JP5523949B2 - Fuel abnormality detection device, fuel adjustment device, and fuel abnormality detection method - Google Patents

Description

  The present invention relates to a fuel abnormality detection device and a fuel abnormality detection method for detecting that a fuel supplied to a combustor of a gas turbine has a high calorie abnormality, and a determination as to whether or not the fuel has a high calorie abnormality. The present invention relates to a fuel adjustment device that adjusts the calorie of fuel based on a result.

Some gas turbines installed in gas turbine power plants and combined cycle power plants mix fuels of different compositions in order to keep the calories of fuel for generating combustion gas constant.
For example, in a BFG-fired power plant that uses BFG (Blast Furnace Gas) as the main fuel, the calorific value of BFG changes according to the operating state of the blast furnace. When the calorie of this BFG is greatly reduced, there is a risk of unstable combustion and consumption. Therefore, the BFG-fired power plant reduces the calorie of fuel by adding COG (Coke Oven Gas), which is higher in calorie than BFG, as a heat-increasing gas when the calorie of BFG falls. The control which cancels is performed (for example, refer patent document 1).

Here, as a general method for detecting the calorie of the fuel, there is a method in which a calorimeter for measuring the calorie of the fuel is installed and the calorie measurement value is directly detected by the calorimeter.
For example, in the power plant 1001 shown in FIG. 6, the fuel mixer 1011 mixes BFG and COG to generate fuel, and supplies the generated fuel to the combustor 1012. The combustor 1012 burns the fuel supplied from the fuel mixer 1011 to generate combustion gas, and rotates the gas turbine 1013 with this combustion gas. The calorimeter 1021 bleeds and burns the fuel produced by the fuel mixer 1011 to measure the calorie of the fuel, and outputs the measured value to the control device 1022. Based on the calorie measurement value output from the calorimeter 1021, the control device 1022 detects a low calorie abnormality and performs calorie recovery control or plant stop.

JP 2009-52557 A

By the way, in the method disclosed in Patent Document 1, it is possible to prevent the consumption of the combustor from being consumed by detecting the low calorie of the fuel, but it is not possible to prevent an abnormal increase in the calorie of the fuel. When the calorie of the fuel rises, the temperature in the combustor rises and the combustor may be damaged. Therefore, it is necessary to promptly detect the increase in fuel calorie and take measures.
However, in the method of adjusting the blending of the fuel based on the calorie measurement value by the calorimeter, it takes time to measure the calorie. That is, the calorimeter usually takes 1 minute or more to measure calorie by delaying the response of the sampling pipe, and including a gas cleaning system for cleaning the gas transmission system and blast furnace gas at the end of the gas calorie measurement. It takes time. If the calorie of the fuel increases due to this measurement time, control for protecting the gas turbine combustor 1012 such as runback is delayed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel abnormality detection device, a fuel adjustment device, and a fuel abnormality detection method that can quickly determine the presence or absence of high-calorie abnormality in fuel. There is.

  The present invention has been made to solve the above-described problem, and a fuel abnormality detection device according to an aspect of the present invention obtains an output change index value representing a change in gas turbine output excluding the influence of a change in fuel demand. When the output change calculation unit and the output change index value obtained by the output change calculation unit are equal to or higher than a predetermined threshold corresponding to a high temperature abnormality of the gas turbine, the output change calculation unit is supplied to the combustor of the gas turbine. And a determination unit that determines that the fuel is abnormal in high calories.

  The fuel abnormality detection apparatus according to one aspect of the present invention is the above-described fuel abnormality detection apparatus, wherein the output change calculation unit includes the current fuel as an output index value representing a gas turbine output excluding the influence of the fuel request. An output index calculation unit for obtaining an output / fuel ratio expressed by a ratio between a difference obtained by subtracting the no-load fuel command from the command and the gas turbine output, and the output index calculation as an output change index value of the gas turbine An output change index calculation unit for obtaining a change amount or a change rate of the output / fuel ratio obtained by the unit.

A fuel abnormality detection device according to an aspect of the present invention is the above-described fuel abnormality detection device, wherein the output index calculation unit calculates the output / fuel ratio as follows: PPF = GTMW / ((1 / τs + 1) ( _{Gf_ref} − _{Gf_ref_FNSL} )). Here, PPF indicates the output / fuel ratio, GTMW indicates the gas turbine output, τ indicates the time constant, s indicates the Laplace operator, G _{f_ref} indicates the fuel command, and G _{f_ref_FNSL} indicates the fuel at no load Indicates a directive.

  The fuel abnormality detection device according to one aspect of the present invention is the above-described fuel abnormality detection device, wherein the output change calculation unit includes the gas as an output index value representing a gas turbine output excluding the influence of the fuel request. An output / chamber pressure ratio represented by a ratio of a difference obtained by subtracting a no-load casing pressure from a current casing pressure of the turbine and the gas turbine output is obtained, and the output change index value of the gas turbine is A change amount or a change rate of the output / cabinet pressure ratio is obtained.

The fuel abnormality detection device according to an aspect of the present invention is the above-described fuel abnormality detection device, wherein the output change calculation unit calculates the output / vehicle compartment pressure ratio as follows: PPP _cs = GTMW / ((1 / _Τs + 1) P _cs −P _{cs_FNSL} ). Here, PPP _cs indicates the output / chamber pressure ratio, GTMW indicates the gas turbine output, τ indicates the time constant, s indicates the Laplace operator, P _cs indicates the chamber pressure, and P _{cs_FNSL} is Indicates no-load cabin pressure.

  The fuel abnormality detection device according to one aspect of the present invention is the above-described fuel abnormality detection device, wherein the output change calculation unit includes the gas as an output index value representing a gas turbine output excluding the influence of the fuel request. An output / CSO ratio indicating a magnitude of the gas turbine output with respect to a difference obtained by subtracting an output command signal at no load from a current output command signal that is an output command to the turbine is obtained, and the output change index value of the gas turbine A change amount or a change rate of the output / CSO ratio is obtained.

The fuel abnormality detection apparatus according to one aspect of the present invention is the above-described fuel abnormality detection apparatus, wherein the output change calculation unit calculates the output / CSO ratio by the following equation: PPC = GTMW / ((1 / τs + 1) (CSO- _{CSO_FNSL} )). Here, PPC represents the output / CSO ratio, GTMW represents a gas turbine output, tau represents the time constant, s indicates a Laplace operator, CSO represents an output command signal, CSO _{_FNSL} the load output command signal (No load).

  According to another aspect of the present invention, there is provided a fuel adjustment device including: any one of the fuel abnormality detection devices described above; and the fuel abnormality detection device, wherein the fuel supplied to the combustor of the gas turbine has a high calorie abnormality. And a fuel adjusting unit that adjusts the mixing of the fuel so that the calorie of the fuel supplied to the gas turbine is reduced.

  A fuel abnormality detection method according to one aspect of the present invention is a fuel abnormality detection method of a fuel abnormality detection device, wherein an output change calculation unit represents a change in gas turbine output excluding the influence of a change in fuel demand. An output change calculation step for obtaining a turbine output change index value, and the gas turbine output change index value obtained by the determination unit in the output change calculation step is equal to or greater than a predetermined threshold corresponding to a high temperature abnormality of the gas turbine. In this case, a determination step of determining that the fuel supplied to the combustor of the gas turbine has a high calorie abnormality is provided.

  According to the present invention, the presence or absence of high-calorie abnormality in fuel can be quickly determined.

It is a block diagram which shows the structure of the power plant in one Embodiment of this invention. It is a block diagram which shows the structure of the fuel abnormality detection apparatus in the same embodiment. In the embodiment, the fuel abnormality detection device is a flowchart showing a processing procedure for detecting that the fuel is in a high calorie abnormality. 4 is a block diagram illustrating a configuration of an output change calculation unit 211 including a delay filter unit that delays a fuel command in the embodiment. FIG. In the embodiment, the fuel abnormality detection device 21 shown in FIG. 4 is a flowchart showing a processing procedure for detecting that the fuel is in a high calorie abnormality. It is a figure which shows the example of the conventional power plant provided with a calorimeter.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a power plant in one embodiment of the present invention. In FIG. 1, a power plant 1 includes a fuel mixer 11, a gas turbine (GT) 100 having a compressor 14, a combustor 12, and a turbine 13, and an exhaust heat recovery boiler (Heat Recovery Stem Generator; (HRSG) 15, steam turbine (ST) 16, generator 17, fuel abnormality detection device 21, and control device 22.
The application range of the present invention is not limited to the gas turbine of the single-shaft combined cycle power plant shown in FIG. The present invention can be applied to various gas turbines in which the calorie of fuel can change.

The fuel mixer 11 mixes BFG and COG to generate fuel, and supplies the generated fuel to the combustor 12 of the gas turbine 100. The compressor 14 of the gas turbine 100 compresses the outside air and supplies the compressed air to the combustor 12. The combustor 12 mixes the compressed air supplied from the compressor 14 and the fuel supplied from the fuel mixer 11 and combusts them to generate combustion gas, and supplies the generated combustion gas to the turbine 13. . The turbine 13 is rotationally driven using the combustion gas supplied from the combustor 12 as a working gas.
The exhaust heat recovery boiler 15 generates steam from the exhaust gas from the turbine 13 and supplies the generated steam to the steam turbine 16. The steam turbine 16 is rotationally driven by steam supplied from the exhaust heat recovery boiler 15.
The generator 17 is rotated by the turbine 13 and the steam turbine 16 to generate power.
The fuel abnormality detection device 21 detects a high calorie abnormality of the fuel generated by the fuel mixer 11. The control device 22 controls the operation of each unit. In particular, when the fuel abnormality detection device 21 detects a high-calorie abnormality in the fuel, the control device 22 controls the fuel mixer 11 so as to reduce the fuel calorie, for example, by reducing the mixing ratio of COG, whereby the turbine 13 Run back.

FIG. 2 is a block diagram illustrating a configuration of the fuel abnormality detection device 21. In the figure, the fuel abnormality detection device 21 includes an output change calculation unit 211 and a determination unit 212. The output change calculation unit 211 includes an output index calculation unit 711, a delay filter unit 712, and a subtraction unit (output change index calculation unit) 713.
The output change calculation unit 211 obtains an output change index value representing a change in gas turbine output excluding the influence of a change in fuel demand. Specifically, the output change calculation unit 211 uses the difference between the current fuel command and the no-load fuel command as the output index value representing the gas turbine output excluding the influence of the fuel request, and the gas turbine output. The power per fuel ratio (PPF) expressed by the ratio is obtained, and the output change index value of the turbine 13 is the change amount of the power / fuel ratio (increase is indicated by a positive value, and decrease is indicated by a negative value) Ask).

The output index calculation unit 711 obtains the current fuel command, the no-load fuel command, and the gas turbine output, and calculates the output / fuel ratio. As a reference signal output unit, the delay filter unit 712 delays the output / fuel ratio calculated by the output index calculation unit 711 so that a predetermined time before the value output from the output index calculation unit 711 to the subtraction unit 713 is obtained. Is output as a reference signal. Note that the reference signal output unit that outputs a value before a certain time as a reference signal is not limited to the delay filter unit 712, but a storage unit that stores a value output from the output index calculation unit 711, and a storage unit that stores the value. A value before a certain time may be extracted and output to the subtracting unit 713.
The subtracting unit 713 calculates the delayed output / fuel ratio (hereinafter referred to as “previous value”) output from the delay filter unit 712 from the output / fuel ratio calculated by the output index calculating unit 711 (hereinafter referred to as “current value”). The change amount of the output / fuel ratio is calculated by subtracting the value).

The determination unit 212 determines the fuel to be supplied to the combustor 12 when the output / fuel ratio change amount obtained by the output change calculation unit 211 is equal to or greater than a predetermined threshold corresponding to a high temperature abnormality of the gas turbine. Is determined to have a high calorie abnormality.
Under normal conditions, the output / fuel ratio generally changes gently according to the gas turbine output command value and the like. On the other hand, when a sudden change in the output / fuel ratio is detected, it is considered that the state is abnormal, and the cause may be, for example, that the calorie of the fuel has changed abruptly. In particular, when the output / fuel ratio increases abruptly, it is conceivable that the calorie of the fuel has increased abruptly. Since the temperature of the combustor 12 increases due to the increase in the calorie of the fuel, it is necessary to reduce the fuel calorie and suppress the temperature of the combustor 12 so as not to damage the combustor 12 due to combustion vibration or the like. There is. Therefore, the fuel abnormality detection device 21 determines whether or not the change amount of the output / fuel ratio is equal to or greater than a predetermined threshold value, and supplies the combustor 12 when the change amount of the output / fuel ratio is equal to or greater than the threshold value. It is determined that the burned fuel has a high calorie abnormality.
As a method for determining this threshold, for example, the output / fuel ratio in the power plant 1 during normal operation is measured, statistics are taken on the amount of change per unit time of the output / fuel ratio, and the amount of change during normal operation is measured. It is conceivable to determine a value that is slightly larger than the amount of change in the output / fuel ratio measured during normal operation, such as setting a constant multiple (for example, 1.5 times) of the maximum value.

  The control device 22 and the fuel mixer 11 constitute a fuel adjustment unit, and the fuel abnormality detection device 21 constitutes a fuel adjustment device. That is, the fuel mixer 11 mixes BFG and COG, which are fuels having different compositions, and supplies them to the turbine 13. Further, the determination unit 212 of the fuel abnormality detection device 21 determines that the fuel supplied to the combustor 12 of the turbine 13 has a high calorie abnormality, and outputs a determination result of “high calorie abnormality” to the control device 22. To do. Based on the determination result of “high calorie abnormality”, the control device 22 changes the fuel mixing ratio or the supply amount so as to reduce the calorie of the fuel supplied to the turbine 13 by the fuel mixer 11 (for example, COG Reducing the mixing ratio).

Next, the operation of the fuel abnormality detection device 21 will be described with reference to FIG.
FIG. 3 is a flowchart showing a processing procedure in which the fuel abnormality detection device 21 detects that the fuel has a high calorie abnormality. The fuel abnormality detection device 21 repeatedly determines whether or not the fuel has a high calorie abnormality by repeatedly performing the process of FIG.
In the process of the figure, first, the output index calculation unit 711 acquires the current fuel command, the no-load fuel command, and the gas turbine output that are output from the control device 22.

Here, the fuel command is, for example, a command value calculated by the control device 22 based on a gas turbine output set value set by a power plant operator and output to the fuel mixer 11. The no-load fuel command is a fixed value obtained on the heat balance, and is stored in advance by the control device 22, for example.
For example, the control device 22 calculates the steam turbine output based on the state quantity of the steam turbine 16, and the calculated steam turbine output is calculated from the total output of the power plant 1 (output of the generator 17). Subtract to calculate. In addition, like a gas turbine power plant (non-combined cycle power plant) that moves a gas turbine alone or a multi-shaft combined cycle power plant, the turbine and the generator are arranged on the same axis in a one-to-one correspondence. In the power generation plant that is used, the output of the generator arranged coaxially with the gas turbine can be used as the turbine output.

Next, the output index calculation unit 711 calculates an output / fuel ratio PPF expressed by a ratio between a difference _obtained by subtracting the no-load-time fuel command G _{f_ref_FNSL} from the current fuel command G _{f_ref} and the output GTMW, as shown in Expression (1). Calculate based on

  This output / fuel ratio is the ratio of the fuel command (relative fuel command obtained by subtracting the no-load fuel command from the current fuel command) to the gas turbine output. It is the value after deducting the impact of the request. The output index calculation unit 711 outputs the calculated output / fuel ratio to the delay filter unit 712 and the subtraction unit 713 (step S1).

The delay filter unit 712 delays the output / fuel ratio output from the output index calculation unit 711 and outputs it to the subtraction unit 713 (step S2).
The subtraction unit 713 subtracts the output / fuel ratio (previous value) output from the delay filter unit 712 from the output / fuel ratio (current value) output from the output index calculation unit 711 to obtain the output / fuel ratio. The amount of change is calculated. The subtraction unit 713 outputs the calculated output / fuel ratio change amount to the determination unit 212 (step S3).

The determination unit 212 determines whether or not the change amount of the output / fuel ratio output from the subtraction unit 713 is equal to or greater than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine (step S4). When it is determined that the change amount of the output / fuel ratio is equal to or greater than the threshold (step S4: YES), the determination unit 212 determines that the fuel supplied to the combustor 12 has a high calorie abnormality, and the abnormality. Is output to the control device 22 (step S5). Thereafter, the process of FIG.
On the other hand, when it is determined in step S4 that the change amount of the output / fuel ratio is less than the threshold (step S4: NO), the determination unit 212 indicates that the fuel supplied to the combustor 12 has a high calorie abnormality. It is determined that there is not, and the process of FIG. Therefore, in this case, the determination unit 212 does not output a signal indicating abnormality.

As described above, the fuel abnormality detection device 21 determines whether the fuel supplied to the combustor 12 has a high calorie abnormality based on the current fuel command, the no-load fuel command, and the gas turbine output. Determine whether. Therefore, since the fuel abnormality detection device 21 can determine whether or not the fuel has a high calorie abnormality without using the calorimeter, it does not require a measurement time by the calorimeter and can quickly determine whether or not the fuel has a high calorie abnormality. Can be determined.
Further, the control device 22 can perform control such as causing the turbine 13 to run back when the fuel is in a high calorie abnormality based on the determination result of the fuel abnormality detection device 21. Thereby, the turbine 13 can be protected from damage due to high temperature abnormality.

  The value indicating the change in the output / fuel ratio obtained by the subtraction unit 713 that is the output change index calculation unit is limited to the above-described difference obtained by subtracting the output / fuel ratio of the previous value from the output / fuel ratio of the current value. Absent. For example, a value indicating the degree of change in the output / fuel ratio, such as a change rate obtained by dividing the current value output / fuel ratio by the previous value output / fuel ratio, may be used.

Note that the output index value calculated by the output change calculation unit 211 is not limited to the output / fuel ratio described above, and may be an output normalized by a parameter correlated with the fuel ratio. For example, the output change calculation unit 211 may calculate the output / cabinet pressure ratio instead of the output / fuel ratio.
In this case, the output index calculation unit 711 receives inputs of the current vehicle compartment pressure, the no-load vehicle compartment pressure, and the gas turbine output. Then, the output index calculation unit 711 calculates an output / chamber pressure ratio PPP _cs expressed by a ratio of a difference _obtained by subtracting the no-load-time cabin pressure P _{cs_FNSL} from the current cabin pressure P _cs and the output GTMW. It calculates based on Formula (2).

  Here, the larger the value of the fuel command, the greater the amount of fuel combusted in the combustor 12 and the higher the cabin pressure. Accordingly, the cabin pressure indicates a value corresponding to the fuel command. The output / cabinet pressure ratio is calculated based on the cabin pressure indicating the value corresponding to the fuel command (the relative cabin pressure obtained by subtracting the no-load cabin pressure from the current cabin pressure), the gas turbine output, As in the case of using the output / fuel ratio described above, the value is obtained by subtracting the influence of the fuel requirement from the gas turbine output.

Hereinafter, as described with reference to FIG. 3, the delay filter unit 712 delays the output / cabinet pressure ratio calculated by the output index calculation unit 711. Then, the subtraction unit 713 subtracts the output / chamber pressure ratio (previous value) delayed by the delay filter unit 712 from the output / chamber pressure ratio (current value) calculated by the output index calculation unit 711, The amount of change in the output / chamber pressure ratio (increase is indicated by a positive value and decrease is indicated by a negative value) is calculated.
When the determination unit 212 determines that the change amount of the output / chamber pressure ratio calculated by the subtraction unit 713 is equal to or greater than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine, the combustor 12 It is determined that the fuel supplied to is high calorie abnormality, and a signal indicating the abnormality is output to the control device 22. On the other hand, if the determination unit 212 determines that the change in the output / chamber pressure ratio calculated by the subtraction unit 713 is less than the threshold value, the fuel supplied to the combustor 12 is not abnormally high in calories. Is determined.

  This threshold is a threshold for determining whether or not the amount of change in the output / chamber pressure ratio is larger than the amount of change during normal operation. What is the threshold when using the above-mentioned output / fuel ratio? It can be a different value. As a method for determining this threshold value, for example, the amount of change in the output / chamber pressure ratio in the power plant 1 during normal operation is measured to obtain statistics, and a value that is 1.5 times the maximum value of the measured amount of change. For example, it may be determined to be a value slightly larger than the amount of change in the output / cabin pressure ratio measured during normal operation.

As described above, the fuel abnormality detection device 21 has a high calorie abnormality in the fuel supplied to the combustor 12 based on the current vehicle compartment pressure, the no-load vehicle compartment pressure, and the gas turbine output. It is determined whether or not. Therefore, the fuel abnormality detection device 21 can quickly determine the presence or absence of a high calorie abnormality in the fuel, as in the case of obtaining the output / fuel ratio described above.
Further, as in the case of obtaining the output / fuel ratio, the control device 22 performs control such as causing the turbine 13 to run back when the fuel has a high calorie abnormality based on the determination result of the fuel abnormality detection device 21. It can be performed. Thereby, the turbine 13 can be protected from damage due to high temperature abnormality.

Further, the output change calculation unit 211 may calculate an output / CSO ratio (Power Per CSO; PPC) instead of the output / fuel ratio.
In this case, the output index calculation unit 711 receives inputs of the current load output command signal, the load output command signal (no load), and the gas turbine output. Then, the output index calculation unit 711 calculates an output / CSO ratio PPC represented by a ratio between the difference _obtained by subtracting the load output command signal (no load) CSO _{cs_FNSL} from the current load output command signal CSO and the output GTMW. It calculates based on Formula (3).

  Here, the larger the value of the load output command signal, the larger the value of the fuel command is set to obtain the load output. Therefore, the load output command signal indicates a value corresponding to the fuel command. The output / CSO ratio is a load output command signal indicating a value corresponding to the fuel command (a relative load output command signal obtained by subtracting the load output command signal (no load) from the current load output command signal), and Since the ratio with the gas turbine output is taken, the value is obtained by subtracting the influence of the fuel demand from the gas turbine output, as in the case of using the above-mentioned output / fuel ratio.

Hereinafter, as described with reference to FIG. 3, the delay filter unit 712 delays the output / CSO ratio calculated by the output index calculation unit 711. Then, the subtracting unit 713 subtracts the output / CSO ratio (previous value) delayed by the delay filter unit 712 from the output / CSO ratio (current value) calculated by the output index calculating unit 711 to obtain the output / CSO ratio. Change amount (increase is indicated by a positive value and decrease is indicated by a negative value).
When the determination unit 212 determines that the change amount of the output / CSO ratio calculated by the subtraction unit 713 is equal to or greater than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine, the determination unit 212 supplies the change to the combustor 12. It is determined that the fuel to be burned has a high calorie abnormality, and a signal indicating the abnormality is output to the control device 22. On the other hand, when the determination unit 212 determines that the change amount of the output / CSO ratio calculated by the subtraction unit 713 is less than the threshold value, the determination unit 212 determines that the fuel supplied to the combustor 12 is not in a high calorie abnormality. To do.

  This threshold is a threshold for determining whether or not the amount of change in the output / CSO ratio is larger than the amount of change during normal operation. The threshold or output / vehicle when using the output / fuel ratio described above. It may be a value different from the threshold value when the chamber pressure is used. As a method for determining this threshold value, for example, the amount of change in the output / CSO ratio in the power plant 1 during normal operation is measured to obtain statistics, and is set to a value 1.5 times the maximum value of the measured amount of change. For example, it may be determined to be a value slightly larger than the amount of change in the output / CSO ratio measured during normal operation.

As described above, the fuel abnormality detection device 21 determines that the fuel supplied to the combustor 12 is high in calories based on the current load output command signal, the load output command signal (no load), and the gas turbine output. It is determined whether or not there is an abnormality. Therefore, the fuel abnormality detection device 21 can quickly determine the presence or absence of a high calorie abnormality in the fuel, as in the case of obtaining the output / fuel ratio described above.
Further, as in the case of obtaining the output / fuel ratio, the control device 22 performs control such as causing the turbine 13 to run back when the fuel has a high calorie abnormality based on the determination result of the fuel abnormality detection device 21. It can be performed. Thereby, the turbine 13 can be protected from damage due to high temperature abnormality.

The fuel abnormality detection device 21 may obtain the output index value using the delayed fuel command. In general, there is a delay time due to the time for the fuel to pass through the pipe, the opening / closing time of the valve, etc., from when the fuel command is updated until it is reflected in the gas turbine output. Therefore, the output index calculation unit of the fuel abnormality detection device obtains an output index value by using the fuel command G _{f_ref} delayed according to the delay time.

Specifically, the output index calculation unit 711 delays the fuel command output from the control device 22 by a time constant τ. Then, the output index calculation unit 711 calculates the ratio between the output GTMW and the difference between the fuel command G _{f_ref} delayed by the time constant τ, that is, the difference _obtained by subtracting the no-load fuel command G _{f_ref_FNSL} from the fuel command considering the delay time. An output / fuel ratio PPF represented by the following equation (4) is calculated.

Here, s represents a Laplace operator.
As a method for determining the value of the time constant τ, for example, in the power plant 1, the delay time from when the fuel command is changed until it is reflected in the gas turbine output is measured, and the value of τ is calculated based on the measurement result. It is possible to decide.

As described above, the fuel abnormality detection device 21 determines whether the fuel supplied to the combustor 12 has a high calorie abnormality based on the delayed fuel command, the no-load fuel command, and the gas turbine output. Determine whether or not. Therefore, as in the case of using the fuel command as it is without delaying as described above, it is possible to quickly determine the presence or absence of a high calorie abnormality of the fuel.
Further, based on the determination result of the fuel abnormality detection device 21, the control device 22 can perform control such as running the turbine 13 back when the fuel has a high calorie abnormality. As a result, the turbine 13 can be protected from damage due to a high temperature abnormality, as in the case where the fuel command is used without delay.
Further, the fuel abnormality detection device 21 determines whether or not the fuel supplied to the combustor 12 has a high calorie abnormality using the fuel command delayed by the time constant τ, that is, the fuel command in consideration of the delay time. Determine. As a result, the output / fuel ratio can be determined more accurately, and it can be expected that the determination of whether or not the fuel has a high calorie abnormality can be made more accurately.

Note that the output index value calculated by the output change calculation unit 211 is not limited to the output / fuel ratio described above, as in the case where the fuel command is used without delay. For example, the output change calculation unit 211 may calculate the output / cabinet pressure ratio instead of the output / fuel ratio.
In this case, the output index calculation unit 711 subtracts the no-load vehicle _interior pressure P _{cs_FNSL} from the vehicle _interior pressure P _cs delayed by the time constant τ, that is, the vehicle _interior pressure corresponding to the current gas turbine output. And the output / cabinet pressure ratio PPP _cs represented by the ratio to the output GTMW is calculated based on the equation (5).

Here, s represents a Laplace operator.
Further, τ is a time constant indicating a delay time from when the casing pressure changes until it is reflected in the gas turbine output. This time constant τ may be a value different from the time constant τ in the case of using the output / fuel ratio described above. As a method for determining the value of the time constant τ, for example, in the power plant 1, the delay time from when the cabin pressure changes until it is reflected in the gas turbine output is measured, and the value of τ is calculated based on the measurement result. It is possible to decide.

Hereinafter, similarly to the case of using the output / fuel ratio described above, the delay filter unit 712 delays the output / cabinet pressure ratio calculated by the output index calculation unit 711. Then, the subtraction unit 713 subtracts the output / chamber pressure ratio (previous value) delayed by the delay filter unit 712 from the output / chamber pressure ratio (current value) calculated by the output index calculation unit 711, The amount of change in the output / chamber pressure ratio (increase is indicated by a positive value and decrease is indicated by a negative value) is calculated.
When the determination unit 212 determines that the change amount of the output / chamber pressure ratio calculated by the subtraction unit 713 is equal to or greater than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine, the combustor 12 It is determined that the fuel supplied to is high calorie abnormality, and a signal indicating the abnormality is output to the control device 22. On the other hand, if the determination unit 212 determines that the change in the output / chamber pressure ratio calculated by the subtraction unit 713 is less than the threshold value, the fuel supplied to the combustor 12 is not abnormally high in calories. Is determined.

As described above, the fuel abnormality detection device 21 detects that the fuel supplied to the combustor 12 has a high calorie abnormality based on the delayed vehicle compartment pressure, the no-load vehicle compartment pressure, and the gas turbine output. It is determined whether or not. Therefore, as in the case of using the output / fuel ratio described above, it is possible to quickly determine the presence or absence of a high calorie abnormality in the fuel.
Further, based on the determination result of the fuel abnormality detection device 21, the control device 22 can perform control such as running the turbine 13 back when the fuel has a high calorie abnormality. As a result, the turbine 13 can be protected from damage due to abnormal high temperature, as in the case of using the power / fuel ratio described above.
Further, the fuel abnormality detection device 21 determines whether or not the fuel supplied to the combustor 12 using the vehicle compartment pressure delayed by the time constant τ, that is, the vehicle compartment pressure considering the delay time, is a high calorie abnormality. Determine whether. As a result, the output / cabin pressure ratio can be determined more accurately, and it can be expected that the determination of whether or not the fuel has a high calorie abnormality can be made more accurately.

Note that the output change calculation unit 211 may calculate the output / CSO ratio instead of the output / fuel ratio as in the case where the fuel command is used as it is without delay.
In this case, the output index calculation unit 711 obtains the load output command signal _{CSO_FNSL} at no load from the load output command signal CSO delayed by the time constant τ, that is, the load output command signal corresponding to the current gas turbine output. An output / CSO ratio PPC represented by a ratio between the subtracted difference and the output GTMW is calculated based on the equation (6).

Here, s represents a Laplace operator.
Τ is a time constant indicating a delay time from when the load output command signal is changed until it is reflected in the gas turbine output. This time constant τ may be a value different from the time constant τ when the output / fuel ratio described above is used or the time constant τ when the output / chamber pressure ratio is used. As a method for determining the value of the time constant τ, for example, in a power plant, the delay time from when the load output command signal changes until it is reflected in the gas turbine output is measured, and the value of τ is calculated based on the actual measurement result. It is possible to decide.

Hereinafter, similarly to the case of using the output / fuel ratio described above, the delay filter unit 712 delays the output / CSO ratio calculated by the output index calculation unit 711. Then, the subtracting unit 713 subtracts the output / CSO ratio (previous value) delayed by the delay filter unit 712 from the output / CSO ratio (current value) calculated by the output index calculating unit 711 to obtain the output / CSO ratio. Change amount (increase is indicated by a positive value and decrease is indicated by a negative value).
When the determination unit 212 determines that the change amount of the output / CSO ratio calculated by the subtraction unit 713 is equal to or greater than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine, the determination unit 212 supplies the change to the combustor 12. It is determined that the fuel to be burned has a high calorie abnormality, and a signal indicating the abnormality is output to the control device 22. On the other hand, when the determination unit 212 determines that the change amount of the output / CSO ratio calculated by the subtraction unit 713 is less than the threshold value, the determination unit 212 determines that the fuel supplied to the combustor 12 is not in a high calorie abnormality. To do.

As described above, the fuel abnormality detection device 21 determines that the fuel supplied to the combustor 12 is high in calories based on the delayed load output command signal, the no-load load output command signal, and the gas turbine output. It is determined whether or not there is an abnormality. Therefore, as in the case of using the output / fuel ratio described above, it is possible to quickly determine the presence or absence of a high calorie abnormality in the fuel.
Further, based on the determination result of the fuel abnormality detection device 21, the control device 22 can perform control such as running the turbine 13 back when the fuel has a high calorie abnormality. As a result, the turbine 13 can be protected from damage due to abnormal high temperature, as in the case of using the power / fuel ratio described above.
Furthermore, the fuel abnormality detection device 21 uses the load output command signal delayed by the time constant τ, that is, the fuel supplied to the combustor 12 using the load output command signal taking into account the delay time, so that the high calorie abnormality occurs. It is determined whether or not. As a result, the output / CSO ratio can be obtained more accurately, and it can be expected that the determination as to whether or not the fuel has a high calorie abnormality can be made more accurately.

In order to obtain a delayed fuel command used when the output index calculation unit 711 obtains an output index value, the output change calculation unit 211 may include a delay filter unit that delays the fuel command. .
FIG. 4 is a block diagram illustrating a configuration of the output change calculation unit 211 including a delay filter unit that delays the fuel command. In the same figure, the delay filter unit 812 delays the fuel command input from the control device 22 and outputs it to the output index calculation unit 711.

FIG. 5 is a flowchart showing a processing procedure in which the fuel abnormality detection device 21 shown in FIG. 4 detects that the fuel has a high calorie abnormality. First, the delay filter unit 812 delays the fuel command output from the control device 22 by the time constant τ, and outputs the delayed fuel command to the output index calculation unit 711 (step S21). The output index calculation unit 711 acquires the delayed fuel command output from the delay filter unit 812 and the no-load fuel command and gas turbine output output from the control device 22. And the output parameter | index calculating part 711 calculates output / fuel ratio PPF based on Formula (4) mentioned above. The output index calculation unit 711 outputs the calculated output / fuel ratio to the delay filter unit 712 and the subtraction unit 713 (step S22). Hereinafter, steps S23 to S26 are the same as steps S2 to S5 of FIG.
The same applies to the case where the passenger compartment pressure is delayed and the load output command signal.

A program for realizing all or part of the functions of the fuel abnormality detection devices 21 and 31 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. By doing so, you may process each part. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short 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. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

  The present invention relates to a fuel abnormality detection device and a fuel abnormality detection method for detecting that a fuel supplied to a combustor of a gas turbine has a high calorie abnormality, and a determination of whether or not a fuel has a high calorie abnormality. It is suitable for use in a fuel adjustment device that adjusts the calorie of fuel based on the results.

1 Power Plant 11 Fuel Mixer 12 Combustor 13 Gas Turbine 14 Compressor 15 Waste Heat Recovery Boiler 16 Steam Turbine 17 Generator 21 Fuel Abnormality Detection Device 22 Controller 211 Output Change Calculation Unit 212 Determination Unit 711 Output Index Calculation Unit 712 Delay Filter unit 713 Subtraction unit

Claims (9)

An output change calculation unit for obtaining an output change index value representing a change in gas turbine output excluding the influence of a change in fuel demand;
When the output change index value obtained by the output change calculation unit is equal to or higher than a predetermined threshold corresponding to the high temperature abnormality of the gas turbine, the fuel supplied to the combustor of the gas turbine is in a high calorie abnormality A determination unit that determines that
A fuel abnormality detection device comprising: The output change calculation unit is expressed as a ratio between a difference obtained by subtracting a no-load fuel command from a current fuel command as an output index value representing a gas turbine output excluding the influence of fuel demand, and the gas turbine output. An output index calculation unit for obtaining an output / fuel ratio;
An output change index calculation unit for determining a change amount or a change rate of the output / fuel ratio obtained by the output index calculation unit as an output change index value of the gas turbine;
The fuel abnormality detection device according to claim 1, comprising: The output index calculation unit calculates the output / fuel ratio by the following formula: PPF = GTMW / ((1 / τs + 1) G _{f_ref−} G _{f_ref_FNSL} )
The fuel abnormality detection device according to claim 2, wherein the fuel abnormality detection device is obtained by:
Here, PPF indicates an output fuel ratio, GTMW indicates a gas turbine output, τ indicates a time constant, s indicates a Laplace operator, G _{f_ref} indicates a fuel command, and G _{f_ref_FNSL} indicates a no-load fuel command. Indicates.   The output change calculation unit includes a difference obtained by subtracting a no-load casing pressure from a current casing pressure of the gas turbine as an output index value representing a gas turbine output excluding the influence of the fuel requirement, and the gas turbine output 2. The fuel abnormality detection according to claim 1, wherein an output / chamber pressure ratio represented by a ratio of the gas turbine and an output / chamber pressure ratio is obtained and a change in the output / chamber pressure ratio is obtained as an output change index value of the gas turbine. apparatus. The output change calculation unit calculates the output / chamber pressure ratio by the following formula: PPP _cs = GTMW / ((1 / τs + 1) P _cs −P _{cs_FNSL} )
The fuel abnormality detection device according to claim 4, wherein the fuel abnormality detection device is obtained by:
Here, PPP _cs indicates an output casing pressure ratio, GTMW indicates a gas turbine output, τ indicates a time constant, s indicates a Laplace operator, P _cs indicates a casing pressure, and P _{cs_FNSL} indicates nothing. Indicates the cabin pressure under load.   The output change calculation unit is based on a difference obtained by subtracting an unloaded output command signal from a current output command signal that is an output command for the gas turbine as an output index value representing a gas turbine output excluding the influence of the fuel requirement. The fuel abnormality detection device according to claim 1, wherein an output / CSO ratio indicating a magnitude of the gas turbine output is obtained, and a change in the output / CSO ratio is obtained as an output change index value of the gas turbine. The output change calculation unit calculates the output / CSO ratio by the following formula: PPC = GTMW / ((1 / τs + 1) CSO− _{CSO_FNSL} )
The fuel abnormality detection device according to claim 6, wherein the fuel abnormality detection device is obtained by:
Here, PPC represents the output / CSO ratio, GTMW represents a gas turbine output, tau represents the time constant, s indicates a Laplace operator, CSO represents an output command signal, CSO _{_FNSL} the load output command signal (No load). A fuel abnormality detection device according to any one of claims 1 to 7,
If the fuel abnormality detection device determines that the fuel supplied to the combustor of the gas turbine has a high calorie abnormality, the fuel mixing is adjusted so that the calorie of the fuel supplied to the gas turbine decreases. A fuel adjustment unit to perform,
A fuel adjusting device comprising: A fuel abnormality detection method of a fuel abnormality detection device,
An output change calculating step for obtaining a gas turbine output change index value representing a change in gas turbine output excluding an influence of a change in fuel demand;
The determination unit supplies the gas turbine combustor when the gas turbine output change index value obtained in the output change calculation step is equal to or higher than a predetermined threshold corresponding to a high temperature abnormality of the gas turbine. A determination step for determining that the fuel to be used is abnormal in high calories;
A fuel abnormality detection method comprising:

Images