GAS TURBINE CONTROL DEVICE

Abstract

The present application relates to a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel with a second fuel having a lower amount of heat per unit volume. This device controls the gas turbine based on a control parameter obtained by correcting a reference value corresponding to mono-combustion of the first fuel using a correction value. The correction value is calculated such that, as the second fuel co-combustion ratio increases, the control parameter becomes smaller or larger than the reference value, and the amount of deviation from the reference value increases.

Description

Technical area

[0001] The present disclosure relates to a gas turbine control apparatus for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel.

[0002] This application claims the benefit of priority based on Japanese Patent Application No. 2023-049185 filed with the Japan Patent Office on March 27, 2023, the contents of which are incorporated herein by reference. State of the art

[0003] For example, in a thermal power plant, improving power generation efficiency and actively using fuels other than fossil fuels, such as hydrogen, are considered as means to reduce the amount of carbon dioxide (CO2) emissions, which is a cause of global warming (see, for example, PTL 1). Citation listPatent literature

[0004] [PTL 1] Japanese Unexamined Patent Application Publication No. 2021-046949 Summary of the inventionTechnical problem

[0005] To reduce carbon dioxide emissions, it is desirable to increase the co-combustion ratio of a second fuel (hydrogen), which has a relatively lower calorific value per unit volume than a first fuel, such as natural gas. However, since hydrogen has low ignition energy and a high combustion rate, increasing the co-combustion ratio of hydrogen increases the possibility of flame backflow or the like.

[0006] At least one embodiment of the present disclosure has been made in view of the above-described circumstances, and an object of the present disclosure is to provide a gas turbine control apparatus capable of maintaining a stable operating state even in a case where a co-combustion ratio of hydrogen is changed. Solution to the problem

[0007] To solve the problems described above, a gas turbine control device according to an embodiment of the present disclosure is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0008] To solve the problems described above, a gas turbine control device according to another embodiment of the present disclosure is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine to perform a partial load operation based on the control parameter obtained by correcting the reference value using the correction value.

[0009] To solve the problems described above, a gas turbine control device according to another embodiment of the present disclosure is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter which is an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0010] To solve the problems described above, a gas turbine control device according to another embodiment of the present disclosure is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter including at least one of a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, a cylinder fuel distribution ratio with respect to a cylinder fuel injector among the plurality of fuel injectors, a fuel distribution ratio between main nozzle groups among the plurality of fuel injectors, and an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0011] To solve the problems described above, a gas turbine control device according to another embodiment of the present disclosure is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a cylinder fuel distribution ratio with respect to a cylinder fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value. Advantageous effects of the invention

[0012] According to at least one embodiment of the present disclosure, it is possible to provide a gas turbine control device that can maintain a stable operating state even in a case where a co-combustion ratio of hydrogen is changed. Brief description of the drawings Fig. 1 is a diagram illustrating a schematic configuration of a gas turbine according to an embodiment. Fig. 2 is a section configuration example of a combustion chamber of Fig. 1. Fig. 3 is a diagram showing an arrangement arrangement of a main fuel injection nozzle and a pilot fuel injection nozzle of Fig. 2 from a downstream side. Fig. 4 is a block diagram illustrating a functional configuration of a gas turbine control device according to an embodiment. Fig. 5 is a graph illustrating behavior with respect to a co-combustion ratio along with a flame temperature and an emission amount of nitrogen oxide in a case where a pilot fuel distribution ratio is selected as a control parameter. Fig. 6 is a graph illustrating behavior with respect to a co-combustion ratio along with a combustion speed and a fuel-air ratio in a case where the pilot fuel distribution ratio or an opening degree of an inlet guide vane of the gas turbine is selected as a control parameter. Fig. 7 is a graph illustrating behavior with respect to a co-combustion ratio along with a combustion speed and an amplitude value of combustion vibration in a case where the pilot fuel distribution ratio, a cylinder fuel distribution ratio, a fuel distribution ratio between main nozzle groups, or an opening degree of an inlet guide vane of the gas turbine is selected as the control parameter. Fig. 8 is a graph illustrating a behavior of a lower combustible limit, a cylinder fuel distribution ratio which is a control parameter, and a fuel-air ratio of the cylinder fuel injector with respect to a co-combustion ratio. Description of embodiments

[0013] Some embodiments of the present invention will be described below with reference to the accompanying drawings. However, configurations described in the embodiments or illustrated in the drawings are not intended to limit the scope of the invention and are merely examples for description.

[0014] First, a gas turbine that is a control target of a gas turbine control device according to at least one embodiment of the present disclosure will be described with reference to Fig. 1 described. Fig. 1 is a diagram illustrating a schematic configuration of a gas turbine 1 according to an embodiment.

[0015] The gas turbine 1 includes a compressor 3 for generating compressed air, a combustion chamber 2 for generating combustion gas by co-combusting the compressed air generated by the compressor 3 and a fuel, a fuel supply system 4 for supplying the fuel to the combustion chamber 2, and a turbine 6 driven by the combustion gas. The compressor 3 and the turbine 6 are connected to each other on a shaft. In the gas turbine 1 with such a configuration, compressed air compressed by the compressor 3 and fuel supplied from the fuel supply system 4 are supplied to the combustion chamber 2, and the compressed air and fuel are mixed and burned to generate combustion gas. The combustion gas flows into the turbine 6 and functions as energy to drive the turbine 6.

[0016] The fuel supply system 4 treats a mixed fuel in which a first fuel F1 and a second fuel F2 are mixed together as the fuel supplied to the combustion chamber 2. The second fuel F2 is a fuel with a lower calorific value per unit volume than the first fuel F1. In the present embodiment, the first fuel F1 is liquefied natural gas (LNG), and the second fuel F2 is hydrogen gas.

[0017] The first fuel F1 is supplied through a first fuel supply line 8 connected to a first fuel supply source 7. A flow meter 10 for detecting the flow rate of the first fuel F1 is provided in the first fuel supply line 8.

[0018] The second fuel F2 is supplied through a second fuel supply line 16 connected to a second fuel supply source 14. The second fuel supply line 16 is provided with a flow meter 15 for detecting the flow rate of the second fuel F2, a first flow control valve 18 for controlling the flow rate of the second fuel F2, and a shutoff valve 13 for shutting off the second fuel F2.

[0019] The first fuel supply line 8 and the second fuel supply line 16 are connected to a main fuel supply line 22 by connecting them to each other on a downstream side. The first fuel F1 and the second fuel F2 are mixed by connecting them at a junction 25 of the first fuel supply line 8 and the second fuel supply line 16, and the mixed fuel (hereinafter referred to as "mixed fuel Fm" as needed) is supplied through the main fuel supply line 22.

[0020] In the main fuel supply line 22, a shut-off valve 24 which shuts off the mixed fuel Fm and a second flow control valve 26 which adjusts the flow rate of the mixed fuel Fm are provided.

[0021] The downstream side of the main fuel supply line 22 branches into a plurality of fuel branch supply lines 28a, 28b, ... to correspond to a plurality of fuel injection nozzles included in the combustion chamber 2. As will be described later with reference to Fig. 2, the plurality of fuel injectors includes a main fuel injector 52, a pilot fuel injector 56, and a cylinder fuel injector 58. Furthermore, at least some of the main fuel injectors 52 may be grouped.

[0022] The plurality of fuel branch supply lines 28a, 28b, ... are each provided with third flow control valves 30a, 30b, ... for adjusting the flow rate of the mixed fuel flowing through each line. Among the plurality of fuel branch supply lines 28a, 28b, ..., the fuel branch supply lines 28a and 28b are connected to the main fuel injectors 52, the fuel branch supply line 28c is connected to the pilot fuel injector 56, and the fuel branch supply line 28d is connected to the cylinder fuel injector 58.

[0023] Fig. 2 is a section configuration example of the combustion chamber 2 of Fig. 1. The combustion chamber 2 includes an outer cylinder 32, a liner 34 (inner cylinder), and a burner 36. The outer cylinder 32 is a cylindrical member provided in an outer peripheral portion of a turbine casing (not shown). An end portion (head) of the outer cylinder 32 on an upstream side (left side in Fig. 2) is closed by an end cover 38. The liner 34 is a cylindrical combustion chamber inner cylinder forming a combustion chamber 40 and is installed within the outer cylinder 32. An annular air flow path 33 is formed between the outer cylinder 32 and the liner 34.

[0024] In addition, a large number of air holes are formed in the liner 34. The combustion chamber 40 is a space formed between the burner 36 and a transition piece 50 on the downstream side through the liner 34, and the fuel discharged from the burner 36 is burned here together with compressed air 42. The transition piece 50 is configured as a member that smoothly connects an inlet (inlet of the first-stage stator blade) of a gas path of the turbine 6 and the liner 34. In addition, the end cover 38 is provided with a fuel distributor 44 that distributes fuel to the burner 36. In addition, although not specifically shown, the combustion chamber 2 is also provided with an ignition device that ignites a fuel-air mixture in the combustion chamber 40.

[0025] The burner 36 is provided in the end cover 38 so as to be positioned between the combustion chamber 40 and the end cover 38. The burner 36 includes a plurality of element burners, a pilot burner 46 is arranged in a central portion of the combustion chamber 2, and a plurality of main burners 48 are arranged on a radially outer side of the pilot burner 46 so as to surround the pilot burner 46.

[0026] Each main burner 48 includes a plurality of main fuel injectors 52 as fuel injectors.

[0027] The pilot burner 46 has a configuration similar to that of the main burner 48 described above and is located in the center of the plurality of main burners 48. The pilot burner 46 includes the pilot fuel injector 56 as a fuel injector.

[0028] The air flow path 33, formed between an inner peripheral side of the outer cylinder 32 and an outer peripheral side of the liner 34, is configured to guide the compressed air 42 from the compressor 3 to the inside of the liner 34. The cylinder fuel injection nozzle 58 for injecting a cylinder fuel is provided in the air flow path 33 as a fuel injection nozzle.

[0029] Fig. 3 is a diagram showing an arrangement arrangement of the main fuel injection nozzle 52 and the pilot fuel injection nozzle 56 of Fig. 2 from the downstream side. The plurality of main fuel injectors 52 are arranged around the pilot fuel injector 56 along a circumferential direction. Furthermore, the plurality of main fuel injectors 52 are classified into a plurality of main fuel injector groups. In the present embodiment, a total of eight main fuel injectors 52 are provided, and the main fuel injectors 52 are divided into a first main fuel injector group 52A, the five main fuel injectors 52 shown below in Fig. 3, and a second main fuel injector group 52B including three remaining main fuel injectors 52. A fuel distribution ratio KMB between the main nozzle groups to be described later is a value obtained by dividing a second main flow rate MBCSO, which is the flow rate of fuel supplied to the second main fuel injector group 52B, by a value obtained by adding a first main flow rate MACSO and a second main flow rate MBCSO, which are flow rates of fuel supplied to the first main fuel injector group 52A. Specifically, the fuel distribution ratio KMB between the main nozzle groups is defined by the following equation. KMB−MBCSO / (MACSO+MBCSO)

[0030] Next, a gas turbine control device 100 for controlling the gas turbine 1 having the above-described configuration will be described. The gas turbine control device 100 is a control unit that controls the gas turbine 1 and is configured, for example, with a central processing unit (CPU), a random-access memory (RAM), a read-only memory (ROM), and a computer-readable storage medium or the like. A series of processing for realizing various functions is stored, for example, in a storage medium or the like in the form of a program, and the CPU reads this program into a RAM or the like and executes processing for information processing and calculation, thereby realizing various functions.The program may be provided in a form preinstalled in the ROM or other storage medium, a form provided in a state in which it is stored on a computer-readable storage medium, or a form delivered via wired or wireless communication means. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

[0031] Fig. 4 is a block diagram illustrating a functional configuration of the gas turbine control device 100 according to an embodiment. The gas turbine control device 100 includes a reference value calculation unit 102, a co-combustion ratio detection unit 104, a correction value calculation unit 106, and a control unit 108.

[0032] The reference value calculation unit 102 is configured to calculate a reference value Pref of a control parameter P for controlling the gas turbine 1. The reference value Pref is calculated as the control parameter P during exclusive combustion using the first fuel F1 (in a case where a co-combustion ratio R is 0%) based on at least one parameter related to the operating state of the gas turbine 1.

[0033] In any case referred to later in Fig. In the embodiment described in Figures 6 to 9, for the sake of simplicity, a case is described in which the reference value Pref is constant regardless of a load L of the gas turbine 1. However, the reference value Pref may be variable according to the load L of the gas turbine 1.

[0034] The co-combustion ratio detecting unit 104 is configured to detect the co-combustion ratio R of the second fuel F2. In the present embodiment, the co-combustion ratio detecting unit 104 is configured to detect the co-combustion ratio R calculated based on the flow rate measurement value of the first fuel F1 measured by the flowmeter 10 arranged in the first fuel supply line 8 and the flow rate measurement value of the second fuel F2 measured by the flowmeter 15 arranged in the second fuel supply line 16.

[0035] The co-combustion ratio detecting unit 104 may detect the calculation result of the co-combustion ratio R from the outside, or may detect the co-combustion ratio R by detecting the measurement results of the flow meters 10 and 15, and the co-combustion ratio detecting unit 104 itself calculates the co-combustion ratio R.

[0036] The correction value calculation unit 106 is configured to calculate a correction value Pamd for obtaining the control parameter P handled by the gas turbine control device 100 by correcting the reference value Pref. The calculation of the correction value Pamd is performed based on the co-combustion ratio R detected by the co-combustion ratio detection unit 104. The correlation between the co-combustion ratio R and the correction value Pamd is determined for each type of control parameter P, as described later with reference to Fig. 6 to 9.

[0037] The combustion speed tends to increase as the co-combustion ratio R increases. As the co-combustion ratio R increases, the position of a flame 37 formed in the combustion chamber 40 shifts (see Fig. 2) to the upstream side. As a result, there is a possibility that an increase in nitrogen oxide (NOx) contained in the exhaust gas from the gas turbine 1, the occurrence of flashback, an increase in the risk of combustion vibration, and the like may occur. Furthermore, there is a possibility that abnormal combustion (for example, ignition of combustible foreign matter such as sealing oil in the combustion chamber 40 and ignition and flame retention of the premixed gas of the cylinder head) is more likely to occur due to the spread of a combustible region 37' (region along the width direction of the flame 37) in the combustion chamber 40. These problems can be appropriately solved by having the correction value calculation unit 106 calculate the correction value Pamd based on the co-combustion ratio R for each type of the control parameter P.

[0038] The control unit 108 is configured to control the gas turbine 1 using the control parameter P obtained by correcting the reference value Pref calculated by the reference value calculation unit 102 using the correction value Pamd calculated by the correction value calculation unit 106. In the present embodiment, the control of the gas turbine 1 is performed based on the control parameter P obtained by adding the correction value Pamd to the reference value Pref.

[0039] Next, embodiments of the gas turbine control by the gas turbine control device 100 will be described with reference to Fig. 5 to 8 are described specifically for each type of control parameter P.

[0040] First, a case will be described in which the pilot fuel distribution ratio with respect to the pilot fuel injector among the plurality of fuel injectors included in the combustion chamber 2 is treated as the control parameter P. Fig. 5 is a graph illustrating the behavior with respect to the co-combustion ratio R together with the flame temperature and the emission amount of nitrogen oxide (NOx) in a case where the pilot fuel distribution ratio is selected as the control parameter P.

[0041] The pilot fuel distribution ratio is defined as a ratio of a fuel flow rate supplied to the pilot fuel injection nozzle to a fuel flow rate supplied to all of the plurality of fuel injection nozzles provided in the combustion chamber 2.

[0042] The correction value calculation unit 106 calculates the correction value Pamd such that the control parameter P becomes smaller than the reference value Pref, and a deviation amount ΔP from the reference value Pref increases as the co-combustion ratio R increases. The reference value Pref is calculated based on at least one parameter indicative of the operating state of the gas turbine 1 so as to correspond to the combustion using only the first fuel F1. In the present embodiment, the reference value Pref is approximately constant regardless of the co-combustion ratio R, and the correction value Pamd is calculated such that the control parameter P decreases as the co-combustion ratio R increases.

[0043] By controlling the gas turbine 1 based on the control parameter P (pilot fuel distribution ratio) obtained by correcting the reference value Pref using the correction value Pamd in this way, the emission amount of nitrogen oxide (NOx) contained in the exhaust gas in the gas turbine 1 subjected to co-combustion operation can be effectively reduced. As the co-combustion ratio R increases, the flame temperature increases due to an increase in the ratio of the second fuel F2 in the mixed fuel. However, by controlling the control parameter (pilot fuel distribution ratio) to a value lower than the reference value Pref, the combustion efficiency can be improved in a state where the co-combustion ratio R is high, and nitrogen oxide (NOx) can be suppressed.In this way, the amount of nitrogen oxide (NOx) emitted during co-combustion operation can be suppressed to be equal to or less than a control value.

[0044] In addition, a lower threshold Plmt can be set for the pilot fuel distribution ratio, which is the control parameter P. The lower threshold Plmt is set to increase as the co-combustion ratio R increases. The larger the co-combustion ratio R, the greater the risk of flashback occurrence. Therefore, by setting the lower threshold Plmt to a larger value according to the co-combustion ratio R in this way, the occurrence of flashback in the gas turbine 1 undergoing co-combustion operation can be effectively avoided.

[0045] An embodiment in which the pilot fuel distribution ratio is treated as the control parameter P in this manner is suitable, for example, in a case where the gas turbine 1 is operated at full load. During full load operation, the emission amount of nitrogen oxide (NOx) is relatively large. Therefore, even when only the first fuel F1 is combusted (in a case where the co-combustion ratio R is 0%), the emission amount of nitrogen oxide (NOx) approaches a control value. In such a case, as the co-combustion ratio R increases as described above, the control parameter P (pilot fuel distribution ratio) is controlled to be smaller than the reference value Pref, so that it becomes easier to meet the control value over a wide range of the co-combustion ratio R.Meanwhile, by setting the lower threshold Plmt for the control parameter P, it is also possible to prevent the occurrence of flameback.

[0046] Next, a case will be described where the pilot fuel distribution ratio with respect to the pilot fuel injector among the plurality of fuel injectors included in the combustor 2 or an opening degree of an inlet guide vane (IGV) of the gas turbine 1 is treated as the control parameter P. Fig. 6 is a graph illustrating the behavior with respect to the co-combustion ratio R together with the combustion speed and the fuel-air ratio in a case where the pilot fuel distribution ratio or the opening degree of the inlet guide vane of the gas turbine is selected as the control parameter P.

[0047] The correction value calculation unit 106 calculates the correction value Pamd such that the control parameter P becomes larger than the reference value Pref, and the deviation amount ΔP from the reference value Pref increases as the co-combustion ratio R increases. The reference value Pref is calculated based on at least one parameter indicative of the operating state of the gas turbine 1 so as to correspond to the exclusive combustion using the first fuel F1. In the present embodiment, the reference value Pref is approximately constant regardless of the co-combustion ratio R, and the correction value Pamd is calculated such that the control parameter P increases as the co-combustion ratio R increases.

[0048] By controlling the gas turbine 1 based on the control parameter P (pilot fuel distribution ratio) obtained by correcting the reference value Pref using the correction value Pamd in this way, the risk of flameback in the gas turbine 1 undergoing co-combustion operation can be effectively reduced. As the co-combustion ratio R increases, the combustion rate increases due to an increase in the ratio of the second fuel F2 in the mixed fuel. However, the combustion rate is suppressed by controlling the control parameter P (pilot fuel distribution ratio or inlet guide vane opening degree) to increase with respect to the reference value Pref, and a fuel-air ratio F / A not exceeding a limit value at which flameback may occur. In this way, the risk of flameback can be effectively suppressed.

[0049] In the present embodiment, if the pilot fuel distribution ratio is treated as the control parameter P, it is suitable, for example, for a case where the gas turbine 1 is operated under a partial load. During the partial load operation, the emission amount of nitrogen oxide (NOx) is smaller than that during the full load operation described above, and thus there is a margin in the control value. In such a case, the pilot fuel distribution ratio can be controlled to increase with respect to the co-combustion ratio R, so that the risk of flashback occurrence can be prioritized over the reduction of the emission amount of nitrogen oxide (NOx).

[0050] Next, a case will be described in which at least one of the pilot fuel distribution ratio with respect to the pilot fuel injector among the plurality of fuel injectors included in the combustion chamber 2, the cylinder fuel distribution ratio with respect to the cylinder fuel injector among the plurality of fuel injectors, the fuel distribution ratio between the main nozzle groups among the plurality of fuel injectors, and an opening degree of an inlet guide vane of the gas turbine is treated as the control parameter P. Fig. 7 is a graph illustrating the behavior of the co-combustion ratio R together with the combustion speed and the amplitude value of the combustion vibration in a case where the pilot fuel distribution ratio, the cylinder fuel distribution ratio, the fuel distribution ratio KMB between the main nozzle groups, or the opening degree of the inlet guide vane of the gas turbine 1 is selected as the control parameter P.

[0051] The cylinder fuel distribution ratio is defined as a ratio of a fuel flow rate supplied to the cylinder fuel injector to the fuel flow rate supplied to all of the plurality of fuel injectors provided in the combustion chamber 2.

[0052] The correction value calculation unit 106 calculates the correction value Pamd such that the control parameter P becomes larger than the reference value Pref, and the deviation amount ΔP from the reference value Pref increases as the co-combustion ratio R increases. The reference value Pref is calculated based on at least one parameter indicative of the operating state of the gas turbine 1 so as to correspond to the exclusive combustion using the first fuel F1. In the present embodiment, the reference value Pref is approximately constant regardless of the co-combustion ratio R, and the correction value Pamd is calculated such that the control parameter P increases as the co-combustion ratio R increases.

[0053] By controlling the gas turbine 1 based on the control parameter P (pilot fuel distribution ratio, cylinder fuel distribution ratio, fuel distribution ratio between main nozzle groups, or intake guide vane opening degree) obtained by correcting the reference value Pref using the correction value Pamd in this way, the risk of combustion oscillation in the gas turbine 1 subjected to co-combustion operation can be effectively reduced. As the co-combustion ratio R increases, the combustion rate increases because the ratio of the second fuel F2 in the mixed fuel increases.However, by controlling the control parameter P (pilot fuel distribution ratio, cylinder fuel distribution ratio, fuel distribution ratio between main nozzle groups, or intake guide vane opening degree) to increase with respect to the reference value Pref, the combustion speed can be suppressed, and the risk of combustion oscillation can be suppressed.

[0054] Next, a case will be described where the cylinder fuel distribution ratio for the cylinder fuel injector 58 among the plurality of fuel injectors included in the combustion chamber 2 is treated as the control parameter P. Fig. 8 is a graph illustrating the behavior of the lower combustible limit, the cylinder fuel distribution ratio which is the control parameter P, and the co-combustion ratio R of the fuel-air ratio F / A at the cylinder fuel injector 58.

[0055] The correction value calculation unit 106 calculates the correction value Pamd such that the control parameter P becomes smaller than the reference value Pref and the deviation amount ΔP from the reference value Pref increases as the co-combustion ratio R increases. The reference value Pref is calculated based on at least one parameter indicative of the operating state of the gas turbine 1 so as to correspond to the exclusive combustion using the first fuel F1. In the present embodiment, the reference value Pref is approximately constant regardless of the co-combustion ratio R, and the correction value Pamd is calculated such that the control parameter P decreases as the co-combustion ratio R increases.

[0056] By controlling the gas turbine 1 based on the control parameter P (cylinder fuel distribution ratio) obtained by correcting the reference value Pref using the correction value Pamd in this way, the risk of abnormal combustion in the gas turbine 1 subjected to co-combustion operation can be effectively reduced. As the co-combustion ratio R increases, the lower combustible limit decreases due to an increase in the ratio of the second fuel F2 in the mixed fuel. However, by controlling the control parameter P (cylinder fuel distribution ratio) to decrease with respect to the reference value Pref, the combustion efficiency can be improved in a state where the co-combustion ratio R is high, and the risk of abnormal combustion can be suppressed.

[0057] As described above, according to each of the above-described embodiments, it is possible to provide the gas turbine control apparatus 100 that can maintain a stable operating state even in a case where the co-combustion ratio R changes.

[0058] Moreover, it is possible to suitably replace the components in the above-described embodiment with known components within the scope not deviating from the concept of the present disclosure, and the above-described embodiments can be suitably combined with each other.

[0059] For example, contents disclosed in each of the embodiments are understood as follows. (1) A gas turbine control device according to one aspect is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0060] According to the aspect of (1) above, the pilot fuel distribution ratio is controlled so that the pilot fuel distribution ratio becomes smaller than the reference value corresponding to the case where only the first fuel is burned, and the deviation amount from the reference value increases as the co-combustion ratio of the second fuel increases. In this way, the gas turbine is controlled so that the pilot fuel distribution ratio decreases as the co-combustion ratio increases, so that the flame temperature and combustion speed are suppressed, and the emission amount of nitrogen oxide (NOx) contained in the exhaust gas can be effectively reduced.

[0061] The pilot fuel distribution ratio is defined as a ratio of a fuel flow rate supplied to the pilot fuel injector to a fuel flow rate supplied to all of the plurality of fuel injectors provided in the combustion chamber.

[0062] (2) In another aspect, in the aspect of the above (1), a lower threshold value of the pilot fuel distribution ratio is set to increase as the co-combustion ratio increases, and the control unit controls the gas turbine in a range where the pilot fuel distribution ratio is equal to or greater than the lower threshold.

[0063] According to the aspect of (2) above, the pilot fuel distribution ratio control is performed based on the co-combustion ratio in a range equal to or greater than the lower threshold. At this time, the lower threshold is set to increase as the co-combustion ratio increases. Thus, it is possible to reduce nitrogen oxide (NOx) contained in the exhaust gas while effectively preventing flashback, which is likely to occur as the co-combustion ratio increases.

[0064] (3) In another aspect, in the aspect of the above (1) or (2), the control unit controls the gas turbine to perform a full load operation.

[0065] According to the aspect of the above (3), during the full load operation in which the emission amount of the nitrogen oxide (NOx) contained in the exhaust gas is smaller than the control value, the nitrogen oxide (NOx) contained in the exhaust gas can be appropriately reduced while effectively preventing the occurrence of flashback.

[0066] (4) A gas turbine control device according to another aspect is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine to perform a partial load operation based on the control parameter obtained by correcting the reference value using the correction value.

[0067] According to the aspect of the above (4), when the gas turbine is controlled to perform the partial load operation, the emission amount of nitrogen oxide (NOx) contained in the exhaust gas has a relatively large margin with respect to the control value. In this case, the pilot fuel distribution ratio is controlled so that the pilot fuel distribution ratio becomes larger than the reference value corresponding to the case where only the first fuel is burned, and the deviation amount from the reference value increases as the co-combustion ratio of the second fuel increases. In this way, while the emission amount of nitrogen oxide (NOx) contained in the exhaust gas satisfies the control value in a high co-combustion ratio range where flashback is likely to occur, the pilot fuel distribution ratio is increased.In this way, the flame position formed in the combustion chamber is shifted to the downstream side, and the risk of flashback can be more effectively reduced.

[0068] (5) A gas turbine control device according to another aspect is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter which is an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0069] According to the aspect of (5) above, the opening degree of the inlet guide vane is controlled so that the opening degree of the inlet guide vane becomes larger than the reference value corresponding to the case where only the first fuel is burned, and the deviation amount from the reference value increases as the co-combustion ratio of the second fuel increases. In this way, the gas turbine is controlled so that the opening degree of the inlet guide vane increases as the co-combustion ratio increases, so that the risk of flashback can be effectively reduced.

[0070] (6) A gas turbine control device according to another aspect is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter including at least one of a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, a cylinder fuel distribution ratio with respect to a cylinder fuel injector among the plurality of fuel injectors, a fuel distribution ratio between main nozzle groups among the plurality of fuel injectors, and an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0071] According to the aspect of the above (6), as the co-combustion ratio of the second fuel increases, at least one of the pilot fuel distribution ratio, the cylinder fuel distribution ratio, the fuel distribution ratio between the main nozzle groups, and the opening degree of the inlet guide vane is controlled so that one becomes larger than the reference value corresponding to the case where only the first fuel is burned, and the deviation amount from the reference value increases as the co-combustion ratio of the second fuel increases. In this way, the gas turbine is controlled so that the control parameters increase as the co-combustion ratio increases, and thus the risk of combustion oscillation can be effectively reduced.

[0072] The cylinder fuel distribution ratio is defined as a ratio of a fuel flow rate supplied to the cylinder fuel injector to the fuel flow rate supplied to all of the plurality of fuel injectors provided in the combustion chamber.

[0073] (7) A gas turbine control device according to another aspect is a gas turbine control device for controlling a gas turbine including a combustor capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device including: a reference value calculation unit for calculating a reference value for a control parameter that is a cylinder fuel distribution ratio with respect to a cylinder fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

[0074] According to the aspect of the above (7), the cylinder fuel distribution ratio is controlled so that the cylinder fuel distribution ratio becomes smaller than the reference value corresponding to the case where only the first fuel is burned, and the deviation amount from the reference value increases as the co-combustion ratio of the second fuel increases.

[0075] In this way, the gas turbine is controlled so that the cylinder fuel distribution ratio increases as the co-combustion ratio increases, so that the risk of abnormal combustion can be effectively reduced. List of reference symbols 1 gas turbine 2 combustion chamber 3 Compressor 6 turbines 7 first fuel supply source 8 first fuel supply line 10 flow meters 13 Shut-off valve 14 second fuel supply source 15 flow meters 16 second fuel supply line 18 first flow control valve 22 Main fuel supply line 24 Shut-off valve 25 connection point 26 second flow control valve 30a, 30b third flow control valve 32 outer cylinders 33 Air flow path 34 lining 36 burners 37 Flame 37' flammable area 38 End cover 42 compressed air 44 fuel distributors 46 pilot burners 48 main burners 50 transition piece 52 Main fuel injector 56 Pilot fuel injector 58 cylinder fuel injector 100 Gas turbine control device 102 Reference value calculation unit 104 Co-combustion ratio detection unit 106 Correction value calculation unit 108 Control unit QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-049185

[0002] JP 2021-046949

[0004]

Claims

[1] A gas turbine control device for controlling a gas turbine including a combustion chamber capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device comprising: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value. [2] A gas turbine control apparatus according to claim 1, wherein a lower threshold value of the pilot fuel distribution ratio is set to increase as the co-combustion ratio increases, and the control unit controls the gas turbine in a range where the pilot fuel distribution ratio is equal to or greater than the lower threshold value. [3] A gas turbine control device according to claim 1 or 2, wherein the control unit controls the gas turbine to perform full load operation. [4] A gas turbine control device for controlling a gas turbine including a combustion chamber capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device comprising: a reference value calculation unit for calculating a reference value for a control parameter that is a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine to perform a partial load operation based on the control parameter obtained by correcting the reference value using the correction value. [5] A gas turbine control device for controlling a gas turbine including a combustion chamber capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device comprising: a reference value calculation unit for calculating a reference value for a control parameter which is an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value. [6] A gas turbine control device for controlling a gas turbine including a combustion chamber capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device comprising: a reference value calculation unit for calculating a reference value for a control parameter including at least one of a pilot fuel distribution ratio with respect to a pilot fuel injector among a plurality of fuel injectors included in the combustion chamber, a cylinder fuel distribution ratio with respect to a cylinder fuel injector among the plurality of fuel injectors, a fuel distribution ratio between main nozzle groups among the plurality of fuel injectors, and an opening degree of an inlet guide vane of the gas turbine, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes larger than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value. [7] A gas turbine control device for controlling a gas turbine including a combustion chamber capable of co-combusting a first fuel and a second fuel having a lower calorific value per unit volume than the first fuel, the gas turbine control device comprising: a reference value calculation unit for calculating a reference value for a control parameter that is a cylinder fuel distribution ratio with respect to a cylinder fuel injector among a plurality of fuel injectors included in the combustion chamber, the reference value corresponding to a case where only the first fuel is burned; a correction value calculation unit for calculating a correction value for correcting the reference value such that the control parameter becomes smaller than the reference value and a deviation amount from the reference value increases as a co-combustion ratio of the second fuel increases; and a control unit for controlling the gas turbine based on the control parameter obtained by correcting the reference value using the correction value.

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