TWI682126B - Fuel reduction rate output system, fuel reduction rate output method, and computer program product for fuel reduction rate output - Google Patents

Abstract

Calculate the fuel reduction rate obtained by the improvement of boiler controllability in real time.

A fuel reduction rate output system 1 that calculates a fuel reduction rate 15 corresponding to a fuel reduction applied to a boiler combustion control system 4 has a deviation determination unit 11 and uses a history of the main vapor pressure measurement value PV as a main vapor pressure Historical record 14 to record, calculate the deviation of the main vapor pressure history record 14 and the main vapor pressure measurement value PV, and output the historical record of the main vapor pressure deviation within a predetermined range as the historical record of the main vapor pressure control value; The standard deviation calculation unit 12 calculates the standard deviation based on the history of the main vapor pressure control value output by the deviation determination unit 11; and the fuel reduction rate output unit 13 calculates the standard deviation based on the standard deviation calculated by the standard deviation calculation unit 12 The improvement rate is calculated based on a reference formula representing the relationship between the standard deviation improvement rate and the fuel reduction rate, and the fuel reduction rate 15 is calculated and output.

Description

Fuel reduction rate output system, fuel reduction rate output method, and computer program product for fuel reduction rate output

The present invention relates to a technique for controlling the combustion of a boiler, and in particular to a fuel reduction rate output system, a fuel reduction rate output method, and a computer program product for fuel reduction rate output, which calculate a fuel reduction rate obtained by improving boiler efficiency Applicable effective technology.

For example, when energy is obtained using boiler equipment, fuel (solid fuel such as coal, liquid fuel, or gas fuel) is supplied to a boiler (stove) and burned, and the heat is absorbed by a heat exchanger to generate steam to obtain thermal energy. The generated steam is supplied to, for example, a steam turbine, thereby converting heat energy into rotational motion, and used for power generation of a generator or the like. The fuel input to the boiler is determined by the load demand (for example, the power generation demand MWD (Mega Watt Demand), which is described below as the load demand MWD) and the fuel input to the boiler (the following is described as the boiler input The relationship between the command value BID (Boiler Input Demand) is determined by the fuel function FX.

Here, there are factors related to boiler equipment, such as changes in fuel properties and calorific value caused by fuel switching, furnace pollution, soot blower, gas and water temperature, etc., and there are boilers Operating conditions, especially when the main vapor pressure changes. Therefore, in general, the following control is performed: 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 is based on the difference between the main vapor pressure and the preset main vapor pressure. (Proportional-Integral-Differential, proportional calculus method) The control finds the feedback correction amount, which is added to the load requirement to correct the fuel input to the boiler.

As a technology related to this, for example, Japanese Patent No. 4522326 (Patent Document 1) describes the following purpose: updating the ratio or difference of the values before and after feedback correction item by item and performing multiple memories simultaneously, from the memory The fuel correction coefficient is obtained from multiple values, and the value after feedback correction is corrected by the correction coefficient. In this way, the change in the thermal efficiency of the boiler caused by the influence of various factors can be taken into account and corrected to an appropriate fuel input amount.

Furthermore, for example, Japanese Patent No. 4791269 (Patent Document 2) describes the following: In a multi-fuel mixed combustion boiler, the fuel correction coefficient used to correct the value after feedback correction is subdivided into three elements, and this is accompanied by The difference in unit heat of fuel and the difference in boiler thermal efficiency due to the change in mixed combustion rate are used to correct the fuel input to the boiler.

[Conventional Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4522326

[Patent Document 2] Japanese Patent No. 4791269

For example, according to the prior art of Patent Documents 1, 2, etc., for the change of boiler thermal efficiency caused by the influence of various factors, the value of the correction factor can be obtained by self-learning. The correction factor is used to compare and measure at any time The value (or other control value) of the load demand amount MWD before and after feedback correction is used to make a determination, and the value after the feedback correction is further corrected based on the determination result to achieve the optimum.

By using these correction coefficients to control to achieve the optimum, although the boiler efficiency can be improved, in the past, performance tests and actual measurements must be carried out to grasp the degree of improvement in boiler efficiency. Specifically, for example, the operation/non-operation of the control function related to energy saving is switched, and the fuel consumption and the amount of steam generation are compared between the operation period and the non-operation period to calculate the fuel reduction rate. However, this method of having to perform performance tests is too roundabout, and the fuel reduction rate cannot be estimated immediately during operation.

Therefore, an object of the present invention is to provide a fuel reduction rate output system, a fuel reduction rate output method, and a computer program product for fuel reduction rate output, which can immediately output the fuel reduction rate obtained by improving the controllability of the boiler , Which is the energy saving rate.

The novel features of the above and other objects of the present invention are apparent from the contents of the description and accompanying drawings.

In the following, a summary of representative technical features of the invention disclosed in this application will be briefly described.

The fuel reduction rate output system of a representative embodiment of the present invention is a fuel reduction rate output system that calculates the fuel reduction rate corresponding to the fuel reduction applied to the boiler combustion control system The boiler combustion control system supplies fuel related to the amount of fuel input to the boiler calculated for the load demand amount to the boiler, and the fuel reduction rate output system includes: a deviation determination unit that records the history of the main vapor pressure measurement value The record is recorded as the main vapor pressure history record, the deviation between the main vapor pressure history record and the main vapor pressure measurement value is calculated, and the historical record of the main vapor pressure deviation within a predetermined range is taken as the historical record of the main vapor pressure control value Output; the standard deviation calculation unit calculates the standard deviation based on the history of the main vapor pressure control value output by the deviation determination unit; and the fuel reduction rate output unit calculates the standard deviation improvement rate based on the standard deviation calculated by the standard deviation calculation unit , And calculates and outputs the fuel reduction rate based on a reference equation indicating the relationship between the standard deviation improvement rate and the fuel reduction rate.

In addition, the present invention can also be applied to the fuel reduction rate output method in the fuel reduction rate output system and the computer program product for fuel reduction rate output that causes a computer to operate as the fuel reduction rate output system.

The following briefly describes the effects obtained by representative technical features in the invention disclosed in this application.

That is, according to the representative embodiment of the present invention, the fuel reduction rate obtained by improving the controllability of the boiler, that is, the energy saving rate can be output in real time.

1‧‧‧ Fuel reduction rate output system

2‧‧‧Boiler

3‧‧‧Steam turbine

4‧‧‧Boiler combustion control system

11‧‧‧ Deviation Judgment

12‧‧‧ Standard deviation calculation department

13‧‧‧Fuel reduction rate output section

14‧‧‧ Main vapor pressure history

15‧‧‧ Fuel reduction rate

PV‧‧‧ Main vapor pressure measurement

PX‧‧‧Main vapor pressure transmitter

MWD‧‧‧load requirement

BID‧‧‧Boiler input command value

FIG. 1 is a diagram schematically showing a configuration example of a fuel reduction rate output system according to an embodiment of the present invention.

2 is a diagram showing an example of the relationship between the improvement rate of the standard deviation of the main vapor pressure and the fuel reduction rate in an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In addition, in all the drawings for explaining the embodiments, the same parts are denoted by the same symbols in principle, and redundant descriptions thereof are omitted. On the other hand, there is also a part marked with a symbol in a certain figure for explanation, and the same symbol is still not mentioned when describing other figures.

(System Components)

FIG. 1 is a diagram schematically showing a configuration example of a fuel reduction rate output system according to an embodiment of the present invention. In FIG. 1, the control of the boiler 2 is performed by the existing boiler combustion control system 4. Boiler combustion control The system 4 takes the load demand amount MWD as an input, and determines the fuel input amount to the boiler, that is, the boiler input command value BID by a combustion function (not shown). For example, in the case where the boiler combustion control system 4 is updated or additionally installed, or as shown in Patent Documents 1, 2 and the like, a response to improve controllability, or a response to predicted fuel reduction (the following exists In the case of collectively referred to as "fuel reduction contribution correspondence"), the fuel reduction rate output system 1 calculates the fuel reduction rate 15 based on the standard deviation of the main vapor pressure of the boiler 2 as described later.

In addition, in the example of FIG. 1, the fuel reduction rate output system 1 is configured as a separate system that is added to the boiler combustion control system 4, but may also be incorporated as a part of the boiler combustion control system 4. Posed. In addition, in the example of FIG. 1, although the fuel reduction rate output system 1 is configured to output the calculated fuel reduction rate 15 as data, it may also be a configuration having a display unit that uses the fuel reduction rate 15 It is displayed on a monitor (not shown) or printed on a printer and output in a predetermined format or layout. By having the above display unit, the fuel reduction rate 15 (or fuel reduction amount) can be grasped instantaneously.

The fuel reduction rate output system 1 may be configured, for example, as a device installed using hardware including a semiconductor circuit (not shown), a microcomputer, or the like, and executes processing related to each function described later. Alternatively, it may be constituted by a virtual server built on a general-purpose server machine or cloud computing service, etc., and a slave HDD (Hard Disk Drive, hard disk) is executed by a CPU (Central Processing Unit) not shown. An intermediary platform such as an OS (Operating System, operating system) or a software running on the memory device, such as a drive device), etc., deployed on the memory, thereby performing processing related to each function described later.

In addition, it can also be configured to properly install the hardware and software. In addition, it is not limited to the structure of assembling the whole with one frame, and it may be a function of assembling a part with another frame, and a structure that connects these frames with each other by a communication cable or the like. That is, the type of installation of the fuel reduction rate output system 1 is not particularly limited, and it can be flexibly configured appropriately according to the environment of the plant side and the like.

As shown in the figure, the fuel reduction rate output system 1 includes various parts such as a deviation determination unit 11 installed by hardware or software, a standard deviation calculation unit 12, and a fuel reduction rate output unit 13. In addition, the data having the main vapor pressure history 14 and the like are installed as files, forms, or databases recorded in a memory or HDD.

(Calculation of fuel reduction rate)

As described above, the fuel reduction rate output system 1 of the present embodiment is premised on some fuel reduction contribution correspondence to the boiler combustion control system 4 (or other system added to the boiler combustion control system 4 ). When energy saving corresponding to such fuel reduction contribution is performed, especially when the controllability is improved according to the prior art as described in Patent Documents 1 and 2, the pressure fluctuation of the main steam generated by the boiler 2 becomes small . As a result, the combustion state in the furnace of the boiler 2 or the state change of the entire unit including the steam turbine 3 for power generation becomes small, and as a result, the fuel consumption is reduced.

In such a boiler combustion control system 4, it is possible to consider the relationship between the size of the state change of the entire unit (that is, the amount of change in the main vapor pressure) and the fuel reduction rate. Therefore, in the fuel reduction rate output system 1 of the present embodiment, the estimated value of the fuel reduction rate is calculated by the following method.

As shown in the figure, the current main vapor pressure measurement value PV is continuously input from the main vapor pressure transmitter PX to the deviation determination unit 11 of the fuel reduction rate output system 1. In the deviation determination unit 11, for example, at a certain interval such as once every one minute period, the main vapor pressure measurement value PV and the main vapor pressure history record 14 are recorded in the past within a certain period of time (for example, during the past 60 minutes) The history of main vapor pressure is compared. In addition, in the main vapor pressure history record 14, the measured value of the main vapor pressure that spans at least a certain time (e.g., 60 minutes) or more in the past is recorded at a frequency that is more than the above certain interval (e.g., 1 minute interval) .

In the deviation determination unit 11, for example, the main vapor pressure history record 14 is used to select a history record of main vapor pressure within ±5% of the current main vapor pressure measurement value PV, and the number is counted. When the number is more than a predetermined number (for example, more than half of all historical data of the selected parent (in other words, more than half of the above-mentioned fixed period)), it is determined that the main vapor pressure is measured with the current main vapor pressure The value PV is controlled to a steady state at a value of the same level, and the history information of the selected main vapor pressure (hereinafter described as “main vapor pressure control value”) is output to the standard deviation calculation unit 12.

The standard deviation calculation unit 12 calculates the standard deviation based on the input history of the main vapor pressure control value and outputs it to the fuel reduction rate output unit 13. For example, the standard deviation improvement rate (%) is calculated by the following formula: standard deviation improvement rate=100-(standard deviation control value/corresponding standard deviation×100).

Here, the standard deviation control value refers to the standard deviation of the historical record of the input main vapor pressure control value, and the pre-correspondence standard deviation refers to the standard of the historical record of the main vapor pressure in the state before the corresponding fuel reduction contribution difference. In addition, the standard deviation before correspondence (that is, the The fuel reduction contribution of the line object corresponds to the main vapor pressure control value in the previous state), for example, it is acquired/recorded in advance before the correspondence of the fuel reduction contribution of the object is started. Alternatively, it can be set to a predetermined variable function and can be changed to an appropriate coefficient.

The fuel reduction rate output unit 13 calculates and outputs an estimated value of the fuel reduction rate from the input standard deviation improvement rate based on a predetermined mathematical formula.

2 is a diagram showing an example of the relationship between the improvement rate of the standard deviation of the main vapor pressure and the fuel reduction rate in the present embodiment. The graph in FIG. 2 shows that the horizontal axis (x axis) is the standard deviation improvement rate (%) of the main vapor pressure, and the vertical axis (y axis) is the fuel reduction rate (%). A graph showing the actual results of various fuel reduction contributions. As shown in FIG. 2, it can be understood that the greater the improvement rate of the standard deviation of the main vapor pressure, the higher the fuel reduction rate. In addition, this correlation can be formulated by linear approximation for each boiler 2 as shown in the figure (in the example of FIG. 2, it is shown as “y=0.0378x+0.1604” in the figure). In the present embodiment, the fuel reduction rate output unit 13 is adapted to input the standard deviation improvement rate of the linear approximation reference formula to calculate the estimated value of the fuel reduction rate.

In addition, in the present embodiment, as shown in FIG. 1, the fuel reduction rate output unit 13 is provided. However, the fuel reduction rate output unit 13 may be provided in plurality for each main vapor pressure measurement. The degree of the value PV (load area) is configured to be distinguished. Alternatively, it may be configured to set a plurality of reference equations for differentiation, and these reference equations represent the above-described standard deviation improvement rate and fuel reduction rate for each load region in one fuel reduction rate output unit 13 relationship. In addition, the above-mentioned reference formula can also be set to a predetermined variable function and can be changed to an appropriate coefficient. In this embodiment, the estimated value of the fuel reduction rate (%) is calculated and output, but it may be multiplied by the boiler input command value BID (fuel input amount to the boiler 2) and used as the fuel reduction Output.

The invention developed by the present inventors has been specifically described above based on the embodiments, but the present invention is not limited to the above-mentioned embodiments, and it is self-evident that various changes can be made without departing from the gist thereof. For example, in order to explain the present invention in an easy-to-understand manner, the above-mentioned embodiments have been described in detail, but it is not necessarily limited to have all the described configurations. In addition, a part of the configuration of the above-described embodiment may be added, deleted, or replaced with another configuration.

In addition, each of the above-mentioned configurations, functions, processing units, processing means, etc. may also be implemented in hardware by, for example, designing with an integrated circuit. In addition, the above-mentioned respective configurations, functions, etc. can also be realized by software by interpreting and executing programs that cause the processor to realize the respective functions. The information of programs, forms, files, etc. that realize each function can be placed on a storage device such as a memory or hard disk, SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.

In addition, in the above figures, the control lines or information lines are shown in consideration of the necessity of description, and are not necessarily limited to represent all the control lines or information lines installed. In fact, it can also be understood that almost all the components are connected to each other.

[Industry availability]

The present invention is applicable to a fuel reduction rate output system, a fuel reduction rate output method, and a computer program product for fuel reduction rate calculation that calculate a fuel reduction rate obtained by improving boiler efficiency.

1‧‧‧ Fuel reduction rate output system

2‧‧‧Boiler

3‧‧‧Steam turbine

4‧‧‧Boiler combustion control system

11‧‧‧ Deviation Judgment

12‧‧‧ Standard deviation calculation department

13‧‧‧Fuel reduction rate output section

14‧‧‧ Main vapor pressure history

15‧‧‧ Fuel reduction rate

PV‧‧‧ Main vapor pressure measurement

PX‧‧‧Main vapor pressure transmitter

MWD‧‧‧load requirement

BID‧‧‧Boiler input command value

Claims (6)

A fuel reduction rate output system that calculates the fuel reduction rate corresponding to the fuel reduction applied to the boiler combustion control system. The boiler combustion control system supplies the fuel supply related to the fuel input to the boiler calculated for the load demand As far as the boiler is concerned, the fuel reduction rate output system includes a deviation determination unit that records the history of the measured value of the main vapor pressure of the boiler as the main vapor pressure history, and calculates the main vapor pressure. The deviation between the historical record and the measured value of the main vapor pressure, and the historical record of the main vapor pressure within a predetermined range is output as the historical record of the main vapor pressure control value; the standard deviation calculation unit outputs based on the deviation determination unit The standard deviation of the main vapor pressure control value history is calculated; and the fuel reduction rate output unit calculates the standard deviation improvement rate based on the standard deviation calculated by the standard deviation calculation unit, and based on the standard deviation improvement rate and Based on the reference formula of the relationship of the fuel reduction rate, the fuel reduction rate is calculated and output. The fuel reduction rate output system as described in item 1 of the patent application range, wherein the reference formula is set in each load region of the boiler. The fuel reduction rate output system as described in item 1 of the patent application range, wherein the above-mentioned reference formula is set as a predetermined variable function. The fuel reduction rate output system as described in item 1 of the patent application range, which includes a display unit that displays the fuel reduction rate output by the fuel reduction rate output unit. A fuel reduction rate output method that calculates the fuel reduction rate corresponding to the fuel reduction applied to the boiler combustion control system, which supplies the fuel supply related to the fuel input to the boiler calculated for the load demand To the above boiler, the fuel reduction rate output method includes: a history recording step, which records the measured history of the main vapor pressure of the boiler, that is, the measured value of the main vapor pressure as the main vapor pressure history record; The deviation determination step calculates the deviation between the main vapor pressure history record and the main vapor pressure measurement value, and outputs the main vapor pressure history record within a predetermined range as the main vapor pressure control value history record; the standard deviation is calculated Step, calculate a standard deviation based on the history of the main vapor pressure control value output from the deviation determination step; and fuel reduction rate output step, calculate a standard deviation improvement rate based on the standard deviation calculated in the standard deviation calculation step, Then, the fuel reduction rate is calculated and output based on a reference equation indicating the relationship between the standard deviation improvement rate and the fuel reduction rate. A computer program product for fuel reduction rate output that enables a computer to function as a fuel reduction rate output system to calculate the fuel reduction rate corresponding to the fuel reduction applied to the boiler combustion control system. The boiler combustion control system will target The fuel related to the fuel input to the boiler calculated by the load demand amount is supplied to the above-mentioned boiler. The computer program product for the fuel reduction rate output causes the above-mentioned computer to perform the following processing: history processing, to measure the measured The main vapor pressure is the historical record of the measured value of the main vapor pressure as the main vapor pressure history record; the deviation determination process calculates the deviation of the main vapor pressure history record and the measured value of the main vapor pressure, and the deviation is within a predetermined range The history of the main vapor pressure is output as the history of the main vapor pressure control value; the standard deviation calculation process calculates the standard deviation based on the historical record of the main vapor pressure control value output from the deviation determination processing step; and the fuel reduction The rate output process calculates the standard deviation improvement rate based on the standard deviation calculated in the standard deviation calculation processing step, and calculates and executes the fuel reduction rate based on a reference equation indicating the relationship between the standard deviation improvement rate and the fuel reduction rate Output.

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