JP5968248B2 - Fuel gas calorie estimation apparatus, fuel gas calorie estimation method and program - Google Patents

Description

  The present invention relates to a fuel gas calorie estimation device, a fuel gas calorie estimation method, and a program.

  In Blast Furnace Gas (BFG) soot gas turbine, BFG is used as fuel to be fed into the gas turbine. This BFG is a by-product gas generated in the blast furnace in the iron making process. For this reason, the gas calorie of BFG changes greatly according to the operating conditions of the blast furnace etc. in a steelworks, and may affect the behavior of a gas turbine main part.

  For example, if the calorific value of BFG suddenly increases, the gas turbine is overloaded (overload). Since overload and misfire are serious events that can cause an emergency stop of the gas turbine body, they must be prevented as much as possible. This is a problem common to plants that use a gas whose gas calorie fluctuates abruptly like a BFG soot gas turbine. In addition to the BFG-fired gas turbine facility, gas calorie fluctuations may occur in an integrated coal gasification combined cycle (IGCC) or the like.

  In order to continuously operate the gas turbine body even if gas calorie fluctuation occurs, a method of reducing calorie fluctuation by mixing a heat increasing gas or a heat reducing gas with an original gas such as BFG is generally used. ing. Specifically, a method of measuring the calorie of the mixed gas or the original gas using a calorimeter and controlling the mixing amount of the heat increasing gas or the heat reducing gas so as to cancel the fluctuation of the calorie is generally used. ing.

  However, the calorimeter generally has a large measurement delay of the order of about 60 seconds. For this reason, detection of a sudden change in gas calories may be delayed. If the control of the sudden change in calories is delayed, the control of the mixing amount of the heat increasing gas and the heat reducing gas does not function effectively, and there is a possibility that overload and misfire cannot be prevented.

On the other hand, several methods for detecting an abrupt change in gas calories and preventing overload and misfire have been proposed.
For example, in the method for controlling a blast furnace gas-only gas turbine described in Patent Document 1, in operation of the blast furnace gas-fired gas turbine, N ₂ or the like is contained in the blast furnace gas for the fuel of the combustor according to the output of the generator. Either the dilution gas for heat reduction or the enrichment gas for heat increase such as LPG is added to control the gas turbine output to be constant.
Thereby, in the control method of the blast furnace gas exclusive combustion type gas turbine described in Patent Document 1, the power generation output is made constant by overcoming the output fluctuation of the gas turbine caused by the blast furnace gas calorie fluctuation inevitably caused by the exclusive combustion type. It can be done.

  However, in the method for controlling a blast furnace gas-only gas turbine described in Patent Document 1, since the gas calorie is controlled according to the output of the generator, the control of the turbine body based on the power generation output and the gas based on the power generation output There is a possibility of interference with the control of calories. Moreover, in the control method of the blast furnace gas exclusive combustion type gas turbine described in patent document 1, the value of gas calorie itself is disregarded regarding control of gas calorie. In this respect, it is not a fundamental measure against overload and misfire due to sudden changes in gas calories.

On the other hand, Patent Document 2 proposes a method for estimating the gas calorie H from the power generation output P and the gas flow rate Q based on the relationship represented by P = ηHQ. However, (eta) shows efficiency (power generation efficiency).
This method estimates the gas calorie from the power generation output, fuel gas flow rate, and power generation efficiency, which means that the dead time and time constant in the gas transmission system and gas cleaning system are significantly larger than the conventional method using a calorimeter. Can be shortened and quick control can be realized.
Moreover, if the method of patent document 2 is used, gas calorie control can be performed based on gas calorie, and interference with control of a turbine body and control of gas calorie can be avoided. Furthermore, if the method described in Patent Document 2 is used, it is possible to control the gas calorie based on the gas calorie, and in this respect, it is possible to take fundamental measures against overload and misfire due to a sudden change in the gas calorie. .

JP 9-317499 A Japanese Patent No. 3,905,829

  In the method described in Patent Document 2, the accuracy of gas calorie estimation depends on the accuracy of power generation efficiency. It is desirable to increase the accuracy of power generation efficiency and to estimate gas calories more accurately.

  The present invention has been made in view of such circumstances, and the object thereof is to improve the accuracy of power generation efficiency and to estimate the fuel gas calorie with high accuracy and the fuel gas calorie estimation device. It is to provide an estimation method and a program.

  The present invention has been made to solve the above-described problem, and a fuel gas calorie estimation apparatus according to an aspect of the present invention includes a fuel gas flow rate acquisition unit that acquires a flow rate of fuel gas flowing into a combustor of a gas turbine, A state quantity acquisition unit that acquires a state quantity of the gas turbine, a storage unit that stores power generation efficiency including an efficiency correction coefficient associated with the state quantity, the fuel gas flow rate, the state quantity, and the state And a fuel gas calorie calculation unit that performs a fuel gas calorie calculation based on the power generation efficiency obtained from the efficiency correction coefficient according to the quantity.

  A fuel gas calorie estimation device according to another aspect of the present invention is the above-described fuel gas calorie estimation device, a calorie measurement value acquisition unit that acquires a fuel gas calorie measurement value, and the fuel gas calorie measurement value. The fuel gas calorie at the timing when the magnitude of the difference between the true value of the fuel gas calorie is determined and the difference between the measured value of the fuel gas calorie and the true value of the fuel gas calorie is determined to be small And an efficiency updating unit that updates the power generation efficiency corresponding to the state quantity based on the measured value and the state quantity.

  A fuel gas calorie estimation apparatus according to another aspect of the present invention is the above-described fuel gas calorie estimation apparatus, wherein the efficiency update unit determines the magnitude of the fluctuation of the fuel gas calorie measurement value. When the fuel gas calorie measurement value is determined to have a small fluctuation over a period longer than the response delay of the fuel gas calorie measurement value, the start time of the period is determined as the fuel gas calorie measurement value and the fuel gas calorie value. It is characterized by detecting the timing when the magnitude of the true value difference is small.

  A fuel gas calorie estimation device according to another aspect of the present invention is the fuel gas calorie estimation device described above, wherein the efficiency update unit reflects the power generation efficiency in a past value of the power generation efficiency. It is characterized by updating.

  Moreover, the fuel gas calorie estimation apparatus according to another aspect of the present invention is the above-described fuel gas calorie estimation apparatus, wherein the efficiency update unit includes a true value of the fuel gas calorie and a measured value of the fuel gas calorie. The correction is performed to cancel the influence of the steady deviation on the power generation efficiency.

  A fuel gas calorie estimation method according to another aspect of the present invention is a fuel gas of a fuel gas calorie estimation apparatus including a storage unit that stores a power generation efficiency including an efficiency correction coefficient associated with a state quantity of a gas turbine. A calorie estimation method, a fuel gas flow rate obtaining step for obtaining a flow rate of fuel gas flowing into a combustor of the gas turbine, a state quantity obtaining step for obtaining a state quantity of the gas turbine, the fuel gas flow rate, And a fuel gas calorie calculation step for performing a fuel gas calorie calculation based on the state quantity and the power generation efficiency obtained from the efficiency correction coefficient corresponding to the state quantity.

  According to another aspect of the present invention, there is provided a program stored in a computer serving as a fuel gas calorie estimation device including a storage unit that stores power generation efficiency including an efficiency correction coefficient associated with a state quantity of a gas turbine. A fuel gas flow rate acquisition step for acquiring a flow rate of fuel gas flowing into the combustor of the turbine, a state amount acquisition step for acquiring a state amount of the gas turbine, the fuel gas flow rate, the state amount, and the state amount This is a program for executing a fuel gas calorie calculation step for performing a fuel gas calorie calculation based on the power generation efficiency obtained from the corresponding efficiency correction coefficient.

  According to the present invention, the accuracy of power generation efficiency can be improved and the gas calorie can be estimated more accurately.

It is a schematic block diagram which shows the installation structure of the electric power generation system in the 1st Embodiment of this invention. It is a schematic block diagram which shows the apparatus structure of the gas turbine power generation equipment in the embodiment. It is a schematic block diagram which shows the function structure of the fuel gas calorie estimation apparatus in the same embodiment. It is a graph which shows the example of estimation of the fuel gas calorie by the fuel gas calorie calculating part in the embodiment. It is a schematic block diagram which shows the function structure of the fuel gas calorie estimation apparatus in the 2nd Embodiment of this invention. It is a graph which shows the example which the efficiency update part in the embodiment determines with the magnitude | size of the fluctuation | variation of a fuel gas calorie measurement value being small over the period more than the response delay of a fuel gas calorie measurement value. It is explanatory drawing which shows the example of the update of the efficiency correction coefficient which the efficiency update part in the embodiment performs. In the same embodiment, it is a flowchart which shows the procedure of the process in which an efficiency update part updates an efficiency correction coefficient.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the equipment configuration of the power generation system according to the first embodiment of the present invention. In the figure, the power generation system 1 includes a fuel gas calorie estimation device 100, a control device 800, and a gas turbine power generation facility 900.
The gas turbine power generation facility 900 generates power using blast furnace gas (BFG), which is a by-product gas generated in the blast furnace during the iron making process, as a main fuel.

FIG. 2 is a schematic configuration diagram illustrating a device configuration of the gas turbine power generation facility 900. In the figure, a gas turbine power generation facility 900 includes a BFG main pipe 911, an N ₂ (nitrogen) gas supply valve 921, a COG (Cokes Oven Gas) supply valve 922, a mixer 931, and an electric dust collector. (Electrostatic Precipitator; EP) 932, a gas compressor 933, a bypass valve 934, a gas cooler 935, a gas turbine 940, a heat recovery steam generator (HRSG) 951, a chimney 952, A steam turbine 961, a condenser 962, a condensing pump 963, a generator 971, a speed increasing gear 972, a calorimeter 991, a flow meter 992, and a wattmeter 993 are provided. The gas turbine 940 includes a filter 941, an air compressor 942, a combustor 943, a gas turbine main body 944, and a rotor (rotor shaft) 945.

The BFG mother pipe 911 is a pipe for supplying BFG generated in the blast furnace to the gas turbine power generation facility 900. The N ₂ gas supply valve 921 is a valve for adjusting the presence / absence and supply amount of N ₂ gas which is a heat reducing gas. The COG supply valve 922 is a valve for adjusting the presence / absence and supply amount of COG which is a heat-increasing gas.

The mixer 931 mixes N ₂ gas and COG supplied according to the calories of the BFG into the BFG from the BFG mother pipe 911.
Here, by adding N ₂ gas to BFG, the gas calorie is reduced (thus reducing heat). On the other hand, by adding COG to BFG, gas calorie increases (thus increasing heat). Therefore, according to the calorific value of BFG from the BFG mother pipe 911, the N ₂ gas supply valve 921 and the COG supply valve 922 adjust whether N ₂ gas and COG are supplied or not, and the mixer 931 is supplied. By adding N ₂ gas or COG to BFG, fluctuations in gas calories can be reduced.
In the following, the gas after passing through the mixer 931 (and therefore, BFG to which these gases are added when N ₂ gas or COG is supplied) will be referred to as “fuel gas”.

The electric dust collector 932 is a device that collects and removes dust and the like contained in the fuel gas.
The gas compressor 933 compresses the fuel gas output from the electric dust collector 932 and introduces it into the combustor 943.
The bypass valve 934 adjusts the flow rate of the gas returned from the fuel gas output from the gas compressor 933 to the outlet side of the mixer 931 as surplus gas. As shown in FIG. 2, the outlet of the gas compressor 933 is connected to the inlet side of the combustor 943 and is connected (bypassed) to the outlet side of the mixer 931 via the gas cooler 935. . The bypass valve 934 adjusts the flow rate of the fuel gas supplied to the combustor 943 by flowing a part of the fuel gas compressed by the gas compressor 933 to the bypass path.

  The gas cooler 935 cools the surplus gas output from the bypass valve 934. The surplus gas output from the bypass valve 934 is at a high temperature due to compression by the gas compressor 933. Therefore, the gas cooler 935 cools the surplus gas from the bypass valve and then returns it to the outlet side of the mixer 931.

The gas turbine 940 burns the fuel gas from the gas compressor 933 to generate a rotational force.
The filter 941 is provided on the inlet side of the air compressor 942 and removes dust and the like from the air (outside air) sucked by the air compressor.
The air compressor 942 compresses the air sucked through the filter 941 and outputs the obtained compressed air to the combustor 943.

The combustor 943 mixes and burns the fuel gas from the gas compressor 933 and the compressed air from the air compressor, and outputs the obtained high-temperature combustion gas to the gas turbine main body 944.
The gas turbine main body 944 is rotatably supported by the rotor 945, and the gas turbine main body 944 itself rotates by the combustion gas from the combustor 943, thereby rotating the rotor 945 together with the steam turbine 961.
The rotor 945 transmits the rotational force from the gas turbine main body 944 and the steam turbine 961 to the air compressor 942, the generator 971, and the speed increasing gear 972.

The exhaust heat recovery boiler 951 generates steam (high pressure steam) using the heat of the combustion gas (exhaust gas) exhausted by the gas turbine body 944 and supplies the obtained high pressure steam to the steam turbine 961. The exhaust heat recovery boiler 951 reheats the steam discharged from the steam turbine 961 and supplies the steam as low pressure steam to the steam turbine 961.
The chimney 952 releases the combustion gas exhausted by the exhaust heat recovery boiler 951 into the atmosphere.

The steam turbine 961 is rotatably supported by a rotor 945, and the steam turbine 961 itself is rotated by steam (high pressure steam and low pressure steam) from the exhaust heat recovery boiler 951, so that the rotor 945 is moved together with the gas turbine body 944. Rotate.
The condenser 962 cools the steam exhausted from the steam turbine 961 and returns it to water (condensate).
The condensate pump 963 sends the condensate from the condenser 962 to the exhaust heat recovery boiler 951. The condensate is heated by the exhaust heat recovery boiler 951 and becomes high-pressure steam.

The generator 971 generates power using the rotational force transmitted from the gas turbine main body 944 and the steam turbine 961 transmitted by the rotor 945.
The speed increasing gear 972 increases the rotational force transmitted from the gas turbine main body 944 and the steam turbine 961 transmitted by the rotor 945 and transmits it to the gas compressor 933.

The calorimeter 991 measures the calorie of the fuel gas.
The flow meter 992 measures the flow rate of the fuel gas flowing into the combustor 943.
The wattmeter 993 measures the power generation output (electric power) of the generator 971. The power generation output measured by the wattmeter 993 correlates with the rotational force generated by the gas turbine 940, and corresponds to an example of a state quantity of the gas turbine.

The fuel gas calorie estimation apparatus 100 estimates the fuel gas calorie based on the fuel gas flow rate measured by the flow meter 992 and the power generation output of the generator 971 measured by the power meter 993. The fuel gas calorie estimation apparatus 100 is configured by a computer, for example.
FIG. 3 is a schematic block diagram showing a functional configuration of the fuel gas calorie estimation apparatus 100. In the figure, the fuel gas calorie estimation apparatus 100 includes a state quantity acquisition unit 111, a fuel gas flow rate acquisition unit 112, a storage unit 121, a fuel gas calorie calculation unit 131, and a calculation result output unit 141.

The state quantity acquisition unit 111 acquires the power generation output of the generator 971 measured by the wattmeter 993.
The fuel gas flow rate acquisition unit 112 acquires the fuel gas flow rate measured by the flow meter 992.
The storage unit 121 stores various data such as power generation efficiency including an efficiency correction coefficient associated with the power generation output of the generator 971. The storage unit 121 is configured using a storage device included in the fuel gas calorie estimation apparatus 100.

  The fuel gas calorie calculation unit 131 includes a power generation output acquired by the state quantity acquisition unit 111, a fuel gas flow rate acquired by the fuel gas flow rate acquisition unit 112, and a power generation efficiency obtained from an efficiency correction coefficient according to the power generation output. , Fuel gas calorie calculation is performed. The fuel gas calorie calculation unit 131 is configured, for example, by a CPU (Central Processing Unit) included in the fuel gas calorie estimation device 100 reading and executing a program stored in the storage unit 121.

The calculation result output unit 141 transmits the fuel gas calorie calculated by the fuel gas calorie calculation unit 131 to the control device 800.
The state quantity acquisition unit 111, the fuel gas flow rate acquisition unit 112, and the calculation result output unit 141 are configured using a communication circuit included in the fuel gas calorie estimation device 100.

Here, the power generation output of the generator 971 is P [kilowatt (KW)], the fuel gas calorie is H [kilojoule per Newton cubic meter (KJ / Nm ³ )], and the fuel gas flow rate is Q [Newton cubic meter per second (Nm). ³ / s)], it is considered that the relationship of the expression (1) is established.

  However, η (P) indicates power generation efficiency (hereinafter, simply referred to as “efficiency”), and can be expressed as in Expression (2).

However, η ₀ (P) represents the efficiency derived in the gas turbine design stage (hereinafter referred to as “initial efficiency”). K _η (P) represents an efficiency correction coefficient (efficiency correction coefficient). For example, when there is no need for correction, k _η (P) = 1.
Expression (3) is obtained from Expression (1) and Expression (2).

Therefore, the storage unit 121 stores the initial efficiency η ₀ (P) and the efficiency correction coefficient k _η (P), and the fuel gas calorie calculation unit 131 calculates the fuel gas calorie H based on the equation (3). Thus, the fuel gas calorie H is estimated.

  FIG. 4 is a graph showing an example of fuel gas calorie estimation by the fuel gas calorie calculating unit 131. In the figure, the horizontal axis indicates time, and the vertical axis indicates calories. A line L11 indicates the actual value of fuel gas calories (hereinafter referred to as “true value”). A line L12 indicates the measured value of the fuel gas calorie by the calorimeter 991. A line L13 indicates an estimated value of the fuel gas calorie by the fuel gas calorie calculating unit 131.

In the example of FIG. 4, until the time T11, the true value (line L11) of the fuel gas calorie is substantially constant at the set value, and the measured value (line L13) by the calorimeter 991 is calculated. All of the estimated values by (line L12) indicate values close to the true value.
On the other hand, after time T11, the true value of fuel gas calories (line L11) decreases. On the other hand, the measured value (line L13) of the fuel gas calorie has a difference from the true value due to the response delay of the calorimeter 991. For example, at time T12, there is a difference indicated by an arrow in the figure.
On the other hand, the estimated value (line L12) of the fuel gas calorie follows the true value by estimating the power generation output that has a quick response to fluctuations in the fuel gas calorie using the value measured by a fast wattmeter. Have changed.

Note that the state quantity used by the fuel gas calorie calculation unit 131 for estimating the fuel gas calorie is not limited to the power generation output of the generator 971. For example, the fuel gas calorie calculation unit 131 may use a state quantity of the gas turbine 940 other than the power generation output, such as the exhaust gas temperature of the gas turbine body 944 or the rotational speed of the gas turbine body 944.
For example, assuming that the exhaust gas temperature of the gas turbine main body 944 is T [Kelvin (K)], the fuel gas calorie calculating unit 131 may estimate the fuel gas calorie based on the equation (4).

However, η ² ₀ (T) indicates the efficiency derived at the gas turbine design stage with respect to the exhaust gas temperature. K ² _η (T) represents an efficiency correction coefficient for the efficiency η ² ₀ (T).

Returning to FIG. 1, the control device 800 controls each part of the gas turbine power generation facility 900. In particular, the control device 800 controls the loads of the gas turbine 940 and the steam turbine 961 according to the power generation output target set by the operator of the gas turbine power generation facility 900. Further, the control device 800 controls the N ₂ gas supply valve 921 and the COG supply valve 922 so that the fuel gas calorie is constant based on the fuel gas calorie calculated by the fuel gas calorie estimation device 100.

  As described above, the fuel gas calorie calculation unit 131 estimates the fuel gas calorie based on the state quantity of the gas turbine 940. Thereby, the fuel gas calorie calculating part 131 can estimate a fuel gas calorie with a quick response according to the fluctuation | variation of a fuel gas calorie. Therefore, the control device 800 can quickly control the gas turbine power generation equipment 900 using the estimation result of the fuel gas calorie calculation unit 131. Furthermore, the control device 800 can control the gas calorie based on the gas calorie by using the estimation result of the fuel gas calorie calculating unit 131, and avoid interference between the control of the turbine body and the control of the gas calorie. Can do. In addition, the control device 800 can control the gas calorie based on the gas calorie by using the estimation result of the fuel gas calorie calculating unit 131. In this regard, the control device 800 can cope with an overload or misfire caused by a sudden change in the gas calorie. Basic measures can be taken.

Further, when estimating the fuel gas calorie, the fuel gas calorie calculating unit 131 uses the power generation efficiency including the efficiency correction coefficient associated with the state quantity of the gas turbine 940.
Here, the efficiency that can be derived at the design stage does not always coincide with the efficiency of the actual machine, and the efficiency gradually changes due to aging and atmospheric temperature fluctuations. The efficiency varies depending on the state quantity of the gas turbine such as the power generation output (load zone).
In contrast, the fuel gas calorie calculation unit 131 multiplies the efficiency η ₀ (P) derived in the design stage by the efficiency correction coefficient k _η (P) for each state quantity (power generation output in this embodiment). The fuel gas calorie can be estimated by using finely adjusted and more accurate efficiency. In this respect, the fuel gas calorie calculation unit 131 can estimate the gas calorie with higher accuracy by improving the accuracy of the power generation efficiency, and can also cope with changes in the environment such as the aging of the gas turbine 940 and the atmospheric temperature. It is possible. And the control apparatus 800 can further reduce the possibility of overload and misfire due to sudden change of gas calorie by controlling the fuel gas calorie using the estimation result of the fuel gas calorie calculating unit 131.
Further, the fuel gas calorie calculating unit 131 can estimate the fuel gas calorie using the state quantity of the gas turbine 940 other than the power generation output, such as the exhaust gas temperature or the rotation speed of the gas turbine 940.

  In addition, the fuel gas calorie estimation apparatus 100 can estimate the fuel gas calorie of various gas turbines not only in the example of FIG. For example, the fuel gas calorie estimation apparatus 100 is used not only for the BFG gas turbine but also for various gas turbine facilities in which the fuel gas calorie can be varied, such as an integrated coal gasification combined cycle (IGCC). it can. Moreover, the fuel gas calorie estimation apparatus 100 can be used not only for combined cycle power generation equipment but also for power generation equipment for a gas turbine alone. Moreover, even in the case of a combined cycle power generation facility, it is not limited to a single-shaft combined cycle. Further, the number of stages of the steam turbine is not limited to two, but may be one or three or more. Furthermore, the fuel gas calorie estimation apparatus 100 can be used for various gas turbines other than power generation applications such as a power gas turbine.

Further, the fuel gas calorie estimated by the fuel gas calorie estimation device 100 may be used for purposes other than the control of the gas turbine power generation facility 900, such as display or recording to an operator.
In the first embodiment, the gas turbine power generation facility 900 may not include a calorimeter.

<Second Embodiment>
In the present embodiment, a fuel gas calorie estimation device 200 shown in FIG. 5 is used instead of the fuel gas calorie estimation device 100 of FIG. The control device 800 and the gas turbine power generation facility 900 are the same as those in the first embodiment.
FIG. 5 is a schematic block diagram showing a functional configuration of the fuel gas calorie estimation apparatus 200. In the figure, a fuel gas calorie estimation apparatus 200 includes a state quantity acquisition unit 111, a fuel gas flow rate acquisition unit 112, a storage unit 121, a fuel gas calorie calculation unit 131, a calculation result output unit 141, and a calorie measurement value. An acquisition unit 213 and an efficiency update unit 251 are provided.
In the same figure, portions having the same functions corresponding to the respective portions in FIG. 3 are denoted by the same reference numerals (111, 112, 121, 131, 141), and description thereof is omitted.

  The fuel gas calorie estimation apparatus 200 estimates the fuel gas calorie based on the fuel gas flow rate measured by the flow meter 992 (FIG. 1) and the power generation output of the generator 971 measured by the power meter 993. In addition, the fuel gas calorie estimation apparatus 200 updates the efficiency correction coefficient based on the fuel gas calorie measured by the calorimeter 991. The fuel gas calorie estimation apparatus 200 is configured by a computer, for example.

The calorie measurement value acquisition unit 213 acquires the fuel gas calorie measurement value measured by the calorimeter 991.
The efficiency updating unit 251 determines the magnitude of the difference between the fuel gas calorie measurement value and the true value of the fuel gas calorie. And the efficiency update part 251 is based on the fuel gas calorie measurement value and the state quantity of the gas turbine 940 at the timing when it is determined that the magnitude of the difference between the fuel gas calorie measurement value and the true value of the fuel gas calorie is small. The power generation efficiency corresponding to the state quantity is updated.

  For example, the efficiency updating unit 251 determines the magnitude of the fluctuation of the fuel gas calorie measurement value by the calorimeter 991, and the magnitude of the fluctuation of the fuel gas calorie measurement value over a period longer than the response delay of the fuel gas calorie measurement value. Is determined to be small, the start of the period is detected as a timing at which the difference between the measured value of the fuel gas calories and the true value of the fuel gas calories is small.

  FIG. 6 is a graph illustrating an example in which the efficiency updating unit 251 determines that the variation in the fuel gas calorie measurement value is small over a period longer than the response delay of the fuel gas calorie measurement value. In the figure, the horizontal axis indicates time, and the vertical axis indicates calories. A line L21 indicates the true value of the fuel gas calorie. A line L22 indicates the measured value of the fuel gas calorie by the calorimeter 991.

  Time T212 indicates the current time. The time T221 indicates the response delay time of the fuel gas calorie measurement value. At the start of the time T221, the true value of the fuel gas calorie (line L21) starts to decrease, whereas the fuel gas calorie measurement value (line L22) starts to decrease at the end of time T221. Time T211 indicates a time past the response delay time indicated by time T221 than the current time (time T212).

In the example of FIG. 6, the fuel gas calorie measurement value (line L22) is substantially constant at the set value for the time from time T211 to time T212.
The efficiency update unit 251 acquires the fuel gas calorie measurement value measured by the calorimeter 991 through the calorie measurement value acquisition unit 213 for each sampling time from time T211 to time T212, for example. And the efficiency update part 251 calculates dispersion | distribution of the obtained fuel gas calorie measured value, and determines whether the obtained dispersion | distribution is below a predetermined threshold value. When it is detected that the variance is equal to or less than the threshold value, the efficiency updating unit 251 determines that the magnitude of the variation in the fuel gas calorie measurement value is small over a period longer than the response delay of the fuel gas calorie measurement value.

  Note that the method by which the efficiency updating unit 251 evaluates the magnitude of the variation in the fuel gas calorie measurement value is not limited to the method using dispersion. For example, the efficiency updating unit 251 calculates the magnitude of the difference between the fuel gas calorie measurement value and the set value at each sampling time of the evaluation target period (from time T211 to time T212 in the example of FIG. 6). Also good. When it is detected that the magnitude of the difference is equal to or less than a predetermined threshold at any sampling time, the efficiency update unit 251 determines the fuel gas calorie measurement value over a period longer than the response delay of the fuel gas calorie measurement value. You may make it determine with the magnitude | size of a fluctuation | variation being small.

  In the example of FIG. 6, the fuel gas calorie measurement value (line L22) is substantially constant during the period from time T211 to time T212 (the magnitude of fluctuation is small). From this, at least at time T211, it can be considered that the fuel gas calorie measurement value (line L22) is equal to the true value (line L21).

Therefore, the efficiency update unit 251 that has determined that the magnitude of the variation in the fuel gas calorie measurement value is small over a period longer than the response delay of the fuel gas calorie measurement value is based on the fuel gas calorie measurement value at time T211. The efficiency correction coefficient corresponding to the power generation output at is updated. Specifically, the efficiency updating unit 251 calculates the fuel gas calorie measurement value of the calorimeter 991, the fuel gas flow rate measurement value of the flow meter 992, and the power generation output measurement value of the watt meter 993 at time T211 using the formula ( Applying the relationship shown in 5), a reference signal (teacher signal) k ^r _η (P) of the efficiency correction coefficient is obtained.

However, P shows a power generation output. Q indicates the fuel gas flow rate. H _s indicates a fuel gas calorie measurement value. η ₀ (P) represents a value corresponding to the power generation output P of the efficiency derived in the design stage.
The efficiency updating unit 251 then replaces the efficiency correction coefficient k _η (P) corresponding to the power generation output P at time T211 with the obtained efficiency correction coefficient reference signal k ^r _η (P).

  For example, the storage unit 121 stores an efficiency correction coefficient corresponding to the power generation output for each section obtained by dividing the power generation output (load band) of the generator 971. Then, the efficiency update unit 251 detects the time detected as the time when the measured value of the fuel gas calorie can be regarded as being equal to the true value among the efficiency correction coefficients stored in the storage unit 121 (in the example of FIG. 6, the time T211. Hereinafter, the efficiency correction coefficient corresponding to the power generation output at “reference time” is replaced with a reference signal of the efficiency correction coefficient.

FIG. 7 is an explanatory diagram illustrating an example of updating the efficiency correction coefficient performed by the efficiency updating unit 251. In the figure, the horizontal axis indicates the power generation output, and the vertical axis indicates the efficiency correction coefficient.
In the example of FIG. 7, the measured value of the power generation output P at the reference time corresponds to P ₂ , and the efficiency update unit 251 calculates the efficiency correction coefficient k _η (P ₂ ) of the power generation output P ₂ as the obtained efficiency. Replace with the reference signal k ^r _η (P) of the correction coefficient.

Next, the operation of the efficiency updating unit 251 will be described with reference to FIG.
FIG. 8 is a flowchart illustrating a procedure of processing in which the efficiency update unit 251 updates the efficiency correction coefficient. For example, the efficiency update unit 251 performs the process illustrated in FIG.
In the process of FIG. 8, the efficiency update unit 251 first calculates the calorie through the calorie measurement value acquisition unit 213 for each sampling time for a predetermined time set as a time longer than the response delay time of the calorimeter 991. The fuel gas calorie measurement value measured by the meter 991 is acquired (step S101).
And the efficiency update part 251 calculates dispersion | distribution of the obtained fuel gas calorie measured value (step S102), and determines whether the obtained dispersion | distribution is below a predetermined threshold value (step S103).

When it is determined that the variance is larger than the threshold (step S103: NO), the process returns to step S101.
On the other hand, when it is determined that the variance is equal to or less than the threshold value (step S103: YES), the efficiency updating unit 251 calculates a reference signal k ^r _η (P) for the efficiency correction coefficient (step S104). Then, the efficiency update unit 251 replaces the efficiency correction coefficient corresponding to the power generation output at the reference time among the efficiency correction coefficients stored in the storage unit 121 with the reference signal of the efficiency correction coefficient (step S105).
Thereafter, the process of FIG.

As described above, the efficiency updating unit 251 determines the magnitude of the difference between the measured fuel gas calorie value and the true value of the fuel gas calorie, and the difference between the measured fuel gas calorie value and the true value of the fuel gas calorie. The power generation efficiency corresponding to the turbine state quantity is updated based on the fuel gas calorie measurement value and the turbine state quantity at the timing when it is determined that the size of the engine is small.
Thereby, the efficiency update part 251 can update an efficiency correction coefficient finely for every electric power generation output, and the fuel gas calorie calculating part 131 calculates a fuel gas calorie more accurately using the said efficiency correction coefficient. can do.

  Further, the efficiency update unit 251 uses the fuel gas calorie measurement value by updating the efficiency correction coefficient at the timing when it is determined that the difference between the fuel gas calorie measurement value and the true value of the fuel gas calorie is small. The efficiency correction coefficient can be updated easily and more accurately.

Further, the efficiency updating unit 251 determines the magnitude of the fluctuation of the fuel gas calorie measurement value, and determines that the fluctuation magnitude of the fuel gas calorie measurement value is small over a period longer than the response delay of the fuel gas calorie measurement value. Then, the start time of the period is detected as a timing at which the difference between the measured value of the fuel gas calorie and the true value of the fuel gas calorie is small.
Thus, instead of constantly updating the efficiency correction coefficient, the efficiency update unit 251 accurately updates the efficiency correction coefficient by performing an update when it is determined that the variation in the fuel gas calorie measurement value is small. Can be updated. Therefore, the fuel gas calorie calculating unit 131 can calculate the fuel gas calorie more accurately using the efficiency correction coefficient.

Note that the state quantity used by the efficiency updating unit 251 for updating the efficiency correction coefficient is not limited to the power generation output of the generator 971, similarly to the state quantity used by the fuel gas calorie calculating unit 131 for estimating the fuel gas calorie. For example, the efficiency updating unit 251 may use a state quantity of the gas turbine 940 other than the power generation output, such as the exhaust gas temperature of the gas turbine body 944 or the rotational speed of the gas turbine body 944.
Further, the state quantity used by the fuel gas calorie calculating unit 131 and the state quantity used by the efficiency updating unit 251 may be the same state quantity or different state quantities.

In addition, the fuel gas calorie estimation apparatus 200 can estimate the fuel gas calorie of various gas turbines not only in the example of FIG. For example, the fuel gas calorie estimation apparatus 200 can be used not only for the BFG gas turbine but also for various gas turbine facilities where the fuel gas calorie can vary, such as coal gasification combined power generation. Moreover, the fuel gas calorie estimation apparatus 200 can be used not only for combined cycle power generation equipment but also for power generation equipment for a gas turbine alone. Moreover, even in the case of a combined cycle power generation facility, it is not limited to a single-shaft combined cycle. Further, the number of stages of the steam turbine is not limited to two, but may be one or three or more. Furthermore, the fuel gas calorie estimation apparatus 200 can be used for various gas turbines other than power generation applications, such as a power gas turbine.
Further, the fuel gas calorie estimated by the fuel gas calorie estimation apparatus 200 may be used for purposes other than the control of the gas turbine power generation facility 900, such as display to an operator or recording.

The format in which the storage unit 121 stores the efficiency correction coefficient is not limited to the format (for example, the table format) in which the power generation output and the efficiency correction coefficient are stored in association with each other as described with reference to FIG.
For example, the storage unit 121 may store an approximate curve indicating the relationship between the power generation output and the efficiency correction coefficient. In this case, the efficiency update unit 251 can update the efficiency correction coefficient by obtaining the parameters of the approximate curve (for example, the coefficient of each term in the polynomial) by, for example, the least square method.

In addition, the method in which the efficiency update part 251 detects the timing when the magnitude of the difference between the fuel gas calorie measurement value and the true value of the fuel gas calorie is small is a method for detecting a period in which the fluctuation of the fuel gas calorie measurement value is small. Not exclusively.
For example, the efficiency updating unit 251 determines whether the fuel gas calorie estimated value calculated by the fuel gas calorie calculating unit 131 is large or small, and the magnitude of the variation is small over a period longer than the response delay of the fuel gas calorie measured value. May be detected. Then, the efficiency update unit 251 may detect the end time of the detected period as a timing when the magnitude of the difference between the measured fuel gas calorie value and the true value of the fuel gas calorie is small.

Note that the efficiency update unit 251 may directly update the efficiency instead of the efficiency correction coefficient. That is, the storage unit 121 stores the efficiency η (P) according to the power generation output, and updates the efficiency according to the power generation output at the time based on the fuel gas calorie measurement value at the reference time. Also good.
Specifically, the efficiency updating unit 251 calculates the fuel gas calorie measurement value of the calorimeter 991, the fuel gas flow rate measurement value of the flow meter 992, and the power generation output measurement value of the watt meter 993 at the reference time by the formula ( Applying the relationship shown in 6), an efficiency reference signal η ^r (P) is obtained.

However, P shows a power generation output. Q indicates the fuel gas flow rate. H _s indicates a fuel gas calorie measurement value.
Then, the efficiency updating unit 251 replaces the efficiency η (P) corresponding to the power generation output P at the reference time with the obtained efficiency reference signal η ^r (P).

Similar to the format in which the storage unit 121 stores the efficiency correction coefficient, various formats can be used as the format in which the storage unit 121 stores the efficiency. For example, the storage unit 121 may store the power generation output and the efficiency in association with each other (for example, in a table format). Or you may make it the memory | storage part 121 memorize | store the approximated curve which shows the relationship between an electric power generation output and efficiency.
As an example of the approximate curve indicating the relationship between the power generation output and the efficiency, the storage unit 121 may use a cubic expression shown in Expression (7) for storage.

However, x shows the state quantity of turbines, such as a power generation output, for example. a ₀ , a ₁ , a ₂ , and a ₃ each indicate a coefficient. y (x) represents an approximate value of efficiency. In the formula (7), the superscript number indicates a multiplier.
The storage unit 121 stores, for example, the approximate curve of Expression (7) by storing the coefficient vector a shown in Expression (8) (in the description of the specification, bold notation indicating a vector or a matrix is omitted). .

Specifically, the storage unit 121 first stores an initial value of a coefficient vector a (for example, a coefficient vector that approximates efficiency at the design stage) that is obtained in advance using a method such as a least square method. . Then, the efficiency updating unit 251 updates the coefficient vector a based on the reference signal η ^r (P). For example, the efficiency updating unit 251 updates the coefficient vector a based on Expression (9) using an LMS (Least Mean Square) algorithm.

However, a _new and a _old indicate coefficient vectors after update and before update, respectively. The vector P is a vector based on the power generation output P shown in Expression (10). α represents a constant.

However, in the formula (10), the superscript number indicates a multiplier.
The efficiency update unit 251 updates the efficiency using the LMS algorithm, thereby avoiding a steep fluctuation in the efficiency (estimated value thereof). The true value of the efficiency gradually changes according to the secular change of the gas turbine 940, the atmospheric temperature, and the like, and should not change steeply. Therefore, it is expected that the efficiency update unit 251 can obtain an efficiency close to the true value by avoiding a steep fluctuation in efficiency.

When the efficiency updating unit 251 updates the efficiency, the same effect as that when the efficiency correction coefficient is updated can be obtained.
Specifically, in this way, the efficiency update unit 251 can finely update the efficiency for each power generation output, and the fuel gas calorie calculation unit 131 uses the efficiency to more accurately calculate the fuel gas calorie. Can be calculated.
In addition, the efficiency updating unit 251 can easily use the fuel gas calorie measurement value by updating the efficiency at the timing when it is determined that the difference between the fuel gas calorie measurement value and the true value of the fuel gas calorie is small. In addition, the update can be performed more accurately and efficiently.

  In addition, the efficiency update unit 251 can update the efficiency with high accuracy by performing the update when it is determined that the magnitude of the variation of the fuel gas calorie measurement value is small instead of constantly updating the efficiency. Therefore, the fuel gas calorie calculating unit 131 can calculate the fuel gas calorie more accurately using the efficiency.

  The efficiency updating unit 251 may update the efficiency to a value reflecting the past value of the efficiency. For example, the efficiency update unit 251 uses the forgetting coefficient β (β is a constant satisfying 0 <β ≦ 1) to update the efficiency correction coefficient based on the equation (11), so that the efficiency correction coefficient is steep. Suppress fluctuations.

  The closer the value of the forgetting factor β is to 1, the greater the influence of the current information. Conversely, the closer the value of the forgetting factor β is to 0, the greater the influence of past efficiency correction factors. The value of the forgetting factor β is set by the user of the fuel gas calorie estimation apparatus 200, for example.

The method in which the efficiency updating unit 251 updates the efficiency to a value reflecting the past value of the efficiency is not limited to the method using the forgetting factor. For example, the efficiency update unit 251 applies an integration filter to the reference signal k ^r _η (P) of the efficiency correction coefficient to generate a first-order lag, and the efficiency stored in the storage unit 121 using the reference signal in which the first-order lag has occurred The correction coefficient may be updated.

As described above, the efficiency update unit 251 updates the efficiency to a value reflecting the past value of the efficiency. Thereby, the efficiency update part 251 can suppress the steep fluctuation | variation of an efficiency correction coefficient.
As described above, the true value of efficiency should not change steeply, and the true value of the efficiency correction coefficient should not change steeply. Therefore, it is expected that the efficiency update unit 251 can obtain an efficiency correction coefficient close to the true value by avoiding a sharp change in efficiency. And the fuel gas calorie calculating part 131 can obtain | require a fuel gas calorie estimated value accurately by using the said efficiency correction coefficient.

Note that the efficiency updating unit 251 may perform correction to cancel the influence on the efficiency of the steady deviation between the true value of the fuel gas calorie and the measured value of the fuel gas calorie.
Here, when the fuel gas calorie measurement value measured by the calorimeter 991 includes a steady deviation (offset) with respect to the true value, the efficiency correction coefficient updated by the efficiency updating unit 251 based on the fuel gas calorie measurement value or Efficiency can also include steady-state deviations. Therefore, the efficiency updating unit 251 may generate a coefficient for correcting the steady-state deviation, such as the coefficient j _η shown in Expression (12).

F (s) represents a filter such as a first-order lag system 1 / (Ts + 1) having a time constant T [second (sec)], for example. 1 / s indicates an integral operator (s is a differential operator).
The efficiency updating unit 251 can set j _η k _η (P) as a new efficiency correction coefficient. For example, for the efficiency correction coefficient reference signal k ^r _η (P), the efficiency update unit 251 determines the efficiency correction coefficient corresponding to the power generation output P among the efficiency correction coefficients stored in the storage unit 121 as j _η k ^r. It can be updated to _η (P).
Alternatively, when the efficiency updating unit 251 updates the efficiency, the efficiency corresponding to the power generation output P among the efficiency stored in the storage unit 121 can be updated to j _η η (P).

In addition, the true value H of the fuel gas calorie shown in Formula (12) cannot usually be obtained. Therefore, the efficiency update unit 251 acquires the coefficient j _η based on, for example, the deviation between the target value of the power generation output and the measurement value of the power generation output.
Here, when the steady deviation between the true value and the measured value of the fuel gas calorie affects the estimated fuel gas calorie value output from the fuel gas calorie estimation device 200, the control device 800 uses the estimated fuel gas calorie value. This also affects the control of the power generation output. That is, the steady deviation between the true value and the measured value of the fuel gas calorie is indicated by the deviation between the target value of the power generation output and the measured value.
Therefore, for example, the efficiency updating unit 251 acquires the coefficient j _η corresponding to the steady deviation between the true value of the fuel gas calories and the measured value based on the deviation between the target value of the generated power output and the measured value of the generated power output. .

As described above, the efficiency updating unit 251 performs correction to cancel the influence on the efficiency of the steady deviation between the true value of the fuel gas calorie and the measured value of the fuel gas calorie.
Thereby, the efficiency update part 251 can further improve the precision of efficiency. And by using the said efficiency, the fuel gas calorie calculating part 131 can further improve the precision of a fuel gas calorie estimated value.

In addition, a program for realizing all or part of the functions of the fuel gas calorie estimation apparatus 100 or 200 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by a computer system, The processing of each unit may be performed by executing. 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.

DESCRIPTION OF SYMBOLS 1 Power generation system 100, 200 Fuel gas calorie estimation apparatus 111 State quantity acquisition part 112 Fuel gas flow rate acquisition part 121 Storage part 131 Fuel gas calorie calculation part 141 Calculation result output part 213 Calorie measurement value acquisition part 251 Efficiency update part 800 Control apparatus 900 Gas turbine power generation equipment

Claims (7)

A fuel gas flow rate acquisition unit for acquiring a flow rate of the fuel gas flowing into the combustor of the gas turbine;
A state quantity obtaining unit for obtaining a state quantity of the gas turbine;
A storage unit for storing power generation efficiency including an efficiency correction coefficient associated with the state quantity;
A fuel gas calorie calculation unit that performs a fuel gas calorie calculation based on the fuel gas flow rate, the state quantity, and the power generation efficiency obtained from the efficiency correction coefficient according to the state quantity;
A fuel gas calorie estimation apparatus comprising: A calorie measurement value acquisition unit for acquiring a fuel gas calorie measurement value;
The magnitude of the difference between the measured fuel gas calorie value and the true value of the fuel gas calorie is determined, and the magnitude of the difference between the measured fuel gas calorie value and the true value of the fuel gas calorie is determined to be small. An efficiency update unit that updates the power generation efficiency corresponding to the state quantity based on the measured fuel gas calorie value and the state quantity at
The fuel gas calorie estimation apparatus according to claim 1, comprising:   The efficiency update unit determines the magnitude of the fluctuation of the fuel gas calorie measurement value, and when the fluctuation magnitude of the fuel gas calorie measurement value is small over a period longer than the response delay of the fuel gas calorie measurement value 3. The fuel gas calorie estimation according to claim 2, wherein when the determination is made, the start time of the period is detected as a timing at which a difference between the measured value of the fuel gas calorie and the true value of the fuel gas calorie is small. apparatus.   The fuel gas calorie estimation device according to claim 2 or 3, wherein the efficiency update unit updates the power generation efficiency to a value reflecting a past value of the power generation efficiency.   The said efficiency update part performs the correction | amendment which negates the influence with respect to the said power generation efficiency of the stationary deviation of the true value of the said fuel gas calorie, and the said fuel gas calorie measured value. The fuel gas calorie estimation apparatus according to claim 1. A fuel gas calorie estimation method for a fuel gas calorie estimation device comprising a storage unit for storing power generation efficiency including an efficiency correction coefficient associated with a state quantity of a gas turbine,
A fuel gas flow rate acquisition step for acquiring a flow rate of fuel gas flowing into the combustor of the gas turbine;
A state quantity obtaining step for obtaining a state quantity of the gas turbine;
A fuel gas calorie calculation step for calculating a fuel gas calorie based on the fuel gas flow rate, the state quantity, and the power generation efficiency obtained from the efficiency correction coefficient corresponding to the state quantity;
A fuel gas calorie estimation method comprising: In a computer as a fuel gas calorie estimation device comprising a storage unit for storing power generation efficiency including an efficiency correction coefficient associated with the state quantity of the gas turbine,
A fuel gas flow rate acquisition step for acquiring a flow rate of fuel gas flowing into the combustor of the gas turbine;
A state quantity obtaining step for obtaining a state quantity of the gas turbine;
A fuel gas calorie calculation step for calculating a fuel gas calorie based on the fuel gas flow rate, the state quantity, and the power generation efficiency obtained from the efficiency correction coefficient corresponding to the state quantity;
A program for running

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