JP2023064933A - Denitration control device, denitration control method and program - Google Patents

Abstract

To provide a denitration control device, a denitration control method and a program capable of performing denitration control for properly controlling the supply amount of ammonia without installing an analyzer for measuring the concentration of a nitrogen oxide at the inlet of a denitration device.SOLUTION: In a denitration control device for controlling the supply amount of ammonia in a denitration device for reducing the content of a nitrogen oxide in an exhaust gas containing the nitrogen oxide generated by combustion in a gas turbine: a nitrogen oxide concentration prediction model for predicting the concentration of the nitrogen oxide at the inlet of the denitration device by a model arithmetic operation is provided; and an analyzer for measuring the concentration of the nitrogen oxide is not installed at the inlet of the denitration device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a denitration control device, a denitration control method, and a program.

Exhaust gas from gas turbines contains nitrogen oxides ( _NOx ), which are environmental pollutants. By reacting the oxides with ammonia, they are decomposed into nitrogen and water, and the amount of nitrogen oxides discharged from the stack is reduced to manage environmental regulation values.

As a method for controlling the injection amount of ammonia in a denitration apparatus, paragraph 0005 of Patent Document 1 describes a set value of the nitrogen oxide concentration at the outlet or the smoke entrance of the denitration apparatus and a measured value of the nitrogen oxide concentration at the inlet of the denitration apparatus. To the basic ammonia injection amount corresponding to the amount of nitrogen oxides calculated from the deviation from A control method is disclosed that further corrects for

Japanese Patent Application Laid-Open No. 2003-80026

By the way, an analyzer for measuring the concentration of nitrogen oxides at the inlet of the denitrification apparatus has a delay in the sampling gas intake time and the analysis time. For example, the concentration of nitrogen oxides contained in the flue gas passing through the denitrification device is measured at the inlet of the denitrification device, and the amount of ammonia to be supplied to the flue gas (the flue gas whose nitrogen oxide concentration was measured) is calculated. Even if calculated, the exhaust gas (exhaust gas whose nitrogen oxide concentration was measured) has already passed through the denitration device at the moment when the calculated amount of ammonia is supplied to the denitration device.
In other words, when an analyzer is used to measure the concentration of nitrogen oxides at the inlet of the denitrification equipment, the exhaust gas whose concentration of nitrogen oxides is measured by the analyzer when passing through the denitration equipment Exhaust gas) does not match the exhaust gas (exhaust gas to which ammonia is supplied) to which the amount of ammonia calculated based on the concentration of nitrogen oxides measured by the analyzer does not match, and there is an excess or deficiency in the amount of ammonia supplied. As a result, denitration control cannot be performed properly.

In the technique described as Example 2 in Patent Document 1, the nitrogen oxide concentration at the inlet of the denitrification apparatus is adjusted to compensate for the excess or deficiency of the supply of ammonia due to the analysis delay of the analyzer (inlet nitrogen oxide detection means). As a correction (advance correction, feedback correction, nitrogen dioxide compensation amount correction) for the ammonia supply amount (basic ammonia amount) set by the prediction circuit (inlet nitrogen oxide concentration estimation means), according to the load change of the gas turbine Correction (preliminary correction) by adding the amount of ammonia in advance is performed, but the excess or deficiency of the ammonia supply amount due to the mismatch of the supply timing of ammonia caused by the delay in the analysis of the nitrogen oxide concentration may not be resolved.

In addition, in order to maintain the measurement accuracy of the analyzer that measures nitrogen oxide concentration, periodic maintenance such as indication calibration and parts replacement is required, resulting in high running costs.

In view of the above points, the present invention provides a denitration control device capable of performing denitration control to appropriately control the amount of ammonia supplied without installing an analyzer for measuring the concentration of nitrogen oxides at the entrance of the denitration device. An object of the present invention is to provide a denitration control method and program.

One aspect of the present invention is to control the amount of ammonia supplied to a denitration device that reduces the content of nitrogen oxides in exhaust gas containing nitrogen oxides generated by combustion in a gas turbine. In the denitration control device, an analyzer for measuring the concentration of the nitrogen oxides is not installed at the entrance of the denitration device, and the concentration of the nitrogen oxides at the entrance of the denitration device is determined by model calculation. A denitrification control device comprising a nitrogen oxide concentration prediction model for prediction.

In the denitrification control device according to one aspect of the present invention, the combustor of the gas turbine performs premixed combustion and diffusion combustion, and the gas turbine has a ratio of fuel and air used for combustion in the combustor. and a combustor bypass valve that controls a fuel/air ratio of , and the nitrogen oxide concentration prediction model uses a first fuel amount, which is the fuel amount used for the premixed combustion, and a first fuel amount, which is the fuel amount used for the diffusion combustion. a predetermined first relationship between a second fuel amount that is an amount of fuel to be used and a predicted nitrogen oxide concentration value that is a predicted value of the concentration of the first fuel amount, the second fuel amount, and the concentration of the nitrogen oxides; a first three-dimensional function calculator for calculating the predicted nitrogen oxide concentration value, a first nitrogen oxide concentration correction amount calculated according to the fuel/air ratio, and opening of the combustor bypass valve and a multiplier for correcting the predicted nitrogen oxide concentration value calculated by the first three-dimensional function unit, based on the degree.

In the denitration control device according to one aspect of the present invention, the nitrogen oxide concentration prediction model includes a combustion air temperature, which is the temperature of the air used for combustion in the combustor, and the humidity of the air used for combustion in the combustor. and a second nitrogen oxide concentration correction amount for further correcting the predicted nitrogen oxide concentration value corrected by the combustion air temperature, the combustion air humidity, and the multiplier. and a second three-dimensional function unit for calculating the second nitrogen oxide concentration correction amount based on the obtained second relationship.

In the denitration control device according to one aspect of the present invention, the nitrogen oxide concentration prediction model is a plurality of process signals related to combustion in a combustor of the gas turbine, and a process signal selection unit that selects a plurality of process signals assumed to affect the concentration; and the plurality of process signals selected by the process signal selection unit are used as explanatory variables, and the nitrogen oxide concentration is used as an objective variable. and a process signal selection unit that performs multiple regression analysis as a multiple regression analysis, wherein the process signal selection unit is a weighted signal that indicates the degree of influence of the plurality of process signals selected by the process signal selection unit on the concentration of nitrogen oxides. Based on the t value of regression analysis, a plurality of sorted process signals, which are a plurality of process signals used for predicting the concentration of nitrogen oxides, are selected from the plurality of process signals selected by the process signal selection unit. and the nitrogen oxide concentration prediction model includes a compatibility evaluation unit that evaluates the compatibility of the plurality of post-sorting process signals selected by the process signal selection unit based on a correction R2 of multiple regression analysis, The suitability evaluation unit determines a plurality of regression coefficients by which the plurality of post-selection process signals selected by the process signal selection unit are multiplied in the multiple regression equation, and determines the nitrogen oxide concentration prediction model. is based on the plurality of post-sorting process signals selected by the process signal selection unit, the plurality of regression coefficients determined by the suitability evaluation unit, and the intercept of the multiple regression equation, the denitrification device and a nitrogen oxide concentration prediction unit for predicting the concentration of the nitrogen oxides at the inlet of the.

In the denitrification control device according to one aspect of the present invention, the combustor of the gas turbine performs premixed combustion and diffusion combustion, and the gas turbine has a ratio of fuel and air used for combustion in the combustor. and the compressor of the gas turbine is equipped with an IGV (inlet guide vane), selected by the process signal selector. The plurality of process signals include a process signal indicative of fuel flow rate for combustion, a process signal indicative of combustion air flow rate, a process signal indicative of fuel distribution ratio for diffusion combustion, a process signal indicative of fuel distribution ratio for premixed combustion, and an IGV angle. process signal indicating combustor bypass valve opening, process signal indicating gas turbine exhaust gas temperature, process signal indicating gas turbine blade path temperature, process signal indicating air compressor inlet temperature, air compressor outlet temperature , a process signal indicative of air compressor inlet pressure, and a process signal indicative of combustion air humidity.

In the denitrification control device of one aspect of the present invention, the compressor of the gas turbine is provided with an IGV (inlet guide vane), and the nitrogen oxide concentration prediction model is based on combustion in the combustor of the gas turbine. The reaction rate of the concentration of nitrogen oxides is determined based on the fuel flow rate used and the predetermined relationship between the fuel flow rate and the predicted value of the reaction rate of the concentration of nitrogen oxides at the inlet of the denitration apparatus. Combustion air, which is the amount of air used for combustion in the combustor, is provided with a two-dimensional function calculator for calculating a predicted value, and the predicted value of the reaction rate of the concentration of nitrogen oxides calculated by the two-dimensional function calculator is used for combustion in the combustor The nitrogen oxide concentration at the inlet of the denitrifier may be predicted by correcting for the amount and the IGV angle, which is the angle of the IGV.

In the denitrification control device according to one aspect of the present invention, the combustor of the gas turbine performs premixed combustion and diffusion combustion, and the gas turbine has a ratio of fuel and air used for combustion in the combustor. is provided with a combustor bypass valve that controls a fuel/air ratio of , the compressor of the gas turbine is provided with an IGV (inlet guide vane), and the nitrogen oxide concentration prediction model is based on the A first fuel amount that is the amount of fuel used for premixed combustion, a second fuel amount that is the amount of fuel used for diffusion combustion, the first fuel amount, the second fuel amount, and the nitrogen oxide concentration a first three-dimensional function unit for calculating the predicted nitrogen oxide concentration value based on a predetermined first relationship with the predicted nitrogen oxide concentration value, which is the predicted value of the fuel/air ratio; A multiplier for correcting the predicted nitrogen oxide concentration value calculated by the first three-dimensional function unit based on the first nitrogen oxide concentration correction amount calculated by the above calculation and the opening degree of the combustor bypass valve , a combustion air temperature that is the temperature of the air used for combustion in the combustor, a combustion air humidity that is the humidity of the air used for combustion in the combustor, the combustion air temperature and the combustion air said second nitrogen oxide concentration correction based on a second predetermined relationship between humidity and a second nitrogen oxide concentration correction amount for further correcting said nitrogen oxide concentration predicted value corrected by said multiplier; A three-dimensional functional model comprising a second three-dimensional function for calculating a quantity, a plurality of process signals related to combustion in said combustor, which affect the concentration of said oxides of nitrogen at an inlet of said denitrifier and Multiple regression analysis is performed using a process signal selection unit that selects a plurality of assumed process signals, the plurality of process signals selected by the process signal selection unit as explanatory variables, and the nitrogen oxide concentration as an objective variable. , the plurality of process signals selected by the process signal selection unit based on the t value of multiple regression analysis indicating the degree of influence of the process signals on the concentration of nitrogen oxides, the plurality of signals selected by the process signal selection unit a process signal selection unit for selecting a plurality of post-selection process signals, which are a plurality of process signals used for predicting the concentration of nitrogen oxides, from the process signals; and the plurality of selections selected by the process signal selection unit. The suitability of the post-process signal is evaluated based on the correction R2 of the multiple regression analysis, and in the multiple regression equation, the plurality of post-sorting process signals sorted by the process signal sorting unit are multiplied by a plurality of A suitability evaluation unit that determines a regression coefficient, the plurality of post-sorting process signals selected by the process signal selection unit, the plurality of regression coefficients determined by the suitability evaluation unit, and the multiple regression equation a nitrogen oxide concentration prediction unit that predicts the concentration of the nitrogen oxides at the inlet of the denitrification device based on the intercept, a fuel flow rate used for combustion in the combustor, and the fuel Based on a reaction rate formula that is a predetermined relationship between the flow rate and the predicted value of the reaction rate of the nitrogen oxide concentration at the inlet of the denitrification apparatus, the predicted value of the reaction rate of the nitrogen oxide concentration is calculated. a two-dimensional function unit for calculating the predicted value of the reaction rate of the concentration of nitrogen oxides calculated by the two-dimensional function unit; at least two models of kinetic models for predicting the concentration of the nitrogen oxides at the inlet of the denitrification device by correcting them based on the IGV angle, which is the angle of the IGV; One of the at least two models may be selected for use or a combination of the at least two models may be used, depending on the characteristics of the gas turbine plant to which is applied.

One aspect of the present invention is to control the amount of ammonia supplied to a denitration device that reduces the content of nitrogen oxides in exhaust gas containing nitrogen oxides generated by combustion in a gas turbine. In the denitration control method for a denitration control device comprising an ammonia supply amount control step, an analyzer for measuring the concentration of nitrogen oxides is not installed at the entrance of the denitration device, and the entrance of the denitration device is a nitrogen oxide concentration prediction step of predicting the concentration of nitrogen oxides in the denitrification control method by model calculation.

One aspect of the present invention is a denitrification device in which a computer installed in a denitration control device reduces the content of nitrogen oxides in exhaust gas containing nitrogen oxides generated by combustion in a gas turbine. and a nitrogen oxide concentration prediction step of predicting the nitrogen oxide concentration at the inlet of the denitrification apparatus by model calculation. In the program, an analyzer for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitrification device.

According to the present invention, a denitration control device, a denitration control method, and a denitration control device capable of appropriately controlling the amount of ammonia supplied without installing an analyzer for measuring the concentration of nitrogen oxides at the entrance of the denitration device. program can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the gas turbine plant (gas turbine power generation equipment) GP to which the denitrification control apparatus 1 of 1st Embodiment was applied. 3 is a diagram showing an example of a nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment; FIG. FIG. 4 is a diagram showing an example of a first relationship used in the three-dimensional function unit A10; FIG. 4 is a diagram showing an example of a first relationship used in the three-dimensional function unit A10; FIG. 4 is a diagram for explaining an example of processing executed in the denitration control device 1 of the first embodiment; FIG. FIG. 10 is a diagram showing an example of a nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the second embodiment; FIG. 11 is a diagram showing an example of a nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the third embodiment;

Hereinafter, embodiments of the denitration control device, the denitration control method, and the program of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a diagram showing an example of a gas turbine plant (gas turbine power generation equipment) GP to which the denitration control device 1 of the first embodiment is applied.
The gas turbine plant GP to which the denitration control device 1 of the first embodiment is applied includes the denitration control device 1, the ammonia flow rate adjustment valve 3, the smoke inlet nitrogen oxide concentration analyzer 4, the gas turbine 5, the smoke A road 6, a denitrification device 7 and a chimney 8 are installed.
The denitration control device 1 controls the amount of ammonia supplied in the denitration device 7 . The ammonia flow control valve 3 adjusts the flow rate of ammonia supplied in the denitrification device 7 . The smoke inlet nitrogen oxide concentration analyzer 4 measures the concentration of nitrogen oxides in the flue gas at the inlet of the chimney 8 .

The gas turbine 5 has the same functions as the gas turbine described in Japanese Patent No. 4831820, for example, and includes a compressor, a combustor, a turbine, and a combustor bypass valve. The combustor of the gas turbine 5 performs premixed combustion and diffusion combustion. The combustor bypass valve controls the fuel/air ratio, which is the ratio of fuel and air used for combustion in the combustor. The compressor is equipped with inlet guide vanes (IGV). The IGV adjusts the amount of air used for combustion in the combustor of the gas turbine 5 by changing the angle (opening degree). A flue 6 connects the gas turbine 5 and a chimney 8 .
A denitrification device 7 is arranged in the flue 6 . The denitrification device 7 reduces the content of nitrogen oxides in the exhaust gas by supplying ammonia to the exhaust gas containing nitrogen oxides generated by combustion in the gas turbine 5 .

In the example shown in FIG. 1, the exhaust gas emitted by the combustion of the gas turbine 5 passes through the flue 6 and is released from the chimney 8 to the outside air. In the process, in the denitrification device 7 having a catalyst using ammonia as a reducing agent, nitrogen oxides contained in the exhaust gas are reacted with ammonia to be decomposed into nitrogen and water. The flue gas whose nitrogen oxide content has been reduced in the denitrification device 7 is released to the outside air through a chimney 8 .

The unreacted nitrogen oxide contained in the exhaust gas emitted from the chimney 8 to the outside air is required to control the average travel time value below the regulation value according to the Environmental Impact Assessment Law. Determined by agreement value.
The amount of ammonia used as a reducing agent in the denitration device 7 to reduce nitrogen oxides in the exhaust gas from the gas turbine 5 is calculated by the denitration control device 1 . The amount of ammonia calculated by the denitration control device 1 is supplied to the denitration device 7 by operating the ammonia flow control valve 3 .

In general gas turbine power generation equipment, in order to calculate the amount of ammonia in the denitrification control device 1, an analyzer 2 (see FIG. 1) that measures the concentration of nitrogen oxides in the exhaust gas generated by combustion of the gas turbine 5 is provided. , is installed together with a smoke inlet nitrogen oxide concentration analyzer 4 for analyzing the concentration of nitrogen oxides in the exhaust gas emitted from the chimney 8 to the outside air.
On the other hand, in the gas turbine plant GP to which the denitration control device 1 of the first embodiment is applied, the analyzer 2 (see FIG. 1) for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitration device 7 .

In the example shown in FIG. 1, the denitration control device 1 includes a nitrogen oxide concentration prediction model 11, a nitrogen oxide treatment amount calculator 12, an ammonia flow rate calculator 13, and a feedback correction amount calculator 14. .
The nitrogen oxide concentration prediction model 11 predicts the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitration device 7 by model calculation. The nitrogen oxide processing amount calculator 12 needs to be processed (decomposed into nitrogen and water) in the denitrification device 7 based on the nitrogen oxide concentration in the exhaust gas predicted by the nitrogen oxide concentration prediction model 11. The amount of nitrogen oxides (nitrogen oxide treatment amount) is calculated.
The ammonia flow rate calculation unit 13 calculates the amount of ammonia required to treat the amount of nitrogen oxides calculated by the nitrogen oxide treatment amount calculation unit 12, and generates a control signal for the ammonia flow rate adjustment valve 3. Output. The feedback correction amount calculation unit 14 calculates the nitrogen oxide concentration in the exhaust gas at the inlet of the stack 8 measured by the smoke inlet nitrogen oxide concentration analyzer 4 and the nitrogen oxide concentration in the exhaust gas discharged from the stack 8 in advance. A feedback correction amount corresponding to the deviation from the set control value is calculated, and the feedback correction amount is output to the ammonia flow rate calculation unit 13 .

That is, the nitrogen oxide processing amount calculator 12 of the denitration control device 1 calculates the nitrogen oxide processing amount based on the nitrogen oxide concentration predicted by the nitrogen oxide concentration prediction model 11 . The ammonia flow rate calculator 13 calculates the amount of ammonia necessary for treating nitrogen oxides, and outputs an operation amount command to the ammonia flow rate control valve 3 . Further, the feedback correction amount calculation unit 14 calculates a feedback correction amount according to the deviation between the analysis value of the smoke inlet nitrogen oxide concentration analyzer 4 and the controlled value of the nitrogen oxide concentration in the exhaust gas discharged from the stack 8. It is given to the ammonia flow rate calculator 13 .

FIG. 2 is a diagram showing an example of the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment.
In the example shown in FIG. 2, the nitrogen oxide concentration prediction model 11 is composed of a three-dimensional function model 11A. The three-dimensional function model 11A includes a three-dimensional function device A10, a three-dimensional function device A11, a multiplier A12, a subtractor A13, a combustor bypass valve opening information acquisition unit A14, and a fuel/air ratio calculation unit A15. , a two-dimensional function unit A16, a fixed value setter A17, and a switcher A18.
The three-dimensional function unit A10 calculates a predicted nitrogen oxide concentration value, which is a predicted value of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 . Specifically, the three-dimensional function A10 is a first fuel amount that is used for premixed combustion in the combustor of the gas turbine 5 and a fuel amount that is used for diffusion combustion in the combustor of the gas turbine 5. A predicted nitrogen oxide concentration value is calculated based on the second fuel amount and a predetermined first relationship (see FIGS. 3 and 4). The first relationship is the relationship between the first fuel amount, the second fuel amount, and the predicted nitrogen oxide concentration value.

3 and 4 are diagrams showing an example of the first relation used in the three-dimensional function unit A10. In detail, FIG. 3 shows the first relationship by a matrix table, and FIG. 4 three-dimensionally (three-dimensionally) shows the first relationship.
In FIG. 3, the horizontal axis indicates the amount of the first fuel used for premixed combustion in the combustor of the gas turbine 5, and the vertical axis indicates the amount of the second fuel used for diffusion combustion in the combustor of the gas turbine 5. ing. "X0", "X1", "X2", "X3", "X4", . . . , "Xi" on the horizontal axis of FIG. Y0", "Y1", "Y2", "Y3", "Y4", . , . . . , 'n33', . . . , 'n44', .
For example, when the value of the first fuel amount is "X0" and the value of the second fuel amount is "Y0", the three-dimensional function unit A10 calculates the predicted nitrogen oxide concentration value "n00". When the value of the first fuel amount is "X1" and the value of the second fuel amount is "Y2", the three-dimensional function unit A10 calculates the predicted nitrogen oxide concentration value "n12". When the value of the first fuel amount is "X4" and the value of the second fuel amount is "Yi", the three-dimensional function unit A10 calculates the predicted nitrogen oxide concentration value "n4i".
The first fuel amount values "X0", ..., "Xi", the second fuel amount values "Y0", ..., "Yi", and the predicted nitrogen oxide concentration values "n00", ..., The relationship (first relationship) with "nii" is set in advance by performing experiments, simulations, or the like, for example.

In FIG. 4, the X-axis indicates the amount of the first fuel used for premixed combustion in the combustor of the gas turbine 5, and the Y-axis indicates the amount of the second fuel used for diffusion combustion in the combustor of the gas turbine 5. , and the Z axis indicates the predicted nitrogen oxide concentration value calculated by the three-dimensional function unit A10.
In the example shown in FIG. 4, the predicted nitrogen oxide concentration value increases as the first fuel amount increases, and the predicted nitrogen oxide concentration value increases as the second fuel amount increases.
The relationship (first relationship) between the first fuel amount indicated by the X-axis, the second fuel amount indicated by the Y-axis, and the predicted nitrogen oxide concentration value indicated by the Z-axis in FIG. is set in advance by

In the example shown in FIG. 2 , the fuel/air ratio calculator A15 calculates the ratio of fuel and air (fuel/air ratio) used for combustion in the combustor of the gas turbine 5 .
A two-dimensional function unit A16 is a first nitrogen oxidation function for correcting the predicted nitrogen oxide concentration value calculated by the three-dimensional function unit A10 based on the fuel/air ratio calculated by the fuel/air ratio calculation unit A15. Calculate the concentration correction amount. More specifically, the two-dimensional function unit A16 uses the fuel/air ratio calculated by the fuel/air ratio calculator A15 and the preset relationship between the fuel/air ratio and the first nitrogen oxide concentration correction amount. Based on this, the first nitrogen oxide concentration correction amount is calculated. The relationship between the fuel/air ratio and the first nitrogen oxide concentration correction amount is set in advance by conducting experiments, simulations, or the like, for example.

The combustor bypass valve opening information acquisition unit A14 acquires information indicating the opening of the combustor bypass valve that controls the fuel/air ratio.
The fixed value setter A17 outputs the value "1" as the first nitrogen oxide concentration correction amount.
The switch A18 switches the value as the first nitrogen oxide concentration correction amount output to the multiplier A12. Specifically, when the combustor bypass valve is open, the switch A18 transfers the value "1" output from the fixed value setter A17 to the multiplier A12 as the first nitrogen oxide concentration correction amount. Output. In this case, the predicted nitrogen oxide concentration value calculated by the three-dimensional function unit A10 is not corrected by the multiplier A12. On the other hand, when the combustor bypass valve is not open, the switch A18 outputs the first nitrogen oxide concentration correction amount calculated by the two-dimensional function unit A16 to the multiplier A12. In this case, the predicted nitrogen oxide concentration value calculated by the three-dimensional function device A10 is corrected by the multiplier A12 based on the first nitrogen oxide concentration correction amount calculated by the two-dimensional function device A16.

A multiplier A12 multiplies the predicted nitrogen oxide concentration value calculated by the three-dimensional function unit A10 by the value (first nitrogen oxide concentration correction amount) output from the switch A18 to obtain a three-dimensional function Correct the nitrogen oxide concentration predicted value calculated by the device A10.
That is, the multiplier A12 uses the three-dimensional function unit A10 Correct the nitrogen oxide concentration predicted value calculated by

The three-dimensional function A11 is the combustion air temperature, which is the temperature of the air used for combustion in the combustor of the gas turbine 5, and the combustion air humidity, which is the humidity of the air used for combustion in the combustor of the gas turbine 5. , a second nitrogen oxide concentration correction amount for further correcting the nitrogen oxide concentration predicted value corrected by the multiplier A12 is calculated.
Specifically, the three-dimensional function unit A11 calculates a third 2 Calculate the nitrogen oxide concentration correction amount. The second relationship, which is the relationship between the combustion air temperature, the combustion air humidity, and the second nitrogen oxide concentration correction amount, is set in advance by performing experiments, simulations, or the like, for example.

The subtractor A13 subtracts the second nitrogen oxide concentration correction amount calculated by the three-dimensional function unit A11 from the nitrogen oxide concentration predicted value corrected by the multiplier A12. Further correct the nitrogen oxide concentration prediction value.
In the example shown in FIG. 2, the nitrogen oxide concentration prediction model 11 (three-dimensional function model 11A) converts the value output from the subtractor A13 into the predicted value of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7. output as

That is, in the denitrification control device 1 of the first embodiment, the concentration of nitrogen oxides generated by combustion in the combustor of the gas turbine 5 depends on the fuel distribution ratio between diffusion combustion and premixed combustion in the combustor of the gas turbine 5. is taken into account. Specifically, in the denitrification control device 1 of the first embodiment, a matrix table ( 3), by setting prediction data (predicted nitrogen oxide concentration values) corresponding to the analysis values of the analyzer 2 (see FIG. 1) at the entrance of the denitrification device 7, the analyzer at the entrance of the denitration device 7 2 (see FIG. 1), the three-dimensional function device A10 can calculate (predict) the nitrogen oxide concentration prediction value corresponding to the analysis value of the analyzer 2.

Further, in the denitrification control device 1 of the first embodiment, the concentration of nitrogen oxides generated by combustion in the combustor of the gas turbine 5 depends on the ratio of fuel and air used for combustion in the combustor (fuel/air ratio). are also considered to depend on Specifically, in the denitrification control device 1 of the first embodiment, the fuel/air ratio calculator A15 calculates the ratio of fuel and air used for combustion in the combustor of the gas turbine 5 (fuel/air ratio). , a two-dimensional function unit A16 calculates a first nitrogen oxide concentration prediction value calculated by the three-dimensional function unit A10 based on the fuel/air ratio calculated by the fuel/air ratio calculation unit A15. An oxide concentration correction amount is calculated.

Furthermore, in the denitrification control device 1 of the first embodiment, it is taken into consideration that the concentration of nitrogen oxides produced by combustion in the combustor of the gas turbine 5 also depends on the temperature and humidity of the air used for combustion in the combustor. It is Specifically, in the denitrification control device 1 of the first embodiment, a matrix table (not shown) similar to the matrix table shown in FIG. ), the three-dimensional function device A11 calculates the second nitrogen oxide concentration correction amount from the temperature and humidity of the air used for combustion in the combustor. .

As described above, when the analyzer 2 (see FIG. 1) that measures the concentration of nitrogen oxides at the inlet of the denitrification system is used, there is a delay in the analysis time (generally about 1 minute). The exhaust gas whose nitrogen oxide concentration is measured by the analyzer 2 when passing through 7 coincides with the exhaust gas to which the amount of ammonia calculated based on the nitrogen oxide concentration measured by the analyzer 2 is supplied. Otherwise, the supply amount of ammonia becomes excessive or insufficient, and as a result, denitrification control cannot be properly performed.

On the other hand, in the gas turbine plant GP to which the denitration control device 1 of the first embodiment is applied, the analyzer 2 (see FIG. 1) for measuring the concentration of nitrogen oxides is not installed at the entrance of the denitration device 7. The analysis time delay problem can be resolved. Furthermore, in the denitration control device 1 of the first embodiment, the ammonia supply amount is controlled based on the nitrogen oxide concentration predicted by the nitrogen oxide concentration prediction model 11 (that is, the nitrogen oxide concentration without analysis time delay). Therefore, appropriate denitrification control can be performed.

FIG. 5 is a diagram for explaining an example of processing executed in the denitration control device 1 of the first embodiment.
In the example shown in FIG. 5, in step S1, the nitrogen oxide concentration prediction model 11 (three-dimensional function model 11A) of the denitrification control device 1 predicts the concentration of nitrogen oxides in the flue gas at the inlet of the denitration device .
Next, in step S2, the ammonia flow rate calculator 13 of the denitrification control device 1 calculates the amount of ammonia to be supplied to reduce the nitrogen oxide content in the exhaust gas, and outputs a control signal to the ammonia flow rate control valve 3. is generated and output. As a result, the ammonia flow rate control valve 3 is driven, and the amount of ammonia calculated by the ammonia flow rate calculator 13 is supplied to the denitrification device 7 . That is, in the denitrification device 7, the amount of ammonia supplied to the exhaust gas containing nitrogen oxides is controlled.

[Second embodiment]
A second embodiment of the denitration control device, denitration control method and program of the present invention will be described below.
The denitration control device 1 of the second embodiment is configured in the same manner as the denitration control device 1 of the first embodiment described above, except for the points described later. Therefore, according to the denitration control device 1 of the second embodiment, the same effects as those of the denitration control device 1 of the first embodiment described above can be obtained except for the points described later.

A gas turbine plant GP to which the denitration control device 1 of the second embodiment is applied is configured in the same manner as the gas turbine plant GP to which the denitration control device 1 of the first embodiment shown in FIG. 1 is applied.
That is, the gas turbine plant GP to which the denitration control device 1 of the second embodiment is applied includes the denitration control device 1, the ammonia flow control valve 3, the smoke inlet nitrogen oxide concentration analyzer 4, and the gas turbine 5. , a flue 6 , a denitration device 7 and a chimney 8 are installed, and the analyzer 2 (see FIG. 1 ) for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitration device 7 .
The denitration control device 1 of the second embodiment controls the amount of ammonia supplied in the denitration device 7, like the denitration control device 1 of the first embodiment.

In an example of a gas turbine plant GP to which the denitration control device 1 of the second embodiment is applied, similarly to the example shown in FIG. A calculator 12 , an ammonia flow rate calculator 13 , and a feedback correction amount calculator 14 are provided.
Similar to the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment, the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the second embodiment is the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment. The concentration of oxides is predicted by model calculation.

FIG. 6 is a diagram showing an example of the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the second embodiment.
In the example shown in FIG. 6, the nitrogen oxide concentration prediction model 11 is composed of a multiple regression analysis model 11B. The multiple regression analysis model 11B includes a process signal selection section B20, a process signal selection section B21, a compatibility evaluation section B22, and a nitrogen oxide concentration prediction section B23.
The process signal selector B20 selects a plurality of process signals P1 which are related to combustion in the combustor of the gas turbine 5 and which are assumed to affect the concentration of nitrogen oxides at the inlet of the denitrification device 7. , P2, P3, P4, P5, . . . , Pi.
The plurality of process signals P1, P2, P3, P4, P5, . Process signal indicating fuel distribution ratio for combustion, process signal indicating fuel distribution ratio for premixed combustion, process signal indicating IGV angle (opening), process signal indicating combustor bypass valve opening, gas Process signal indicating turbine exhaust gas temperature, process signal indicating gas turbine blade path temperature, process signal indicating air compressor inlet temperature, process signal indicating air compressor outlet temperature, process signal indicating air compressor inlet pressure, for combustion Process signals indicating air humidity, etc. are included.

The process signal indicating the combustion fuel flow rate corresponds to, for example, the main fuel flow control valve opening command value and the pilot fuel flow control valve opening command value described in paragraph 0045 of JP-A-2007-309279. The process signal indicating the combustion air flow rate corresponds to, for example, the input signal (input data) of the combustion air flow rate described in paragraph 0034 of JP-A-2015-183619. The process signal indicating the fuel distribution ratio for diffusion combustion and the process signal indicating the fuel distribution ratio for premixed combustion correspond to, for example, the fuel distribution limit signal described in paragraph 0083 of JP-A-10-127098.
The process signal indicating the IGV angle corresponds to, for example, the load command (load signal) described in paragraphs 0002 and 0003 of JP-A-6-241062. The process signal indicating the combustor bypass valve opening corresponds to, for example, the combustor bypass valve opening command value described in paragraph 0045 of JP-A-2007-309279.
The process signal indicating the gas turbine exhaust gas temperature corresponds to, for example, a signal measured by an exhaust gas thermometer described in paragraph 0023 of JP-A-2016-142212. The process signal indicating the gas turbine blade path temperature corresponds to, for example, a signal measured by a blade path thermometer described in paragraph 0023 of JP-A-2016-142212.

The process signal indicating the air compressor inlet temperature corresponds to, for example, the output signal of the temperature sensor that measures the compressor inlet temperature described in paragraph 0023 of WO2019/078309. The process signal indicating the air compressor outlet temperature corresponds to, for example, the output signal of the compressor outlet temperature sensor described in paragraph 0017 of JP-A-2012-167550. The process signal indicating the air compressor inlet pressure corresponds to, for example, the output signal of the intake pressure gauge described in paragraph 0035 of JP-A-2016-142212. The process signal indicating the combustion air humidity is, for example, the output signal of a hygrometer installed on the suction side of the intake port of the intake duct described in paragraph 0033 of JP-A-2020-002792, JP-A-2013-029095. corresponds to the output signal of the inlet air humidity detector described in paragraph 0021 of .

In the example shown in FIG. 6, the process signal selection unit B21 uses the plurality of process signals P1, P2, P3, P4, P5, . A multiple regression analysis is performed with the concentration of nitrogen oxides at the target variable.
, Pi selected by the process signal selection unit B20 are applied to the concentration of nitrogen oxides at the inlet of the denitrification device 7. A plurality of process signals P1, P2, P3, P4, P5 selected by the process signal selection unit B20 based on the t value of multiple regression analysis indicating the degree of influence (for the t value, see, for example, the URL below), , Pi, a plurality of sorted process signals P1, P2, P4, .
https://www.sangiin.go.jp/japanese/annai/chousa/keizai_prism/backnumber/r02pdf/202019202.pdf

The suitability evaluation unit B22 evaluates the suitability of the plurality of post-sorting process signals P1, P2, P4, . (see URL, etc.).
https://www.soumu.go.jp/ict_skill/pdf/ict_skill_3_4.pdf
In addition, the suitability evaluation unit B22 uses the multiple regression equation (concentration of nitrogen oxides at the inlet of the denitrification device 7 = P1 × A + P2 × B + P4 × C + ... + Pi × i + intercept) to select a plurality of A plurality of regression coefficients A, B, C, . . . , i by which the sorted process signals P1, P2, P4, .

In the example shown in FIG. 6, a plurality of sorted process signals P1, P2, P4, . Pi is selected and a plurality of regression coefficients A, B, C, . . . , i are determined. A plurality of sorted process signals P1, P2, P4, . . . , Pi may be sorted and a plurality of regression coefficients A, B, C, .

In the example shown in FIG. 6, the nitrogen oxide concentration prediction unit B23 is determined by the plurality of post-sorting process signals P1, P2, P4, . The concentration of nitrogen oxides at the inlet of the denitration device 7 is predicted based on the multiple regression coefficients A, B, C, . . . , i and the intercept of the multiple regression equation.
Specifically, the nitrogen oxide concentration prediction unit B23 includes a multiplication unit B24, an intercept setting unit B25, and an addition unit B26. , Pi selected by the process signal selection unit B21 and the regression coefficients A, B, . . . Multiply each of C, . . . , i. The intercept setting unit B25 sets the intercept of the multiple regression equation. The adder B26 adds the values multiplied by the multiplier B24 (P1×A, P2×B, P4×C, . Calculate the concentration of nitrogen oxides at the inlet of 7.

[Third Embodiment]
A third embodiment of the denitration control device, denitration control method and program of the present invention will be described below.
The denitration control device 1 of the third embodiment is configured in the same manner as the denitration control device 1 of the first embodiment described above, except for the points described later. Therefore, according to the denitration control device 1 of the third embodiment, the same effects as those of the denitration control device 1 of the first embodiment described above can be obtained except for the points described later.

A gas turbine plant GP to which the denitration control device 1 of the third embodiment is applied is configured in the same manner as the gas turbine plant GP to which the denitration control device 1 of the first embodiment shown in FIG. 1 is applied.
That is, the gas turbine plant GP to which the denitration control device 1 of the third embodiment is applied includes the denitration control device 1, the ammonia flow rate adjustment valve 3, the smoke inlet nitrogen oxide concentration analyzer 4, and the gas turbine 5. , a flue 6 , a denitration device 7 and a chimney 8 are installed, and the analyzer 2 (see FIG. 1 ) for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitration device 7 .
The denitration control device 1 of the third embodiment controls the amount of ammonia supplied in the denitration device 7, like the denitration control device 1 of the first embodiment.

In an example of a gas turbine plant GP to which the denitration control device 1 of the third embodiment is applied, as in the example shown in FIG. A calculator 12 , an ammonia flow rate calculator 13 , and a feedback correction amount calculator 14 are provided.
The nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the third embodiment is similar to the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment. The concentration of oxides is predicted by model calculation.

FIG. 7 is a diagram showing an example of the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the third embodiment.
In the example shown in FIG. 7, the nitrogen oxide concentration prediction model 11 is composed of a reaction rate model 11C. The reaction rate model 11C includes a fuel flow rate acquisition unit C30, a two-dimensional function unit C31, a combustion air amount acquisition unit C32, an IGV angle acquisition unit C33, a two-dimensional function unit C34, a divider C35, and a multiplication unit. and a multiplier C36 and a multiplier C37.

The fuel flow rate acquisition unit C30 acquires information indicating the fuel flow rate used for combustion in the combustor of the gas turbine 5 . The information indicating the fuel flow rate acquired by the fuel flow rate acquisition unit C30 includes, for example, the main fuel flow control valve opening command value and the pilot fuel flow control valve opening command value described in paragraph 0045 of Japanese Patent Application Laid-Open No. 2007-309279. Equivalent to a value, etc.
The two-dimensional function C31 calculates a predicted value (FX [fuel flow rate]) of the reaction rate of the nitrogen oxide concentration in the exhaust gas at the inlet of the denitrification device 7 . Specifically, the two-dimensional function C31 is obtained by calculating the fuel flow rate used for combustion in the combustor of the gas turbine 5 obtained by the fuel flow rate obtaining unit C30, the fuel flow rate, and the nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7. of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 based on a predetermined relationship (predicted value = FX [fuel flow]) with the predicted value of the reaction rate (FX [fuel flow]) of the concentration of Calculate the predicted value of the concentration reaction rate (FX [fuel flow rate]). The relationship between the fuel flow rate and the predicted value of the reaction rate of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 (predicted value = FX [fuel flow rate]) is determined in advance by conducting experiments, simulations, or the like. .

The combustion air amount acquisition unit C32 acquires information indicating the amount of combustion air, which is the amount of air used for combustion in the combustor of the gas turbine 5 . The information indicating the combustion air amount acquired by the combustion air amount acquisition unit C32 corresponds to, for example, the input signal (input data) of the combustion air flow rate described in paragraph 0034 of Japanese Patent Application Laid-Open No. 2015-183619. .
The IGV angle acquisition unit C33 acquires information indicating the IGV angle. The information indicating the IGV angle acquired by the IGV angle acquisition section C33 corresponds to, for example, the load command (load signal) described in paragraphs 0002 and 0003 of JP-A-6-241062.
The two-dimensional function device C34 predicts the reaction rate of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 calculated by the two-dimensional function device C31 based on the IGV angle acquired by the IGV angle acquisition unit C33. Calculate the reference air amount used to correct the value. Specifically, the two-dimensional function unit C34 calculates the reference air amount based on the IGV angle obtained by the IGV angle obtaining section C33 and the preset relationship between the IGV angle and the reference air amount. The relationship between the IGV angle and the reference air amount is set in advance by performing experiments, simulations, or the like, for example.

The divider C35 divides the combustion air amount acquired by the combustion air amount acquisition unit C32 by the reference air amount calculated by the two-dimensional function C34, thereby obtaining the amount of air used for combustion in the combustor of the gas turbine 5. Calculate the required air density.
A multiplier C36 multiplies the air density calculated by the divider C35 by a predetermined coefficient to obtain the reaction of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitration device 7 calculated by the two-dimensional function C31. A value ([air density] ^α ) for correcting the predicted speed value (FX [fuel flow rate]) is calculated.
The multiplier C37 combines the predicted value (FX [fuel flow rate]) of the reaction rate of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitration device 7 calculated by the two-dimensional function C31 with the value calculated by the multiplier C36. value ([air density] ^α ), the reaction rate of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 (d [NOx]/dt = [air density] ^α × FX [fuel flow rate ]) is calculated, and the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7 is predicted.
That is, the reaction rate model 11C uses the predicted value of the reaction rate of the concentration of nitrogen oxides (FX [fuel flow rate]) calculated by the two-dimensional function C31 as the combustion in the combustor of the gas turbine 5. The concentration of nitrogen oxides in the flue gas at the inlet of the denitrification device 7 is predicted by correcting based on the amount of air used and the IGV angle.

Specifically, the generation of nitrogen oxides by combustion in the combustor of the gas turbine 5 is a chemical reaction and depends on the air and the combustion temperature. The concentration prediction model 11 predicts the concentration of nitrogen oxides in the flue gas at the inlet of the denitrification device 7 by applying the reaction rate equations (1) and (2) (Arrhenius equation) below.
d[NOx]/dt=k×[N ² ] ^α・[O ² ] ^β (1)
k=A×exp(−E/RT) (2)

The above formulas (1) and (2) can be represented by the following formula (3).
d[NOx]/dt=A×combustion air concentration ^α ×exp (−β/combustion temperature) (3)

From the above equation (3), in developing the reaction rate model 11C that predicts the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitrification device 7, the combustion air concentration is regarded as the air density, and the change in combustion temperature is By making it a two-dimensional function (FX [fuel flow rate] described above) by an FX curve from the fuel flow rate, it can be expressed by the following equation (4).
d[NOx]/dt=[air density] ^α ×FX[fuel flow rate] (4)

The above-described relationship used for calculating the predicted value (FX [fuel flow rate]) of the reaction rate of the concentration of nitrogen oxides in the exhaust gas at the inlet of the denitration device 7 in the two-dimensional function C31 is the combustion of the gas turbine 5. FX obtained by plotting experimental results, simulation results, etc., with the fuel flow rate used for combustion in the gas turbine 5 on the X axis and the predicted concentration of nitrogen oxides generated by combustion in the combustor of the gas turbine 5 on the Y axis. curve.

The above-mentioned relationship used for calculating the reference air amount in the two-dimensional function unit C34 is obtained by plotting experimental results, simulation results, etc. with the IGV angle as the X axis and the reference air amount as the Y axis. is.

[Fourth embodiment]
A fourth embodiment of the denitration control device, denitration control method and program of the present invention will be described below.
The denitration control device 1 of the fourth embodiment is configured in the same manner as the denitration control device 1 of the first embodiment described above, except for the points described later. Therefore, according to the denitration control device 1 of the fourth embodiment, the same effects as those of the denitration control device 1 of the first embodiment described above can be obtained except for the points described later.

A gas turbine plant GP to which the denitration control device 1 of the fourth embodiment is applied is configured in the same manner as the gas turbine plant GP to which the denitration control device 1 of the first embodiment shown in FIG. 1 is applied.
That is, the gas turbine plant GP to which the denitration control device 1 of the fourth embodiment is applied includes the denitration control device 1, the ammonia flow control valve 3, the smoke inlet nitrogen oxide concentration analyzer 4, and the gas turbine 5. , a flue 6 , a denitration device 7 and a chimney 8 are installed, and the analyzer 2 (see FIG. 1 ) for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitration device 7 .
The denitration control device 1 of the fourth embodiment controls the amount of ammonia supplied in the denitration device 7, like the denitration control device 1 of the first embodiment.

In an example of a gas turbine plant GP to which the denitration control device 1 of the fourth embodiment is applied, as in the example shown in FIG. A calculator 12 , an ammonia flow rate calculator 13 , and a feedback correction amount calculator 14 are provided.
Similar to the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment, the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the fourth embodiment is the nitrogen oxide concentration prediction model 11 of the denitration control device 1 of the first embodiment. The concentration of oxides is predicted by model calculation.

In the denitration control device 1 of the fourth embodiment, the nitrogen oxide concentration prediction model 11 includes a three-dimensional function model 11A shown in FIG. 2, a multiple regression analysis model 11B shown in FIG. 6, and a reaction rate model shown in FIG. 11C with at least two models.
In the denitration control device 1 of the fourth embodiment, the nitrogen oxide concentration prediction model 11 is one of the above-described at least two models according to the characteristics of the gas turbine plant GP to which the denitration control device 1 of the fourth embodiment is applied. One of the models may be selected and used, or a combination of at least two of the models described above may be used.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and examples, and can be changed as appropriate without departing from the scope of the present invention. can be added. You may combine the structure as described in each embodiment and each example which were mentioned above.

All or part of the functions of the units provided in the denitration control apparatus 1 in the above-described embodiment are recorded on a computer-readable recording medium by recording a program for realizing these functions. It may be realized by loading the program into a computer system and executing it. It should be noted that the "computer system" referred to here includes hardware such as an OS and peripheral devices.
The term "computer-readable recording medium" refers to portable media such as flexible discs, magneto-optical discs, ROMs and CD-ROMs, and storage units such as hard discs incorporated in computer systems. Furthermore, "computer-readable recording medium" means a medium that dynamically retains a program for a short period of time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. It may also include a device that holds a program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client in that case. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

DESCRIPTION OF SYMBOLS 1... Denitrification control apparatus, 11... Nitrogen oxide concentration prediction model, 11A... Three-dimensional function model, A10... Three-dimensional function device, A11... Three-dimensional function device, A12... Multiplier, A13... Subtractor, A14... Burner Bypass valve opening information acquisition unit A15 Fuel/air ratio calculation unit A16 Two-dimensional function unit A17 Fixed value setting device A18 Switching device 11B Multiple regression analysis model B20 Process signal selection unit B21... process signal selection unit, B22... compatibility evaluation unit, B23... nitrogen oxide concentration prediction unit, B24... multiplication unit, B25... intercept setting unit, B26... addition unit, 11C... reaction rate model, C30... fuel flow rate Acquisition unit, C31... Two-dimensional function unit, C32... Combustion air amount acquisition unit, C33... IGV angle acquisition unit, C34... Two-dimensional function unit, C35... Divider, C36... Multiplier, C37... Multiplier, 12... Nitrogen oxide treatment amount calculator 13 Ammonia flow rate calculator 14 Feedback correction amount calculator 3 Ammonia flow rate control valve 4 Smoke inlet nitrogen oxide concentration analyzer 5 Gas turbine 6 Flue , 7... Denitrification device, 8... Chimney, GP... Gas turbine plant

Claims (9)

A denitration control device for controlling the amount of ammonia supplied to a denitration device for reducing the content of nitrogen oxides in exhaust gas containing nitrogen oxides generated by combustion in a gas turbine, the denitration control device comprising: ,
An analyzer for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitrification device,
a nitrogen oxide concentration prediction model that predicts the concentration of the nitrogen oxides at the inlet of the denitrification device by model calculation;
Denitration controller. In the combustor of the gas turbine, premixed combustion and diffusion combustion are performed,
The gas turbine is provided with a combustor bypass valve that controls a fuel/air ratio, which is the ratio of fuel and air used for combustion in the combustor,
The nitrogen oxide concentration prediction model is
A first fuel amount that is the fuel amount used for the premixed combustion, a second fuel amount that is the fuel amount used for the diffusion combustion, and the first fuel amount, the second fuel amount, and the nitrogen oxide a first three-dimensional function unit for calculating the predicted nitrogen oxide concentration value based on a predetermined first relationship with the predicted nitrogen oxide concentration value, which is the predicted concentration value;
The nitrogen oxide concentration calculated by the first three-dimensional function unit based on the first nitrogen oxide concentration correction amount calculated according to the fuel/air ratio and the opening degree of the combustor bypass valve. a multiplier that corrects the predicted value,
The denitration control device according to claim 1. The nitrogen oxide concentration prediction model is
Combustion air temperature, which is the temperature of the air used for combustion in the combustor; Combustion air humidity, which is the humidity of the air used for combustion in the combustor; and the combustion air temperature and the combustion air humidity The second nitrogen oxide concentration correction amount is calculated based on a predetermined second relationship between the predicted nitrogen oxide concentration corrected value corrected by the multiplier and a second nitrogen oxide concentration correction amount for further correcting the second nitrogen oxide concentration correction amount. comprising a second three-dimensional function unit that calculates
The denitration control device according to claim 2. The nitrogen oxide concentration prediction model is
A process signal selector that selects a plurality of process signals associated with combustion in the combustor of the gas turbine that are assumed to affect the concentration of the nitrogen oxides at the inlet of the denitrification device. and,
a process signal selection unit that performs multiple regression analysis using the plurality of process signals selected by the process signal selection unit as explanatory variables and the nitrogen oxide concentration as an objective variable;
The process signal selection unit selects the process signal selection unit based on the t value of multiple regression analysis that indicates the degree of influence of the plurality of process signals selected by the process signal selection unit on the concentration of nitrogen oxides. from the plurality of process signals selected by selecting a plurality of sorted process signals that are the plurality of process signals used to predict the concentration of the nitrogen oxides;
The nitrogen oxide concentration prediction model is
a suitability evaluation unit that evaluates the suitability of the plurality of post-sorting process signals selected by the process signal selection unit based on a correction R2 of multiple regression analysis;
The suitability evaluation unit determines a plurality of regression coefficients by which the plurality of post-selection process signals selected by the process signal selection unit are multiplied in the multiple regression equation,
The nitrogen oxide concentration prediction model is
Based on the plurality of post-sorting process signals selected by the process signal selection unit, the plurality of regression coefficients determined by the suitability evaluation unit, and the intercept of the multiple regression equation, the inlet of the denitrification device a nitrogen oxide concentration prediction unit that predicts the concentration of the nitrogen oxides in
The denitration control device according to claim 1. In the combustor of the gas turbine, premixed combustion and diffusion combustion are performed,
The gas turbine is provided with a combustor bypass valve that controls a fuel/air ratio, which is the ratio of fuel and air used for combustion in the combustor,
The compressor of the gas turbine is equipped with an IGV (inlet guide vane),
The plurality of process signals selected by the process signal selection unit include a process signal indicating a fuel flow rate for combustion, a process signal indicating a combustion air flow rate, a process signal indicating a fuel distribution ratio for diffusion combustion, and a process signal for premixed combustion. Process signal indicating fuel distribution ratio, process signal indicating IGV angle, process signal indicating combustor bypass valve opening, process signal indicating gas turbine exhaust gas temperature, process signal indicating gas turbine blade path temperature, air compressor inlet temperature a process signal indicative of air compressor outlet temperature; a process signal indicative of air compressor inlet pressure; and a process signal indicative of combustion air humidity.
The denitration control device according to claim 4. The compressor of the gas turbine is equipped with an IGV (inlet guide vane),
The nitrogen oxide concentration prediction model is
Based on the fuel flow rate used for combustion in the combustor of the gas turbine and a predetermined relationship between the fuel flow rate and the predicted value of the reaction rate of the nitrogen oxide concentration at the inlet of the denitrification device, Equipped with a two-dimensional function unit for calculating the predicted value of the reaction rate of the concentration of nitrogen oxides,
The predicted value of the reaction rate of the concentration of nitrogen oxides calculated by the two-dimensional function unit is combined with the combustion air amount, which is the amount of air used for combustion in the combustor, and the IGV angle, which is the angle of the IGV. predicting the nitrogen oxide concentration at the inlet of the denitrifier by correcting based on
The denitration control device according to claim 1. In the combustor of the gas turbine, premixed combustion and diffusion combustion are performed,
The gas turbine is provided with a combustor bypass valve that controls a fuel/air ratio, which is the ratio of fuel and air used for combustion in the combustor,
The compressor of the gas turbine is equipped with an IGV (inlet guide vane),
The nitrogen oxide concentration prediction model is
A first fuel amount that is the fuel amount used for the premixed combustion, a second fuel amount that is the fuel amount used for the diffusion combustion, and the first fuel amount, the second fuel amount, and the nitrogen oxide a first three-dimensional function unit for calculating the predicted nitrogen oxide concentration value based on a predetermined first relationship with the predicted nitrogen oxide concentration value, which is the predicted concentration value;
The nitrogen oxide concentration calculated by the first three-dimensional function unit based on the first nitrogen oxide concentration correction amount calculated according to the fuel/air ratio and the opening degree of the combustor bypass valve. a multiplier for correcting the predicted value;
Combustion air temperature, which is the temperature of the air used for combustion in the combustor; Combustion air humidity, which is the humidity of the air used for combustion in the combustor; and the combustion air temperature and the combustion air humidity The second nitrogen oxide concentration correction amount is calculated based on a predetermined second relationship between the predicted nitrogen oxide concentration corrected value corrected by the multiplier and a second nitrogen oxide concentration correction amount for further correcting the second nitrogen oxide concentration correction amount. a three-dimensional function model comprising a second three-dimensional function unit for calculating
a process signal selection unit that selects a plurality of process signals associated with combustion in the combustor that are assumed to affect the concentration of the nitrogen oxides at an inlet of the denitration device;
Multiple regression analysis is performed using the plurality of process signals selected by the process signal selection unit as explanatory variables and the nitrogen oxide concentration as an objective variable, and the plurality of process signals selected by the process signal selection unit are: Used to predict the concentration of nitrogen oxides from the plurality of process signals selected by the process signal selection unit based on the t value of multiple regression analysis that indicates the degree of influence on the concentration of nitrogen oxides. a process signal selection unit that selects a plurality of sorted process signals, which are a plurality of process signals;
The suitability of the plurality of post-sorting process signals sorted by the process signal sorting unit is evaluated based on the correction R2 of multiple regression analysis, and in the multiple regression equation, the plurality of sorted process signals sorted by the process signal sorting unit a suitability evaluator that determines a plurality of regression coefficients that are respectively multiplied by the sorted process signal;
Based on the plurality of post-sorting process signals selected by the process signal selection unit, the plurality of regression coefficients determined by the suitability evaluation unit, and the intercept of the multiple regression equation, the inlet of the denitrification device a nitrogen oxide concentration prediction unit that predicts the concentration of the nitrogen oxides in the fuel flow rate used for combustion in the combustor; and the fuel flow rate and the nitrogen oxidation at the inlet of the denitration device. a two-dimensional function unit for calculating the predicted value of the reaction rate of the concentration of nitrogen oxides based on a reaction rate formula that is a predetermined relationship between the predicted value of the reaction rate of the concentration of the substance and the predicted value of the reaction rate of the concentration of the substance;
The predicted value of the reaction rate of the concentration of nitrogen oxides calculated by the two-dimensional function unit is combined with the combustion air amount, which is the amount of air used for combustion in the combustor, and the IGV angle, which is the angle of the IGV. at least two kinetic models that predict the concentration of the nitrogen oxides at the inlet of the denitrifier by correcting based on
One of the at least two models is selected and used, or the at least two models are used in combination, according to the characteristics of the gas turbine plant to which the denitrification control device is applied.
The denitration control device according to claim 1. an ammonia supply amount control step of controlling the supply amount of ammonia supplied to an exhaust gas containing nitrogen oxides generated by combustion in a gas turbine in a denitrification device for reducing the content of the nitrogen oxides in the exhaust gas; A denitration control method for a denitration control device comprising:
An analyzer for measuring the concentration of nitrogen oxides is not installed at the entrance of the denitrification device,
a nitrogen oxide concentration prediction step of predicting the concentration of the nitrogen oxides at the inlet of the denitrification device by model calculation;
Denitrification control method. The computer installed in the denitrification control device
an ammonia supply amount control step of controlling the supply amount of ammonia supplied to a denitration device for reducing the content of nitrogen oxides in the exhaust gas containing nitrogen oxides generated by combustion in the gas turbine; ,
and a nitrogen oxide concentration prediction step of predicting the concentration of the nitrogen oxides at the entrance of the denitrification device by model calculation,
An analyzer for measuring the concentration of nitrogen oxides is not installed at the inlet of the denitrification device.
program.

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