WO2018211598A1

WO2018211598A1 - Boiler combustion control system and boiler combustion control method

Info

Publication number: WO2018211598A1
Application number: PCT/JP2017/018399
Authority: WO
Inventors: 雄治岡村; 谷口　一徳; 山下　亨; 伸浩鹿島; 健一郎首藤
Original assignee: 郵船商事株式会社; 出光興産株式会社; 日本郵船株式会社
Priority date: 2017-05-16
Filing date: 2017-05-16
Publication date: 2018-11-22
Also published as: AU2018270018B2; MY197403A; KR102422056B1; WO2018212224A1; CN110832250A; CN110832250B; TW201901083A; TWI672469B; KR20200029383A; JPWO2018212224A1; JP6894503B2; AU2018270018A1

Abstract

Disclosed is a boiler combustion control system that outputs a fuel correction coefficient for correcting a load demand amount after feedback correction. This system comprises: a fuel correction coefficient computation unit that calculates a fuel correction coefficient on the basis of a ratio between load demand amounts before and after feedback correction, and an initial value and a fine adjustment function that define an initial value of a relationship between the load demand amount and a fuel supply amount; and a reference curve correction unit that outputs a reference curve correction coefficient for correcting the initial value and the fine adjustment function. The reference curve correction unit includes: a deviation determination unit that calculates the deviation between a measured main steam pressure and a setting main steam pressure; a period determination unit that acquires a period related to the fluctuation of the deviation; an amplitude determination unit that acquires amplitude; a reference curve correction coefficient output unit that calculates and outputs the reference curve correction coefficient on the basis of a reference curve correction function; and a reference curve correction determination unit that corrects the reference curve correction function in cases where the combination of the period and the amplitude satisfies a predetermined condition.

Description

Boiler combustion control system and boiler combustion control method

The present invention relates to a technology for controlling combustion of a boiler, and more particularly to a technology effective when applied to a boiler combustion control system and a boiler combustion control method for determining a fuel input amount to a boiler based on a required load amount of the boiler. Is.

For example, when using boiler equipment to obtain energy, fuel (solid fuel, liquid fuel, or gaseous fuel) is supplied to the boiler (furnace) and burned, the heat is absorbed by the heat exchanger, and the steam is Generate heat energy. The generated steam is converted from thermal energy into rotational motion by being supplied to a steam turbine, for example, and used for power generation by a generator. The amount of fuel input to the boiler is a load requirement amount (for example, a power generation requirement amount MWD (Mega Watt Demand), and may be referred to as a load requirement amount MWD in the following), and a fuel injection amount (hereinafter referred to as a fuel requirement amount MWD). Then, it is determined by the fuel function FX which is a relational expression between the boiler input command value BID (may be described as Boiler Input Demand).

Here, fluctuations may occur in the operating state of the boiler, particularly the main steam pressure, due to the influence of various factors related to the boiler equipment, such as fuel properties, heat generation, furnace dirt, suit blower, air / water temperature, and the like. Therefore, the fuel related to the fuel input amount obtained by the fuel function FX is supplied to the boiler, the generated main vapor pressure is measured, and the PID (Proportional-) is based on the difference between this and the preset main vapor pressure. In general, control has been performed in which a feedback correction amount is obtained by Integral-Differential control, and this is added to a load request amount to correct the fuel injection amount to the boiler.

As a technique related to this, for example, in Japanese Patent No. 4522326 (Patent Document 1), a plurality of ratios or differences between values before and after feedback correction are sequentially updated and stored, and the stored multiple values are used. It is described that a fuel correction coefficient is obtained and a value after feedback correction is corrected by this correction coefficient. Thus, it is possible to correct the fuel injection amount in consideration of changes in the thermal efficiency of the boiler due to the influence of various factors.

Furthermore, for example, in Japanese Patent No. 4791269 (Patent Document 2), a fuel correction coefficient for correcting a value after feedback correction is subdivided into three elements in a multiple-type fuel mixed combustion boiler. It is described that the amount of fuel input to the boiler is corrected in accordance with the difference in unit calorific value and the difference in boiler thermal efficiency due to the change in the mixed combustion rate.

Japanese Patent No. 4522326 Japanese Patent No. 4791269

For example, according to prior arts such as Patent Documents 1 and 2, the value of the load request amount MWD before and after the feedback correction (or other control value) is compared as needed for changes in the thermal efficiency of the boiler due to the influence of various factors. It is possible to determine this by measuring, and acquire the value of the correction coefficient for further correcting and optimizing the value after feedback correction based on the determination result by self-learning.

On the other hand, the fuel function FX that defines the relationship between the required load amount MWD and the corresponding boiler input command value BID as a function (curve) is set reflecting the characteristics of the boiler. These are set as fixed values calculated in advance based on the accumulation of past actual measurement data. However, the behavior of the main steam pressure based on the characteristics of the boiler is different for each boiler, and even in one boiler, it can be changed by updating the boiler equipment. That is, there may be a slight difference between the actual behavior of the main vapor pressure and the expected value (optimum value) assumed in the fuel function FX. This divergence becomes a divergence from the optimum value of the fuel input amount, destabilizes the combustion control process of the boiler, and results in energy loss.

Accordingly, an object of the present invention is to detect a deviation from the optimum value assumed by the fuel function FX in the behavior of the main vapor pressure, and to correct the fuel function FX autonomously and self-containedly. And providing a boiler combustion control method.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

A boiler combustion control system according to a representative embodiment of the present invention supplies a fuel related to a fuel input amount to a boiler, which is calculated based on a predetermined fuel function with respect to a load requirement amount, and is measured. Further, a feedback correction amount is obtained based on a measured main steam pressure that is the main steam pressure of the boiler and a set main steam pressure that is a main steam pressure of the boiler that is set in advance, and the load is determined based on the feedback correction amount. A boiler combustion control system that outputs a fuel correction coefficient for correcting the load request amount or the fuel input amount after the feedback correction to a plant that corrects the required amount or the fuel input amount, wherein the feedback correction The ratio of the load request amount before and after and an initial value that defines the initial value of the relationship between the load request amount and the fuel input amount for the boiler. A fuel correction coefficient calculation unit that calculates the fuel correction coefficient based on a fine adjustment function, and a reference curve correction unit that outputs a reference curve correction coefficient that corrects the initial value and the fine adjustment function. is there.

The reference curve correction unit includes a deviation determination unit that calculates a deviation between the measured main vapor pressure and the set main vapor pressure, a cycle determination unit that acquires and records a cycle related to the variation in the deviation, An amplitude determination unit that acquires and records an amplitude related to a variation in deviation, a reference curve correction coefficient output unit that calculates and outputs the reference curve correction coefficient based on a predetermined reference curve correction function, the period and the amplitude A reference curve fuel function correction determination unit that corrects the reference curve correction function based on a control state for the boiler when the combination is satisfied. Have.

Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

That is, according to the representative embodiment of the present invention, the deviation from the optimum value assumed by the fuel function FX in the behavior of the main vapor pressure is detected, and the fuel function FX is corrected autonomously and self-contained. Is possible.

It is the figure which showed the outline | summary about the structural example of the boiler combustion control system which is one embodiment of this invention. It is the figure which showed the outline | summary about the structural example of the reference | standard curve correction | amendment part in one embodiment of this invention. It is the flowchart which showed the example of the flow of a process which correct | amends the initial value and fine adjustment function in one embodiment of this invention. It is the figure which showed the outline | summary about the example of the behavior of the main vapor pressure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted. On the other hand, parts described with reference numerals in some drawings may be referred to with the same reference numerals although not illustrated again in the description of other drawings.

As described above, when energy is acquired using boiler equipment, the input amount (boiler input command value BID) of fuel (for example, coal or biomass fuel) corresponding to the steam request amount (load request amount MWD) of the boiler is , Determined using the fuel function FX. At this time, the required load amount MWD is controlled to perform feedback correction so as to bring the main steam pressure of the boiler closer to a desired set main steam pressure.

On the other hand, in the conventional techniques described in the above-mentioned Patent Documents 1 and 2, etc., in order to further improve the accuracy of control, the ratio of the required load amount MWD before and after performing feedback correction, that is, feedback of the main steam pressure. A fuel correction coefficient is obtained by self-learning based on an index indicating the correction operation level, and the load request amount MWD (or boiler input command value BID) is further corrected by this fuel correction coefficient. This correction can be said to be substantially equivalent to correcting the fuel function FX.

The boiler combustion control system according to an embodiment of the present invention corrects the reference curve that is the basis / starting point of self-learning by AI (Artificial Intelligence) in order to further improve the accuracy with respect to the above-described conventional technology. To do. This reference curve shows the initial value of the relationship between the required load amount MWD defined for the target boiler and the boiler input command value BID. In the prior art, this reference curve is set as a fixed value calculated in advance based on the accumulation of past actual measurement data, like the fuel function FX. In this case, depending on the equipment update of the boiler and other changes in the state, the behavior of the main steam pressure slightly deviates from the optimum value assumed in the fuel function FX corrected by the fuel correction coefficient, and the combustion control of the boiler is performed. The process may become unstable and efficiency may be reduced.

On the other hand, in the boiler fuel control system of the present embodiment, the behavior / state change of the main steam pressure of the boiler is constantly analyzed and determined based on past data, and the above reference curve is adjusted based on the determination result By doing so, a slight deviation occurring in the fuel function FX is corrected. In this embodiment, this series of processing is performed autonomously and in real time by a self-contained processing loop.

<System configuration>
FIG. 1 is a diagram showing an outline of a configuration example of a boiler combustion control system according to an embodiment of the present invention. As described above, the boiler combustion control system 1 determines the fuel correction coefficient K by adjusting the reference curve using the initial value and the fine adjustment function FXAI so that the amount of fuel input to the boiler 2 in the plant is optimized. The control information is output to an existing circuit or the like that inputs fuel into the boiler 2 (that is, the combustion of the boiler 2 is controlled by substantially correcting the fuel function FX).

The boiler combustion control system 1 may be configured as, for example, a device that is implemented by hardware including a semiconductor circuit (not shown), a microcomputer, and the like that executes processing related to each function described below. Alternatively, it is composed of general-purpose server devices, virtual servers built on cloud computing services, etc., and expanded on memory from a recording device such as HDD (Hard Disk Drive) by a CPU (Central Processing Unit) (not shown) By executing middleware such as an OS (Operating System) or software operating on the middleware, processing related to each function described later may be executed.

Further, these hardware implementations and software implementations may be combined as appropriate. In addition, the configuration is not limited to a configuration in which the entirety is mounted in one casing, and a configuration in which some functions are mounted in another casing and the casings are mutually connected by a communication cable or the like may be used. That is, the implementation form of the boiler combustion control system 1 is not particularly limited, and can be configured flexibly as appropriate according to the plant environment and the like.

As shown in the figure, the boiler combustion control system 1 includes various units such as a division unit 11, a reference curve correction unit 12, a multiplication unit 13, and a fuel correction coefficient calculation unit 14 that are implemented by hardware or software. In addition, there are files such as files and tables recorded in a memory, HDD, etc., and data such as fine adjustment functions FXAI.

In the plant, the main steam generated by burning the fuel in the boiler 2 based on the information of the fuel input amount (boiler input command value BID in the figure) is supplied to the steam turbine 3, for example, by a generator (not shown) Used for power generation. The required load amount MWD (input steam required amount) of the boiler 2 corresponding to the output from the generator is input, for example, by an operation panel (not shown) in the boiler 2 and also input to the boiler combustion control system 1.

On the other hand, for example, the pressure of the main steam generated in the boiler 2 is measured by a pressure gauge (not shown) provided in the boiler 2, and the measured value is input to the main steam pressure transmitter PX. The measured main steam pressure PV transmitted from the main steam pressure transmitter PX is input to the PID control unit 4 and is compared with the set main steam pressure SV which is the main steam pressure that should be originally in the PID control unit 4. Is called. At this time, for example, if the fuel input amount is determined using the fuel function FX obtained under the conditions in which the state of the boiler 2 (furnace fouling, etc.), fuel properties, and other factors are maintained, measurement is performed. A difference between the main steam pressure PV and the set main steam pressure SV hardly occurs, and a desired load (generator output) is obtained by the fuel function FX. However, as described above, for example, a pressure difference may occur between the measured main steam pressure PV and the set main steam pressure SV with changes in the state of the boiler 2, changes in fuel properties, and other factors. is there.

In the PID control unit 4, when a pressure difference between the measured main steam pressure PV and the set main steam pressure SV is detected, it is generated by a feedback correction amount, that is, a fuel shortage (or excess) by a known PID control technique. A deviation (error amount) of the main vapor pressure is calculated and sent to the adding unit 5. The adding unit 5 adds the feedback correction amount sent from the PID control unit 4 to the load request amount MWD that is also input to the boiler combustion control system 1 to output the load request amount MWD ′ after feedback correction. (The PID control unit 4 and the addition unit 5 may be referred to as a feedback control unit).

In the boiler fuel control system 1 of the present embodiment, as described above, in order to follow the deviation from the optimum value due to changes in characteristics such as efficiency of the boiler 2 as in the prior arts of Patent Documents 1 and 2 and the like. An index indicating the degree of feedback correction operation by the feedback control unit (PID control unit 4 and addition unit 5), that is, a ratio between the load request amount MWD and the load request amount MWD ′, which is a command value before and after the feedback correction 11 is obtained. Then, using this as an input, the fuel correction coefficient calculator 14 calculates the fuel correction coefficient K by self-learning and outputs it.

The output fuel correction coefficient K is multiplied by the load request amount MWD ′ by the multiplier 6. Using this corrected load requirement amount MWD "as an input, the fuel input amount calculation unit 7 converts this into a boiler input command value BID by the fuel function FX. Based on this boiler input command value BID, the fuel to the boiler 2 is converted. Input is controlled.

Note that, as a method for calculating the fuel correction coefficient K in the fuel correction coefficient calculation unit 14 of the boiler combustion control system 1, for example, a technique similar to that described in Patent Documents 1 and 2 can be used as appropriate. The detailed description again here is omitted. Further, as described in Patent Documents 1 and 2 and the like, the connection relationship and processing order of each part of the plant including the boiler combustion control system 1 are not limited to those shown in FIG. Thus, various variations of configurations can be employed as appropriate. For example, in the example of FIG. 1, the fuel correction coefficient K is corrected by multiplying the load request amount MWD ′ after feedback correction, but the boiler input command value BID obtained by the fuel input amount calculation unit 7 is multiplied. It is good also as a structure corrected. Further, the fuel function FX may be directly corrected.

As described above, in the determination of the fuel correction coefficient K, self-learning is performed starting from the reference curve, but in the prior art, a fixed value set in advance is used for the reference curve. In this case, along with changes in characteristics such as efficiency of the boiler 2, the reference curve may be slightly deviated from the optimum value, and the combustion control process of the boiler 2 may become unstable and efficiency may be reduced. Therefore, in the present embodiment, the reference curve correction unit 12 always performs comparative measurement between the measured main steam pressure PV of the boiler 2 and the set main steam pressure SV, which is a set value that should be supposed to be, so that the main A change in vapor pressure behavior is analyzed and determined, and a reference curve correction coefficient KP is set based on the determination result. Then, the initial value and the initial value of the reference curve defined in the fine adjustment function FXAI are corrected in real time by multiplying the initial value and the fine adjustment function FXAI by the multiplication unit 13.

FIG. 4 is a diagram showing an outline of an example of the behavior of the main vapor pressure. Each of the diagrams shows a curve of an example of the change in the measured main steam pressure PV over time, and also shows the set main steam pressure SV in a straight line. The upper diagram shows a case where the degree of correction (correction by the fuel correction coefficient K and integral correction by PID control) is set strongly, and the measured main steam pressure PV varies greatly across the set main steam pressure SV. It shows that. On the other hand, the middle diagram shows a case where the degree of correction is optimal, and shows that the measured main steam pressure PV fluctuates in the vicinity of the set main steam pressure SV. On the other hand, the lower diagram shows a case where the degree of correction is set to be weak, and the measured main vapor pressure PV fluctuates greatly slowly across the set main vapor pressure SV as a whole while repeating small fluctuations. It is shown that.

Here, in the boiler combustion control system 1 of the present embodiment, the behavior of the main steam pressure is centered on the vibration of the measured main steam pressure PV based on the set main steam pressure SV, that is, the set main steam pressure SV. It grasps | ascertains with an amplitude and a period (interval of the timing at which the measurement main vapor pressure PV cross | intersects setting main vapor pressure SV). The state in which the main vapor pressure (measured main vapor pressure PV) is optimal basically refers to a state in which the amplitude is small and the cycle is short, as shown in the middle diagram. In addition, the state with a long period means that the state in which the measured main vapor pressure PV is away from the set main vapor pressure SV continues for a long period of time as shown in the lower diagram.

As described above, for example, if the fuel input amount is determined using the fuel function FX obtained under conditions where the state of the boiler 2, the fuel properties, and other factors are maintained, the measured main vapor pressure PV And the difference between the set main steam pressure SV hardly occur. Actually, for example, as shown in the middle diagram of FIG. 4, the measured main vapor pressure PV is oscillated with a small amplitude around the set main vapor pressure SV. However, a pressure difference (deviation) may occur between the measured main steam pressure PV and the set main steam pressure SV with changes in the state of the boiler 2, changes in fuel properties, and other factors. In the present embodiment, this deviation is measured to detect a state where the measured main vapor pressure PV is in an optimum state, that is, a state where the amplitude and period values are small, and the fuel function is based on the state at that time. A correction coefficient for FX (in this embodiment, an initial value and a fuel function correction coefficient KP for fine adjustment function FXAI) is calculated.

FIG. 2 is a diagram showing an outline of a configuration example of the reference curve correction unit 12 in the present embodiment. For example, the reference curve correction unit 12 further includes, as its configuration, a deviation determination unit 121, a period determination unit 122, an amplitude determination unit 123, a reference curve correction determination unit 124, and a reference curve correction coefficient output implemented by hardware or software. Each part such as the part 125 is included. In addition, the data includes a period history 126, amplitude history 127, optimum value information 128, reference curve correction function VFX, and the like implemented as files or tables recorded in a memory, HDD, or the like.

The measured main steam pressure PV and the set main steam pressure SV input to the reference curve correction unit 12 are input to the deviation determination unit 121, and the difference (deviation) is calculated. The calculated difference is input to the period determination unit 122 and the amplitude determination unit 123, respectively, and the period and amplitude of the fluctuation are calculated as information characterizing the behavior of the measurement main vapor pressure PV. As described above, the behavior of the measurement main vapor pressure PV is not constant but changes every moment. Therefore, the period and the amplitude are calculated as a moving average over a long time (for example, 30 minutes). For this reason, the calculated period and amplitude information are recorded in a memory, HDD, or the like as the period history 126 and the amplitude history 127, respectively.

The calculated period and amplitude values are input to the reference curve correction determination unit 124. In the reference curve correction determination unit 124, it is determined whether or not the values of the period and the amplitude are optimum values (including a suitable value within a certain range corresponding thereto). The information related to the optimum value is recorded as, for example, the optimum value information 128 in a memory or HDD. When it is determined that the period and the amplitude are in the optimum state, the value of the reference curve correction function VFX set as a variable function is moved until the period and the amplitude are out of the optimum state.

Based on the reference curve correction function VFX, the reference curve correction coefficient output unit 125 acquires and outputs a reference curve correction coefficient KP corresponding to the load requirement amount MWD. The reference curve correction coefficient KP is multiplied by the initial value and the fine adjustment function FXAI to correct the initial value and the fine adjustment function FXAI.

<Initial Value and Fine Adjustment Function FXAI Correction Process>
FIG. 3 is a flowchart showing an example of a flow of processing for correcting the initial value and the fine adjustment function FXAI in the present embodiment. Here, the flow of processing up to the part where the reference curve correction function VFX is set in the reference curve correction determination unit 124 of the reference curve correction unit 12 is shown. Thereafter, the reference curve correction coefficient output unit 125 of the reference curve correction unit 12 acquires and outputs a reference curve correction coefficient KP corresponding to the load requirement amount MWD based on the set reference curve correction function VFX.

In the reference curve correction unit 12, first, the deviation determination unit 121 acquires the set main vapor pressure SV (S01). The set main steam pressure SV may be preset in the system as a constant as shown in FIG. 1, or may be acquired as an external input from the boiler 2 or the like. Thereafter, the measurement main vapor pressure PV transmitted from the main vapor pressure transmitter PX is acquired (S02). The above processing order is an example, and may be executed in reverse order or in parallel. When the set main steam pressure SV and the measured main steam pressure PV are acquired, a deviation process for obtaining a difference between them is performed (S03). The deviation determination unit 121 inputs the calculated difference information to the period determination unit 122 and the amplitude determination unit 123, respectively, and returns to step S01 to continue the process.

The cycle determining unit 122 measures the fluctuation cycle of the measured main steam pressure PV based on the set main steam pressure SV based on the information on the difference in main steam pressure acquired from the deviation determining unit 121 (S11). For example, the timing at which the sign of the difference is reversed is grasped based on the history information of the past difference stored in a memory or the like (not shown), and the time interval is set as the period. As described above, the behavior of the measured main vapor pressure PV is not constant and changes every moment. Therefore, the period is calculated as a moving average based on a past long time (for example, 30 minutes) history. Thereafter, it is determined whether or not the measured cycle is normal (is not an abnormal value such as minus) (S12). If it is not normal (is an abnormal value) (S12: N), the process returns to step S11 to continue the cycle measurement process.

Similarly, the amplitude determination unit 123 measures the amplitude of fluctuation in the measured main steam pressure PV based on the set main steam pressure SV based on the difference information of the main steam pressure acquired from the deviation determination unit 121 ( S21). For example, the absolute value of the difference is grasped as the amplitude. The amplitude is also calculated as a moving average of history information for the past long time (for example, 30 minutes). Thereafter, it is determined whether or not the measured amplitude is normal (S22). If not normal (S22: N), the process returns to step S21 to continue the amplitude measurement process.

When the period and amplitude values are both normal (S12: Y, S22: Y), the calculated period and amplitude values are input to the reference curve correction determination unit 124. The reference curve correction determination unit 124 acquires a transition of a cycle within a past fixed time range (for example, 5 minutes) (S31), and determines whether each cycle is within a predetermined range (S32). ). If it does not fall within the predetermined range (S32: N), nothing is done, or if the correction process for the reference curve correction function VFX has already been performed, this is ended (S38). Thereby, the reference curve correction coefficient output unit 125 at the subsequent stage acquires and outputs the reference curve correction coefficient KP based on the reference curve correction function VFX at this time.

On the other hand, if the period within the past fixed time range is within the predetermined range (S32: Y), whether or not the measured period and amplitude are the minimum values so far in the past fluctuation history. Is determined (S33). The minimum value information so far may be recorded in the optimum value information 128, for example. In addition, about a period, after being in the predetermined range in step S32, it is determined whether it is the minimum value. If at least one of the period and the amplitude is not the minimum value (S33: N), nothing is done, or if the correction process for the reference curve correction function VFX has already been performed, this is ended (S38).

On the other hand, if both of the measured period and amplitude are minimum values (S33: N), information on the period and amplitude related to the optimum value so far is obtained from the optimum value information 128 (S34) and compared with this. In step S35, it is determined whether the combination of the measured period and amplitude is the optimum value. As a method for determining which is the optimum value, for example, an appropriate method can be used, for example, it is assumed that the smaller value of the period is optimum while the amplitude value is within a predetermined range. If the measured combination of period and amplitude is not the optimum value (S35: N), nothing is done, or if the correction process for the reference curve correction function VFX has already been performed, this is ended (S38).

On the other hand, when the combination of the measured period and amplitude is the optimum value (S35: Y), the content of the optimum value information 128 is updated by this combination (S36), and correction processing for the reference curve correction function VFX is started. (S37). The reference curve correction function VFX is set as a variable function that defines a curve of a correspondence relationship between the load requirement amount MWD and the reference curve correction coefficient KP that is a correction coefficient for the initial value and the fine adjustment function FXAI. Correction is made by moving a predetermined amount. This correction is continued until, for example, the measured period and amplitude deviate from the optimum state. Note that such a correction method is an example. For example, the reference curve correction function VFX is used by using another index such as the boiler input command value BID in the control state when the combination of the measured period and amplitude is the optimum value. Alternatively, a method of correcting the initial value and the fine adjustment function FXAI may be used.

As described above, according to the boiler combustion control system 1 which is an embodiment of the present invention, the deviation of the variation of the measured main steam pressure PV from the set main steam pressure SV is measured as a period and an amplitude. Based on the transition of time, the timing at which the period and amplitude are in the optimum state is specified. Then, a reference curve correction coefficient KP for correcting the fuel function FX (specifically, the initial value and the fine adjustment function FXAI in the present embodiment) is output based on the state when the period and the amplitude are optimal. That is, it is possible to substantially correct a slight deviation occurring in the fuel function FX in real time autonomously and self-containedly.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of the above-described embodiment.

In addition, each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

Further, in each of the above drawings, control lines and information lines indicate what is considered necessary for explanation, and not all control lines and information lines on mounting are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

The present invention can be used in a boiler combustion control system and a boiler combustion control method that determine the amount of fuel input to the boiler based on the required load amount of the boiler.

DESCRIPTION OF SYMBOLS 1 ... Boiler combustion control system, 2 ... Boiler, 3 ... Steam turbine, 4 ... PID control part, 5 ... Addition part, 6 ... Multiplication part, 7 ... Fuel injection amount calculating part,
DESCRIPTION OF SYMBOLS 11 ... Division part, 12 ... Base curve correction | amendment part, 13 ... Multiplication part, 14 ... Fuel correction coefficient calculating part,
DESCRIPTION OF SYMBOLS 121 ... Deviation determination part, 122 ... Period determination part, 123 ... Amplitude determination part, 124 ... Reference curve correction determination part, 125 ... Reference curve correction coefficient output part, 126 ... Period history, 127 ... Amplitude history, 128 ... Optimal value information ,
SV: set main steam pressure, PV: measurement main steam pressure, PX: main steam pressure transmitter, MWD, MWD ', MWD "... load requirement, BID: boiler input command value, K ... fuel correction coefficient, KP ... standard Curve correction coefficient, FX ... fuel function, FXAI ... initial value and fine adjustment function, VFX ... reference curve correction function

Claims

A fuel related to the amount of fuel input to the boiler calculated based on a predetermined fuel function with respect to the load demand is supplied to the boiler, and a measured main steam pressure that is a measured main steam pressure of the boiler, Obtaining a feedback correction amount based on the set main steam pressure that is the main steam pressure of the boiler, for the plant that corrects the required load amount or the fuel input amount based on the feedback correction amount, A boiler combustion control system that outputs a fuel correction coefficient for correcting the load requirement amount or the fuel input amount after feedback correction,
The fuel correction coefficient based on a ratio of the load request amount before and after the feedback correction, and an initial value and a fine adjustment function that define an initial value of a relationship between the load request amount and the fuel input amount for the boiler A fuel correction coefficient calculation unit for calculating
A reference curve correction unit that outputs a reference curve correction coefficient for correcting the initial value and the fine adjustment function,
The reference curve correction unit is
A deviation determination unit for calculating a deviation between the measured main vapor pressure and the set main vapor pressure;
A period determination unit that acquires and records a period related to the variation of the deviation;
An amplitude determination unit that acquires and records the amplitude according to the variation of the deviation;
A reference curve correction coefficient output unit that calculates and outputs the reference curve correction coefficient based on a predetermined reference curve correction function;
A reference curve correction determination unit that determines whether a combination of the period and the amplitude satisfies a predetermined condition and corrects the reference curve correction function based on a control state for the boiler when the condition is satisfied. And having a boiler combustion control system.
In the boiler combustion control system according to claim 1,
The boiler combustion control system, wherein the condition is that the amplitude is within a predetermined range, and the period is the smallest in a history of a predetermined time range in the past.
In the boiler combustion control system according to claim 1,
The boiler combustion control system, wherein the cycle determination unit and the amplitude determination unit acquire the cycle and the amplitude by a moving average in a past fixed time, respectively.
In the boiler combustion control system according to claim 1,
The reference curve correction function is set as a variable function,
The boiler curve control system, wherein the reference curve correction determination unit corrects the reference curve correction function by moving the reference curve correction function while the combination of the period and the amplitude satisfies the condition.
A fuel related to the amount of fuel input to the boiler calculated based on a predetermined fuel function with respect to the load demand is supplied to the boiler, and a measured main steam pressure that is a measured main steam pressure of the boiler, Obtaining a feedback correction amount based on the set main steam pressure that is the main steam pressure of the boiler, for the plant that corrects the required load amount or the fuel input amount based on the feedback correction amount, A boiler combustion control method in a boiler combustion control system that outputs a fuel correction coefficient for correcting the load requirement amount or the fuel input amount after feedback correction,
The fuel correction coefficient based on a ratio of the load request amount before and after the feedback correction, and an initial value and a fine adjustment function that define an initial value of a relationship between the load request amount and the fuel input amount for the boiler A fuel correction coefficient calculation step for calculating
A reference curve correction step for outputting a reference curve correction coefficient for correcting the initial value and the fine adjustment function,
The reference curve correction step includes
A deviation determining step of calculating a deviation between the measured main vapor pressure and the set main vapor pressure;
A period determination step of acquiring and recording a period related to the variation of the deviation;
An amplitude determination step of acquiring and recording an amplitude related to the variation of the deviation;
A reference curve correction coefficient output step of calculating and outputting the reference curve correction coefficient based on a predetermined reference curve correction function;
A reference curve correction determination step of determining whether a combination of the period and the amplitude satisfies a predetermined condition and correcting the reference curve correction function based on a control state for the boiler when the condition is satisfied. And a boiler combustion control method.