Flow volume ratio calculation device, control device equipped therewith, gas turbine plant equipped with this control device, flow volume ratio calculation method, and fuel line control method

Abstract

A flow volume ratio calculation device (140) configured to calculate a flow volume ratio (PL0) of fuels flowing in a plurality of fuel systems (61, 62, 63) in a gas turbine (10) comprising the plurality of fuel systems (61, 62, 63), a compressor (11) that compresses air to generate compressed air, a combustion chamber (31) that combusts the fuels from the plurality of fuel systems (61, 62, 63) in the compressed air to generate combustion gas, and a turbine (21) driven by the combustion gas, the flow volume ratio calculation device (140) comprising: a computer which receives values ​​of two parameters which can express a combustion state in the combustion chamber (31) and which calculates the flow volume ratio (PL0) relative to the received values ​​of the two parameters based on a predetermined relationship between the two parameters and the flow volume ratio (PL0), The calculator includes: a flow volume ratio calculating device (141p) that determines the flow volume ratio (PL0) relative to the received value of the first parameter based on a predetermined relationship between the first parameter and the flow volume ratio (PL0); a correction value calculating device (142p) that determines a correction value (Cp) in accordance with the received value of the second parameter based on a predetermined relationship between the second parameter and a correction value for the flow volume ratio (PL0); and a correction device (144p) which corrects the flow volume ratio (PL0) determined by the flow volume ratio calculation device (141p) with the correction value (Cp) determined by the correction value calculation device (142p), wherein the predetermined relationship used by the correction value calculating means (142p) is a relationship between the second parameter and the flow volume ratio (PL0) when the first parameter is constant.

Description

[0001] The present invention relates to a technology for calculating a flow volume ratio of fuels supplied to a combustor from a plurality of fuel systems.

[0002] A gas turbine comprises a compressor that compresses air, a combustion chamber that burns fuel in the air compressed by the compressor to produce combustion gas, and a turbine driven by the combustion gas. Some combustors include a pilot burner that subjects a fuel to diffusion combustion and a main burner that subjects a fuel to premixed combustion. With such a combustor, the flow-volume ratio of the fuels supplied to the respective burners must be managed, for example, to improve the combustion stability of the fuels.

[0003] According to the technology disclosed in JP 2007-77867 A, for example, a flow volume ratio of fuels supplied to the respective burners is determined in accordance with a value indicated by a combustion load command received by non-dimensionalizing the temperature of an inlet of a turbine into which combustion gas flows from the combustion chamber.

[0004] From JP 2004-108 315 A, a gas turbine system and an operating method for a gas turbine system are known, which comprises a combustion gas temperature calculation part for an abrupt change, which is installed separately from a combustion gas temperature calculation part and calculates the temperature of the combustion gas at the inlet of the gas turbine using a fuel flow instruction value, and an operation detection part for an abrupt change, which detects the occurrence of the abrupt change in the operating state of the gas turbine.

[0005] When the abrupt change occurs, the rate of fuel flow supplied to a premixed combustor and a diffused combustor is calculated using the result of calculating the combustion gas temperature at the inlet of the gas turbine, which was calculated by the combustion gas temperature calculation part for the abrupt change. This allows the gas turbine system to be switched to an optimal combustion mode according to a change in the actual combustion gas temperature at the inlet of a gas turbine, even when an abrupt change in the operating state of the gas turbine occurs, and a

[0006] From JP 2010-127242 A, a gas turbine control device is known for preventing the occurrence of combustion oscillations in a gas turbine plant by providing greater freedom in adjusting an air or fuel flow rate depending on a target load, thereby improving combustion stability. A gas turbine controller comprises a first function generator for adjusting the fuel or air flow rate supplied to a combustion chamber in accordance with a target load, an intake air temperature sensor for detecting the intake temperature at the inlet of a compressor, a second function generator for setting a correction amount of a target value of the fuel flow rate or the air flow rate based on the value detected by the intake air temperature sensor, and a third function generator for setting a modification amount of the correction amount taking the target load into account.a first multiplier for operating a modified correction amount from a correction amount set by the second function generator and a modification amount set by the third function generator, and a second multiplier for calculating the fuel or air flow rate supplied to a combustion chamber by adding the modified correction amount to the value of the fuel flow rate or air flow rate set by the first function generator.

[0007] In recent years, restrictions on gas turbine exhaust gases have become increasingly stringent, requiring fuel to be burned in combustion chambers under strict conditions. This requires technology that can burn fuel stably, even under conditions that are not conducive to combustion.

[0008] In view of the foregoing, an object of the present invention is to provide a technology that can improve combustion stability in a combustion chamber.

[0009] In order to achieve the above-described object, a flow volume ratio calculating device according to claim 1 is proposed.

[0010] The combustion state in the combustion chamber can be expressed by two parameters. According to this flow-volume ratio calculation device, the values ​​of the two parameters that can express the combustion state are received, and a flow-volume ratio is determined according to these values. Consequently, according to this flow-volume ratio calculation device, the combustion state can be better understood if the flow-volume ratio is determined according to a combustion state determined only by a combustion load command value, and a flow-volume ratio can be determined according to this combustion state. Note that the combustion load command value is a value obtained by non-dimensionalizing the inlet temperature of the turbine into which the combustion gas flows from the combustion chamber.Consequently, according to the flow volume ratio calculating device, the combustion stability of the fuel can be further improved by setting the flow volume ratio of the fuels flowing in the plurality of fuel systems to the flow volume ratio calculated by the flow volume ratio calculating device.

[0011] Here, in the flow volume ratio calculating device, of the two parameters received by the calculator, a first parameter may be an inlet temperature correlated value, which is a value that changes in correlation with a change in an inlet temperature of the combustion gas in the turbine or the inlet temperature itself, and a second parameter may be a flow velocity correlated value, which changes in correlation with a change in the flow velocity of the combustion gas in the combustion chamber.

[0012] In this case, the value correlated with the flow rate may be one of an output of the gas turbine, a load factor which is a percentage of a current load relative to a maximum allowable load in the gas turbine, a total flow volume of the fuels supplied to the combustor from the multiple fuel systems, and a flow volume of the air drawn in by the compressor.

[0013] Further, in the flow volume ratio calculating device, of the two parameters received by the calculator, a first parameter may be a total flow volume of the fuels supplied to the combustion chamber from the plurality of fuel systems, and a second parameter may be a flow volume of the air sucked by the compressor.

[0014] Further, in the flow volume ratio calculating device according to the present invention, the calculator comprises: a flow volume ratio calculating device that determines the flow volume ratio relative to the received value of the first parameter from a predetermined relationship between the first parameter and the flow volume ratio; a correction value calculating device that determines a correction value in accordance with the received value of the second parameter based on a predetermined relationship between the second parameter and a correction value for the flow volume ratio; and a correcting device that corrects the flow volume ratio determined by the flow volume ratio calculating device with the correction value determined by the correction value calculating device.

[0015] Further, in the flow volume ratio calculating device including the correction value calculating device according to the invention, the predetermined relationship used by the correction value calculating device is a relationship between the second parameter and the flow volume ratio when the first parameter is constant.

[0016] Further, in the flow volume ratio calculation device, in the case where the combustor includes a first burner that subjects a fuel to diffusion combustion and a second burner that subjects a fuel to premixed combustion, and the gas turbine includes, as the plurality of fuel systems, a first fuel system that supplies fuel to the first burner and a second fuel system that supplies fuel to a second burner, the flow volume ratio may include a ratio of a flow volume of the fuel supplied to the combustion chamber from the first fuel system to the total flow volume of the fuels supplied to the combustion chamber from the plurality of fuel chambers.

[0017] Further, in the flow volume ratio calculation device, in the case where the combustor includes a burner that injects a fuel, and the gas turbine includes, as the plurality of fuel systems, a fuel system that supplies fuel to the burner and an upstream supply system that supplies fuel to the compressed air supplied to the burner, the flow volume ratio may include a ratio of a flow volume of the fuel supplied to the combustion chamber from the burner system to the total flow volume of the fuels supplied to the combustion chamber from the plurality of fuel systems.

[0018] To achieve the above-described object, a control device according to the invention comprises: the flow volume ratio calculation device according to the invention; a total flow volume calculation device that determines the total flow volume of the fuels supplied to the combustion chamber from the plurality of fuel systems; a system flow volume calculation device that determines a fuel flow volume in each of the plurality of fuel systems based on the total flow volume determined by the total flow volume calculation device and the flow volume ratio calculated by the flow volume ratio calculation device;and a valve control device that outputs a control signal to a fuel flow volume control valve provided in each of the plurality of fuel systems such that the fuel flow volume in each of the plurality of fuel systems becomes the corresponding fuel flow volume determined by the system flow volume calculating device;

[0019] In order to achieve the above-described object, a gas turbine plant according to the invention comprises the control device according to the invention and a gas turbine.

[0020] In order to achieve the above-described object, a flow volume ratio calculation method having the features of claim 9 is proposed.

[0021] In the flow volume ratio calculation method, of the two parameters received by the computer in the receiving step, a first parameter may be an inlet temperature correlated value, which is a value that changes in correlation with a change in an inlet temperature of the combustion gas in the turbine or the inlet temperature itself, and a second parameter may be a flow velocity correlated value, which changes in correlation with a change in the flow velocity of the combustion gas in the combustion chamber.

[0022] In this case, the value correlated with the flow rate may be one of an output of the gas turbine, a load factor which is a percentage of a current load relative to a maximum allowable load in the gas turbine, a total flow volume of the fuels supplied to the combustor from the multiple fuel systems, and a flow volume of the air drawn in by the compressor.

[0023] Further, in the flow volume ratio calculation method, of the two parameters received in the receiving step, a first parameter may be a total flow volume of the fuels supplied to the combustor from the plurality of fuel systems, and the second parameter may be a flow volume of the air sucked by the compressor.

[0024] Furthermore, in the flow volume ratio calculation method according to the present invention, the calculation step includes: a flow volume ratio calculation step for determining the flow volume ratio relative to the value of the first parameter received in the receiving step based on a predetermined relationship between the first parameter and the flow volume ratio; a correction volume calculation step for determining a correction value in accordance with the value of the second parameter received in the receiving step based on a predetermined relationship between the second parameter and a correction value for the flow volume ratio; and a correction step for correcting the flow volume ratio determined in the flow volume ratio calculation step with the correction value determined in the correction value calculation step.

[0025] According to the invention, the predetermined relationship used in the correction value calculation step is a relationship between the second parameter and the flow volume ratio when the first parameter is constant.

[0026] To achieve the above-described object, a fuel system control method according to the invention comprises the features of claim 13, including the flow volume ratio calculation method of the invention and the following: a total flow volume calculation step for determining a total flow volume of the fuels supplied to the combustion chamber from the plurality of fuel systems; a system flow volume calculation step for determining a fuel flow volume in each of the plurality of fuel systems based on the total flow volume determined in the total flow volume calculation step and the flow volume ratio calculated by the flow volume ratio calculation method;and a valve control step for outputting a control signal to a fuel flow volume control valve provided in each of the plurality of fuel systems such that the fuel flow volume in each of the plurality of fuel systems becomes the corresponding fuel flow volume determined in the system flow volume calculation step;

[0027] According to the present invention, the combustion stability of fuel in a combustion chamber can be improved. Fig. 1 is a plant diagram illustrating a gas turbine plant according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of a combustion chamber according to the embodiment of the present invention. Fig. 3 is a cross-sectional view of the main portion of the combustion chamber according to the embodiment of the present invention. Fig. 4 is a functional block diagram illustrating a control device according to the embodiment of the present invention. Fig. 5 is a functional block diagram illustrating a combustion load command generator according to the embodiment of the present invention. Fig. 6 is a functional block diagram illustrating a load factor calculating apparatus according to the embodiment of the present invention. Fig. 7 is a functional block diagram illustrating a fuel flow volume command generator according to the embodiment of the present invention. Fig. 8 is a functional block diagram illustrating a flow volume ratio calculating apparatus according to the embodiment of the present invention. Fig. 9 is a functional block diagram illustrating a system flow volume calculating device and a valve control device according to the embodiment of the present invention. Fig. 10 is a graph illustrating a relationship between a load factor and an IGV opening according to the embodiment of the present invention. Fig. 11 is a graph illustrating the relationship between a pre-correction ignition ratio (PL0 ratio) and a combustion load command value CLCSO according to the embodiment of the present invention. Fig. 12 is a graph illustrating the relationship between an ignition ratio correction value Cp and the combustion load command value CLCSO according to the embodiment of the present invention. Fig. 13 is a graph illustrating the relationship between a pre-correction cylinder hat ratio (TH0 ratio) and the combustion load command value CLCSO according to the embodiment of the present invention. Fig. 14 is a graph illustrating the relationship between the pre-correction cylinder hat ratio (TH0 ratio) and a post-correction cylinder hat ratio (TH ratio), and a load factor %Load; and a relationship between a cylinder hat ratio correction value Ct and the load factor %Load according to the embodiment of the present invention. Fig. 15A to 15F are graphs illustrating the changes of various parameters depending on the changes in a state of a gas turbine according to the embodiment of the present invention. In particular, Fig. 15A is a graph showing a relationship between the load factor %Load and the IGV opening. Fig. 15B is a graph showing a relationship between the load factor %Load and the combustion load command value CLCSO. Fig. 15C is a graph showing a relationship between the combustion load command value CLCSO and the pre-correction ignition ratio (PL0 ratio). Fig. Figure 15D is a graph showing a relationship between the load factor %Load and the pre-correction ignition ratio (PL0 ratio). Fig. 15E is a graph showing a relationship between the load factor %Load and the correction value Cp. Fig. Figure 15F is a graph showing a relationship between the load factor %Load and the post-correction and pre-correction ignition ratios (PL ratio and PL0 ratio, respectively). Fig. 16 is a flowchart illustrating the operations of the control device according to the embodiment of the present invention. Fig. Figure 17 is an explanatory diagram showing different parameters expressing combustion states of fuel in the combustion chamber. Fig. 18 is a functional block diagram illustrating a flow volume ratio calculating apparatus according to a modification of the embodiment of the present invention.

[0028] An embodiment of a flow volume ratio calculating device, a control device, and a gas turbine plant including the control device according to the present invention will be described below with reference to the drawings.

[0029] As in Fig. As shown in Figure 1, the gas turbine plant according to the present embodiment includes a gas turbine 10 and a generator 29 driven by the gas turbine 10 to generate electricity. The gas turbine 10 includes a compressor 11 that compresses air, a combustor 31 that combusts a fuel F in the air compressed by the compressor 11 to generate combustion gas, and a turbine 21 driven by the high-temperature, high-pressure combustion gas.

[0030] The compressor 11 includes a compressor rotor 13 that rotates about an axis of the compressor 11, a compressor housing 12 that covers the compressor rotor 13 while allowing the compressor rotor 13 to rotate, and an inlet guide vane (IGV) 14 provided at an inlet port of the compressor housing 12. The IGV 14 includes a plurality of guide vanes 15 and a driver 16 that drives the plurality of guide vanes 15. The IGV 14 adjusts a flow volume of air admitted into the compressor housing 12.

[0031] The turbine 21 includes a turbine rotor 23, which is rotated about its axis by the combustion gas from the combustion chamber 31, and a turbine casing 22, which covers the turbine rotor 23 while allowing the turbine rotor 23 to rotate. The turbine rotor 23 and the compressor rotor 13 rotate about the same axis and are connected to each other to form a gas turbine rotor 28. A rotor of the generator 29 is connected to this gas turbine rotor 28.

[0032] As in Fig. 2, the combustor 31 includes: an outer cylinder 32 attached to the turbine casing 22; a combustion liner 33 (or transition piece) 33 disposed within the turbine casing 22 and directing the combustion gas into a combustion gas flow passage of the turbine 21; and a fuel supplier 41 that supplies fuel and air to the combustion liner 33.

[0033] As in Fig. 2 and Fig. 3, the fuel supplier 41 includes: a combustor basket 42; a pilot burner (first burner) 43 arranged on the central axis line of the combustor basket 42; a plurality of main burners (second burners) 53 arranged at equal intervals in a circumferential direction around the pilot burner 43; and a cylinder-shaped nozzle 51 arranged on the inner peripheral side of the outer cylinder 32 and an outer peripheral side of the combustor basket 42. Hereinafter, with respect to a direction in which the central axis line of the combustor basket 42 extends, a side toward which combustion gas G flows in the combustion liner 33 is referred to as a "downstream side," and the opposite side is referred to as an "upstream side."

[0034] The pilot burner 43 includes an ignition nozzle 44 arranged on the central axis line of the combustion chamber basket 42, and a tubular pilot air pipe 45 surrounding the outer periphery of the ignition nozzle 44. A downstream side of the pilot air pipe 45 forms an ignition cone 46 whose diameter gradually increases toward the downstream side. The inner peripheral side of the pilot air pipe 45 forms an pilot air passage 48 through which compressed air Ac from the compressor 11 flows as pilot air Ap. Pilot fuel Fp injected from the pilot nozzle 44 is combusted (by diffusion combustion) in the pilot air Ap discharged from the pilot air passage 48 to form a diffusion flame 49.

[0035] Each of the main burners 53 includes: a tubular air inner cylinder 55 surrounding the outer circumference of the pilot air pipe 45; a tubular air outer cylinder 56 surrounding the outer circumference of the main air inner cylinder 55; a plurality of partition plates 57; and a main nozzle 54 provided between the plurality of partition plates 57. The plurality of partition plates 57 divide an annular space between the outer circumference side of the main air inner cylinder 55 and the inner circumference side of the main air outer cylinder 56 into a plurality of spaces in the circumferential direction. The plurality of spaces defined by the main air inner cylinder 55, the main air outer cylinder 56, and the plurality of partition plates 57 form a main air passage 58 in which the compressed air Ac from the compressor 11 flows as a main air Am. A main fuel Fm is injected from the main nozzle 54 arranged in the main air passage 58 into the main air Am flowing in the main air passage 58.Therefore, a premixed gas, which is a mixture of the main air Am and the main fuel Fm, flows into the main air passage 58 from a tip end portion (downstream end) toward the main nozzle 54 toward the downstream side. After flowing out of the main air passage 58, this premixed gas is combusted (by premixed combustion) and forms a premixed flame 59. The diffusion flame 49 described above fulfills a role of stabilizing this premixed flame 59.

[0036] A space between the inner peripheral side of the outer cylinder 32 and the outer peripheral side of the combustion chamber basket 42 forms a compressed air passage 52, which guides the compressed air Ac from the compressor 11 to the combustion chamber basket 42. The cylinder hat nozzle 51 injects a cylinder hat fuel Ft into this compressed air passage 52. Therefore, when cylinder hat fuel Ft is injected into the compressed air passage 52, the cylinder hat fuel Ft is mixed into the main air Am and the ignition air Ap.

[0037] As in Fig. 1 and Fig. 2, the gas turbine plant according to the present embodiment further includes: a pilot fuel line (first fuel system) 61 that supplies the pilot fuel Fp to the pilot nozzle 44; a main fuel line (second fuel system) 62 that supplies the main fuel Fm to the main nozzle 54; a top hat fuel line (upstream supply system) 63 that supplies the top hat fuel Ft to the top hat fuel nozzle 51; a pilot fuel valve 65 that adjusts a flow volume of the pilot fuel Fp; a main fuel valve 66 that adjusts a flow volume of the main fuel Fm; a top hat fuel valve 67 that adjusts a flow volume of the top hat fuel Ft; and a control device 100 that controls operations of the fuel valves 65, 66, 67, and the like.

[0038] The pilot fuel line 61, the main fuel line 62, and the cylinder hat fuel line 63 all branch off from a fuel line 60. The pilot fuel valve 65 is provided in the pilot fuel line 61, the main fuel valve 66 is provided in the main fuel line 62, and the cylinder hat valve 67 is provided in the cylinder hat fuel line 63.

[0039] As in Fig. As shown in Figure 1, the gas turbine plant according to the present embodiment further includes: a speed detector 71 that detects a rotational speed N of the gas turbine rotor 28; an output detector 72 that detects an output PW of the generator 29; an inlet temperature detector 73 that detects an inlet temperature Ti, which is a temperature of air A taken in from the compressor 11; an inlet pressure detector 74 that detects an inlet pressure (atmospheric pressure) Pi, which is a pressure of the air taken in from the compressor 11; a vane path temperature detector 75 that detects a vane path temperature Tb; and an exhaust gas temperature detector 76 that detects a temperature Te of exhaust gas. The vane path temperature Tb detected by the vane path temperature detector 75 is the temperature of the combustion gas immediately after the last stage of the turbine 21.The temperature Te of the exhaust gas detected by the exhaust gas temperature measuring device 76 is the temperature of the exhaust gas in an exhaust stack downstream of the last stage of the turbine 21.

[0040] As in Fig. As shown in Figure 4, the control device 100 includes: an interface 180 that receives detection values ​​from the detection measuring devices and the like; a combustion load command generator 110 that generates a combustion load command value CLCSO; a load factor calculator 120 that determines a current load factor %Load of the gas turbine 10; a fuel flow volume command generator 130 that generates a fuel flow volume command value CSO; an ignition ratio calculator 140p that calculates an ignition ratio (PL ratio), which is the ratio of a pilot fuel flow volume Fpf to a total fuel flow volume; a cylinder hat ratio calculator 140t that calculates a cylinder hat ratio (TH ratio), which is the ratio of a cylinder hat fuel flow volume Ftf to the total fuel flow volume.a system flow volume calculator 160 that calculates the flow volumes in the fuel lines 61, 62, and 63; and a valve control device 170 that outputs control signals to the fuel valves 65, 66, and 67 in accordance with the respective flow volumes in the fuel lines 61, 62, and 63. Note that, in the present embodiment, the ignition ratio calculator 140p and the cylinder hat ratio calculator 140t constitute a flow volume ratio calculator 140.

[0041] The combustion load command value CLCSO is a parameter obtained by non-dimensionalizing an inlet temperature of the combustion gas in the turbine 21 and has a positive correlation with the inlet temperature. The combustion load command value CLCSO is set to be 0% when the inlet temperature is at its lower limit and 100% when the inlet temperature is at its upper limit. For example, if the lower limit of the inlet temperature is 700°C and the upper limit of the inlet temperature is 1500°C, the combustion load command value CLCSO is expressed by the following equation. CLCSO(%)={(measured value of generator output−700°CMW) / (1,500°CMW−700°CMW)}×100, where 700 °CMW is the generator output when the inlet temperature is at its lower limit of 700 °C, and 1,500 °CMW is the generator output when the inlet temperature is at its upper limit of 1,500 °C.

[0042] As in Fig. As shown in Figure 5, the combustion load command generator 110 includes a first output computing device 111a, a second output computing device 111b, a standard atmospheric pressure generator 112, a first divider 113, a first multiplier 114a, a second multiplier 114b, a first subtractor 115a, a second subtractor 115b, a second divider 116, and a limiter 117. The first output computing device 111a determines the generator output 700°CMW, which occurs when the inlet temperature is at its lower limit of 700°C. The second output computing device 111b determines the generator output 1500°CMW, which occurs when the inlet temperature is at its upper limit of 1500°C. The standard atmospheric pressure generator 112 generates a predetermined, standard atmospheric pressure Ps.The first divider 113 determines an input pressure ratio Pr, which is the ratio of the input pressure Pi detected by the input pressure gauge 74 to the standard atmospheric pressure (standard input pressure) Ps. The first multiplier 114a multiplies the generator output 700 °CMW determined by the first output calculator 111a by the input pressure ratio Pr. The second multiplier 114b multiplies the generator output 1500 °CMW determined by the second output calculator 111b by the input pressure ratio Pr. The first subtractor 115a subtracts the multiplication result obtained by the first multiplier 114a from the measured output PW of the generator 29 detected by the output gauge 72.The second subtractor 115b subtracts the multiplication result obtained by the first multiplier 114a from the multiplication result obtained by the second multiplier 114b. The second subtractor 116 subtracts the multiplication result obtained by the first multiplier 115a from the multiplication result obtained by the second multiplier 115b. The limiter 117 limits a rise / fall ratio of the output from the second divider 116.

[0043] The first output computing device 111a determines the generator output 700°CMW, which occurs when the input temperature is 700°C, using a function H1x and defining the input temperature Ti and an IGV opening command value as variable parameters. The second output computing device 111b determines the generator output 1500°CMW, which occurs when the input temperature is 1500°C, using a function H2x and defining the input temperature Ti and the IGV opening command value as variable parameters.

[0044] The IGV opening command value here is a command value transmitted to the drive 16 of the IGV 14 by the control device 100, and this specifies an IGV opening. This IGV opening command value is determined, for example, by the atmospheric pressure Pi, which is the pressure at the inlet of the compressor 11, a pressure at the outlet of the compressor 11, the current load factor %Load of the gas turbine 10, and the like. A relationship between the load factor %Load and the IGV opening is, for example, as shown in Fig. 10 illustrates a relationship in which the IGV opening increases as the load factor %Load increases. The amount of increase in the IGV opening relative to an amount of increase in the load factor %Load, the load factor %Load at which the IGV opening starts to increase, and the like change depending on the operation schedule for the gas turbine 10, the atmospheric pressure Pi, which is the pressure at the inlet of the compressor 11, and the like. Although the above describes an example of determining the IGV opening from the load factor %Load, the IGV opening may be determined using the output PW of the generator 29, which is the output of the gas turbine 10, instead of the load factor %Load.

[0045] The output calculation devices 111a and 111b of the combustion load command generator 110 change the respective known values ​​of 700 °CMW and 1,500 °CMW in the case where the inlet temperature and the IGV opening command value are reference values ​​for values ​​corresponding to the actual inlet temperature Ti and the IGV opening command value, and output the respective post-change values ​​as 700 °CMW and 1,500 °CMW.

[0046] Furthermore, the 700°CMW and the 1500°CMW are corrected in accordance with a measured value Pi of the inlet pressure (atmospheric pressure). Specifically, the first divider 113 determines the inlet pressure ratio Pr, which is the ratio of the inlet pressure (atmospheric pressure) Pi detected by the inlet pressure gauge 74 to the standard atmospheric pressure (standard inlet pressure) Ps from the standard atmospheric pressure generator 112. The first multiplier 114a multiplies the 700°CMW from the first output calculating device 111a by an inlet pressure ratio Pr to correct the 700°CMW to a value corresponding to the inlet pressure ratio Pr. The second multiplier 114b multiplies the 1,500 °CMW from the second output calculating device 111b by an input pressure ratio Pr to correct the 1,500 °CMW to a value corresponding to the input pressure ratio Pr.In other words, by the above, the known values ​​of 700 °CMW and 1,500 °CMW in the case where the inlet temperature and the IGV opening command value are reference values ​​are corrected to values ​​corresponding to the measured inlet temperature Ti, the IGV opening command value and the measured inlet pressure ratio Pr.

[0047] The first subtractor 115a subtracts the 700 °CMW corrected by the input pressure ratio Pr from the measured output PW of the generator 29 detected by the output measuring device 72. In other words, the first subtractor 115a determines the value of the numerator in the above equation. The second subtractor 115b subtracts the 700 °CMW corrected by the input pressure ratio Pr from the 1500 °CMW corrected by the input pressure ratio Pr. In other words, the second subtractor 115b determines the value of the denominator in the above equation.

[0048] The second divider 116 divides the value of the numerator in the above equation, determined by the first subtractor 115a, by the value of the denominator in the above equation, determined by the second subtractor 115b, and outputs the resulting value as the combustion load command value. The limiter 117 limits the increase / decrease ratio of the combustion load command value, which is a change in the combustion load command value from the second divider 116 per unit time, such that the increase / decrease ratio is less than or equal to a predetermined value.

[0049] Although the above describes the lower limit of the inlet temperature of the combustion gas in the turbine 21 as 700 °C and the upper limit thereof as 1,500 °C, the lower limit and the upper limit of the inlet temperature of the combustion gas in the turbine 21 may have different values ​​from those in the above example depending on the model type of the combustor 31 and the like.

[0050] The combustion load command value CLCSO, with the rise / fall ratio thereof limited by the limiter 117, is output from the combustion load command generator 110.

[0051] The load factor %Load of the gas turbine 10 is a percentage of a current load PW relative to a maximum load PWmax that is permitted in the current state of the gas turbine 10. As in Fig. 6, the load factor calculating device 120 comprises a maximum load calculating device 121 which determines the maximum load PWmax permitted in the current state of the gas turbine 10, and a divider 127 which divides the measured load PW, which is the output of the generator 29 and is detected by the output measuring device 72, by the maximum load PWmax.

[0052] The maximum load calculation device 121 includes: a first load coefficient calculation device 122 that determines a maximum load coefficient Ip based on the inlet pressure Pi; a second load coefficient calculation device 123 that determines a maximum load coefficient It based on the inlet temperature Ti; a first multiplier 124 that multiplies the maximum load coefficient Ip by the maximum load coefficient It; a derating coefficient generator 125 that generates a derating coefficient K based on an operating time of the gas turbine 10; and a second multiplier 126 that multiplies the multiplication result of the first multiplier 124 by the derating coefficient K.In other words, the maximum load calculation device 121 determines the maximum load PWmax based on the measured inlet pressure Pi detected by the inlet pressure gauge 74, the measured inlet temperature Ti detected by the inlet temperature gauge 73, and the derating coefficient K of the gas turbine 10. As described above, the divider 127 divides the measured load PW, which is the output of the generator 29 detected by the output gauge 72, by the maximum load PWmax, and outputs the resulting value as the load factor %Load.

[0053] The fuel flow volume command value CSO is a value that specifies a total flow volume of fuel supplied to the combustion chamber 31 (hereinafter referred to as "total fuel flow volume"). Therefore, the fuel flow volume command generator 130 serves as a total flow volume calculation device. Therefore, as described below, the fuel flow volume command generator 130 performs a total fuel flow volume calculation step in which the total fuel flow volume is calculated.

[0054] As in Fig. As shown in Figure 7, the fuel flow volume command generator 130 includes a speed controller 131, a load controller 132, a first temperature controller 133, a second temperature controller 134, a low-value selector 135, and a limiter 136. The speed controller 131 outputs a command value for controlling the total fuel flow volume such that the rotational speed N of the gas turbine rotor 28 becomes a target rotational speed. The load controller 132 outputs a command value for controlling the total fuel flow volume such that the generator output PW corresponds to the generator output command value. The first temperature controller 133 outputs a command value for controlling the total fuel flow volume such that the blade path temperature Tb of the gas turbine does not exceed its upper limit.The second temperature control device 134 outputs a command value for controlling the total fuel flow volume such that the exhaust gas temperature Te does not exceed its upper limit. The low-value selector 135 outputs the minimum or lowest value among the command values ​​from the control devices 131 to 134. The limiter 136 limits a rise / fall ratio of the command from the low-value selector 135.

[0055] The speed control device 131 receives the speed N of the gas turbine rotor 28 from the speed measuring device 71 and outputs a command value GVCSO for controlling the total fuel flow volume such that the speed N of the gas turbine rotor 28 corresponds to the target speed. Specifically, the speed control device 131 compares the measured speed N of the gas turbine rotor 28 with a predetermined GV setting value and outputs a proportional control signal as the command value GVCSO.

[0056] The load control device 132 receives the measured output PW of the generator 29 from the output measuring device 72 and the generator output command value from a host control device 90 (see Fig. 1). The load control device 132 outputs a command value for controlling the total fuel flow volume LDCSO such that the measured output PW corresponds to the generator output command value. Specifically, the load control device 132 compares the measured output PW with the generator output command value, calculates a proportional integral, and outputs the calculation result as the command value LDCSO.

[0057] The first temperature control device 133 receives the vane path temperature Tb from the vane path temperature measuring device 75 and outputs a command value BPCSO for controlling the total fuel flow volume such that the vane path temperature Tb does not exceed its upper limit. Specifically, the first temperature control device 133 compares the measured vane path temperature Tb with the upper limit thereof, calculates a proportional integral, and outputs the calculation result as the command value BPCSO.

[0058] The second temperature control device 134 receives the exhaust gas temperature Te from the exhaust gas temperature measuring device 76 and outputs a command value EXCSO for controlling the total fuel flow volume such that the exhaust gas temperature Te does not exceed its upper limit. Specifically, the second temperature control device 134 compares the measured exhaust gas temperature Te with the upper limit thereof, calculates a proportional integral, and outputs the calculation result as the command value EXCSO.

[0059] The low-value selector 135 selects the minimum or lowest value among the command values ​​from the controllers 131 to 134 and outputs the selected command value. The limiter 136 limits the increase / decrease ratio of the command from the low-value selector 135 and outputs the result as the fuel flow volume command value CSO.

[0060] The ignition ratio (PL ratio) is a ratio of the ignition fuel flow volume Fpf to the total fuel flow volume. As in Fig. As shown in Fig. 8, the ignition ratio calculator 140p includes: a PL0 ratio calculator (flow volume ratio calculator) 141p that determines the PL0 ratio, which is the ignition ratio, based on the combustion load command value CLCSO; a correction value calculator 142p that determines a correction value Cp based on the load factor %Load; and a correction device 144p that corrects the PL0 ratio with the correction value Cp.

[0061] The PL0 ratio calculation device 141p has a function F1x that defines the relationship between the combustion load command value CLCSO, which has a positive correlation with the inlet temperature of the combustion gas in the turbine 21, and the PL0 ratio. As shown in Fig. As shown in Figure 11, the function F1x is a function in which the PL0 ratio gradually decreases as the combustion load command value CLCSO increases, or in other words, as the inlet temperature of the combustion gas increases. The PL0 ratio calculating device 141p receives the combustion load command value CLCSO from the combustion load command generator 110 and determines the PL0 ratio corresponding to this combustion load command value CLCSO using the function F1x. Although the relationship between the combustion load command value CLCSO and the PL0 ratio is defined here by the function F1x, the relationship may be defined by a map.

[0062] As in Fig. As shown in Figure 12, the correction value calculation device 142p has a function G1x that defines the relationship between the load factor %Load and the correlation value Cp. The correction value calculation device 142p receives the load factor %Load from the load factor calculation device 120 and determines a correlation value Ci based on the current load factor %Load using the function G1x. Although the relationship between the load factor %Load and the correction value Cp is defined here by the function G1x, the relationship may be defined by a map.

[0063] The cylinder hat ratio (TH ratio) is a ratio of the cylinder hat fuel flow volume Ftf to the total fuel flow volume. As in Fig. As shown in Fig. 8, the cylinder hat ratio calculator 140t includes: a TH0 ratio calculator (flow volume ratio calculator) 141t that determines the TH0 ratio, which is the cylinder hat ratio, based on the combustion load command value CLCSO; a correction value calculator 142t that determines a correction value based on the load factor %Load; a variation detector 144t that detects the change in the fuel flow volume command value CSO; and a correction device 144t that corrects the TH0 ratio with the correction value Ct.

[0064] The TH0 ratio calculating device 141t has a function F2x that defines a relationship between the combustion load command value CLCSO and the TH0 ratio. As shown in Fig. As shown in Figure 13, the function F2x is a function in which the TH0 ratio gradually increases as the combustion load command value CLCSO increases, or in other words, as the inlet temperature of the combustion gas increases. The TH0 ratio calculation device 141t receives the combustion load command value CLCSO from the combustion load command generator 110 and determines the TH0 ratio corresponding to this combustion load command value CLCSO using the function F2x. Although the relationship between the combustion load command value CLCSO and the TH0 ratio is defined here by the function F2x, the relationship may be defined by a map.

[0065] As in Fig. As shown in Figure 14, the correction value calculation device 142t has a function G2x that defines the relationship between the load factor %Load and the correlation value Ct. The correction value calculation device 142t receives the load factor %Load from the load factor calculation device 120 and determines the correlation value Ct based on the current load factor %Load using the function G2x. Although the relationship between the load factor %Load and the correction value Ct is defined here by the function G2x, the relationship may be defined by a map.

[0066] As in Fig. 9, the system flow volume calculator 160 includes: a first multiplier 161 that determines the pilot fuel flow volume Fpf using the PL ratio calculated by the pilot ratio calculator 140p; a second multiplier 162 that determines the cylinder hat fuel flow volume Ftf from the TH ratio calculated by the cylinder hat ratio calculator 140t; a first subtractor 163 that subtracts the cylinder hat fuel flow volume Ftf from the flow volume command value CSO specifying the total fuel flow volume; and a second subtractor 164 that further subtracts the pilot fuel flow volume Fpf from the subtraction result obtained by the first subtractor 163.

[0067] The first multiplier 161 multiplies the fuel flow volume command value CSO, which specifies the total fuel flow volume, by the PL ratio determined by the ignition ratio calculator 140p to determine the ignition fuel flow volume Fpf, and outputs the ignition fuel flow volume Fpf to the valve control device 170. The second multiplier 162 multiplies the fuel flow volume command value CSO, which specifies the total fuel flow volume, by the TH ratio determined by the cylinder hat ratio calculator 140t to determine the cylinder hat fuel flow volume Ftf, and outputs the cylinder hat fuel flow volume Ftf to the valve control device 170. The first subtractor 163 subtracts the cylinder hat fuel flow volume Ftf from the fuel flow volume command value CSO, which specifies the total fuel flow volume, as described above.The second subtractor 164 further subtracts the pilot fuel flow volume Fpf from the subtraction result obtained by the first subtractor 163, and outputs the subtraction result to the valve control device 170 as a main fuel flow volume Fmf. In other words, the system flow volume calculation device 160 performs a system flow volume calculation step in which each of the fuel flow volumes is determined.

[0068] As in Fig. 9, the valve control device 170 includes: a valve drive amount calculator 171 that determines a drive amount of the pilot fuel valve 65; a valve control signal generator 175 that outputs a control signal to the pilot fuel valve 65; a valve drive amount calculator 172 that determines a drive amount of the cylinder hat fuel valve 67; a valve control signal generator 176 that outputs a control signal to the cylinder hat signal valve 67; a valve drive amount calculator 173 that determines a drive amount of the main fuel valve 66; and a valve control signal generator 177 that outputs a control signal to the main fuel valve 66.

[0069] The valve drive amount calculation device 171, which determines the drive amount of the pilot fuel valve 65, determines the drive amount of the pilot fuel valve 65 in accordance with the pilot fuel flow volume Fpf determined by the system flow volume calculation device 160. The valve control signal generator 175 generates a control signal in accordance with the drive amount of the pilot fuel valve 65 and outputs the control signal to the pilot fuel valve 65. The valve drive amount calculation device 172, which determines the drive amount of the cylinder hat fuel valve 67, determines the drive amount of the cylinder hat fuel valve 67 in accordance with the cylinder hat fuel flow volume Ftf determined by the system flow volume calculation device 160.The valve control signal generator 176 generates a control signal in accordance with the drive amount of the cylinder-top fuel valve 67 and outputs the control signal to the cylinder-top fuel valve 67. The valve drive amount calculator 173, which determines the drive amount of the main fuel valve 66, determines the drive amount of the main fuel valve 66 in accordance with the main fuel flow volume Fmf determined by the system flow volume calculator 160. The valve control signal generator 177 generates a control signal in accordance with the drive amount of the main fuel valve 66 and outputs the control signal to the main fuel valve 66. In other words, the valve control device 170 performs a valve control step in which the control signal is output to each of the fuel valves.

[0070] Next, operations of the control device 100 are carried out in accordance with the Fig. 16 shown flow chart.

[0071] As described above, the combustion load command generator 110 determines the combustion load command value CLCSO, which is a parameter having a positive correlation with the inlet temperature of the combustion gas in the turbine 21, using the measured output PW of the generator 29 detected by the output measuring device 72, the IGV opening command value, the inlet pressure Pi detected by the inlet pressure measuring device 74, and the inlet temperature Ti detected by the inlet temperature measuring device 73 (S10: a calculation step of the value correlated with the inlet temperature).

[0072] The load factor calculation device 120 determines the current load factor %Load of the gas turbine 10 (S20: a load factor calculation step). At this time, as described above, the load factor calculation device 120 determines the maximum load PWmax of the gas turbine 10 based on the current inlet pressure Pi and the inlet temperature Ti, the inlet pressure Pi detected by the inlet pressure gauge 74, and the inlet temperature Ti detected by the inlet temperature gauge 73. The load factor calculation device 120 divides the measured load PW, which is the output of the generator 29 detected by the output gauge 72, by the maximum load PWmax and outputs the resulting value as the load factor %Load.

[0073] The fuel flow volume command generator 130 determines the fuel flow volume command value CSO that specifies the total flow volume of fuel supplied to the combustor of the gas turbine 10 (S30: a total flow volume calculation step). As described above, the fuel flow volume command generator 130 determines a plurality of command values ​​at this time and outputs a minimum or lowest value among the plurality of command values ​​as the fuel flow volume command value CSO.

[0074] The above calculation step of the value correlated with the inlet temperature (S10), the load factor calculation step (S20) and the total flow volume calculation step (S30) are executed sequentially or in parallel.

[0075] The flow volume ratio calculation device calculates the respective flow volume ratios of the fuels flowing into the fuel lines 61, 62, and 63 (S40: a flow volume ratio calculation step). This flow volume ratio calculation step (S40) includes a PL ratio calculation step (S40p) for calculating the ignition ratio (PL ratio), which is the ratio of the ignition fuel flow volume Fpf to the total fuel flow volume; and a TH ratio calculation step (S40t) for calculating the cylinder hat ratio (TH ratio), which is the ratio of the cylinder hat fuel flow volume Ftf to the total fuel flow volume.

[0076] In the PL ratio calculation step (S40p), the ignition ratio calculation device 140p receives the combustion load command value CLCSO output from the combustion load command generator 110 and the load factor %Load output from the load factor calculation device 120 (S41p: a receiving step). From the value and factor, the PL ratio is determined (S42p: a PL ratio calculation step). In the PL ratio calculation step (S42p), the PL0 ratio calculation device 141p, as described above, determines the PL0 ratio corresponding to the combustion load command value CLCSO previously obtained using the function F1x (S43p: a PL0 ratio calculation step).Thereafter, or in parallel with the PL0 ratio calculation step (S43p), the correction value calculation device 142p determines the correction value Cp corresponding to the previously received load factor %Load using the function G1x (S44p: a correction value Cp calculation step). Then, the correction device 144p adds the correction value Cp to the PL0 ratio and outputs the resulting value as a corrected ignition ratio (PL ratio) (S45p: a correction step).

[0077] In the TH ratio calculation step (S40t), the cylinder hat ratio calculation device 140t receives the combustion load command value CLCCSO output from the combustion load command generator 110 and the load factor %Load output from the load factor calculation device 120 (S41t: a receiving step). From the value and factor, the TH ratio is determined (S42t: a TH ratio calculation step). In the TH ratio calculation step (S42t), the TH0 ratio calculation device 141t, as described above, determines the TH0 ratio corresponding to the combustion load command value CLCSO previously received using the function F2x (S43t: a TH0 ratio calculation step).Thereafter, or in parallel with the TH0 ratio calculation step (S43t), the correction value calculation device 142t determines the correction value Ct corresponding to the previously received load factor %Load using the function G2x (S44t: a correction value Ct calculation step). Then, the correction device 144t adds the correction value Ct to the TH0 ratio and outputs the resulting value as a corrected ignition ratio (PL ratio) (S45t: a correction step).

[0078] The flow volume ratio calculation step (S40) is then completed.

[0079] As described above, the system flow volume calculator 160 determines the pilot fuel flow volume Fpf, the cylinder hat fuel flow volume Ftf, and the main fuel flow volume Fmf relative to the total fuel flow volume indicated by the fuel flow volume command value CSO, the PL ratio determined by the ignition ratio calculator 140p, and the TH ratio determined by the cylinder hat ratio calculator 140t, and outputs the flow volumes to the valve control device 170 (S50: the system flow volume calculation step).

[0080] As described above, the valve control device 170 determines the drive amount of the pilot fuel valve 65 such that the pilot fuel flow volume Fpf can be ensured, and outputs a control signal specifying the drive amount to the pilot fuel valve 65. The valve control device 170 determines the drive amount of the main fuel valve 66 such that the main fuel flow volume Fmf can be ensured, and outputs a control signal specifying the drive amount to the main fuel valve 66. Further, the valve control device 170 determines the drive amount of the cylinder hat fuel valve 67 such that the cylinder hat fuel flow volume Ftf can be ensured, and outputs a control signal specifying the drive amount to the cylinder hat fuel valve 67 (S60: the valve control step).

[0081] After the control signals are output to the fuel valves 65, 66, and 67 from the valve control signal generators 175, 176, and 177, respectively, the fuel valves 65, 66, and 67 operate in accordance with the drive amounts specified by the respective control signals. Therefore, the pilot fuel Fp flows into the pilot fuel line 61 at the flow volume Fpf in accordance with the PL ratio determined by the ignition ratio calculator 140p. The cylinder head fuel Ft flows into the cylinder head fuel line 63 at the flow volume Ftf in accordance with the TH ratio determined by the cylinder head ratio calculator 140t. In addition, the main fuel Fm flows into the main fuel line 62 with the flow volume Fmf obtained by subtracting the pilot fuel flow volume Fpf and the cylinder hat fuel flow volume Ftf from the total fuel flow volume.

[0082] The series of control steps for the fuel valves 65, 66, and 67 performed by the control device 100 is then completed. These control steps are repeatedly performed each time, for example, the interface 180 receives the detection values ​​from the respective detection measuring devices and the like.

[0083] Hereinafter, changes in various parameters indicating operating conditions of the gas turbine 10 will be described with reference to Fig. 15. Note that the state of the gas turbine 10 under S1s of Fig. 15A to 15F is uniform. In the same way, the state of the gas turbine 10 is uniform under states with the same reference symbol, namely each of S2s, S3s, S4s, S5s and S6s of Fig. 15A to 15F.

[0084] In the example of operation of the gas turbine 10 according to the present embodiment, the IGV opening is constant at a minimum opening until the state S4 where the load factor %Load is a medium load factor of, for example, approximately 50%, as shown in Fig. 15A. When the load factor %Load exceeds the mean load factor, the IGV opening increases as the load factor %Load increases. This tendency continues until state S5, which is immediately before the load factor %Load reaches 100%. The IGV opening reaches 100% in state S5. Therefore, the IGV opening is constant at 100% from state S5, which is immediately before the load factor %Load reaches 100%, to state S6, where the load factor %Load is 100%. Note that the graph of Fig. 15A the same as the graph of Fig. 10.

[0085] The inlet temperature of the combustion gas in the turbine 21 and the combustion load command value CLCSO, which has a positive correlation therewith, increase as the fuel / air ratio (F / A) increases. Therefore, as long as the fuel / air ratio (F / A) is substantially constant, the inlet temperature and the combustion load command value CLCSO are also substantially constant, even if the load factor %Load increases. Further, as the fuel / air ratio (F / A) increases, the inlet temperature and the combustion load command value CLCSO also increase regardless of an increase / decrease in the load factor %Load.

[0086] As previously described, the IGV opening is constant at the minimum opening, and an input flow volume of the compressor 11 is substantially constant from the minimum load factor state S1 to the intermediate load factor state S4. However, the flow volume of fuel supplied to the combustor 31 of the gas turbine 10 increases as the load factor %Load increases, even outside of this period. Therefore, the combustion load command value CLCSO also increases during this period, as shown in Fig. 15B.

[0087] As described above, as the load factor %Load increases, the IGV opening increases, and the inlet flow volume of the compressor 11 also increases as the load factor %Load increases, from the state S4 of the intermediate load factor to the state S5 immediately before the load factor %Load reaches 100%. However, the flow volume of fuel supplied to the combustor 31 of the gas turbine 10 increases as the load factor %Load increases, even during this period. Therefore, the fuel-air ratio hardly undergoes any change during this period, and the combustion load command value CLCSO also hardly changes even as the load factor %Load increases. In other words, the combustion load command value CLCSO is substantially constant during this period.

[0088] Furthermore, as mentioned with reference to Fig. 11, the pre-correction PL0 ratio is set to decrease gradually as the combustion load command value CLCSO increases (see Fig. 15C). Therefore, in a period in which the combustion load command value CLCSO increases as the load factor %Load increases, such as from the state S1 of the minimum load factor to the state S4 of the medium load factor, the pre-correction PL0 ratio gradually decreases as the load factor %Load increases, as in Fig. 15D. In a period in which the combustion load command value CLCSO is substantially constant even when the load factor %Load increases, such as from the state S4 of the medium load factor to the state S5 immediately before the load factor %Load reaches 100%, the pre-correction PL0 ratio is substantially constant even when the load factor %Load increases. Note that the graph of Fig. 15C the same as the graph of Fig. 11.

[0089] The combustion state in the combustion lining 33 of the combustion chamber 31 (see Fig. 2) changes when the load factor %Load changes, even when the combustion load command value CLCSO, or in other words, the inlet temperature of the combustion gas in the turbine 21, remains constant. The ignition ratio (PL ratio) is one of the operating parameters of the gas turbine 10 that is changed to ensure combustion stability while ensuring that the exhaust gas of the gas turbine 10 meets an environmental specification. However, since the pre-correction PL0 ratio is constant, in the case where the combustion load command value CLCSO remains constant, even though the load factor %Load changes and the combustion state in the combustion liner 33 changes, it may not be possible to ensure combustion stability if the pre-correction PL0 ratio is used in the current state.

[0090] Accordingly, in the present embodiment, the PL0 ratio is corrected with the correction value Cp such that the PL ratio is set to a range excluding the ranges Ri (range determined by the PL ratio and the load factor %Load) in which the combustion state becomes unstable, such as the occurrence of combustion oscillation, in the case where the load factor %Load changes although the combustion load command value CLCSO is constant, as shown in Fig. 15F is shown.

[0091] The correction value Cp is determined as follows. First, the ranges Ri (ranges determined by the PL ratio and the load factor %Load) in which the combustion state becomes unstable when the combustion load command value CLCSO is kept constant and the load factor %Load changes are defined in advance through experiments or the like. Next, a relationship between the PL ratio and the load factor %Load is defined, which makes it possible to avoid the ranges Ri in which the combustion state becomes unstable when the combustion load command value CLCSO is constant. Then, a difference between the PL ratio relative to the load factor %Load determined from this relationship and the PL0 ratio determined in accordance with the combustion load command value CLCSO is used as the correction value Cp, as shown in Fig. 15E. Note that the graph of Fig. 15E the same as the graph of Fig. 12 is.

[0092] According to the present embodiment, therefore, the combustion stability can be improved by adding the correction value Cp in accordance with the current load factor %Load to the pre-correction PL0 ratio and using the resulting value as the final PL ratio.

[0093] According to the present embodiment, also with respect to the cylinder hat ratio (TH ratio), the TH0 ratio is corrected with the correction value Ct such that the TH ratio is set to a range excluding the ranges Ri (ranges determined by the TH ratio and the load factor %Load) in which the combustion state becomes unstable in the case where the load factor %Load changes although the combustion load command value CLCSO is constant, as shown in Fig. 14 is shown.

[0094] The correction value Ct is determined as follows, in the same way as the correction value Cp described previously. First, the ranges Ri (ranges determined by the TH ratio and the load factor %Load) in which the combustion state becomes unstable in the case where the combustion load command value CLCSO is kept constant and the load factor %Load changes are determined in advance by experiments or the like. Next, a relationship between the TH ratio and the load factor %Load is defined, which makes it possible to avoid the ranges Ri in which the combustion state becomes unstable when the combustion load command value CLCSO is constant. Then, a difference between the TH ratio relative to the load factor %Load, determined from this relationship, and the TH0 ratio, determined in accordance with the combustion load command value CLCSO, is used as the correction value Ct.

[0095] The combustion state of the fuel in the combustion liner 33 of the combustor 31 can be expressed by the inlet temperature of the combustion gas in the turbine 21 and the gas flow velocity in the combustion liner 33. As described above, the combustion load command value CLCSO is a value that has a positive correlation with the inlet temperature of the combustion gas in the turbine 21. Since the load factor %Load has a positive correlation with the gas flow volume in the combustion liner 33, it can also be said that the load factor %Load is a value that has a positive correlation with the gas flow velocity in the combustion liner 33. Therefore, according to the present embodiment, the PL ratio and the like are determined in accordance with the combustion state from the combustion load command value CLCSO and the load factor %Load.Therefore, the combustion state can be understood more accurately than when the PL ratio and the like are determined in accordance with the combustion state determined only by the combustion load command value CLCSO, and the PL ratio and the like can be determined in accordance with the combustion state. Consequently, according to the present embodiment, the occurrence of combustion vibration in the combustion liner 33 of the combustion chamber and the like can be prevented, and the combustion stability in the combustion liner 33 can be further improved.

[0096] A further development of the flow volume ratio calculation device described above is described with reference to Fig. 17 and Fig. 18 described.

[0097] The combustion state of the fuel in the combustion lining 33 of the combustion chamber 31 (see Fig. 17) can be expressed by two parameters. As previously described, of the two parameters, a first parameter is a parameter that correlates with the inlet temperature of the combustion gas in the turbine 21, and a second parameter is a parameter that correlates with the gas flow velocity in the combustion liner 33.

[0098] Accordingly, the inlet temperature of the combustion gas in the turbine 21 can be used as the first parameter instead of the previously described combustion load command value CLCSO.

[0099] Furthermore, another parameter that correlates with the gas flow velocity in the combustion liner 33 can be used as the second parameter instead of the load factor %Load described above. As previously described, the gas flow velocity in the combustion liner 33 has a positive correlation with the gas flow volume in the combustion liner 33. As shown in Fig. 17, the gas flow volume includes, in addition to the load factor %Load Factor described in the above embodiment, the outlet of the gas turbine 10, a total flow volume Gf of the fuel F supplied to the combustor 31 from the plurality of fuel systems, and a flow volume Ga of the air A taken in from the compressor 11.

[0100] The output of the gas turbine 10 can be expressed by the output PW of the generator 29 connected to the gas turbine 10. Therefore, the output PW of the generator 29 detected by the output measuring device 72 can be used as the second parameter.

[0101] The total flow volume Gf of the fuel F supplied to the combustion chamber 31 from the multiple fuel systems can be detected by a flow volume meter 78 provided in the fuel line 60 before branching into the multiple fuel systems. The total flow volume Gf of the fuel F supplied to the combustion chamber 31 from the multiple fuel systems can also be detected by a valve lift of the flow volume control valve 79 for the fuel flowing in the fuel line 60. Accordingly, the flow volume of the fuel detected by the flow volume meter 78 provided on the fuel line 60 or the flow volume of the fuel specified by a valve lift command value of the flow volume control valve 79 can be used as the second parameter.

[0102] Although the flow volume of air A admitted by the compressor 11 can be directly measured with a flow volume meter, few systems are equipped with such a flow volume meter. Therefore, for example, a relationship between a mass flow volume Ga of air A admitted by the compressor 11, the IGV opening, and the inlet temperature can be detected in advance, and this relationship can then be used to determine the mass flow volume Ga of air admitted by the compressor 11 from the IGV opening specified by the IGV opening command value and the inlet temperature detected by the inlet temperature meter 73.Note that in this case, the mass flow volume Ga of the air A admitted from the compressor 11 is a mass flow volume when the generator 29 connected to the gas turbine 10 is connected to a power system and the rotational speeds of the generator 29 and the gas turbine 10 correspond to a system frequency.

[0103] The combustion state of the fuel in the combustion liner 33 of the combustion chamber 31 can be expressed by the total flow volume of the fuel supplied to the combustion chamber 31 and the flow volume of the air supplied to the combustion chamber 31, or, in other words, the flow volume of the air admitted from the compressor 11. Accordingly, the total flow volume of the fuel supplied to the combustion chamber 31 can be used as the first parameter, and the flow volume of the air admitted from the compressor 11 can be used as the second parameter.Therefore, as described above, the flow volume of fuel detected by the flow volume meter 78 provided on the fuel line 60 or the flow volume of fuel specified by a valve lift command value of the flow volume control valve 79 can be used as the first parameter, and the flow volume of air admitted from the compressor 11 by the method described above can be used as the second parameter.

[0104] As in Fig.18, a flow volume ratio calculation device 141A according to the present embodiment includes: an ignition ratio calculator 140Ap that receives the values ​​of the first parameter and the second parameter, examples of which were given above, and calculates the PL ratio; and a cylinder hat calculator 140At that receives the values ​​of the first parameter and the second parameter, examples of which were given above, and calculates the TH ratio.

[0105] The ignition ratio calculator 140Ap includes a PL0 ratio calculator (flow volume ratio calculator) 141Ap that determines the PL0 ratio according to the value of the first parameter; a correction value calculator 142Ap that calculates a correction value Cp according to the value of the second parameter; and a correction value calculator 144Ap that corrects the PL0 ratio with the correction value Cp. Like the PL0 ratio calculator 141p according to the above-described embodiment, the PL0 ratio calculator 141Ap has a function that defines a relationship between the first parameter and the PL0 ratio. Like the correction value calculator 142p according to the above-described embodiment, the correction value calculator 142Ap further has a function that defines a relationship between the second parameter and the correction value Cp.

[0106] The cylinder hat ratio calculator 140At includes a TH0 ratio calculator (flow volume ratio calculator) 141At that determines the TH0 ratio according to the value of the first parameter; a correction value calculator 142At that calculates a correction value Ct according to the value of the second parameter; and a correction device 144At that corrects the TH0 ratio with the correction value Ct. Like the TH0 ratio calculator 141t according to the above-described embodiment, the TH0 ratio calculator 141At has a function that defines a relationship between the first parameter and the TH0 ratio. Like the correction value calculator 142t according to the above-described embodiment, the correction value calculator 142At further has a function that defines a relationship between the second parameter and the correction value Ct.

[0107] Note that substantially the same effects as those of the above-described embodiment can be achieved even if the flow volume ratio calculating device 140 of the control device 100 in the above-described embodiment is replaced with the above-described flow volume ratio calculating device 140A.

[0108] According to the present invention, the combustion stability of fuel in a combustion chamber can be improved. List of reference symbols 10 gas turbines 11 Compressor 14 IHR 21 turbines 31 Combustion chamber 33 Combustion lining (or transition piece) 43 pilot burners 44 Ignition nozzle 51 cylinder head nozzle 53 main burners 54 Main jet 60 fuel line 61 Pilot fuel line 62 Main fuel line 63 Cylinder hat fuel line 65 Pilot fuel valve 66 Main fuel valve 67 Cylinder head fuel valve 71 Tachometer 72 Output measuring device 73 Input temperature measuring device 74 Inlet pressure gauge 75 wing path temperature measuring device 76 exhaust gas temperature measuring device 100 control device 110 Combustion load command generator 120 Load factor calculator 130 Fuel flow volume command generator (total flow volume computing device) 140, 140A Flow Volume Ratio Calculator (Flow Volume Ratio Calculator) 140p, 140Ap ignition ratio calculator 141p, 141Ap PL0 ratio calculator (flow volume ratio calculator) 142p, 142Ap correction value calculating device 144p, 144Ap correction device 140t, 140At cylinder hat ratio calculator 141t, 141At TH0 ratio calculator (flow volume ratio calculator) 142t, 142At correction value calculator 144t, 144At correction device 160 System flow volume calculator 170 Valve control device 180 interface

Claims

[1] A flow volume ratio calculation device (140) configured to calculate a flow volume ratio (PL0) of fuels flowing in a plurality of fuel systems (61, 62, 63) in a gas turbine (10) comprising the plurality of fuel systems (61, 62, 63), a compressor (11) that compresses air to generate compressed air, a combustion chamber (31) that burns the fuels from the plurality of fuel systems (61, 62, 63) in the compressed air to generate combustion gas, and a turbine (21) driven by the combustion gas, the flow volume ratio calculation device (140) comprising: a computer which receives values ​​of two parameters which can express a combustion state in the combustion chamber (31) and which calculates the flow volume ratio (PL0) relative to the received values ​​of the two parameters based on a predetermined relationship between the two parameters and the flow volume ratio (PL0), the calculator includes: a flow volume ratio calculating device (141p) that determines the flow volume ratio (PL0) relative to the received value of the first parameter based on a predetermined relationship between the first parameter and the flow volume ratio (PL0); a correction value calculating device (142p) that determines a correction value (Cp) in accordance with the received value of the second parameter based on a predetermined relationship between the second parameter and a correction value for the flow volume ratio (PL0); and a correction device (144p) which corrects the flow volume ratio (PL0) determined by the flow volume ratio calculation device (141p) with the correction value (Cp) determined by the correction value calculation device (142p), wherein the predetermined relationship used by the correction value calculating means (142p) is a relationship between the second parameter and the flow volume ratio (PL0) when the first parameter is constant. [2] The flow volume ratio calculating device (140) according to claim 1, wherein, of the two parameters received by the calculator, a first parameter is an inlet temperature correlated value which is a value that changes in correlation with a change in the inlet temperature of the combustion gas in the turbine (21) or the inlet temperature itself, and a second parameter is a flow velocity correlated value which changes in correlation with the change in a flow velocity of the combustion gas in the combustion chamber (31). [3] The flow volume ratio calculating device (140) according to claim 2, wherein the value correlated with the flow rate is one of an output of the gas turbine (10), a load factor which is a percentage of a current load relative to an allowable maximum load in the gas turbine (10), a total flow volume of the fuels supplied to the combustor (31) from the plurality of fuel systems (61, 62, 63), and a flow volume of the air sucked by the compressor (11). [4] The flow volume ratio calculating device (140) according to claim 1, wherein, of the two parameters received by the calculator, a first parameter is a total flow volume of the fuels supplied to the combustion chamber (31) from the plurality of fuel systems (61, 62, 63), and a second parameter is a flow volume of the air sucked by the compressor (11). [5] Flow volume ratio calculation device (140) according to one of claims 1 to 4, wherein the combustion chamber (31) comprises a first burner (43) which subjects a fuel to diffusion combustion and a second burner (53) which subjects a fuel to premix combustion; the gas turbine (10) comprises, as the plurality of fuel systems (61, 62, 63), a first fuel system (61) which supplies a fuel to the first burner (43) and a second fuel system (62) which supplies a fuel to the second burner (53); and the flow volume ratio (PL0) includes a ratio of a flow volume of the fuel supplied to the combustion chamber (31) from the first fuel system (61) to the total flow volume of the fuels supplied to the combustion chamber (31) from the plurality of fuel systems (61,62,63). [6] Flow volume ratio calculation device (140) according to one of claims 1 to 5, wherein the combustion chamber (31) comprises a burner which injects a fuel; the gas turbine (10) comprises, as the plurality of fuel systems (61, 62, 63), a burner system (61, 62) that supplies a fuel to the burner, and an upstream supply system (63) that supplies a fuel to the compressed air supplied to the burner; and the flow volume ratio (PL0) includes a ratio of a flow volume of the fuel supplied to the combustion chamber (31) from the burner system to the total flow volume of the fuels supplied to the combustion chamber (31) from the plurality of fuel systems (61,62,63). [7] Control device (100) comprising: the flow volume ratio calculating device (140) according to any one of claims 1 to 6; a total flow volume calculator (130) that determines the total flow volume of fuels supplied to the combustion chamber (31) from the plurality of fuel systems (61,62,63); a system flow volume calculation device (160) that determines a fuel flow volume in each of the plurality of fuel systems (61, 62, 63) based on the total flow volume determined by the total flow volume calculation device (130) and the flow volume ratio (PL0) calculated by the flow volume ratio calculation device (140); and a valve control device (170) that outputs a control signal to a fuel flow volume control valve (65, 66, 67) provided in each of the plurality of fuel systems (61, 62, 63) such that the fuel flow volume in each of the plurality of fuel systems (61, 62, 63) becomes the corresponding fuel flow volume determined by the system flow volume computing device (160). [8] Gas turbine plant, comprising: the control device (100) according to claim 7; and a gas turbine (10). [9] A flow volume ratio calculation method for calculating a flow volume ratio (PL0) of fuels flowing in a plurality of fuel systems (61, 62, 63) in a gas turbine (10) comprising the plurality of fuel systems (61, 62, 63), a compressor (11) that compresses air to generate compressed air, a combustion chamber (31) that burns the fuels from the plurality of fuel systems (61, 62, 63) in the compressed air to generate combustion gas, and a turbine (21) driven by the combustion gas, the flow volume ratio calculation method comprising: a receiving step (S41p) for receiving values ​​of two parameters that can express a combustion state in the combustion chamber (31); and a calculation step (S40) for determining the flow volume ratio (PL0) relative to the values ​​of the two parameters received in the receiving step based on a predetermined relationship between the two parameters and the flow volume ratio (PL0), wherein the calculation step (S40) comprises: a flow volume ratio calculation step (S40p) for determining the flow volume ratio (PL0) relative to the value of the first parameter received in the receiving step (S41p) based on a predetermined relationship between the first parameter and the flow volume ratio (PL0); a correction value calculation step (S44p) which determines a correction value (Cp) in accordance with the value of the second parameter received in the receiving step (S41p) based on a predetermined relationship between the second parameter and a correction value for the flow volume ratio (PL0); and a correction step (S45p) that corrects the flow volume ratio (PL0) determined in the flow volume ratio calculation step (S40p) with the correction value (Cp) determined in the correction value calculation step (S44p), wherein the predetermined relationship used in the correction value calculation step (S44p) is a relationship between the second parameter and the flow volume ratio (PL0) when the first parameter is constant. [10] The flow volume ratio calculation method according to claim 9, wherein, of the two parameters received in the receiving step (S41p), a first parameter is an inlet temperature correlated value which is a value that changes in correlation with a change in an inlet temperature of the combustion gas in the turbine (21) or the inlet temperature itself, and a second parameter is a flow velocity correlated value which changes in correlation with a change in the flow velocity of the combustion gas in the combustion chamber (31). [11] The flow volume ratio calculation method according to claim 10, wherein the value correlated with the flow rate is one of an output of the gas turbine (10), a load factor which is a percentage of a current load relative to an allowable maximum load in the gas turbine (10), a total flow volume of the fuels supplied to the combustor (31) from the plurality of fuel systems (61, 62, 63), and a flow volume of the air sucked by the compressor (11). [12] The flow volume ratio calculation method according to claim 9, wherein, of the two parameters received in the receiving step (S41p), a first parameter is a total flow volume of the fuels supplied to the combustor (31) from the plurality of fuel systems (61, 62, 63), and the second parameter is a flow volume of the air sucked by the compressor (11). [13] A fuel system control method, wherein the flow volume ratio calculation method according to any one of claims 9 to 12 is carried out, the fuel system control method comprising: a total flow volume calculation step (S30) that determines a total flow volume of the fuels supplied to the combustion chamber (31) from the plurality of fuel systems (61, 62, 63); a system flow volume calculation step (S40) that determines a fuel flow volume in each of the plurality of fuel systems (61, 62, 63) based on the total flow volume determined in the total flow volume calculation step (S30) and the flow volume ratio (PL0) calculated by the flow volume ratio calculation method; and a valve control step (S60) for outputting a control signal to a fuel flow volume control valve (65, 66, 67) provided in each of the plurality of fuel systems (61, 62, 63) such that the fuel flow volume in each of the plurality of fuel systems (61, 62, 63) becomes the corresponding fuel flow volume determined in the system flow volume calculation step (S40).

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