control section 160 Advance control signal generator 162,166 Switch 170 Advance control signal adjustment unit 172 Adjustment required time calculation section 174 Load change calculation section 176 Adjustment start load value calculation unit 178 Adjustment start timing determination unit

Claims

1. an advance control signal generating unit for generating an advance control signal for the boiler based on a load index indicating a load of the boiler; an advance control signal adjusting unit for adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; Equipped with 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, The advance control signal adjusting unit a required adjustment time calculation unit that calculates a required adjustment time for adjusting the advance control signal to zero; a load change amount calculation unit that calculates a load change amount during adjustment of the advance control signal; an adjustment start load value calculation unit for calculating an adjustment start load value at which adjustment of the advance control signal should be started; an adjustment start timing determination unit that determines the time when the load reaches the adjustment start load value as the adjustment start timing; A boiler control device comprising:

2. The boiler control device according to claim 1 , wherein the advance control signal is calculated based on a load change rate indicating a speed of load change of the boiler and a load change width indicating a difference in the load before and after the load change.

3. The boiler control device according to claim 1 or 2, wherein the required adjustment time calculation unit calculates the required adjustment time based on the magnitude of the advance control signal and the adjustment rate.

4. The boiler control device according to claim 1 , wherein the load change amount calculation unit calculates the load change amount based on the required adjustment time and a rate of change in the load.

5. The boiler control device according to claim 1 , 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.

6. The boiler control device according to claim 1 , wherein the advance control signal adjuster fixes the adjusted advance control signal to zero after the load reaches a target load until the load changes next time.

7. an advance control signal generator for generating an advance control signal for the boiler based on a change in the load of the boiler; an advance control signal adjusting unit for adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; a required adjustment time calculation unit that calculates a required adjustment time for adjusting the advance control signal to zero; a load change amount calculation unit that calculates a load change amount during adjustment of the advance control signal; an adjustment start load value calculation unit for calculating an adjustment start load value at which adjustment of the advance control signal should be started; an adjustment start timing determination unit that determines the time when the load reaches the adjustment start load value as the adjustment start timing; Equipped with The boiler control device, wherein the advance control signal adjuster is configured to adjust the advance control signal at a substantially constant adjustment rate from the adjustment start timing before the target load value is reached.

8. generating an advance control signal for the boiler based on a change in load on the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; calculating a required adjustment time for adjusting the advance control signal to zero; calculating a load change amount during adjustment of the advance control signal; calculating an adjustment start load value at which adjustment of the advance control signal should be started; determining a time when the load reaches the adjustment start load value as adjustment start timing; Equipped with The boiler control method, wherein the advance control signal is adjusted at a substantially constant adjustment rate from the adjustment start timing before the target load value is reached.

9. Using a computer, generating an advance control signal for the boiler based on a change in load on the boiler; adjusting the advance control signal so that the advance control signal becomes zero when the load reaches a target load value; calculating a required adjustment time for adjusting the advance control signal to zero; calculating a load change amount during adjustment of the advance control signal; calculating an adjustment start load value at which adjustment of the advance control signal should be started; determining a time when the load reaches the adjustment start load value as adjustment start timing; is executable, The advance control signal is adjusted at a substantially constant adjustment rate from the adjustment start timing before the target load value is reached.

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