Combustion control method and combustion control device for gas turbine

Abstract

A combustion adjustment method and a combustion control device of a gas turbine suitable for combustion control of a combustor are provided. The combustion adjustment method selects a combustion parameter with respect to a load of the gas turbine, and executes a first process of raising or lowering an instruction value of the combustion parameter from a reference position. If the instruction value reaches an upper limit value of a target margin or a lower limit value of the target margin, the first process is ended. A second process of lowering or raising the instruction value in a direction opposite to the first process is also executed. A combustion margin confirming process in which a combustion margin range of the combustion parameter is confirmed if the instruction value reaches the lower limit value of the target margin or the upper limit value of the target margin is included, and the second process is ended.

Description

Technical Field

[0001] This invention relates to a combustion adjustment method and combustion control device for a gas turbine.

[0002] This application claims priority based on Japanese Patent Application No. 2020-180324, filed on October 28, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] For a gas turbine to operate stably, it is crucial to establish operating conditions that suppress combustion vibrations within permissible levels. Therefore, various solutions have been proposed regarding combustion adjustment methods that predict the generation of combustion vibrations and suppress them within permissible levels, as well as correction mechanisms for combustion control devices. Patent Document 1 discloses an example of predicting the generation of combustion vibrations after the gas turbine has entered normal operation and automatically selecting operating conditions that suppress combustion vibrations within permissible levels.

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-84523 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] However, during the commissioning of a gas turbine or the restart after a periodic inspection, the method disclosed in Patent Document 1 sometimes fails to transition to a state of normal combustion control due to differences in burner structure, fuel properties, and atmospheric conditions. In particular, the permissible range of operating conditions that can suppress combustion vibrations within acceptable levels is sometimes narrow, depending on the fuel-air ratio, thus requiring a startup time to reach rated operation. Therefore, it is crucial to confirm the permissible range of operating conditions for the fuel-air ratio before commencing commissioning.

[0009] The present invention was made to solve the above-mentioned problems. Its purpose is to provide a combustion adjustment method and combustion control device for confirming the combustion margin range of the fuel-air ratio of the burner as a preliminary work for the start of trial operation of a gas turbine or the restart of operation after periodic inspection.

[0010] Organizations used to solve technical problems

[0011] To address the aforementioned issues, the combustion adjustment method used in burner combustion control includes a combustion margin confirmation process, which confirms the combustion margin range of combustion parameters. This combustion margin confirmation process includes the following steps:

[0012] The combustion parameters for the fuel-air ratio set for the load of the gas turbine are selected; a first step is executed, consisting of either a first increase instruction step (increasing the command value of the combustion parameters from the origin) or a first decrease instruction step (decreasing the command value); if the burner does not produce combustion vibration and the command value reaches the upper or lower limit of the target margin, the first step ends and the command value of the combustion parameters returns to the origin; a second step is executed, consisting of either a second decrease instruction step (decreasing the command value from the origin in the opposite direction to the first step) or a second increase instruction step (increasing the command value); and if the burner does not produce combustion vibration and the command value of the second step reaches the lower or upper limit of the target margin, the second step ends and the command value of the combustion parameters in the second step returns to the origin.

[0013] Invention Effects

[0014] The combustion margin verification method according to the present invention makes combustion margin verification effective without relying on the skills of the operator, and simplifies combustion adjustment. Furthermore, it improves the reliability of the gas turbine. Attached Figure Description

[0015] Figure 1 This is a schematic diagram showing the structure of a gas turbine device.

[0016] Figure 2 This is a diagram showing the structure of the combustion control device.

[0017] Figure 3 This is a diagram showing the structure of the combustion margin verification section.

[0018] Figure 4 This is a diagram representing the confirmation pattern for the first combustion margin.

[0019] Figure 5 This is a diagram representing the confirmation pattern for the second combustion margin.

[0020] Figure 6 This is a diagram representing the confirmation pattern for the third combustion margin.

[0021] Figure 7 This is a diagram representing the confirmation pattern for the fourth combustion margin.

[0022] Figure 8 This is a flowchart showing the overall process of the combustion margin adjustment section.

[0023] Figure 9 This is a flowchart illustrating the process for verifying combustion margin.

[0024] Figure 10A This is a graph showing the relationship between combustion parameters and combustion load variables in Example 1.

[0025] Figure 10B This is a graph showing the relationship between the gas turbine inlet temperature and the combustion load variable in Example 1.

[0026] Figure 10C This is a graph showing the relationship between the combustion parameters and the gas turbine inlet temperature in Example 1.

[0027] Figure 11A This is a graph showing the relationship between combustion parameters and combustion load variables in Example 2.

[0028] Figure 11B This is a graph showing the relationship between the gas turbine inlet temperature and the combustion load variable in Example 2.

[0029] Figure 11C This is a graph showing the relationship between the combustion parameters and the gas turbine inlet temperature in Example 2.

[0030] Figure 12 This is a flowchart representing the combustion load variable correction process.

[0031] Figure 13 This is the logic diagram of the combustion load variable correction unit.

[0032] Figure 14 This is a diagram illustrating an example of a change in a setting value. Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0034] Device Structure

[0035] A schematic diagram of the gas turbine assembly is shown below. Figure 1 The gas turbine 1 includes: a compressor 2, which has inlet guide vanes 11 and draws in atmospheric air from the outside to generate compressed air; a combustor 3, which burns fuel FL supplied separately with the generated compressed air to generate combustion gas FG; a turbine 4, which is driven to rotate by the generated combustion gas FG; a generator 5, which is connected to the turbine 4 and is driven to rotate to generate electricity; and a combustion control device 100, which controls the gas turbine 1.

[0036] Each burner 3 is equipped with a combustion nozzle 30 consisting of a main nozzle 31, a top cap nozzle 32, and a pilot nozzle 33. The main nozzles 31 are arranged in a ring around the pilot nozzle 33. The burner 3 also includes a bypass valve 44 and a tailpipe 24. The burner 3 further includes a main fuel flow control valve 41, a top cap fuel flow control valve 42, and a pilot fuel flow control valve 43. Of the fuel FL supplied to the burner 3, fuel for the main combustion nozzles is supplied to the main nozzles 31 via the main fuel flow control valve 41. Top cap fuel is supplied to the top cap nozzles 32 via the top cap fuel flow control valve 42, and pilot fuel is supplied to the pilot nozzles 33 via the pilot fuel flow control valve 43. The flow rates of the main fuel, top cap fuel, and pilot fuel are controlled by the respective flow control valves of the main fuel flow control valve 41, the top cap fuel flow control valve 42, and the pilot fuel flow control valve 43. The combustion gas FG generated by the burner 3 is supplied to the turbine 4 via the tailpipe 24 and drives the turbine 4 to rotate.

[0037] Combustion Control Device

[0038] Figure 2 This diagram shows a schematic structure of the combustion control device 100 of the gas turbine 1 in this embodiment. The combustion control device 100 includes a process measurement unit 101, a pressure change measurement unit 102, an acceleration measurement unit 103, a NOx measurement unit 104, a valve operation unit 105, a frequency analysis unit 123, and a control unit 110, all provided on the gas turbine 1.

[0039] The process measurement unit 101 is equipped with various measuring devices that measure process quantities representing the operating conditions or operating status of the gas turbine 1. At predetermined intervals, it sends the measurement results to the control unit 110 of the combustion control device 100. Process quantities include, for example, turbine output, atmospheric temperature, humidity, fuel flow rate and fuel pressure of each component, air flow rate and air pressure of each component, combustion gas temperature, combustion gas pressure, the rotational speeds of the compressor 2 and turbine 4, and the concentrations of waste products such as nitrogen oxides (NOx) and carbon monoxide (CO) in the exhaust gas emitted from the turbine 4.

[0040] The pressure change measuring unit 102 is a pressure measuring device disposed in each of the multiple burners 3, and periodically outputs the pressure change measurement value of each burner 3 to the control unit 110 according to the instructions from the control unit 110. The acceleration measuring unit 103 is an acceleration measuring device disposed in each burner 3, and periodically measures the acceleration according to the instructions from the control unit 110 and outputs the measurement value to the control unit 110. The NOx measuring unit 104 is a NOx measuring device in the exhaust gas of the burner 3, and periodically measures NOx according to the instructions from the control unit 110, and outputs the measurement value to the control unit 110.

[0041] The valve operating unit 105 is a mechanism that operates the opening degree of each control valve of the main fuel flow control valve 41, the top cap fuel flow control valve 42, the pilot fuel flow control valve 43, and the bypass valve 44, as well as the opening degree of the inlet guide vane 11 of the compressor 2, according to instructions from the control unit 110. The valve operating unit 105 performs main fuel control, top cap fuel control, pilot fuel control, flow control of the air flow supplied to each burner 3, and flow control of the atmospheric air supplied to the compressor 2.

[0042] The frequency analysis unit 123 performs frequency analysis on the pressure changes and acceleration changes detected by the pressure change measurement unit 102 and the acceleration measurement unit 103, and outputs the results to the control unit 110.

[0043] In addition to the various measuring units, measuring units, valve operating units, and control units 110 mentioned above, the combustion control device 100 also includes an automatic combustion adjustment unit 120 and a combustion margin adjustment unit 130. The control unit 110 receives output signals from the process measuring unit 101, the pressure change measuring unit 102, the acceleration measuring unit 103, and the frequency analysis unit 123, and sends them to the automatic combustion adjustment unit 120. Furthermore, the control unit 110 outputs signals indicating the valve opening degrees of the main fuel flow control valve 41, the top cap fuel flow control valve 42, the pilot fuel flow control valve 43, the bypass valve 44, and the inlet guide vanes 11 of the compressor 2 to the valve operating unit 105.

[0044] Automatic Combustion Adjustment Department

[0045] Figure 2 The automatic combustion adjustment unit 120 shown is configured to include an input unit 121, an operating status control unit 122, a combustion characteristic control unit 124, a correction unit 125, and an output unit 126. When combustion vibration occurs in the burner 3, the automatic combustion adjustment unit 120 controls each process quantity in the direction that is most effective in suppressing combustion vibration.

[0046] The automatic combustion adjustment unit 120 receives process quantities, pressure, and acceleration data from the control unit 110 via the input unit 121. Furthermore, based on the frequency analysis results within the gas turbine 1 analyzed by the frequency analysis unit 123, the operating status of the gas turbine 1 is monitored in the operating status monitoring unit 122, and the combustion characteristics of each burner 3 are monitored in the combustion characteristic monitoring unit 124. The correction unit 125 determines a control method that will not cause combustion vibration in the gas turbine 1 based on the data monitored by the operating status monitoring unit 122 and the combustion characteristic monitoring unit 124. For example, it determines whether it is necessary to adjust the valve opening of the main fuel flow control valve 41, the top cap fuel flow control valve 42, the pilot fuel flow control valve 43, the bypass valve 44, and the inlet guide vane 11 of the compressor 2. When valve opening adjustment is required, the adjustment amount is determined and output to the control unit 110 via the output unit 126.

[0047] Combustion Margin Adjustment Department

[0048] Before starting a test run of a gas turbine with limited storage of past operating condition data, the combustion margin adjustment unit 130 determines the area where combustion vibration will not occur, sends this data to the automatic combustion adjustment unit 120, and stores it in the database 127 within the automatic combustion adjustment unit 120. The purpose of the combustion margin adjustment unit 130 is to prepare operating conditions that allow the gas turbine to transition to rated operation without combustion vibration during startup after the test run or periodic inspection of the gas turbine 1, using data from the automatic combustion adjustment unit 120 that reflects the stored data, and to enable the gas turbine to transition to rated operation in a short time.

[0049] Therefore, when restarting operation at the start of trial operation or after the completion of periodic inspection, the combustion margin adjustment unit 130 automates combustion adjustment work, such as confirming the margin range of combustion vibration previously performed by combustion adjustment personnel, so as to make the combustion adjustment work appropriate.

[0050] like Figure 3 As shown, the combustion margin adjustment unit 130 consists of a combustion margin confirmation unit 132, a combustion load variable correction unit 134, and a setpoint change unit 136. Furthermore, the combustion load variable correction unit 134 consists of a maximum load correction unit 134a and a setpoint conversion unit 134b.

[0051] In the combustion margin verification unit 132, before the start of the trial run of the gas turbine 1 or before the restart of operation after the completion of the periodic inspection, the combustion parameters PM are verified according to the combustion margin verification procedure S20 described later. Figure 8 , Figure 9 The combustion margin of various combustion margin patterns in the process is confirmed, and the combustion margin range of the combustion vibration generated in the burner 3 is confirmed in advance and acquired as stable data 128, so as to realize the storage of various operating data at the start of the operation of the gas turbine 1.

[0052] The purpose of the combustion load variable correction unit 134 is to maintain the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM while outputting the planned maximum output MOP of the gas turbine 1 at the rated value (100%) of the combustion load variable CLP, and to optimize the relationship between the combustion parameter PM and the combustion load variable CLP. Details will be described later. The maximum load correction unit 134a corrects the combustion load variable CLP by making it the rated value (100%) at the planned maximum output MOP. The setpoint conversion unit 134b converts the setpoint for the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP based on the corrected combustion load variable CLP, so as to maintain the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM. By setting the combustion load variable correction unit 134, the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM is maintained, and combustion vibration of the burner 3 is suppressed, thereby achieving stable operation of the gas turbine 1. In the following description, the gas turbine load (gas turbine output) is sometimes referred to simply as GT load (GT output) instead of gas turbine load (gas turbine output).

[0053] The purpose of the setpoint change unit 136 is to automatically change the setpoint of the combustion load variable CLP from the previous setpoint to the corrected setpoint during the combustion margin verification process S20, when combustion vibration occurs and causes a shift in the origin (origin offset) as described later.

[0054] The main function of the combustion margin adjustment unit 130 is as follows: Regarding each combustion parameter PM in the combustion margin adjustment unit 130, the combustion vibration generated in the burner 3 is suppressed to within the allowable level, and a combustion margin range that does not generate combustion vibration is confirmed. The combustion margin range is defined as the reference operating point, set as the origin OP, by defining the position or value of the combustion parameter PM for the combustion load variable CLP. Using the origin OP as a reference, it is confirmed whether combustion vibration occurs at different operating points under the GT load, and a stable operating range without combustion vibration is set. Furthermore, for convenience, the combustion load variable CLP at the planned maximum load MOP or rated load of the gas turbine 1 is set to the rated value (100%), and the combustion load variable CLP at the no-load output NOP of the gas turbine is set to 0 (zero)%. Any gas turbine load is represented by the combustion load variable CLP. The combustion parameter PM for any gas turbine load can be represented as the set value of the corresponding combustion load variable CLP.

[0055] Method for confirming flammability margin

[0056] Next, the concept of the combustion margin verification method and the combustion margin pattern, which are common to various combustion parameters PM, will be explained. Furthermore, in the following explanation, the verification of the combustion margin range refers to the range and width within the burner 3 where no combustion vibration occurs for each combustion parameter PM, but is sometimes simply referred to as combustion margin verification. No combustion vibration indicates that the combustion vibration within the burner 3 is suppressed within the permissible level; combustion vibration indicates that the combustion vibration exceeds the permissible level.

[0057] The combustion parameters PM used to determine the combustion margin range are the pilot ratio PL, the top cap ratio TH, and the bypass valve opening BV. The pilot ratio PL is the distribution ratio of fuel supplied to the pilot nozzle 33 relative to the total fuel flow FL, expressed as a percentage (%). The top cap ratio TH is the distribution ratio of fuel supplied to the top cap nozzle 32 relative to the total fuel flow FL, expressed as a percentage (%). The bypass valve opening BV is the valve opening relative to the bypass valve 44 when it is fully open, expressed as a percentage (%). Whether combustion vibration occurs within the burner 3 depends on the set values ​​ST of the pilot ratio PL, top cap ratio TH, and bypass valve opening BV for the specified GT load. Additionally, other parameters that affect the combustion state of the burner 3 can be selected as combustion parameters PM.

[0058] Priority of Combustion Parameters

[0059] In the combustion margin adjustment unit 130, regarding all the combustion parameters PM mentioned above, the combustion margin confirmation process S20, which confirms the combustion margin range (described later), is performed. Figure 8 , Figure 9 To expedite the determination of the combustion margin range, the priority order of combustion parameter PM is prioritized for the combustion margin confirmation process S20, which prioritizes combustion parameter PM, which is prone to combustion vibration. The range that does not generate combustion vibration refers to the level of combustion vibration for the combustion load variable CLP being within the permissible range, and specifically the range of GT loads between the operating points of the upper and lower limits of the permissible GT load. For example, if combustion vibration occurs during the combustion margin confirmation process S20 for the pilot ratio PL after completing the combustion margin confirmation process S20 for the top cap ratio TH, the combustion margin confirmation process S20 for the top cap ratio TH needs to be repeated. This results in repetitive work of the combustion margin confirmation process S20, and the determination of the combustion margin range of combustion parameter PM takes a long time. Therefore, the selection of the priority order of combustion parameter PM affects the commissioning process during gas turbine startup, either during the trial run of gas turbine 1 or at the start of operation after periodic inspections, and thus requires careful selection.

[0060] Relationship with Gas Turbine Load

[0061] Depending on the frequency band and location of combustion vibrations generated within the burner 3 due to the GT load, the GT load selected for combustion margin verification is within the range of 0% to the rated value (100%). The rated value (100%) of the GT load represents the planned maximum load (planned maximum output) or the rated load (rated output) of the gas turbine.

[0062] Upgrading and downgrading instruction processes

[0063] The following explains several modification patterns and their priority for the purpose of confirming the flammability margin range of each flammability parameter in the flammability margin confirmation process S20.

[0064] exist Figure 4 An example of a combustion margin confirmation pattern is shown. In the combustion margin confirmation process S20, it is necessary to confirm whether combustion vibration occurs in the two processes on both sides: the increase command process STU, which increases the command value CM representing the output of the combustion parameter PM, and the decrease command process STD, which decreases the command value CM. The combustion margin range of both processes is confirmed after the combustion margin range confirmation on both sides, and the combustion vibration and combustion margin width under the specified GT load are confirmed. In addition, under the specified GT load, whether the increase command process STU or the decrease command process STD is prioritized depends on the combustion parameter PM. After the increase command process STU and the decrease command process STD are completed, the stability data 128 in each process is extracted. In addition, the combustion margin confirmation process S20 ends the two processes of increase command process STU and decrease command process STD, and one cycle of the combustion parameter PM margin confirmation is completed. Whether the increase command process STU is selected in the first process PR1 of the first half and the decrease command process STD is selected in the second process PR2 of the second half, or the selection is in the reverse order, depends on the characteristics of the burner or the combustion state.

[0065] Furthermore, during the initial setup upon restarting operation after trial operation or periodic inspection, the target margin width TMW for confirming the combustion margin range is set. The target margin width TMW is expressed as the difference between the target margin upper limit value TMUL, which sets the upper limit of the command value CM in the increase command step STU, and the target margin lower limit value TMLL, which sets the lower limit of the command value CM in the decrease command step STD. Essentially, the target margin upper limit value TMUL and the target margin lower limit value TMLL are preferably selected to be the same width from the origin OP, which serves as the reference for confirming the combustion margin output. Furthermore, the command value CM in the increase command step STU and the decrease command step STD can be selected to increase or decrease the command value CM in one direction at a constant rate, such as... Figure 4As shown, the command value CM can also be increased or decreased along the stepped steps S. The choice of method depends on the characteristics of the burner or the operating state of the gas turbine. Furthermore, it is preferable to set the step width SW to a uniform width, and to set the number of steps S in the increasing command step STU or decreasing command step STD from the origin OP to the target margin upper limit TMUL or target margin lower limit TMLL to confirm the combustion margin range. In the increasing command step STU, the command value CM is selected by setting the origin OP to zero (%) and increasing the command value CM in the (+) direction from the origin OP. Conversely, in the decreasing command step STD, the origin OP is set to zero (%) and decreasing the command value CM in the (-) direction from the origin OP. The target margin width TMW is preferably set to be variable within a range that will not adversely affect the device.

[0066] The following is a specific example of the combustion margin confirmation pattern for the combustion parameter PM.

[0067] Figure 4 This is an example of the first combustion margin verification pattern. Regarding a combustion parameter PM under a specified GT load, an example is shown where the commanded value CM of combustion parameter PM is within the range of the target upper margin limit TMUL or the target lower margin limit TMLL, and combustion vibration suppression is within the permissible level, thus ending the combustion margin verification process. Figure 5 This is an example of the second flammability margin confirmation pattern. Similarly, the second flammability margin confirmation pattern is an example of flammability vibration occurring when, in the Boosting Instruction (STU) process, the flammability parameter PM's instruction value CM reaches the target margin upper limit value TMUL before flammability vibration exceeds the permissible level. Figure 6 This is an example of the third flammability margin confirmation pattern. Similarly, the third flammability margin confirmation pattern is an example of flammability vibration occurring when, in the two processes of raising the command step STU and lowering the command step STD, the command value CM of the flammability parameter reaches the target margin upper limit value TMUL and the target margin lower limit value TMLL, respectively, the flammability vibration exceeds the permissible level. Figure 7 This is an example of the fourth flammability margin confirmation pattern. The fourth flammability margin confirmation pattern is... Figure 5 The variation of the second combustion margin confirmation pattern shown is an example in which combustion vibration occurs in the reduction instruction process (STD) before the instruction value (CM) of the combustion parameter (PM) reaches the target margin lower limit (TMLL).

[0068] First flammability margin confirmation pattern

[0069] Figure 4In the first combustion margin confirmation pattern shown, in the STU step of the first step PR1 (increase command step), combustion vibration is suppressed within the allowable level up to the target margin upper limit TMUL, confirming that no combustion vibration has occurred. Furthermore, the following implementation is shown: In the STD step of the next second step PR2 (decrease command step), combustion vibration is suppressed within the allowable level up to the target margin lower limit TMLL, confirming that no combustion vibration has occurred. The command value CM is then returned to the origin OP position, confirming the combustion margin range for one cycle at the specified GT load and the specified origin OP. Here, "combustion vibration suppression within the allowable level" means that at the specified set value ST, combustion vibration is suppressed within the allowable level up to a certain holding time.

[0070] refer to Figure 4 The first flammability margin confirmation pattern is explained in detail. The first flammability margin confirmation pattern shows an example where, after the first step PR1 (priority increase command step STU) ends, the second step PR2 (decrease command step STD) is executed. In the first step PR1's increase command step STU, the command value CM is set by adding a predetermined command value input rate BIR, starting from the initial setting origin OP. If the command value CM reaches a predetermined new command value CM, it is held for a predetermined holding time T1 to check for any flammability vibration. After confirming no flammability vibration, the command value CM is added to the predetermined command value input rate BIR to set a new command value CM for the next step S. After the command value CM reaches the new command value CM for the next step S, it is held for a predetermined holding time T1 to check for any flammability vibration. This step is repeated with a certain step width SW of the same width until the command value CM reaches the target margin upper limit value TMUL. The predetermined holding time T1 is then maintained to check for any flammability vibration. If no combustion vibration occurs after the specified holding time T1, it is determined that the combustion margin range of the origin OP at the initial setting in the boost command step STU has been confirmed. If the combustion margin range of the origin OP at the initial setting is confirmed, the command value CM reaches the target margin upper limit value TMUL, and the specified holding time T2 is maintained from the holding time T1, while the stable data 128 of the gas turbine 1 is extracted. If the stable data 128 is extracted, it is determined that the first step PR1 has ended, and the command value CM returns to the original origin OP position at the specified origin recovery command value release rate BRR. In addition, the command value CM is set by applying a specified bias voltage to the current command value CM that has maintained the holding time T1 (first holding time) without combustion vibration. Furthermore, the holding time T1 (first holding time) can be selected according to the characteristics of the burner or the operating state of the gas turbine.

[0071] Next, step PR2, starting from the origin OP, confirms the combustion margin range of the reduction command step STD, which is in the opposite direction to the increase command step STU. In the reduction command step STD, a new command value CM is set by subtracting the prescribed command value input rate BIR from the origin OP. If the command value CM reaches the prescribed new command value CM, it is held for a prescribed holding time T1 to check for combustion vibration. After confirming that no combustion vibration has occurred, a new command value CM for the next step S is set by subtracting the prescribed command value input rate BIR from the command value CM. After the command value CM reaches the next new command value CM, it is held for a prescribed holding time T1 with the new command value CM to check for combustion vibration. This step is repeated with a step width SW of the same width. When the command value CM reaches the target margin lower limit TMLL, it is held for a prescribed holding time T1 to check for combustion vibration. When no combustion vibration occurs after the prescribed holding time T1, it is determined that the combustion margin range of the origin OP in the reduction command step STD has been confirmed. When the command value CM reaches the target margin lower limit TMLL, it is held for a specified holding time T2 (the second holding time) after the holding time T1 has elapsed, and stable data 128 is extracted. If stable data 128 is extracted, it is determined that the second process PR2 has ended, and the command value CM returns to the original position OP at the command value release rate BRR when the origin is restored. The confirmation work of one cycle of the specified GT load and the specified combustion margin range at the origin OP of the first combustion margin confirmation pattern is completed. The extracted stable data 128 of the gas turbine 1 is sent to the database 127. In addition, the command value input rate BIR can be a constant fixed value in a stepped manner, or it can be an inclination rate with a certain tilt.

[0072] Second flammability confirmation pattern

[0073] Figure 5 The second combustion margin confirmation pattern shown is consistent with Figure 4 The first combustion margin confirmation pattern shown is different, illustrating an example where the combustion margin range cannot be confirmed using the target margin upper limit value TMUL in the first step PR1's boosting command step STU. Specifically, it shows a case where combustion vibration occurs in the boosting command step STU after the command value CM reaches the target margin upper limit value TMUL, but before the holding time T1 has elapsed. When combustion vibration occurs due to the inability to maintain the holding time T1 at the command value CM of the target margin upper limit value TMUL, the command value CM of the step S immediately preceding the step S where combustion vibration occurs is set as the actual margin upper limit value AMUL of the boosting command step STU.

[0074] Figure 5The second flammability margin confirmation pattern shown is an example of a process where, as the first step PR1, the increase command step STU is executed first, and after the increase command step STU is completed, the second step PR2, i.e., the decrease command step STD, is executed. In the increase command step STU, similar to the first flammability margin confirmation pattern, a new command value CM is set by adding a predetermined command value input rate BIR, starting from the initial setting origin OP. If the command value CM reaches the predetermined new command value CM, it is held for a predetermined holding time T1 to check for any combustion vibration. After confirming that no combustion vibration has occurred, the predetermined command value input rate BIR is added to the command value CM again, and it is checked for any combustion vibration at the new command value CM of the next step S. This step is repeated in the same way as the first flammability margin confirmation pattern.

[0075] However, in Figure 5 In the case of the second combustion margin confirmation pattern shown, an example is illustrated where combustion vibration occurs within a time T0 shorter than the holding time T1 after the command value CM reaches the target margin upper limit TMUL. Thus, when combustion vibration occurs before reaching the target margin upper limit TMUL and the combustion margin range cannot be confirmed, the command value CM at the step S immediately preceding the step S where combustion vibration occurred is set as the actual margin upper limit AMUL, and this is set as the upper limit of the command value CM for the escalation command step STU. At this time, the escalation command step STU of the first step PR1 ends at the point where combustion vibration occurred. That is, in the escalation command step STU, the target combustion margin range that should have been confirmed was confirmed at the point where combustion vibration did not occur at the command value CM below the target margin upper limit TMUL. However, Figure 5 In the example shown, combustion vibration occurred during the boost command step STU, so the boost command step STU ended with one step less than required. At this point, the command value CM of the immediately preceding step S, where no combustion vibration occurred and the combustion margin range was confirmed, was returned, and this command value CM was set to the actual margin upper limit value AMUL. The holding time is maintained for T2 from the time point PF where combustion vibration occurred at this command value CM, and the stable data 128 of the gas turbine 1 is extracted. The extracted stable data 128 is sent to the database 127. Here, it is determined that the first step PR1 has ended, and the command value CM returns to the origin OP.

[0076] Next, as described above, in the lifting instruction step STU of the first step PR1, the original target step S is one step short. Therefore, in the lowering instruction step STD, the combustion margin verification step S20 is performed with one more step than the original target lowering instruction step STD. As described above, the premise of the initial target margin width TMW is to maintain its width. Therefore, it is preferable to maintain the total number of steps or the target margin width TMW between the initial target margin upper limit value TMUL and the target margin lower limit value TMLL. Therefore, as Figure 5 As shown, in the reduction command step STD of the second combustion margin confirmation pattern, combustion margin confirmation is performed by reducing the command value CM by one step from the initially set target margin lower limit value TMLL. When no combustion vibration occurs at the command value CM, which is reduced by one step from the target margin lower limit value TMLL, and the holding time is maintained for T1, it is determined that the combustion margin range under the command value CM has been confirmed, and the command value CM is set as the actual margin lower limit value AMLL. The specific combustion margin range confirmation steps in the reduction command step STD of the second combustion margin confirmation pattern are the same as those in the reduction command step STD of the first combustion margin confirmation pattern, except for the difference in the number of steps. If no combustion vibration occurs at the actual margin lower limit value AMLL and the holding time is maintained for T1, it is determined that the combustion margin range under the command value CM has been confirmed, the command value CM reaches the actual margin lower limit value AMLL, the holding time is maintained for T2 after the holding time T1 has elapsed, and the stable data 128 of the gas turbine 1 in the improvement command step STU is extracted. Therefore, step 2 is considered complete.

[0077] The second combustion margin confirmation pattern differs from the first combustion margin confirmation pattern at points where the number of steps differs in the increase command step STU and the decrease command step STD. That is, as described above, it is preferable to have the same number of steps in both the increase command step STU and the decrease command step STD, centered on the origin OP. Therefore, the position of the origin OP in the second combustion margin confirmation pattern is preferably set at the midpoint (midpoint) between the actual upper limit of the actual margin (AMUL) of the increase command step STU and the actual lower limit of the actual margin (AMLL) of the decrease command step STD. Therefore, after confirming the combustion margin range, the position of the origin OP moves from the initial setting to the position of the command value CM, which is reduced by one step in the direction of the decrease command value, and this position is set as the new origin NOP. If the extraction of stable data 128 in the decrease command step STD is completed, the second step PR2 ends, and the command value CM moves to the position of the new origin NOP at the predetermined release rate BRR during origin recovery. When the result of confirming the combustion margin range shows that the origin OP has moved to the new origin NOP, it is determined that an origin offset has occurred.

[0078] in addition, Figure 5 The second combustion margin confirmation pattern shown is implemented as follows: In the first step PR1, after the command value CM reaches the target margin upper limit value TMUL, it is impossible to maintain the holding time T1, and combustion vibration occurs within a time T0 that is shorter than the holding time T1. This implementation is the same as the case where combustion vibration occurs before reaching the command value CM, i.e., the target margin upper limit value TMUL, of the next step S from the step S immediately preceding the step S where combustion vibration occurs, and during the increase of the command value CM. That is, the command value CM at the step S where the combustion margin range immediately preceding the combustion vibration is confirmed is set as the actual margin upper limit value AMUL in the increase command step STU. At this time, the step of confirming the combustion margin range in the decrease command step STD of the second step PR2 is the same as... Figure 4 The first combustion margin confirmation pattern shown is the same, and the initial setting origin OP is preferably moved to the new origin NOP. Furthermore, in Figure 5 In the first step PR1, the increase command step STU, even if combustion vibration occurs at the command value CM which is reduced by more than two steps from the target margin upper limit value TMUL, the command value CM at the step S immediately preceding the step S where the combustion margin range of the combustion vibration occurred can be confirmed as the actual margin upper limit value AMUL. Furthermore, in the second step PR2, the decrease command step STD, a new number of steps is set in the direction of decreasing the command value, based on the difference between the target margin lower limit value TMLL and the target margin upper limit value TMUL of the increase command step STU where combustion vibration occurred, and the number of steps in the actual margin upper limit value AMUL, where the combustion margin range cannot be confirmed. Based on this new number of steps, the combustion margin is reduced by an amount equivalent to the number of steps not reached in the direction of decreasing the command value CM from the target margin lower limit value TMLL, and the combustion margin confirmation of the decrease command step STD is performed. In the reduction instruction step STD, when no combustion vibration occurs and the combustion margin range is confirmed, the instruction value CM at the final step S of the reduction instruction step STD is set to the actual margin lower limit value AMLL. The instruction value CM at the midpoint (the location of the midpoint) between the actual margin upper limit value AMUL and the actual margin lower limit value AMLL is set as the new origin NOP. At this time, it is also determined that an origin offset has occurred.

[0079] Third flammability margin confirmation pattern

[0080] Figure 6 The third combustion margin confirmation pattern shown is... Figure 5Similarly, in the second combustion margin confirmation pattern shown, the first step PR1 prioritizes increasing the command step STU. However, there is an example where, in both the increasing command step STU and the decreasing command step STD, at the point where combustion vibration occurs... Figure 5 The second combustion margin confirmation pattern shown is different. Furthermore, the third combustion margin confirmation pattern is different from the first and second combustion margin confirmation patterns. The total number of steps between the actual upper margin value AMUL and the actual lower margin value AMLL does not reach the total number of steps between the target upper margin value TMUL and the target lower margin value TMLL set at the initial time. The combustion margin range confirmation ends with a state where the number of steps is still not reached.

[0081] like Figure 6 As shown, in the STU (Standard Tube) of the promotion instruction process, and... Figure 5 Similarly, in the second combustion margin confirmation pattern shown, the STU (Upgrade Command) step also exhibits an example where, after the command value CM reaches the target margin upper limit value TMUL, combustion vibration occurs within a short period T0, which is less than the holding time T1. Therefore, in the case of this pattern, similar to... Figure 5 Similarly, the second combustion margin confirmation pattern shown is an example where combustion vibration occurs at the target margin upper limit TMUL set to the original target, the combustion margin range is not confirmed, and the lifting command step STU ends without reaching the target margin by one step. At this time, the command value CM is also lowered to the command value CM of the step S immediately preceding the combustion vibration, and the command value CM at step S is set as the actual margin upper limit AMUL. From the time the command value CM reaches the actual margin upper limit AMUL (the time point PF where combustion vibration occurred), the holding time is maintained for T2, and the stable data 128 of the gas turbine 1 is extracted. The first step PR1 is judged to be completed, and the command value CM returns to the origin OP position. The extracted stable data 128 is sent to the database 127.

[0082] In the reduction instruction step STD, similar to the reduction instruction step STD of the second combustion margin verification pattern, from the viewpoint of maintaining the target margin width TMW at the initial setting, it is preferable to perform the combustion margin verification step S20 with a number of steps S that is one more step than the original target number of steps, and maintain the total number of steps between the specified target margin upper limit value TMUL and the target margin lower limit value TMLL. Therefore, in Figure 5 In the reduction instruction step STD of the second combustion margin confirmation pattern shown, the combustion margin confirmation is performed by reducing the target margin lower limit value TMLL from the initial setting by one step in the direction of reducing the instruction value CM.

[0083] However, in Figure 6In the reduction command step STD of the third flammability margin confirmation pattern shown, an example is illustrated where flammability vibration occurs in step S before the command value CM reaches the target margin lower limit TMLL. Specifically, the flammability margin confirmation ends at the stage from the origin OP to three steps S in the reduction direction of the set value ST, and flammability vibration occurs during the process of reducing the command value CM to the next step S. In this pattern, in the reduction command step STD, in order to meet the target margin width TMW set initially, the flammability margin should be confirmed at the command value CM at a position where the command value CM has decreased by one step in the reduction direction of the command value CM from the step S of the target margin lower limit TMLL. However, as described above, the pattern is as follows: flammability vibration occurs in step S before reaching the target margin lower limit TMLL, making it impossible to confirm the flammability margin within the original target range. The flammability margin confirmation step S20 ends with multiple steps S that remain unconfirmed in the first step PR1's increase command step STU and the second step PR2's reduction command step STD, leaving the flammability margin range unconfirmed. In this embodiment, the setpoint ST is returned to the command value CM of the step S immediately preceding the combustion vibration, and this command value CM is set as the actual margin lower limit value AMLL in the command step STD. The setpoint ST is maintained for a holding time T2 from the time point CM when the actual margin lower limit value AMLL is returned (the time point PF when combustion vibration occurred), and after extracting the stability data 128 of the gas turbine 1, it is sent to the database 127. Thus, the second step PR2 of this pattern is determined to be complete.

[0084] like Figure 6As shown, in this embodiment, combustion vibration is generated in the lifting command step STU, and the combustion margin verification step S20 of the lifting command step STU ends with a state where the step S is not yet reached, and an upper limit value lower than the target margin upper limit value TMUL, i.e., the actual margin upper limit value AMUL, is set. Similarly, combustion vibration is generated in the lowering command step STD, and the combustion margin verification step S20 of the lifting command step STU ends with a state where the step S is not yet reached, and a lower limit value lower than the target margin lower limit value TMLL, i.e., the actual margin lower limit value AMLL, is set. That is, in this embodiment, the range of combustion margin confirmed (the width between the actual margin upper limit value AMUL and the actual margin lower limit value AMLL) is less than the total number of steps of the lifting command step STU and the lowering command step STD at the initial setting, thus ending the combustion margin verification step S20 within a range narrower than the target margin width TMW at the initial setting. Furthermore, in confirming the combustion margin range using this method, the initial setpoint OP is changed to the midpoint (the middle point) between the actual upper margin limit value AMUL and the actual lower margin limit value AMLL. In the third combustion margin confirmation pattern, after extracting the stable data 128 of the gas turbine 1 in the reduction command step STD, the command value CM moves to the new origin NOP position at the release rate BRR specified during origin recovery. At this time, it is also determined that an origin offset has occurred.

[0085] Fourth Flammability Confirmation Pattern

[0086] Figure 7 The fourth combustion margin confirmation pattern shown is for... Figure 5 The second combustion margin confirmation pattern shown is a variation of the first process PR1 and the second process PR2. That is, Figure 7 The fourth combustion margin confirmation pattern shown in the diagram executes the reduction command step STD in the first step PR1, prioritizing the increase command step STU. This is consistent with... Figure 5 The second flammability margin confirmation pattern shown is slightly different. In this embodiment, the fourth flammability margin confirmation pattern is shown where combustion vibration occurs during the reduction command step STD, and the number of unreached steps that prevent the flammability margin range from being confirmed ends the first step PR1 of the reduction command step STD. Furthermore, it is an example where, in the second step PR2 of the increase command step STU, the flammability margin range is confirmed after adding the unreached step S to the target margin upper limit value TMUL, and the flammability margin confirmation step S20 ends. Except for the difference in the priority order of the increase command step STU and the reduction command step STD, the other steps are the same. Figure 5The second combustion margin confirmation pattern shown is identical. In this pattern, in the reduction instruction step STD of the first step PR1, the instruction value CM of the step S immediately preceding the step S that generates combustion vibration is set as the actual lower margin limit value AMLL. In the increase instruction step STU of the second step PR2, the instruction value CM of the step S that is not reached by adding the target upper margin value TMUL is set as the actual upper margin value AMUL. The range of combustion margin confirmed in this pattern (the width between the actual upper margin value AMUL and the actual lower margin value AMLL) is the same as the target margin width TMW initially set.

[0087] and Figure 5 Similarly, in the second combustion margin confirmation pattern shown, the position of the origin OP in the fourth combustion margin confirmation pattern is preferably set at the midpoint (midpoint) between the actual margin lower limit value AMLL of the reduction command step STD and the actual margin upper limit value AMUL of the increase command step STU. Therefore, after confirming the combustion margin range, the origin OP moves from the initial set origin OP to the position where the command value CM is added in the direction of increasing the command value CM by a number not reaching the required step, and is set as the new origin NOP. If the extraction of stable data 128 in the increase command step STU is completed, the command value CM moves to the position of the new origin NOP at the release rate BRR when the origin is restored, and the second step PR2 ends. In addition, in the reduction command step STD, the command value CM of the step S immediately preceding the step S that generates combustion vibration is maintained at the actual margin lower limit value AMLL for a holding time T2 from the time point PF where combustion vibration occurred, and the stable data 128 of the gas turbine 1 is extracted and sent to the database 127. In the STU (Standard Tube) procedure, the stable data 128 of the gas turbine 1 extracted from the command value CM under the actual margin upper limit value AMUL is sent to the database 127.

[0088] Combustion Adjustment Overall Process

[0089] The following describes the overall process of combustion adjustment for a gas turbine, based on the various combustion margin confirmation patterns described above. As mentioned above, the combustion margin range is confirmed by selecting multiple GT loads, including the rated load, within the range of no load (0%) to rated load (100% GT load). In confirming the combustion margin range, considering factors such as the ease of generating combustion vibration, it is preferable to select either the GT load increase direction (setting the GT load at the beginning of combustion margin range confirmation to the minimum load and gradually increasing the GT load) or the GT load decrease direction (setting the GT load to the maximum load and gradually decreasing the GT load). Figure 8 This is a flowchart illustrating the overall combustion adjustment process to indicate the direction of increasing GT load. However, Figure 8The illustrated process flow is an example, and is not limited to this specific example. For example, Figure 8 In the example, the combustion load variable correction step S40 is performed after the combustion margin confirmation step S20, but the combustion load variable correction step S40 can be performed before the combustion margin confirmation step S20.

[0090] Figure 8 This refers to the overall process, including the combustion margin verification step S20, which describes the direction of increasing the GT load from a small GT load to a large GT load rated load (100%), based on multiple GT loads selected for combustion adjustment. Figure 3 When the combustion margin adjustment unit 130 shown performs the overall process of adjusting the combustion margin in the direction of increasing GT load, such as... Figure 8 As shown, the process consists of the following steps: a setpoint input step S10, which involves inputting various operating data and parameters for combustion adjustment; a combustion margin confirmation step S20, which operates the gas turbine 1 and confirms the combustion margin range of the combustion parameter PM; a setpoint change step S30, which, when an origin offset occurs in the combustion margin confirmation step S20, changes the setpoint of the combustion load variable CLP based on the new origin NOP; and a combustion load variable correction step S40, which corrects the maximum load of the planned maximum output by making the combustion load variable CLP at the planned maximum output the rated value (100%) by a maximum load correction step S50, and a setpoint conversion step S70 that corrects the corrected combustion load variable CLP by maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM. Alternatively, if no origin offset occurs in the combustion margin confirmation step S20, the setpoint change step S30 can be skipped and the process can proceed to the next combustion load variable correction step S40.

[0091] "Setup Input Procedures for Combustion Adjustment"

[0092] In the setpoint input process S10 involved in combustion adjustment, the GT load range, the priority order of combustion parameters PM, the setpoint of the combustion load variable CLP of combustion parameters PM, the target margin width TMW, the input rate BIR of the command value CM, the holding time T1 at each step S, the holding time T2 required for extracting stable data 128, the release rate BRR during origin recovery, the step width SW, and the number of steps SN are input to the input unit 121 and sent to the combustion margin confirmation process S20. As described above, the combustion margin confirmation process S20 adopts a bias input method that changes the command value CM of combustion parameters PM along the stepped steps S and confirms the combustion margin range. Figures 4 to 7As shown, the target margin width TMW of the combustion parameter PM is centered at the origin OP. The lifting command process STU and the lowering command process STD are distinguished by the same step width SW. For each process, the same step width SW, the number of steps SN, and the input rate BIR between steps are assigned as input data. Furthermore, in the lifting command process STU and the lowering command process STD, the step width SW of each step S in the lifting command process STU and the step width SW of each step S in the lowering command process STD can be the same width or different widths.

[0093] Combustion margin verification process

[0094] Figure 9 This describes the process flow for step S20, which verifies the combustion margin of combustion parameter PM. According to... Figure 9 The combustion margin confirmation process S20 shown begins the process of confirming the combustion margin range. In the combustion margin confirmation process S20, the priority order of the combustion parameters PM for combustion margin range confirmation is first set. Based on the priority order of the combustion parameters PM input by the input unit 121, the priority order of the combustion parameters PM for performing combustion margin range confirmation is set, and the combustion parameter PM with the first priority order is set as PM1, the combustion parameter PM with the second priority order is set as PM2, and the combustion parameter PM with the third priority order is set as PM3 (S21).

[0095] Alternatively, priority pattern data stored in the database 127 of the automatic combustion adjustment unit 120 for the purpose of confirming the combustion margin range can be retrieved, and the priority order of the combustion parameter PM can be set. The priority pattern data can be, for example, a database capable of automatically selecting the priority order of the combustion parameter PM based on the combustion load variable CLP. Furthermore, the priority pattern data may include data that sets the priority order of the increase command step STU or decrease command step STD for the set combustion parameter PM based on the combustion load variable CLP.

[0096] In the combustion parameter priority setting process S21, if the priority allocation of combustion parameter PM is completed, the gas turbine load (GT load) used for performing combustion margin range confirmation is set (S22). As described above, multiple GT loads are set within the range of 0 to 100% of the GT load. The selected GT load is input to the input unit 121. 100% GT load corresponds to the planned maximum output or rated output, and 0% GT load corresponds to the output when there is no load. In addition, in the confirmation of the combustion margin range, it is preferable to perform the confirmation of the combustion margin range with the same GT load until the confirmation of the combustion margin range of each of the combustion parameters (pilot ratio PL, top cap ratio TH, bypass valve opening BV) is completed.

[0097] In the GT load setting process S22, if a GT load for confirming the combustion margin range is set, then the combustion margin confirmation of the first priority combustion parameter PM1 is performed (S23). The specific steps and implementation content of confirming the combustion margin range of the first priority combustion parameter PM1 are as follows: Figure 4 or Figure 5 or Figure 7 The following pattern is executed (S23): the first combustion margin confirmation pattern, the second combustion margin confirmation pattern, or the fourth combustion margin confirmation pattern. In the combustion margin confirmation of the first combustion parameter PM1, if no combustion vibration occurs in either the increase command step STU or the decrease command step STD, the combustion margin confirmation of the first combustion parameter PM1 ends, the combustion margin confirmation step S20 is determined to continue (S23), and the process proceeds to the next step (S25). Furthermore, the position of the origin OP1 of the first combustion parameter PM1 is maintained. In the following description, the origin OP of the first combustion parameter PM1, the second combustion parameter PM2, and the third combustion parameter PM3 are represented by OP1, OP2, and OP3, the new origin NOP is represented by NOP1, NOP2, and NOP3, and the target margin width TMW is represented by TMW1, TMW2, and TMW3.

[0098] In confirming the combustion margin range of the first combustion parameter PM1, if combustion vibration occurs in either the increase instruction step STU or the decrease instruction step STD, it is determined whether the specified combustion margin width, i.e., the target margin width TMW1, can be ensured by offsetting the origin (S24). If it is determined that the specified combustion margin range of the first combustion parameter PM1 can be ensured, the combustion margin confirmation of the first combustion parameter PM1 ends, the combustion margin confirmation step S20 is determined to continue (S24), and proceeds to the next step (S25).

[0099] In this embodiment, the origin offset of the first combustion parameter PM1 is generated, so the position of the origin OP1 of the first combustion parameter PM1 moves to the new origin NOP1. The stable data 128 of the gas turbine 1 with the first combustion parameter PM1 and the position data of the new origin NOP1 are extracted and sent to the database 127 (S24).

[0100] Next, when the combustion margin verification process S20 is determined to be continuous (S24), the process proceeds to verify the combustion margin range of the second combustion parameter PM2. Additionally, in Figure 6In the case of the third combustion margin confirmation pattern shown, the specified combustion margin width, i.e., the target margin width TMW1, cannot be determined. However, if it is determined that even a margin width narrower than the target margin width TMW1 can maintain a range without combustion vibration, then it is determined that the combustion margin width required for the continuous and stable operation of the gas turbine 1 is ensured. In this case, the confirmation of the combustion margin range of the first combustion parameter PM1 ends, the combustion margin confirmation process S20 is determined to continue (S24), and proceeds to the next process (S25). When it is determined that the combustion margin width required for the stable operation of the gas turbine 1 with the first combustion parameter PM1 cannot be ensured, the continuation of the combustion margin confirmation process S20 is determined to be impossible, and the combustion margin confirmation process S20 ends (S24).

[0101] If the confirmation of the combustion margin range of the first combustion parameter PM1 is completed, and the combustion margin confirmation process S20 is determined to be ongoing, then the combustion margin confirmation of the second combustion parameter PM2 is executed (S25). Similar to the first combustion parameter PM1, the specific implementation steps and work content for confirming the combustion margin range of the second combustion parameter PM2 are as follows: Figure 4 or Figure 5 or Figure 7 The pattern shown is any one of the first, second, or fourth combustion margin confirmation patterns. Regarding the second combustion parameter PM2, when no combustion vibration occurs in either the increase command step STU or the decrease command step STD, the combustion margin confirmation of the second combustion parameter PM2 ends, the combustion margin confirmation step S20 is determined to continue (S25), and proceeds to the next step (S27). Furthermore, at this time, the position of the origin OP2 of the second combustion parameter PM2 is maintained.

[0102] In confirming the combustion margin range of the second combustion parameter PM2, if combustion vibration occurs in either the increase command step STU or the decrease command step STD of the second combustion parameter PM2, the origin of the second combustion parameter PM2 is offset, and it is determined whether the specified combustion margin range, i.e., the target margin width TMW2, can be ensured (S26). If it is determined that the specified target margin width TMW2 of the second combustion parameter PM2 can be ensured, the confirmation of the combustion margin range of the second combustion parameter PM2 ends, and the combustion margin confirmation step S20 is determined to continue (S26).

[0103] However, in this implementation, an origin shift occurs for the second combustion parameter PM2. Therefore, the position of the origin OP2 of the second combustion parameter PM2 moves to a new origin NOP2, and the process returns to the step (S23) (S26) of confirming the combustion margin of the first priority combustion parameter PM, i.e., the first combustion parameter PM1. The reason for returning to the step (S23) of confirming the combustion margin of the first combustion parameter PM1 is that in the step (S25) of confirming the combustion margin of the second combustion parameter PM2, an origin shift occurs for the second combustion parameter PM2, and the position of the origin OP2 of the second combustion parameter PM2 moves to the new origin NOP2. This changes the combustion conditions of the burner 3 from which the stable data 128 of the first combustion parameter PM1 has been extracted. Furthermore, an origin shift occurs for the second combustion parameter PM2, and therefore the position of the origin OP2 moves to the new origin NOP2. This new origin NOP2, along with the stable data 128 of the gas turbine 1 from which the second combustion parameter PM2 has been extracted, is sent to the database 127.

[0104] Additionally, when confirming the combustion margin range of the second combustion parameter PM2, step (S25) is... Figure 6 When verifying the third combustion margin pattern as shown, it is impossible to ensure the specified combustion margin width, i.e., the target margin width TMW2, but it is determined that a margin width narrower than the target margin width TMW2 can be maintained without causing combustion vibration. In this case, it is determined that the combustion margin width required for the continuous and stable operation of the gas turbine 1 has been ensured, and the verification of the combustion margin range of the second combustion parameter PM2 ends, and the combustion margin verification process S20 is determined to continue (S26). In this embodiment, for the same reason as above, the origin of the second combustion parameter PM2 is shifted, so the position of the origin OP2 of the second combustion parameter PM2 moves to the new origin NOP2, and returns to the step (S23) (S26) of verifying the combustion margin range of the first priority combustion parameter, i.e., the first combustion parameter PM1. When it is determined that the specified combustion margin range of the second combustion parameter PM2 cannot be ensured, the continuation of the combustion margin verification process S20 is determined to be impossible, and the combustion margin verification process S20 ends (S26).

[0105] When the combustion margin confirmation of the second combustion parameter PM2 is completed and the process returns to the step of confirming the combustion margin of the first combustion parameter PM1 (S23), the confirmation of the combustion margin range of the first combustion parameter PM1 is performed again, and the presence or absence of combustion vibration is confirmed again (S23). The steps after performing the combustion margin confirmation of the first combustion parameter PM1 (S23) are the same as the steps described above.

[0106] If the combustion margin confirmation of the second combustion parameter PM2 is completed, and the combustion margin confirmation process S20 is determined to be continuous, then the combustion margin confirmation of the third combustion parameter PM3 (S27) is executed. The specific implementation steps and work content of the combustion margin confirmation of the third combustion parameter PM3 are as follows: Figure 4 or Figure 5 or Figure 7 The pattern shown is one of the first, second, or fourth combustion margin confirmation patterns. Regarding the third combustion parameter PM3, when no combustion vibration occurs in either the STU (increase command) or STD (decrease command) processes, the confirmation of the combustion margin range of the third combustion parameter PM3 ends, the combustion margin confirmation process S20 is determined to continue (S27), and proceeds to the next process (S29). The position of the origin OP3 of the third combustion parameter PM3 is maintained, and the stable data 128 of the gas turbine 1 with the third combustion parameter PM3 is extracted and sent to the database 127.

[0107] In the combustion margin confirmation of the third combustion parameter PM3, if combustion vibration occurs in either the STU (Increase Command) step or the STD (Decrease Command) step, it is determined whether the specified combustion margin range, i.e., the target margin width TMW3, can be ensured by offsetting the origin (S28). If it is determined that the specified target margin width TMW3 of the third combustion parameter PM3 can be ensured, the combustion margin confirmation of the third combustion parameter PM3 ends, and the combustion margin confirmation step S20 is determined to continue (S28).

[0108] In this embodiment, similar to the embodiment where an origin shift occurred during the combustion margin confirmation of the second combustion parameter PM2 described above, an origin shift occurred for the third combustion parameter PM3. Therefore, the position of the origin OP3 of the third combustion parameter PM3 moved to a new origin NOP3, and the process returned to the step (S23) (S26) of confirming the combustion margin of the first combustion parameter PM1. The reason for returning to the step (S23) of confirming the combustion margin of the first combustion parameter PM1 is the same as when an origin shift occurred for the second combustion parameter PM2. Furthermore, the stability data 128 of the gas turbine 1 with the third combustion parameter PM3 extracted, along with the position data of the new origin NOP3, was sent to the database 127.

[0109] Additionally, when the step (S27) confirms the combustion margin of the third combustion parameter PM3 is Figure 6When confirming the third combustion margin pattern as shown, it is impossible to ensure the specified combustion margin width, i.e., the target margin width TMW3. However, if it is determined that a margin width narrower than the target margin width TMW3 can be maintained without causing combustion vibration, it is determined that the combustion margin width required for the continuous and stable operation of the gas turbine 1 is ensured, and the combustion margin confirmation of the third combustion parameter PM3 ends, and the combustion margin confirmation process S20 is determined to continue (S28). In this embodiment, for the same reason as above, the origin of the third combustion parameter PM3 is shifted, so the position of the origin OP3 of the third combustion parameter PM3 moves to the new origin NOP3, and returns to the step of confirming the combustion margin range of the first combustion parameter PM1 (S23) (S28). When it is determined that the specified combustion margin range of the third combustion parameter PM3 cannot be ensured, the continuation of the combustion margin confirmation process S20 is determined to be impossible, and the combustion margin confirmation process S20 ends (S28).

[0110] When the combustion margin confirmation of the third combustion parameter PM3 ends (S28) and the process returns to the step of confirming the combustion margin of the first combustion parameter PM1 (S23), the confirmation of the combustion margin range of the first combustion parameter PM1 is performed again, and the presence or absence of combustion vibration is confirmed again (S23). The execution steps for confirming the combustion margin of the first combustion parameter PM1 are the same as those described above.

[0111] If the combustion margin confirmation of the third combustion parameter PM3 ends (S28), proceed to the next step (S29) and determine whether the GT load has reached the maximum load (S29). If the GT load has not reached the maximum load, return to the GT load setting step S22 and set the next GT load according to the initial GT load (S22). Based on the new GT load, repeat the combustion margin confirmation of the combustion parameters (S23-S29). If the GT load reaches the maximum load, the combustion margin confirmation step S20 ends (S29), and proceed to the next step. Figure 8 The setpoint change process S30 is shown. When it is determined that the specified combustion margin range of the third combustion parameter PM3 cannot be ensured, the combustion margin verification process S20 is determined to be unacceptable, and the combustion margin verification process S20 ends (S28). Furthermore, Figure 9 The process shown is the combustion margin confirmation step S20 in the direction of increasing GT load. However, in the case of the combustion margin confirmation step S20 in the direction of decreasing GT load, it is determined whether the GT load has reached the minimum load (S29), the next GT load is set (S22), and the combustion margin confirmation step S20 is executed.

[0112] Combustion Load Variable Correction Procedure

[0113] like Figure 8As shown, the combustion load variable correction process S40 is a process required to correct the setpoint ST representing the relationship between the combustion parameter PM and the combustion load variable CLP so that the gas turbine 1 outputs the planned maximum output MOP at the rated value (100%) of the combustion load variable CLP. Specifically, the combustion load variable correction process S40 consists of the following steps: a maximum load correction process S50, which corrects the combustion load variable CLP to the rated value (100%) at the planned maximum output MOP of the gas turbine 1, based on the premise of maintaining an appropriate relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM; and a setpoint conversion process S70, which converts the setpoint of the combustion load variable CLP according to the corrected combustion load variable CLP, in a manner that maintains the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM.

[0114] Instead of the gas turbine inlet temperature GTIT, the combustion load variable CLP, expressed by the following formula, is used to control the GT load. Specifically, the GT load (GT output) is controlled by combustion parameters PM, namely pilot ratio PL, top cap ratio TH, and bypass valve opening BV, etc., and each combustion parameter PM is expressed as a function of the combustion load variable CLP. The combustion load variable CLP of the combustion parameter PM can be calculated by the following [Equation 1].

[0115] [Equation 1]: Combustion load variable CLP (%) = [(Turbine output - No-load equivalent output) / (Planned maximum output - No-load equivalent output)] × 100

[0116] Here, the planned maximum output (MOP) refers to the turbine output (gas turbine output) at the planned output or rated output, and the no-load equivalent output (NOP) refers to the turbine output at no load. When the turbine output is the planned maximum output (MOP) or rated output, the combustion load variable (CLP) is the rated value (100%), and when the turbine output is the no-load equivalent output (NOP), the combustion load variable (CLP) is equivalent to 0 (%).

[0117] During the commissioning of the gas turbine or the restart after a periodic inspection, a slight deviation sometimes occurs in the relationship between the gas turbine inlet temperature GTIT, required for proper combustion control of the burner 3, and the combustion load variable CLP. As mentioned above, the combustion adjustment of the gas turbine 1 is controlled by the combustion parameter PM, which is a function of the combustion load variable CLP. Therefore, deviations in the combustion load variable CLP relative to the gas turbine inlet temperature GTIT can sometimes lead to combustion vibrations and negatively impact combustion adjustment. Therefore, to effectively utilize the stable data 128 obtained in the combustion margin verification step S20, the results of the combustion margin verification step S20 should accurately reflect the setpoint representing the relationship between the combustion parameter PM and the combustion load variable CLP. To achieve stable operation, it is preferable to correct the combustion load variable CLP.

[0118] refer to Figures 10A to 10C and Figures 11A to 11C The basic concept of correcting the setpoints of the combustion parameter PM and the combustion load variable CLP for combustion control of burner 3 is explained. To perform proper combustion control of gas turbine 1, it is necessary to maintain the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, while simultaneously setting the relationship between the combustion parameter PM and the combustion load variable CLP to output the planned maximum load (planned maximum output) MOP at the rated value (100%) of the combustion load variable CLP. The combustion control device 100 is set such that the combustion load variable CLP corresponding to the planned maximum output MOP is at its rated value (100%). Therefore, even if the setpoint of the combustion load variable CLP is set below or above its rated value, proper combustion control will not be performed, which would adversely affect the control of gas turbine 1. That is, by setting the combustion load variable correction procedure S40 and correcting the deviation of the combustion load variable CLP during the initial setting during trial operation or restart after periodic checks, the learning circuit described later can operate appropriately, and the gas turbine 1 can continue to operate stably for a long time.

[0119] Figures 10A to 10C The concept of a correction mechanism is shown when the gas turbine 1 reaches the planned maximum output MOP at a position where the combustion load variable CLP has not reached the rated value (100%) (Example 1). Figure 10A The graph shows the relationship between the combustion parameter PM and the combustion load variable CLP in Example 1, with the vertical axis representing the combustion parameter PM and the horizontal axis representing the combustion load variable CLP. Figure 10B The graph shows the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP in Example 1, with the vertical axis representing the gas turbine inlet temperature GTIT and the horizontal axis representing the combustion load variable CLP. Figure 10CThis graph illustrates the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM in Example 1, with the vertical axis representing the combustion parameter PM and the horizontal axis representing the gas turbine inlet temperature GTIT. Additionally, in Figures 10A to 10C In general, the curve [I-1] and straight line [I-1] represented by dashed lines are the data immediately after being acquired in the combustion margin verification process S20. The curve [II-1] and straight line [II-1] represented by dotted lines are the data after correction in the maximum load correction process S50. The curve [III] and straight line [III] represented by solid lines are the data after conversion in the setpoint conversion process S70.

[0120] Figures 11A to 11C The concept of a correction mechanism is shown when the gas turbine 1 reaches the planned maximum output MOP (Example 2) at a position where the setpoint ST of the combustion load variable CLP exceeds the rated value (100%). Figure 11A The graph shows the relationship between the combustion parameter PM and the combustion load variable CLP in Example 2, with the vertical axis representing the combustion parameter PM and the horizontal axis representing the combustion load variable CLP. Figure 11B The graph shows the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP in Example 2, with the vertical axis representing the gas turbine inlet temperature GTIT and the horizontal axis representing the combustion load variable CLP. Figure 11C This graph illustrates the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM in Example 2, with the vertical axis representing the combustion parameter PM and the horizontal axis representing the gas turbine inlet temperature GTIT. Additionally, in Figures 11A to 11C In general, the curve [I-2] and straight line [I-2] represented by dashed lines are the data immediately after being acquired in the combustion margin verification process S20. The curve [II-2] and straight line [II-2] represented by dotted lines are the data after correction in the maximum load correction process S50. The curve [III] and straight line [III] represented by solid lines are the data after conversion in the setpoint conversion process S70.

[0121] refer to Figures 10A to 10C Let's illustrate with example 1. Figure 10ACurve [I-1] shows the setpoint representing the relationship between the combustion parameter PM and the combustion load variable CLP obtained in the combustion margin confirmation process S20. In this embodiment, curve [I-1] shows an example where the combustion parameter PM decreases as the combustion load variable CLP increases with the increase of the GT load. The setpoint represented by curve [I-1] represents the optimal setpoint of the combustion load variable CLP for the current gas turbine inlet temperature GTIT of the unit, which is the most appropriate setpoint for combustion control that can produce combustion vibration. However, in curve [I-1], the setpoint of the combustion load variable CLP under the planned maximum output (GT load 100%) MOP is not the rated value (100%), but reaches the planned maximum output (GT load 100%) MOP at a position Y (%) lower than the rated value (100%).

[0122] On the other hand, the combustion control device 100 is set to make the combustion load variable CLP a rated value (100%) under the planned maximum output (GT load 100%) MOP. Figure 10A Curve [III] shown represents the setpoints that indicate the relationship between the combustion parameter PM programmed into the combustion control device 100 and the combustion load variable CLP. If the nominal value (100%) of the combustion parameter PM shown on the horizontal axis deviates from the Y (%) coordinate axis, it will adversely affect the combustion control of the gas turbine 1. Therefore, it is necessary to maintain the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, and to ensure that... Figure 10A The relationship between curves [I-1] and curve [III] is consistent with the correction mechanism for the combustion load variable CLP, so as to maintain the same relationship as the set value programmed into the combustion control device 100. In addition, curve [II-1] shows the relationship between the combustion parameter PM and the combustion load variable CLP before the set value conversion, which will be described later, and is consistent with curve [I-1].

[0123] Figure 10B This will indicate Figure 10A The setpoints for the relationship between the combustion parameter PM and the combustion load variable CLP are replaced with a graph showing the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, and then compared. Figure 10A The relationship between curves [I-1], [II-1], and [III] shown can be replaced by the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, which is equivalent to... Figure 10B The lines [I-1], [II-1], and [III] are shown. Figure 10B The relationships between the gas turbine inlet temperature GTIT and the combustion load variable CLP for the straight lines [I-1], [II-1] and [III] shown are all proportional.

[0124] Figure 10C This will indicate Figure 10A The setpoints showing the relationship between combustion parameter PM and combustion load variable CLP are replaced with a graph showing the relationship between combustion parameter PM and gas turbine inlet temperature GTIT, and then compared. Figure 10A The relationship between curves [I-1], [II-1], and [III] shown can be replaced by the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, which is equivalent to... Figure 10C The curves shown are [I-1], [II-1], and [III].

[0125] Before detailing the correction mechanism for the combustion load variable CLP, a general overview of the correction mechanism is provided below. The meaning of the correction based on [Equation 2] in the specific correction mechanism described later represents maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, and correcting the relationship between GT load and the combustion load variable CLP. Figure 10B In this context, a correction mechanism is used to adjust the position of point P1-1 in the direction of the difference (deviation) between the combustion load variable Y (%) at the maximum output temperature TMX (the gas turbine inlet temperature GTIT corresponding to the planned maximum output) and the position of point P3 at the rated value (100%) of the combustion load variable CLP, which is used to reduce the deviation from the initial set value, and to make the straight line [I-1] consistent with the straight line [III]. This correction mechanism replaces the data of the straight line [I-1] with the data of the straight line [III], thereby eliminating the deviation of the initial setting of the combustion load variable CLP.

[0126] The following [Equation 2] provides the following correction mechanism: Figure 10BIn this process, the straight line [I-1] is moved to the position of the straight line [III] and the straight line [I-1] is corrected to the straight line [III] until the position of point P1-1 under the maximum output temperature TMX coincides with the position of point P3. By performing the correction mechanism based on [Equation 2], the straight line [I-1] is located at the position of the nominal value (100%) of the combustion load variable CLP and overlaps with the straight line [III] passing through point P3 representing the maximum output temperature TMX, and is converted into the straight line [II-1] for the combustion load variable CLP in the range of 0 to Y (%). When the straight line [I-1] is corrected and converted into the straight line [II-1], the position of point P1-1 of the straight line [I-1] is moved to point P2-1 on the straight line [II-1] when the combustion load variable CLP is Y (%), and the gas turbine inlet temperature GTIT when the combustion load variable CLP is Y (%) decreases from the inlet temperature TMX to the inlet temperature TMX1 (the inlet temperature when the corrected combustion load variable CLP is Y (%)). That is, it represents Figure 10A The curve [I-1] showing the relationship between the combustion parameter PM and the combustion load variable CLP is replaced with... Figure 10B The straight line [II-1] shown represents a decrease in the gas turbine inlet temperature GTIT for the combustion load variable CLP.

[0127] If in Figure 10C Observing this relationship, the combustion parameter PM and gas turbine inlet temperature GTIT shown in curve [I-1] are corrected to curve [II-1]. That is, after the combustion margin confirmation process S20 is completed, curve [I-1] with the set value that enables appropriate combustion control has the same relationship between the combustion parameter PM and gas turbine inlet temperature GTIT as curve [III]. However, the corrected curve [II-1] has a relatively lower gas turbine inlet temperature GTIT compared to the target curve [III].

[0128] and, Figure 10A The curve shown [I-1] and Figure 10B The position of point P11-1, corresponding to any combustion load variable CLP and X1 (%) on the straight line [I-1] shown, is adjusted by the aforementioned correction mechanism. Figure 10A Regarding the relationship between the combustion parameter PM, curve [II-1] is consistent with curve [I-1] and shows no difference; therefore, the position of point P12-1 is also consistent with point P11-1. On the other hand, in relation to... Figure 10BRegarding the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, point P11-1 is moved to point P12-1 on the straight line [II-1] when the combustion load variable CLP is X1 (%). That is, even after correction, the relationship between the combustion load variable CLP and the combustion parameter PM remains unchanged, but the gas turbine inlet temperature GTIT decreases under the same combustion load variable CLP after correction. As mentioned above, the correction mechanism relies on maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, which is not maintained. Therefore, in order to satisfy the condition of maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, other correction mechanisms are needed besides the aforementioned mechanism.

[0129] As described above, to perform proper combustion control of gas turbine 1, it is necessary to maintain the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, while simultaneously setting the relationship between the combustion parameter PM and the combustion load variable CLP to output the planned maximum load (planned maximum output) MOP at the rated value (100%) of the combustion load variable CLP. Preferably, a correction mechanism is applied according to its purpose. From this perspective, the selected mechanism through correction... Figure 10C The curve shown is [II-1] ( Figure 10B The straight line (II-1) does not satisfy the condition for maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, and it is also necessary to make Figure 10C The curve shown is [II-1] ( Figure 10B The straight line [II-1] and the curve [III] Figure 10B The straight line (III) is consistent with the correction mechanism.

[0130] Specifically, in Figure 10C In this process, the combustion parameter PM on the vertical axis of curve [II-1] is maintained so that the gas turbine inlet temperature GTIT on the horizontal axis is converted from being consistent with the inlet temperature TMX1 to being consistent with the inlet temperature TMX (simply sliding the setpoint of the combustion load variable CLP axially towards the horizontal axis) (setpoint conversion process S70). By executing the setpoint conversion process S70, in Figure 10C In the middle, without changing the combustion parameter PM, the point P2-1 on the curve [II-1] representing the planned maximum output is moved to the point P3 on the curve [III]. The point P12-1 on the curve [II-1] with any combustion load variable CLP being X1 (%) is... Figure 10A The curve is moved to point P13 on curve [III] where the combustion load variable CLP is X2 (%). Finally, curve [II-1] is aligned with curve [III], thus eliminating the deviation from the initial set value.

[0131] That is, according to [Equation 2], the preferred calibration mechanism is the maximum load calibration process S50, which is a calibration mechanism that sets the combustion load variable CLP to a rated value (100%) with the output planned maximum load MOP, and the set value conversion process S70, which is a calibration mechanism that maintains the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM.

[0132] Through the aforementioned calibration mechanism, while maintaining the relationship between the gas turbine inlet temperature GTIT and the combustion parameter PM, the setpoints of the combustion parameter PM and the combustion load variable CLP are calibrated to output the planned maximum load (planned maximum output) MOP at the rated value (100%) of the combustion load variable CLP. That is, in the combustion margin confirmation step S20, the combustion margin range is confirmed, and a setpoint suitable for appropriate combustion control is selected. However, the aforementioned calibration mechanism eliminates the adverse effects on combustion control caused by deviations from the initial setpoints of the combustion load variable CLP (rated value, 100%) that outputs the planned maximum load (planned maximum output) MOP. Through calibration during initial setting, long-term stable operation is possible even during the stable operation phase.

[0133] The concept of the correction mechanism described above is an explanation of Example 1, but the same concept can also be applied to Example 2. For example... Figure 11A As shown, Example 2 illustrates the situation where the gas turbine 1 reaches its planned maximum output when the set value of the combustion load variable CLP exceeds the rated value (100%), i.e., when the combustion load variable CLP is Z (%). Figure 11A Curve [I-2] illustrates the relationship between the combustion parameter PM, obtained in the combustion margin verification step S20, and the setpoint of the combustion load variable CLP. However, in curve [I-2], the setpoint of the combustion load variable CLP under the planned maximum output (GT load 100%) MOP is not the rated value (100%). The planned maximum output (GT load 100%) is reached at a position Z (%) where the combustion load variable CLP exceeds the rated value (100%), which differs from Example 1. Curve [II-2] shows the relationship between the combustion parameter PM and the combustion load variable CLP after the maximum load correction step S50 corrects the combustion load variable CLP.

[0134] Figure 11B It is Figure 11A The relationship between curves [I-2], [II-2], and [III] is replaced with a graph showing the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, and then compared. Figure 11AThe relationship between curves [I-2], [II-2], and [III] shown can be replaced by the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, which is equivalent to... Figure 11B The lines [I-2], [II-2], and [III] are shown. Furthermore, Figure 11C It is Figure 11A The relationship between curves [I-2], [II-2], and [III] is replaced with a graph showing the relationship between combustion parameter PM and gas turbine inlet temperature GTIT, and then compared. Figure 11A The relationship between curves [I-2], [II-2], and [III] shown can be replaced by the relationship between the gas turbine inlet temperature GTIT and the combustion load variable CLP, which is equivalent to... Figure 11C The curves shown are [I-2], [II-2], and [III].

[0135] In Example 2, the correction mechanism replaces curves [I-1] and [II-1] from Example 1 with curves [I-2] and [II-2], and straight lines [I-1] and [II-1] with straight lines [I-2] and [II-2]. Furthermore, by replacing points P1-1, P2-1, P11-1, and P12-1 with points P1-2, P2-2, P11-2, and P12-2, the content described in Example 1 can also be applied to Example 2. However, in the case of Example 1, the gas turbine inlet temperature GTIT decreased by correcting the data obtained in the combustion margin verification process S20. To maintain the decreased gas turbine inlet temperature GTIT at the original inlet temperature, a correction mechanism that corrects during setpoint conversion is applied. On the other hand, in the case of Example 2, the gas turbine inlet temperature GTIT increases instead of being corrected. Therefore, in order to maintain the increased gas turbine inlet temperature GTIT at the original gas turbine inlet temperature, a correction is made during the setpoint conversion, which is different from the correction mechanism in Example 1.

[0136] The following is a detailed explanation of the calibration mechanism.

[0137] The following [Equation 2] is a formula for calculating the combustion load variable CLP that is corrected by the combustion load variable correction mechanism for the deviation of the initial set value of combustion parameter PM and combustion load variable CLP in [Equation 1], and is composed of the correction mechanism of combustion load variable correction process S40 (maximum load correction process S50, set value conversion process S70).

[0138] [Equation 2]: Combustion load variable CLP (%) = [(Turbine output (actual output) - No-load equivalent output) / (Planned maximum output × First correction factor × Second correction factor - No-load equivalent output)] × 100

[0139] The first correction factor 156a and the second correction factor 157a are correction factors set in the combustion load variable correction procedure S40 described later. Furthermore, the concepts of planned maximum output and no-load equivalent output are the same as in [Equation 1].

[0140] The first correction factor, 156a, is used to correct the deviation between the initial set values ​​of the combustion parameter PM and the combustion load variable CLP. The second correction factor, 157a, is used after the gas turbine 1 has entered stable operation to correct the deviation between the set values ​​of the combustion parameter PM and the combustion load variable CLP caused by the deterioration of the gas turbine. The calibration mechanism corrects the combustion load variable CLP by multiplying the planned maximum output MOP by the first correction factor 156a and the second correction factor 157a.

[0141] use Figure 12 and Figure 13 The correction mechanism in the combustion load variable correction process S40 is explained in detail. Figure 12 This is a flowchart illustrating the operation of the combustion load variable correction process S40. Figure 13 The control logic diagram of the calculated and corrected combustion load variable CLP shown in Equation 2 is presented, and the structure of the combustion load variable correction unit 134, which constitutes the correction mechanism of the combustion load variable correction process S40, is shown.

[0142] Equation 2 is a formula for calculating the combustion load variable CLP, which includes the first correction factor 156a. However, when the turbine output is consistent with the planned maximum output MOP or the rated output, the combustion load variable CLP shown in Equation 2 is consistent with Equation 1. In this case, the first correction factor 156a in Equation 2 is set to the initial value of "1".

[0143] Figure 12 The combustion load variable correction process S40 shown consists of the following processes: a maximum load correction process S50, which corrects the combustion load variable CLP shown in Equation 2 in such a way that the combustion load variable CLP for the planned maximum output MOP becomes the rated value (100%); and a setpoint conversion process S70, which converts the setpoint of the combustion load variable CLP based on the corrected combustion load variable CLP in such a way that the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT is maintained.

[0144] like Figure 12As shown, the combustion load variable correction process S40 calculates the deviation between the turbine output sent from the input unit 121 and the corrected planned maximum output output from the second maximum load multiplier 157 (described later) (S51). Next, a proportional-integral operation is performed on the calculated deviation to calculate an intermediate correction value 151a (S52). A predetermined value α is added to the calculated intermediate correction value 151a to calculate the second correction value 152a (S53). The predetermined value α is usually selected as 1.0. After the maximum load correction process S50 is started, it is determined whether a predetermined time has elapsed (S54). If it is determined that the predetermined time has not elapsed, the second correction coefficient 157a shown in [Equation 2] is updated to the second correction value 152a (S55). The combustion load variable CLP shown in [Equation 2] is calculated based on the updated second correction coefficient 157a (S56), and the set value of the combustion load variable CLP of each combustion parameter PM is sent to the control unit 110 (S57). Based on the set value of the corrected combustion load variable CLP, a control signal is sent from the control unit 110 to the gas turbine 1. Based on the set value of the corrected combustion load variable CLP, the deviation between the actual output, i.e., the turbine output, and the planned maximum output is calculated (S51). The calculation of the deviation between the turbine output and the corrected planned maximum output (S51), the calculation of the intermediate correction value 151a and the second correction value 152a based on the deviation (S52, S53), the updating of the second correction coefficient 157a to the second correction value 152a (S55), and the calculation of the corrected combustion load variable CLP (S56) and its transmission to the control unit 110 (S57) are repeated until a predetermined time has elapsed. By repeating these steps, the deviation between the turbine output and the planned maximum output gradually decreases.

[0145] On the other hand, if a predetermined time has elapsed, a combustion load variable correction command 161 is sent from the correction command unit 160 (S60). When the combustion load variable correction command 161 is sent, the switch 154 switches from the OFF state to the ON state, and the second correction value 152a is input to the switch 154 (S61). The switch 154 switches back to the OFF state within a short time, and the second correction value 152a is replaced by the first correction value 154a (S62). The second correction value 152a is reset to its initial value (S62). The first correction coefficient 156a shown in [Equation 2] is updated to the first correction value 154a (S63). Through this process, the combustion load variable CLP shown in [Equation 2] is obtained as the corrected setpoint value of the combustion load variable CLP that enables the planned maximum output at the rated value (100%).

[0146] The setpoint conversion process S70 corrects the gas turbine inlet temperature GTIT using the first correction coefficient 156a based on the corrected combustion load variable CLP in a manner that maintains the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT, and converts the setpoint that sets the relationship between the combustion parameter and the combustion load variable CLP.

[0147] If the combustion load variable correction process S40, which consists of the maximum load correction process S50 and the set value conversion process S70, is completed, the deviation of the initial set value of the combustion parameter PM and the corresponding combustion load variable CLP is eliminated, thereby enabling appropriate combustion control of the burner 3.

[0148] Next, according to Figure 13 The structure and control logic of the combustion load variable correction unit 134 are explained. For example... Figure 13 As shown, the planned maximum output calculation mechanism, i.e., function generator 141, calculates the planned maximum output based on the measured values ​​of the intake air temperature, intake air flow rate, and IGV opening command value. Similarly, the no-load equivalent output calculation mechanism, i.e., function generator 142, calculates the no-load equivalent output based on the measured values ​​of the intake air temperature, intake air flow rate, and IGV opening command value. Divider 147 calculates the atmospheric pressure ratio by dividing the measured intake pressure by the standard atmospheric pressure. In multiplier 148, the planned maximum output calculated by function generator 141 is multiplied by the atmospheric pressure ratio calculated by divider 147 to calculate the planned maximum output taking into account the atmospheric pressure ratio. Multiplier 149 multiplies the no-load equivalent output calculated by function generator 142 by the atmospheric pressure ratio calculated by divider 147 to calculate the no-load equivalent output taking into account the atmospheric pressure ratio. Subtractor 145 subtracts the turbine output sent from input unit 121 from the no-load equivalent output output from multiplier 149. Next, in the first maximum load multiplier 156 and the second maximum load multiplier 157, the planned maximum output shown in [Equation 2] is corrected according to the first correction coefficient 156a and the second correction coefficient 157a, which will be described later. In the subtractor 143, the corrected planned maximum output from the second maximum load multiplier 157 is subtracted from the no-load equivalent output from the multiplier 149 (refer to [Equation 2]). In the divider 144, the corrected combustion load variable CLP shown in [Equation 2] is calculated based on the results of the subtractors 143 and 145.

[0149] Next, the maximum load correction unit 134a, which is part of the combustion load variable correction unit 134 involved in the correction of the planned maximum output, will be described. Additionally, as... Figure 3As shown, the combustion load variable correction unit 134 consists of a maximum load correction unit 134a and a setpoint conversion unit 134b. The maximum load correction unit 134a is a mechanism for correcting deviations in the initial setpoint value of the combustion parameter PM for the combustion load variable CLP, so that it can be... Figure 13 The range enclosed by the dashed line is used to represent the maximum load correction unit 134a, which corresponds to the maximum load correction process S50, and the set value conversion unit 134b, which corresponds to the set value conversion process S70.

[0150] The maximum load correction unit 134a consists of a subtractor 150 that calculates the deviation between the turbine output and the corrected planned maximum output MOP; a PI arithmetic unit 151 that calculates an intermediate correction value 151a; an adder 152 that adds a predetermined value α output from the signal generator 153 to the intermediate correction value 151a to calculate a second correction value 152a; and a second maximum correction value 152a that receives the second correction value 152a output from the adder 152 and replaces the existing value of the second correction coefficient 157a. The system comprises a high-load multiplier 157, a switch 154 that receives a second correction value 152a according to a combustion load variable correction command 161 from a correction command unit 160, a data memory 155 that stores the second correction value 152a output from the switch 154 as a new first correction value 154a, and a first maximum load multiplier 156 that receives the first correction value 154a output from the data memory 155 and updates it to the first correction value 154a instead of the existing value of the first correction coefficient 156a.

[0151] The subtractor 150 receives the turbine output from the control unit 110 via the input unit 121 and the corrected planned maximum output MOP, corrected by the second maximum load multiplier 157. The subtractor 150 calculates the deviation between the turbine output and the corrected planned maximum output MOP. The deviation between the turbine output output from the subtractor 150 and the corrected planned maximum output MOP is input to the PI calculator 151. The PI calculator 151 performs a proportional-integral operation on the deviation between the turbine output and the corrected planned maximum output MOP and calculates an intermediate correction value 151a. The adder 152 adds the generated intermediate correction value 151a to a predetermined value α input from the signal generator 153 to calculate the second correction value 152a. The second correction value 152a output from the adder 152 is input to the second maximum load multiplier 157. The second correction coefficient 157a of the second maximum load multiplier 157 shown in [Equation 2] is replaced by the second correction value 152a. Based on the updated second correction factor 157a, the corrected planned maximum output is calculated. The corrected planned maximum output is input to subtractor 143, and the no-load equivalent output NOP input from multiplier 149 is subtracted. In divider 144, based on the calculation results from subtractor 143 and subtractor 145, the corrected combustion load variable CLP shown in Equation 2 is calculated and output to control unit 110.

[0152] On the other hand, if the maximum load correction process S50 has started and a predetermined time has elapsed, it is determined that the deviation between the turbine output calculated by the subtractor 150 and the corrected planned maximum output MOP falls within the allowable value of the output deviation, and a combustion load variable correction command 161 is sent. If the combustion load variable correction command 161 is input to the PI calculator 151 and the switch 154, the signal of the combustion load variable correction command 161 is temporarily "on", and the signal of the second correction value 152a output from the adder 152 is input to the data memory 155 and stored as the first correction value 154a. The first correction value 154a is input from the data memory 155 to the first maximum load multiplier 156. In the first maximum load multiplier 156, the existing value of the first correction coefficient 156a shown in [Equation 2] is updated to the first correction value 154a, and the corrected planned maximum output MOP is calculated based on the updated first correction coefficient 156a. Furthermore, if the combustion load variable correction command 161 is input to the PI arithmetic unit 151, the second correction value 152a is reset and updated to the initial setting value. Additionally, when the switch 154 is in the ON state according to the combustion load variable correction command 161, the time for the first correction coefficient 156a of the first maximum load multiplier 156 to be updated to the first correction value 154a ends within a short period. After the switch 154 switches to the OFF state, the signal of the second correction value 152a from the upstream side of the switch 154 entering the circuit of the switch 154 is cut off. Simultaneously with the switch 154 switching to the OFF state, the second correction value 152a is reset and updated to the initial setting value (typically [1]). The second correction value 152a output from the adder 152 is updated to the initial setting value, but the updated second correction value 152a is not input to the switch 154 but is sent to the second maximum load multiplier 157. Therefore, the first correction coefficient 156a input to the first maximum load multiplier 156 receives the combustion load variable correction command 161, and the second correction value 152a input when the switch 154 is on changes to the first correction value 154a, and the state of the first correction value 154a is maintained. The first correction value 154a input to the data memory 155 is stored in the data memory 155. However, the second correction value 152a when the switch 154 is on is the value when the deviation between the turbine output and the corrected planned maximum output MOP falls within the allowable value, and this second correction value 152a is stored in the data memory 155 as the first correction value 154a.As shown in Equation 2, the first correction factor 156a is used to correct the planned maximum output using the first correction factor 156a and the second correction factor 157a. The correction factor is selected to output the planned maximum output MOP at the rated value (100%) of the combustion load variable CLP. Therefore, the first correction factor 156a is updated to the first correction value 154a, which remains unchanged even when transitioning to stable operation.

[0153] The setpoint conversion unit 134b maintains the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT by converting the setpoint of the corrected combustion load variable CLP calculated by the maximum load correction unit 134a. That is, through the correction by the maximum load correction unit 134a, the deviation in inlet temperature arising from the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT is corrected by the conversion of the setpoint of the combustion load variable CLP in the setpoint conversion unit 134b. Specifically, the gas turbine inlet temperature GTIT is divided by the first correction factor 156a and set as the corrected new gas turbine inlet temperature GTIT. As a result of this conversion, the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT is maintained as the relationship between the combustion parameter PM and the gas turbine inlet temperature GTIT when the combustion margin range is confirmed.

[0154] Based on Equation 2, which includes a first correction coefficient 156a updated to the first correction value 154a selected by the maximum load correction unit 134a, the combustion load variable CLP is calculated, and the corrected planned maximum output MOP is calculated. Additionally, the second correction coefficient 157a, updated to the second correction value 152a, receives the combustion load variable correction command 161, and the second correction value 152a is reset to its initial setting value (usually [1]), thus the second correction coefficient 157a also returns to its initial setting value. The combustion load variable before correction is replaced with the corrected combustion load variable CLP based on Equation 2, and sent to the control unit 110. Upon receiving the combustion load variable correction command 161, the first correction coefficient 156a of the first maximum load multiplier 156 is updated to the first correction value 154a selected under the condition that the planned maximum output is approximately consistent with the turbine output, and the second correction coefficient 157a is sent to the control unit 110 while maintaining its initial setting value. The combustion load variable CLP shown in Equation 2 is replaced with the set value of the planned maximum output MOP at the rated value (100%) of the combustion load variable CLP. Therefore, the combustion control of the corrected burner 3 eliminates the deviation of the initial set value of the combustion load variable CLP and is in a state where appropriate combustion control can be performed.

[0155] Furthermore, as described above, during trial operation or reoperation after periodic inspection, the deviation of the initial set value is eliminated in the maximum load correction process S50. Therefore, the planned maximum output is corrected using the first correction coefficient 156a, so that the planned maximum output is output at the rated value (100%) of the combustion load variable CLP. After correction, the gas turbine 1 enters stable operation. However, even after entering stable operation, a deviation between the planned maximum output and the actual output occurs due to the deterioration of the gas turbine 1. In this case, in order to eliminate the deviation of the set value ST, the planned maximum output is corrected using the same concept as shown in [Equation 2]. However, the correction mechanism for the deviation of the set value ST of the combustion load variable CLP accompanying the deterioration of the gas turbine 1 during stable operation is slightly different from the above correction mechanism, and is applied in... Figure 12 The learning circuit in the maximum load correction process S50 shown performs the processing of processes S51 to S57, excluding process S54. By repeating this process, the deviation between the planned maximum output MOP and the set value ST of the combustion load variable CLP is automatically eliminated. That is, the first correction factor 156a, selected by the correction performed during trial operation or startup after the periodic inspection, is kept unchanged, and the deviation between the planned maximum output MOP and the set value ST of the combustion load variable CLP is corrected using the second correction factor 157a.

[0156] As described above, during the initial setting of the combustion load variable CLP of the combustion parameter PM at the start of the trial operation of the gas turbine 1 or during the restart of operation after a periodic inspection, the planned maximum output is corrected using the second correction coefficient 157a until the deviation between the turbine output and the planned maximum output falls within the allowable value. The corrected planned maximum output MOP is then calculated, and the corrected combustion load variable CLP is also calculated. During this period, the first correction coefficient 156a is fixed to the previous setting value. On the other hand, after the deviation between the turbine output and the planned maximum output falls within the allowable value and the deviation of the initial setting value is corrected, the gas turbine 1 enters stable operation. When entering stable operation, deviations in the setting values ​​ST of the combustion parameter PM and the combustion load variable CLP occur due to the deterioration of the gas turbine 1. However, the first correction coefficient 156a is fixed to a new setting value updated to the first correction value 154a, and the second correction coefficient 157a is updated until the deviation between the turbine output and the planned maximum output MOP falls within the allowable value. With the update of the second correction factor 157a, the planned maximum output MOP is corrected, and the combustion load variable CLP is automatically corrected.

[0157] In the calculation formula for the combustion load variable CLP shown in Equation 2, the planned maximum output is multiplied by the first correction factor 156a and the second correction factor 157a as a correction mechanism. The reason for using two correction factors is that, during the initial settings at the start of trial operation and upon restarting operation after periodic checks, the first correction factor 156a and the second correction factor 157a are updated to select the optimal first correction factor 156a. During stable operation, the first correction factor 156a is fixed, and only the second correction factor 157a is updated to select the optimal second correction factor 157a. The correction method of changing the combustion load variable CLP during the initial settings at the start of trial operation and upon restarting operation after periodic checks, and during stable operation, is to correct deviations in the set value during initial settings and automatically correct deviations in the set value accompanying GT deterioration during stable operation, thereby achieving long-term operation of the gas turbine.

[0158] Additionally, when not applicable Figure 12 If all steps of the maximum load correction step S50 shown are executed, but only steps S51 to S57 are performed, and steps S60 and beyond are omitted before entering stable operation, it may have a detrimental effect on combustion adjustment. That is, this is because the deviation of the initial set value of the combustion load variable CLP is not eliminated before entering stable operation, thus making it impossible to maintain an appropriate relationship between the GT load and the combustion load variable CLP.

[0159] Setting value change procedure

[0160] like Figure 8 As shown, the setpoint change procedure S30 is a procedure that changes the setpoints of the combustion parameter PM and the combustion load variable CLP when an origin offset occurs in the combustion margin confirmation procedure S20. The setpoint change procedure S30 is performed before the combustion margin confirmation procedure S20 and the combustion load variable correction procedure S40.

[0161] As described above, the setpoint change procedure S30 is a procedure that changes the setpoint of the combustion load variable CLP of the combustion parameter PM when an origin shift occurs in the combustion margin confirmation procedure S20. The setpoint change procedure S30 automatically corrects the combustion parameter PM when an origin shift occurs as a result of performing the combustion margin confirmation procedure S20 on the combustion parameter PM (pilot ratio PL, top cap ratio TH, bypass valve opening BV) for setting the setpoint of the combustion parameter PM for the combustion load variable CLP. Specifically, this means that for each combustion parameter PM, when an origin shift occurs for each combustion parameter PM before combustion margin confirmation, the setpoint of the combustion parameter PM for the specified combustion load variable CLP is changed according to the setpoint change method described later, and the setpoint ST of the combustion load variable CLP of the combustion parameter PM is corrected.

[0162] By changing the setpoint ST of each combustion parameter PM based on the results of the combustion margin verification process S20, an appropriate setpoint ST for the combustion parameter PM for the combustion load variable CLP is selected, thereby enabling the setting of a combustion parameter PM that can suppress combustion vibration.

[0163] Figure 14 This is an example of a method for changing the setpoint, showing a graph illustrating a change in the setpoint ST of the pilot ratio PL in the combustion parameter PM. The horizontal axis represents the combustion load variable CLP, and the vertical axis represents the pilot ratio PL (%). In the combustion margin verification step S20, the combustion load variable CLP corresponding to the specified GT load is selected, and the combustion margin range is verified.

[0164] exist Figure 14 In the diagram, point P1 represents the position of the origin OP before the combustion margin verification step S20, and point P2 represents the position of the new origin NOP after the result of the combustion margin verification step S20, indicated by the arrow, shows the origin shift and the origin OP has moved. That is, in Figure 14 In this diagram, point P1, representing the location of the origin OP, is represented by the position where the combustion load variable CLP is X1 (%) and the pilot ratio PL is Y1 (%). The new origin NOP, i.e., point P2, is represented by the position where the combustion load variable CLP is X2 (%) and the pilot ratio PL is Y2 (%). In this embodiment, for example, Figure 7 The example shows the results of the combustion margin confirmation, in Figure 14 In the process, the direction of the increase in the pilot ratio PL caused the origin to shift. Therefore, the combustion load variable CLP, i.e., X1, at the original point P1 changed to the direction of decrease, i.e., the new combustion load variable X2.

[0165] In this embodiment, such as Figure 14 As shown, points P3 and P4 are adjacent to point P1, and point P3 is shown on the side where the combustion load variable CLP increases and point P4 on the side where it decreases. Furthermore, the positions shown for points P1 to P4 indicate their relative positions in... Figure 9 The position corresponding to the selected GT load in the GT load setting step S22 of the combustion margin confirmation step S20 shown. Figure 14This is an example where, as a result of combustion margin confirmation, no origin shift occurred at points P3 and P4, but an additional origin shift occurred at point P1, which is sandwiched between points P3 and P4. The relationship between the immediate preceding leader ratio PL and the combustion load variable CLP, indicating the origin shift at point P1, is represented by a dashed line passing through points P3, P1, and P4. The relationship between the leader ratio PL and the combustion load variable CLP, when the origin OP changes to a new origin NOP due to the origin shift at point P1, is represented by a solid line passing through points P3, P2, and P4. Furthermore, the point P11, where the dashed line segment P1~P4 intersects the vertical axis passing through the X2 of the combustion load variable CLP, represents the position where the original origin OP moved along the line segment P1~P4 by an amount equivalent to the reduction in the combustion load variable CLP (X1-X2) due to the origin shift. The position of point P2 after offsetting the lead ratio PL (%) at point P11 by an amount equivalent to the origin shift width WST is the same as the position of point P2 after offsetting from the origin.

[0166] From different perspectives, the origin OP position before combustion margin confirmation, i.e., point P1 where the combustion load variable CLP is X1 (%) and the pilot ratio PL is Y1 (%), is the original target origin setting value. However, in the actual combustion margin confirmation process S20, it is difficult to accurately set the target origin position, and the actual origin position deviates slightly from the target origin position, i.e., point P1, towards point P11. Therefore, the position of point P11 can be considered as the actual running origin position for combustion margin confirmation. An example where combustion margin confirmation is performed at the running origin, i.e., point P11, and the origin position moves to the origin movement width WST, i.e., point P2, can be considered as the result of combustion margin confirmation at the running origin, i.e., point P11.

[0167] Therefore, point P11, the closest point to the initial origin (P1), is set as the operating origin. When the combustion margin verification process S20 results in an origin offset, the setting value change process S30 sets the combustion load variable CLP, the closest to the initial origin setting value, as the operating origin to perform the combustion margin verification process S20. When the initial origin OP setting value ST changes and a new origin NOP is set, the initial origin OP setting value ST is changed to the new origin NOP setting value ST.

[0168] Therefore, in the combustion margin verification process S20, when the origin P1 (with a pilot ratio PL of Y1 (%) and a combustion load variable CLP of X1 (%)) experiences an origin shift, the position of the new origin NOP after the shift can be determined by selecting the position of the combustion load variable CLP, i.e., "X2", and the origin shift width WST of the pilot ratio PL based on the results of the combustion margin verification process S20. Figure 14The position of point P2 in the system. Through this step, when an origin offset occurs, the setting value can be changed to change the position of the origin OP (i.e., point P1) to the position of the new origin NOP (i.e., point P2).

[0169] The content described or shown in the accompanying drawings as an embodiment of the invention is not intended to limit the scope of the invention, but is merely illustrative. Furthermore, the expressions "possessing," "including," "comprises," or "having" a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

[0170] The contents described in the above embodiments can be understood as follows.

[0171] (1) The combustion adjustment method of the gas turbine involved in the first method is applicable to the combustion control of the burner. The combustion adjustment method includes a combustion margin confirmation process for confirming the combustion margin range of the combustion parameters. The combustion margin confirmation process includes the following steps: selecting the combustion parameters for setting the fuel-air ratio for the gas turbine load; executing a first process consisting of an increase instruction process (i.e., a first increase instruction process) that increases the instruction value of the combustion parameters from the origin or a decrease instruction process (i.e., a first decrease instruction process) that decreases the instruction value; if the burner does not produce combustion vibration and the instruction value reaches the target margin upper limit or the target margin. If the lower limit value is reached, the first step ends and the command value of the combustion parameter returns to the origin position; the second step is executed, consisting of a second lowering command step, which lowers the command value from the origin position in the opposite direction to the first step, or a second increasing command step, which increases the command value; and if the burner does not generate combustion vibration and the command value of the second step reaches the target margin lower limit value or the target margin upper limit value, the second step ends and the command value of the combustion parameter in the second step returns to the origin position.

[0172] According to the combustion adjustment method of the gas turbine described in (1) above, the combustion margin range of the direction of the command value of increasing and decreasing combustion parameters can be confirmed in advance based on the origin position. Therefore, the combustion control of the gas turbine can be carried out stably without generating combustion vibration, and the reliability of the gas turbine can be improved.

[0173] (2) The combustion adjustment method of the gas turbine involved in the second method is the combustion adjustment method of the gas turbine in (1), wherein the combustion margin confirmation process is a process of confirming the combustion margin range of the first combustion parameter of the combustion parameter, and the origin, the command value, the upper limit of the target margin and the lower limit of the target margin of the first combustion parameter are the first origin, the first command value, the upper limit of the first target margin and the lower limit of the first target margin.

[0174] According to the combustion adjustment method of the gas turbine described in (2) above, the margin range of combustion vibration of the combustion parameters with high priority can be identified first, thus shortening the margin identification work of combustion vibration and speeding up the start-up time of the gas turbine.

[0175] (3) The combustion adjustment method of the gas turbine involved in the third method is the combustion adjustment method of the gas turbine in (2), wherein the combustion margin confirmation process is a process of confirming the combustion margin range of the second combustion parameter of the combustion parameter, and the origin, the command value, the upper limit of the target margin and the lower limit of the target margin of the second combustion parameter are the second origin, the second command value, the upper limit of the second target margin and the lower limit of the second target margin.

[0176] (4) The combustion adjustment method of the gas turbine involved in the fourth method is the combustion adjustment method of the gas turbine in (3), wherein the combustion margin confirmation process is a process of confirming the combustion margin range of the third combustion parameter of the combustion parameter, and the origin, the command value, the upper limit of the target margin and the lower limit of the target margin of the third combustion parameter are the third origin, the third command value, the upper limit of the third target margin and the lower limit of the third target margin.

[0177] (5) The combustion adjustment method of the gas turbine involved in the fifth method is the combustion adjustment method of the gas turbine in any one of (1) to (4), which further includes a combustion load variable correction process, the combustion load variable correction process consists of the following steps: a maximum load correction process, which corrects the set value of the combustion load variable that is confirmed for the combustion margin range of the obtained combustion parameters in such a way that the combustion load variable for the planned maximum output becomes the rated value; and a set value conversion process, which maintains the relationship between the combustion parameters and the gas turbine inlet temperature, and converts the set value of the combustion load variable calculated in the maximum load correction process.

[0178] According to the combustion adjustment method of the gas turbine described in (5) above, the combustion adjustment range of the combustion parameters is confirmed, the set value of the combustion parameters is corrected, and an appropriate relationship between the combustion parameters and the combustion load variable is set, so that the appropriate combustion control of the burner can be performed.

[0179] (6) The combustion adjustment method of the gas turbine involved in the sixth method is the combustion adjustment method of the gas turbine in any one of (1) to (5), wherein the combustion margin confirmation process is performed in accordance with the combustion load variable representing the load of the gas turbine.

[0180] According to the combustion adjustment method of the gas turbine described above (6), the combustion margin is confirmed based on the combustion load variable corresponding to the GT load, so it is easy to predict the generation of combustion vibration.

[0181] (7) The combustion adjustment method of the gas turbine involved in the seventh method is the combustion adjustment method of the gas turbine in any one of (1) to (6), wherein the combustion margin confirmation process includes the following steps: selecting the priority of the combustion parameter and the priority of the change pattern of the command value of the combustion parameter corresponding to the combustion load variable representing the load of the gas turbine.

[0182] According to the combustion adjustment method of the gas turbine described above (7), the priority of the combustion parameters and the priority of the change pattern of the command value of the combustion parameters can be selected according to the combustion load variable. Therefore, the combustion margin confirmation of the combustion parameters that are prone to combustion vibration can be performed first, thereby reducing the backtracking of the combustion margin confirmation and shortening the combustion margin confirmation work.

[0183] (8) The combustion adjustment method of the gas turbine involved in the eighth method is the combustion adjustment method of the gas turbine in any one of (1) to (7), wherein, after the first step or the second step is completed, when the command value is returned to the origin position, the command value is reduced or increased at a first predetermined rate.

[0184] According to the combustion adjustment method of the gas turbine described above (8), after the lifting command step or the lowering command step of the first or second step is completed, it can return to the origin position at the first specified rate, thus shortening the combustion margin confirmation step.

[0185] (9) The combustion adjustment method of the gas turbine involved in the ninth method is the combustion adjustment method of the gas turbine in any one of (1) to (8), wherein the lifting command step or the lowering command step of the first step or the second step includes the following steps: lifting or lowering the command value from the origin position along a stepped step; and maintaining a first holding time without generating combustion vibration in the step after lifting or lowering the command value by one step.

[0186] According to the combustion adjustment method of the gas turbine described above (9), the generation of combustion vibration is delayed relative to the command value. Therefore, in each step, after reaching the specified set value, the first holding time is maintained. This allows for reliable determination of whether combustion vibration is generated under the command value, and confirmation of whether combustion vibration is generated while raising or lowering the command value. Thus, the combustion vibration range of the combustion parameters can be more reliably confirmed.

[0187] (10) The combustion adjustment method of the gas turbine involved in the 10th method is the combustion adjustment method of the gas turbine of (9), wherein the first step or the second step of the lifting command step or the lowering command step includes the following steps: when the command value is raised by 1 step or lowered by 1 step, the command value is raised or lowered at a second predetermined rate.

[0188] According to the combustion adjustment method of the gas turbine described above (10), there is a region where combustion vibration is not easily generated, depending on the burner. Therefore, by speeding up the change speed of the command value in this region, the combustion margin confirmation work is shortened.

[0189] (11) The combustion adjustment method of the gas turbine involved in the 11th method is the combustion adjustment method of the gas turbine in either (9) or (10), wherein the lifting command step or the lowering command step of the first step or the second step includes the following steps: when the command value is maintained in the step where the command value reaches the upper limit of the target margin or the lower limit of the target margin, and no combustion vibration is generated and the first holding time is reached in the step, the second holding time is maintained from the time point after the first holding time under the command value and stable data is extracted.

[0190] According to the combustion adjustment method of the gas turbine described above (11), when no combustion vibration occurs even after the first holding time is reached, the combustion margin range in the up command process or down command process is confirmed under the set value of the upper limit of combustion margin or the lower limit of combustion margin. Therefore, the second holding time is maintained and the stable data of the gas turbine is extracted to realize the data storage of the automatic combustion adjustment unit, so that appropriate combustion adjustment operation can be performed.

[0191] (12) The combustion adjustment method of the gas turbine involved in the 12th method is the combustion adjustment method of the gas turbine in any one of (1) to (10), wherein the combustion margin confirmation process includes the following steps: in the lifting command process of the first process, when combustion vibration occurs before the command value of the combustion parameter reaches the target margin upper limit value, or when combustion vibration occurs after the step of the command value of the combustion parameter reaches the target margin upper limit value, and before the first holding time is reached below the command value, the command value of the step immediately preceding the combustion vibration is set as the actual margin upper limit value, so that the command value returns to the origin position, and the first process ends; in the lowering command process of the second process in the opposite direction to the lifting command process of the first process, the calculation is performed from the The difference between the number of steps between the origin position and the target margin upper limit value of the first process's lifting instruction process and the number of steps between the origin position and the actual margin upper limit value is added to the difference of the instruction value of the target margin lower limit value of the second process's lower instruction process in the direction of reducing the instruction value of the second process, which is equivalent to the difference of the number of steps in the first process, and set as the actual margin lower limit value; the lowering instruction process is executed on the instruction value of the combustion parameter from the origin position of the second process's lowering instruction process until the actual margin lower limit value is reduced without combustion vibration; and a new origin is set at a position where the distance relative to the origin position in the direction of reducing the instruction value of the second process is equivalent to the difference of the number of steps in the first process.

[0192] According to the combustion adjustment method of the gas turbine described above (12), even if combustion vibration occurs in the lifting command process of the first process, the origin position is moved to the direction of reducing the command value, i.e., the new origin position, and the new origin is set at the midpoint of the target margin width between the upper limit of the direction of increasing the command value from the new origin position, i.e., the upper limit of the actual margin, and the lower limit of the direction of decreasing the command value, i.e., the lower limit of the actual margin, which does not produce combustion vibration. Therefore, a stable operating range without combustion vibration can be ensured.

[0193] (13) The combustion adjustment method of the gas turbine involved in the 13th method is the combustion adjustment method of the gas turbine in any one of (1) to (10), wherein the combustion margin confirmation process includes the following steps: in the reduction command process of the first process, when combustion vibration occurs before the command value of the combustion parameter reaches the target margin lower limit, or after the step of the command value of the combustion parameter reaches the target margin lower limit, and before the command value reaches the first holding time, the command value of the step immediately preceding the combustion vibration is set as the actual margin lower limit, so that the command value returns to the origin position, and the first process ends; in the increase command process of the second process in the opposite direction to the reduction command process of the first process, the calculation is performed from the The difference between the number of steps between the origin position and the target margin lower limit of the first process's reduction instruction step and the number of steps between the origin position and the actual margin lower limit is added to the difference of the instruction value, which is equivalent to the difference of the number of steps in the first process, in the direction of increasing the instruction value of the second process's increase instruction step towards increasing the instruction value of the second process, and set as the actual margin upper limit value; in the increase instruction step of the second process, the increase instruction step is executed from the origin position for the instruction value of the combustion parameter until the actual margin upper limit value is increased without combustion vibration; and a new origin is set at a position where the distance relative to the origin position towards increasing the instruction value of the second process is equivalent to the difference of the number of steps in the first process.

[0194] According to the combustion adjustment method of the gas turbine described above (13), even if combustion vibration occurs in the process of reducing the command in the first process, the origin position is moved to the direction of increasing the command value, i.e., the new origin position. And without changing the target margin width between the upper limit of the direction of increasing the command value from the new origin position, i.e., the actual margin upper limit value, and the lower limit of the direction of reducing the command value, i.e., the actual margin lower limit value, the target margin width is reduced. The new origin is set at the middle position of the target margin width, so a stable operating range without combustion vibration can be ensured.

[0195] (14) The combustion adjustment method of the gas turbine involved in the 14th method is the combustion adjustment method of the gas turbine in any one of (9) to (10), wherein the combustion margin confirmation process includes the following steps: executing the lifting command process or the lowering command process of the first process from the origin position; when combustion vibration occurs before the command value of the step reaches the target margin upper limit value or the target margin lower limit value, or when combustion vibration occurs after the command value of the step reaches the target margin upper limit value or the target margin lower limit value, but before the first holding time is reached, the command value of the step immediately preceding the combustion vibration is set as the actual margin upper limit value or the actual margin lower limit value, and the actual margin upper limit value or the actual margin lower limit value is set as the first setting value of the first process; from the The origin position is reversed in the opposite direction to the lifting or lowering command of the first process. When combustion vibration occurs before the command value of the step reaches the target margin lower limit or the target margin upper limit, or after the command value of the step reaches the target margin lower limit or the target margin upper limit, but before the first holding time is reached, the command value of the step immediately preceding the combustion vibration is set as the actual margin lower limit or actual margin upper limit of the second process, and the actual margin upper limit or actual margin lower limit of the second process is set as the second set value of the second process; and the midpoint between the first set value and the second set value is set as the new origin.

[0196] According to the combustion adjustment method of the gas turbine described above (14), the origin position is moved to the middle position between the upper or lower limit of the non-combustion vibration upper or lower limit of the first process's lifting command process or lowering command process and the lower or upper limit of the non-combustion vibration lower or upper limit of the second process's lowering command process or lifting command process, and the middle point is set as the new origin. Therefore, even if combustion vibration occurs on both sides of the first and second processes' lifting command process and lowering command process, a stable operating range without combustion vibration can be ensured.

[0197] (15) The combustion adjustment method of the gas turbine involved in the 15th method is the combustion adjustment method of the gas turbine in any one of (12) to (14), wherein the combustion margin confirmation process includes the following steps: in the first process or the second process, when combustion vibration is generated and the origin position is moved and the new origin position is selected, the second holding time is maintained from the time point when combustion vibration is generated, and stable data is extracted, at the instruction value that is reduced by 1 step or increased by 1 step from the instruction value that generated combustion vibration.

[0198] According to the combustion adjustment method of the gas turbine described above (15), when the command value that generates combustion vibration is increased by one step or decreased by one step, the second holding time is maintained and stable data is extracted, thus storing stable operating conditions that do not generate combustion vibration, thereby improving the reliability of combustion control of the gas turbine.

[0199] (16) The combustion adjustment method of the gas turbine involved in the 16th method is the combustion adjustment method of the gas turbine in any one of (12) to (15), wherein the combustion load variable closest to the initial origin is set as the running origin to perform the combustion margin confirmation process, the combustion adjustment method includes a set value change process, in which when the set value of the initial origin changes and the new origin is set, the set value of the initial origin is changed to the set value of the new origin.

[0200] According to the combustion adjustment method of the gas turbine described above (16), when the origin offset occurs in the combustion margin confirmation process, the set value of the origin is changed, thereby selecting an appropriate relationship between the set value of the combustion parameters and the combustion load variable, so that combustion parameters that can suppress combustion vibration can be selected.

[0201] (17) The combustion adjustment method of the gas turbine involved in the 17th method is the combustion adjustment method of the gas turbine in (5), wherein the maximum load correction process includes the following steps: performing proportional integration on the deviation between the turbine output and the planned maximum output to calculate an intermediate correction value, adding a predetermined value to the intermediate correction value to calculate a second correction value; if a predetermined time has elapsed after the start of the combustion load variable correction process, a combustion load variable correction instruction is sent; according to the combustion load variable correction instruction, the second correction value is replaced with the first correction value, and the second correction value is reset; and according to the combustion load variable correction instruction, the first correction coefficient is updated to the first correction value.

[0202] According to the combustion adjustment method of the gas turbine described above (17), the maximum load correction process can be used to obtain the set value that can achieve the planned maximum output under 100% combustion load variable.

[0203] (18) The combustion adjustment method of the gas turbine involved in the 18th method is the combustion adjustment method of the gas turbine in (17), wherein the maximum load correction process further includes the step of updating the second correction coefficient to the second correction value.

[0204] According to the combustion adjustment method of the gas turbine described above (18), in addition to the initial setting at the start of trial operation and after periodic inspection, the deviation of the setting value accompanied by GT deterioration is also corrected during stable operation, thereby enabling long-term operation of the gas turbine.

[0205] (19) The combustion adjustment method of the gas turbine involved in the 19th method is the combustion adjustment method of the gas turbine in either (17) or (18), wherein the set value conversion process corrects the gas turbine inlet temperature according to the first correction coefficient.

[0206] According to the combustion adjustment method of the gas turbine described above (19), the gas turbine inlet temperature is corrected according to the first correction coefficient, thus maintaining an appropriate relationship between the combustion parameters and the gas turbine inlet temperature.

[0207] (20) The combustion control device for the gas turbine involved in the 20th method includes: a control unit for controlling the operating state of the gas turbine; an automatic combustion adjustment unit for controlling combustion vibration; and a combustion margin adjustment unit for determining the combustion margin range of combustion parameters that do not produce combustion vibration for the gas turbine load and sending it to the automatic combustion adjustment unit.

[0208] The combustion control device for the gas turbine described above (20) has a combustion margin adjustment unit that can select a combustion margin range that does not produce combustion vibration, thus automating the combustion adjustment work and reducing the burden on the staff.

[0209] (21) The combustion control device of the gas turbine shown in the 21st embodiment is the combustion control device of the gas turbine of (20), wherein the combustion margin adjustment unit includes: a combustion margin confirmation unit, which confirms the combustion margin range of the combustion parameters according to the gas turbine load; a combustion load variable correction unit, which corrects the set value of the combustion load variable for the combustion parameters and sets a new set value; and a set value change unit, which corrects the relationship between the combustion parameters and the combustion load variable according to the new origin when a new origin is set in the combustion margin confirmation unit.

[0210] (22) The combustion control device of the gas turbine shown in the 22nd embodiment is the combustion control device of the gas turbine of (21), wherein the combustion load variable correction unit has a first correction coefficient for correcting the combustion load variable in a manner that makes the combustion load variable for the planned maximum output a rated value, the combustion control device of the gas turbine includes: a maximum load correction unit, the first correction coefficient is updated to a first correction value calculated in a manner that makes the deviation between the gas turbine output and the planned maximum output fall within an allowable value, and the combustion load variable is corrected; and a setpoint conversion unit, which corrects the gas turbine inlet temperature according to the first correction coefficient in a manner that maintains the relationship between the combustion parameters and the gas turbine inlet temperature according to the corrected combustion load variable.

[0211] (23) The combustion control device of the gas turbine shown in the 23rd embodiment is the combustion control device of the gas turbine in (22), wherein the maximum load correction unit includes: a subtractor that calculates the deviation between the turbine output and the planned maximum output; a PI calculator that performs proportional integration on the deviation calculated by the subtractor to calculate an intermediate correction value; an adder that adds a predetermined value to the intermediate correction value calculated by the PI calculator to calculate a second correction value; and a correction command unit that sends a combustion load change command when it detects that the deviation between the turbine output and the planned maximum output falls within an allowable value. The unit includes: a quantity correction command; a switcher that is in an on state according to the combustion load variable correction command sent by the correction command unit; a data memory that outputs from the adder and stores the second correction value as the first correction value via the switcher, and outputs the first correction value; a first maximum load multiplier that takes in the first correction value output from the data memory and has a first correction coefficient updated to the first correction value; and a second maximum load multiplier that takes in the second correction value from the adder and has a second correction coefficient updated to the second correction value.

[0212] Industrial availability

[0213] In one aspect of the invention, combustion margin verification is made more efficient without relying on operator skills, and combustion adjustment is made easier. Furthermore, the reliability of the gas turbine is improved.

[0214] Symbol Explanation

[0215] 1-Gas turbine, 2-Compressor, 3-Burner, 4-Turbine, 5-Generator, 11-Inlet guide vane, 24-Tail stack, 30-Combustion nozzle, 31-Main nozzle, 32-Top cap nozzle, 33-Pilot nozzle, 41-Main fuel flow control valve, 42-Top cap fuel flow control valve, 43-Pilot fuel flow control valve, 44-Bypass valve, 100-Combustion control device, 101-Process measurement unit, 102-Pressure change measurement unit, 103-Acceleration measurement unit, 104-NOx measurement unit, 110-Control unit, 121-Input unit, 122-Operating status monitoring unit, 123-Frequency analysis unit, 124-Combustion characteristic monitoring unit, 125-Correction unit, 126-Output unit, 127 - Database, 130 - Combustion margin adjustment unit, 132 - Combustion margin confirmation unit, 134 - Combustion load variable correction unit, 134a - Maximum load correction unit, 134b - Setpoint conversion unit, 136 - Setpoint change unit, 141 - Function generator (planned maximum output), 142 - Function generator (no-load equivalent output), 143, 145, 150 - Subtractors, 144, 147 - Dividers, 148, 149 - Multipliers, 151 - PI arithmetic unit, 151a - Intermediate correction value, 152 - Adder, 152a - Second correction value, 153 - Signal generator, 154 - Switcher, 154a - First correction value, 155 - Data storage, 156 - First maximum load multiplication 156a - First correction factor, 157 - Second maximum load multiplier, 157a - Second correction factor, 160 - Correction command unit, 161 - Combustion load variable correction command, PL - Pilot ratio, TH - Top cap ratio, BV - Bypass valve opening, CLP - Combustion load variable, GTIT - Gas turbine inlet temperature, PM - Combustion parameter, PM1 - First combustion parameter, PM2 - Second combustion parameter, PM3 - Third combustion parameter, S - Step, SW - Step width, CM - Command value, CM1 - First command value, CM2 - Second command value, CM3 - Third command value, OP - Origin, OP1 - First origin, OP2 - Second origin, OP3 - Third origin, NOP, NOP1, N OP2, NOP3 - New origin, WST - Origin movement width, PR1 - Operation 1, PR2 - Operation 2, STU - Increase instruction operation, STD - Decrease instruction operation, TMW, TMW1, TMW2, TMW3 - Target margin width, TMUL - Upper limit of target margin, TMLL - Lower limit of target margin, AMUL - Upper limit of actual margin, AMLL - Lower limit of actual margin, T1 - First hold time, T2 - Second hold time, T0 - Time not reached, BRR - Instruction value release rate (first specified rate), BIR - Instruction value input rate (second specified rate), α - Specified value, MOP - Planned maximum load (planned maximum output), NOP - Output equivalent to no load.

Claims

1. A combustion adjustment method of a gas turbine, which is suitable for combustion control of a combustor, the combustion adjustment method comprising a combustion margin confirming process of confirming a combustion margin range of a combustion parameter, the combustion margin confirming process comprising the steps of: selecting the combustion parameter that sets a fuel air ratio against a load of the gas turbine; executing a first process constituted by a raising instruction process of raising an instruction value of the combustion parameter from an origin position or a lowering instruction process of lowering the instruction value; ending the first process if the combustor does not generate combustion vibration and the instruction value reaches a target upper margin value or a target lower margin value, and returning the instruction value of the combustion parameter to the origin position; executing a second process constituted by the lowering instruction process of lowering the instruction value from the origin position in a direction opposite to the first process or the raising instruction process of raising the instruction value; and ending the second process if the combustor does not generate combustion vibration and the instruction value of the second process reaches the target lower margin value or the target upper margin value, and returning the instruction value of the second process of the combustion parameter to the origin position.

2. The combustion adjustment method of a gas turbine according to claim 1, wherein the combustion margin confirming process is a process of confirming the combustion margin range of a first combustion parameter of the combustion parameter, and the origin, the instruction value, the target upper margin value and the target lower margin value of the first combustion parameter are a first origin, a first instruction value, a first target upper margin value and a first target lower margin value.

3. The combustion adjustment method of a gas turbine according to claim 2, wherein the combustion margin confirming process is a process of confirming the combustion margin range of a second combustion parameter of the combustion parameter, and the origin, the instruction value, the target upper margin value and the target lower margin value of the second combustion parameter are a second origin, a second instruction value, a second target upper margin value and a second target lower margin value.

4. The combustion adjustment method of a gas turbine according to claim 3, wherein the combustion margin confirming process is a process of confirming the combustion margin range of a third combustion parameter of the combustion parameter, and the origin, the instruction value, the target upper margin value and the target lower margin value of the third combustion parameter are a third origin, a third instruction value, a third target upper margin value and a third target lower margin value.

5. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, further comprising a combustion load variable correction process constituted by the following processes: a maximum load correction process of correcting a set value of a combustion load variable for which the combustion margin range of the combustion parameter is confirmed, so that a combustion load variable for a planned maximum output becomes a rated value; and a minimum load correction process of correcting a set value of a combustion load variable for which the combustion margin range of the combustion parameter is confirmed, so that a combustion load variable for a planned minimum output becomes a rated value. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The set value conversion process maintains a relationship between the combustion parameter and the gas turbine inlet temperature, and converts the set value of the combustion load variable calculated in the maximum load correction process.

6. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein The combustion margin confirmation process is performed in correspondence with a combustion load variable indicating a load of the gas turbine.

7. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein The combustion margin confirmation process includes the steps of: The priority of the combustion parameter and the priority of the change pattern of the command value of the combustion parameter are selected in correspondence with a combustion load variable indicating a load of the gas turbine.

8. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein When the command value is returned to the origin position after the end of the first process or the second process, The command value is decreased or increased at a first prescribed rate.

9. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein The increase command process or the decrease command process of the first process or the second process includes the steps of: The command value is increased or decreased by one step from the origin position; and A first holding time is maintained without generating combustion vibration in the step after the command value is increased by one step or decreased by one step.

10. The combustion adjustment method of a gas turbine according to claim 9, wherein The increase command process or the decrease command process of the first process or the second process includes the steps of: The command value is increased or decreased at a second prescribed rate when the command value is increased by one step or decreased by one step.

11. The combustion adjustment method of a gas turbine according to claim 9, wherein The increase command process or the decrease command process of the first process or the second process includes the steps of: When the command value is maintained in the step in which the command value reaches the target margin upper limit value or the target margin lower limit value, and the first holding time is reached in the step without generating combustion vibration, a second holding time is maintained from the time point at which the first holding time has elapsed and stable data is extracted at the command value.

12. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein The combustion margin confirmation process includes the steps of: In the increase command process of the first process, when combustion vibration is generated before the command value of the combustion parameter reaches the target margin upper limit value, or when combustion vibration is generated before a first holding time is reached at the command value after the command value of the combustion parameter reaches the target margin upper limit value, the command value of the immediately previous step in which combustion vibration is generated is set as an actual margin upper limit value, the command value is returned to the origin position, and the first process is ended. In the lowering instruction process of the second process in the opposite direction to the lowering instruction process of the first process, a difference between the number of steps from the origin position to the target upper limit value of the margin of the lowering instruction process of the first process and the number of steps from the origin position to the actual upper limit value of the margin is added to the target lower limit value of the margin of the lowering instruction process of the second process in the direction of lowering the instruction value of the second process by the instruction value corresponding to the difference in the number of steps of the first process, and is set to the actual lower limit value of the margin; the lowering instruction process is executed from the origin position of the lowering instruction process of the second process to the instruction value of the combustion parameter until combustion vibration does not occur and the actual lower limit value of the margin is reached; and a new origin is set at a position moved by an amount corresponding to the difference in the number of steps of the first process in the direction of lowering the instruction value of the second process with respect to the origin position.

13. The combustion adjustment method of a gas turbine according to any one of claims 1 to 4, wherein the combustion margin confirmation process includes the steps of: in the lowering instruction process of the first process, when combustion vibration occurs before the instruction value of the combustion parameter reaches the target lower limit value of the margin, or when combustion vibration occurs before a first holding time elapses after the instruction value of the combustion parameter reaches the target lower limit value of the margin, the instruction value of the immediately preceding step at which combustion vibration occurred is set to the actual lower limit value of the margin, the instruction value is returned to the origin position, and the first process is ended; in the raising instruction process of the second process in the opposite direction to the lowering instruction process of the first process, a difference between the number of steps from the origin position to the target lower limit value of the margin of the lowering instruction process of the first process and the number of steps from the origin position to the actual lower limit value of the margin is added to the target upper limit value of the margin of the raising instruction process of the second process in the direction of raising the instruction value of the second process by the instruction value corresponding to the difference in the number of steps of the first process, and is set to the actual upper limit value of the margin; in the raising instruction process of the second process, the raising instruction process is executed from the origin position to the instruction value of the combustion parameter until combustion vibration does not occur and the actual upper limit value of the margin is reached; and a new origin is set at a position moved by an amount corresponding to the difference in the number of steps of the first process in the direction of raising the instruction value of the second process with respect to the origin position.

14. The combustion adjustment method of a gas turbine according to claim 9, wherein the combustion margin confirmation process includes the steps of: the raising instruction process or the lowering instruction process of the first process is executed from the origin position; When combustion vibration occurs before the command value of the step reaches the upper limit value or the lower limit value of the target margin, or when combustion vibration occurs after the command value of the step reaches the upper limit value or the lower limit value of the target margin and before a first holding time is reached, the command value of the step immediately before combustion vibration occurs is set as an actual upper limit value or an actual lower limit value, and the actual upper limit value or the actual lower limit value is set as a first set value of the first process; the lowering command process or the raising command process of the second process is executed in a direction opposite to the raising command process or the lowering command process of the first process from the origin position; When combustion vibration occurs before the command value of the step reaches the lower limit value or the upper limit value of the target margin, or when combustion vibration occurs after the command value of the step reaches the lower limit value or the upper limit value of the target margin and before the first holding time is reached, the command value of the step immediately before combustion vibration occurs is set as an actual lower limit value or an actual upper limit value of the second process, and the actual upper limit value or the actual lower limit value of the second process is set as a second set value of the second process; and a midpoint position between the first set value and the second set value is set as a new origin.

15. The combustion adjustment method of a gas turbine according to claim 12, wherein the combustion margin confirmation process includes the steps of: in the raising command process or the lowering command process of the first process or the second process, when combustion vibration occurs and the new origin position is selected by moving the origin position, stable data is extracted while maintaining a second holding time from a time point at which combustion vibration occurs at a command value that is one step lower or one step higher than the command value at which combustion vibration occurs.

16. The combustion adjustment method of a gas turbine according to claim 12, wherein the combustion margin confirmation process is executed by setting a combustion load variable closest to a set value of the initial origin as a run-time origin, the combustion adjustment method of a gas turbine includes a set value changing process in which, when the set value of the initial origin is changed and the new origin is set, the set value of the initial origin is changed to the set value of the new origin.

17. The combustion adjustment method of a gas turbine according to claim 5, wherein the maximum load correction process includes the steps of: an intermediate correction value is calculated by proportional integration of a deviation of a turbine output from the planned maximum output, and a second correction value is calculated by adding a prescribed value to the intermediate correction value; if a prescribed time elapses after the start of execution of the combustion load variable correction process, a combustion load variable correction instruction is transmitted; according to the combustion load variable correction instruction, the second correction value is replaced with a first correction value by a switch, and the second correction value is reset; and the first correction value is calculated by proportional integration of a deviation of a turbine output from the planned maximum output. According to the combustion load variable correction instruction, a first correction coefficient is updated to the first correction value.

18. The combustion adjustment method of a gas turbine according to claim 17, wherein The maximum load correction step further includes a step of updating a second correction coefficient to the second correction value.

19. The combustion adjustment method of a gas turbine according to any one of claims 17 or 18, wherein The set value conversion step corrects the gas turbine inlet temperature according to the first correction coefficient.

20. A combustion control device of a gas turbine, comprising: a control section that controls an operation state of a gas turbine; an automatic combustion adjustment section that controls combustion vibration; and a combustion margin adjustment section that selects a combustion margin range of a combustion parameter that does not generate combustion vibration with respect to a load of the gas turbine, and sends it to the automatic combustion adjustment section, The combustion margin adjustment section includes: a combustion margin confirmation section that confirms a combustion margin range of the combustion parameter according to a load of the gas turbine; a combustion load variable correction section that corrects a set value of a combustion load variable with respect to the combustion parameter, and sets a new set value; and a set value changing section that, when a new origin point is set in the combustion margin confirmation section, corrects a relationship between the combustion parameter and the combustion load variable according to the new origin point.

21. The combustion control device of a gas turbine according to claim 20, wherein The combustion load variable correction section has a first correction coefficient that corrects the combustion load variable in such a way that a combustion load variable with respect to a planned maximum output becomes a rated value, The combustion control device of a gas turbine includes: a maximum load correction section that updates the first correction coefficient to a first correction value that is calculated in such a way that a deviation of a turbine output from a planned maximum output falls within an output deviation allowable value, and corrects the combustion load variable; and a set value conversion section that corrects the gas turbine inlet temperature according to the first correction coefficient in such a way that a relationship between the combustion parameter and the gas turbine inlet temperature is maintained according to the corrected combustion load variable.

22. The combustion control device of a gas turbine according to claim 21, wherein The maximum load correction section includes: a subtracter that calculates a deviation of the turbine output from the planned maximum output; a PI calculator that calculates an intermediate correction value by proportionally integrating the deviation calculated by the subtracter; an adder that calculates a second correction value by adding a prescribed value to the intermediate correction value calculated by the PI calculator; a correction instruction section that detects that the deviation of the turbine output from the planned maximum output falls within an allowable value, and sends a combustion load variable correction instruction; a switch that is in an on state according to the combustion load variable correction instruction sent by the correction instruction section; a data storage that outputs the second correction value from the adder and stores the second correction value as the first correction value via the switch, and outputs the first correction value; a first maximum load multiplier that takes in the first correction value output from the data storage, and has a first correction coefficient that is updated to the first correction value; and A 2nd maximum load multiplier takes in the 2nd correction value from the adder and has a 2nd correction coefficient updated to the 2nd correction value.

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