An automatic combustion adjustment method and system for a 6fa gas turbine

Abstract

The application discloses a 6FA gas turbine automatic combustion adjusting method and system, acquires the pressure value of each combustion chamber of the gas turbine in different frequency bands; if the pressure value is higher than an alarm value, calculates the offset amount for adjusting the pressure value each time; judges whether the offset amount is higher than a preset value, if higher than the preset value, turns to manual adjustment; if lower than the preset value, adds the offset amount to a fuel distribution model constructed in advance, adjusts the fuel flow of the nozzle, and until the pressure value of each combustion chamber in different frequency bands is lower than the alarm value. The application is aimed at the 6FA type gas turbine, through the research on the combustion characteristics of the gas turbine and the development of the adjusting strategy, makes the combustion system of the 6FA gas turbine run in the best matching interval at any time, improves the operation stability, and reduces the number of unplanned shutdowns.

Description

Technical Field

[0001] This invention relates to an automatic combustion adjustment method for a 6FA gas turbine, belonging to the field of gas turbine power generation. Background Technology

[0002] With increasingly stringent environmental protection requirements, gas turbines used for power generation are generally switching from diffusion combustion to premixed combustion to meet increasingly stringent emission standards. Currently, gas turbines using premixed combustion can achieve NOx emissions as low as 50 mg / m³. 3 The following is a summary: Premixed combustion has a narrow combustion stability window, and even slight changes in combustion boundary conditions often lead to combustion instability. Summary of the Invention

[0003] This invention provides an automatic combustion adjustment method for a 6FA gas turbine, which solves the problems disclosed in the background art.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An automatic combustion adjustment method for a 6FA gas turbine: Obtain pressure values ​​at different frequency bands in each combustion chamber of the gas turbine; If the pressure value is higher than the alarm value, calculate the offset amount used to adjust the pressure value each time; Determine if the bias is higher than the preset value; if it is, switch to manual adjustment. If the pressure is lower than the preset value, the offset is added to the pre-built fuel distribution model, and the fuel flow rate of the nozzle is adjusted until the pressure value of different frequency bands in each combustion chamber is lower than the alarm value.

[0005] Furthermore, methods for obtaining pressure values ​​at different frequency bands in each combustion chamber of a gas turbine include: Pressure sensors are installed in each combustion chamber to collect pressure signals. The signals are then processed using FFT to obtain pressure pulsation amplitudes in four frequency bands: B, L, M, and H, covering 10Hz-60Hz, 60Hz-130Hz, 130Hz-250Hz, and pressure signals above 250Hz, respectively. The maximum amplitude in each frequency band from all six combustion chambers is taken and denoted as P. B P L P M P H .

[0006] Furthermore, if the pressure value is higher than the alarm value, the method for calculating the offset amount used to adjust the pressure value each time includes: P B The value is 0.65 higher than the alarm value, B PM3= O PM3 ×R PM3,PB B PM1=O PM1 ×R PM1,PB B PMQ= O PMQ ×R PMQ,PB ; P L The value is 0.55 higher than the alarm value, B PM3= O PM3 ×R PM3,PL B PM1= O PM1 ×R PM1,PL B PMQ= O PMQ ×R PMQ,PL ; P M The value is 0.45 higher than the alarm value, B PM3= O PM3 ×R PM3,PM B PM1= O PM1 ×R PM1,PM B PMQ= O PMQ ×R PMQ,PM ; P H The value is 0.35 higher than the alarm value, B PM3= O PM3 ×R PM3,PH B PM1= O PM1 ×R PM1,PH B PMQ= O PMQ ×R PMQ,PH ; Among them, O PM3 O PM1 O PMQ This is the baseline value for each adjustment step; B PM3 It is the offset of the PM3 nozzle, B PM1 It is the offset of the PM1 nozzle, B PMQ It is the offset of the Quaternary nozzle, R PM1,PB R PM1,PL R PM1,PM R PM1,PH R PM3,PB R PM3,PL R PM3,PM R PM3,PH R PMQ,PB R PMQ,PL R PMQ,PM R PMQ,PH All are correlation coefficients.

[0007] Furthermore, the fuel distribution model includes: Fuel flow rate Q of PM3 nozzlePM3 =FQG×(f FSRPM3 (DWATT, ATID)-B PM3 ); The fuel flow rate Q of the PM1 nozzle PM1 =(FQG-Q PM3 )×(f FSRPM1 (DWATT, ATID)-B PM1 ); Fuel flow rate Q of the Quaternary nozzle quaternary =(FQG-Q PM1 -Q PM3 )×(f FSRPMQ (DWATT, ATID)-B PMQ ); Fuel flow rate Q of PM2 nozzle PM2 =(FQG-Q PM3 -Q PM1 -Q quaternary ); Where FQG is the total fuel flow rate, f FSRPM3 This refers to the PM3 distribution ratio, DWATT is the load, ATID is the compressor inlet temperature, and f FSRPM1 It is the PM1 allocation ratio, f FSRPMQ It is the Quaternary allocation ratio.

[0008] Furthermore, methods for determining that the bias is higher than a preset value include: B PM3 The absolute value of B > 0.05 PM1 The absolute value of B is greater than 0.04. PMQ The absolute value is greater than 0.04.

[0009] Furthermore, O PM3 O PM1 O PMQ The recommended baseline value is 0.03. Furthermore, automatic adjustment is allowed when DWATT > 30MW.

[0010] A second aspect of the present invention provides an automatic combustion adjustment system for a 6FA gas turbine: The pressure monitoring module is used to acquire pressure values ​​at different frequency bands in each combustion chamber of the gas turbine; The bias calculation module is used to calculate the bias amount used to adjust the pressure value each time when the pressure value is higher than the alarm value. The bias determination module is used to determine whether the bias is higher than the preset value. If it is higher than the preset value, it will switch to manual adjustment. The fuel distribution module is used to adjust the fuel flow of the nozzle by adding offset when the offset is lower than the preset value, until the pressure value of different frequency bands in each combustion chamber is lower than the alarm value.

[0011] A third aspect of the present invention provides a computer-readable storage medium for storing one or more programs, characterized in that: the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0012] A fourth aspect of the present invention provides a computing device, comprising: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods described above.

[0013] The beneficial effects achieved by this invention are as follows: This invention targets the 6FA gas turbine. Through research on the combustion characteristics of the gas turbine and the formulation of adjustment strategies, the combustion system of the 6FA gas turbine is made to operate in the optimal ratio range at all times, thereby improving operational stability and reducing the number of unplanned shutdowns. Attached Figure Description

[0014] Figure 1 This is a schematic diagram showing the location of the gas turbine nozzles; Figure 2 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0016] like Figure 1 As shown, the GE 6FA gas turbine's combustion chamber adopts a ring-shaped structure, with the upper and lower halves of the combustion chamber shell connected as a single unit to the compressor and turbine's outer cylinder. Six burners are evenly and obliquely inserted into the combustion chamber shell along the unit's circumference. Each combustion chamber nozzle consists of five premixed nozzles (MP3, PM2, and a central standby nozzle (PM1)) arranged in a circle, and 15 quadrature nozzles located upstream. The fuel distribution ratio of these nozzles continuously changes with load variations. The opening degree of the PM3, PM2, PM1, and quadrature nozzles is determined by a linear relationship built into the control system, automatically adjusting with load increases and decreases. When preset parameters fail to meet requirements (e.g., sudden extreme weather or a sudden change in natural gas calorific value), the ratio of the aforementioned regulating valves needs to be adjusted continuously to ensure combustion stability while meeting emission standards.

[0017] like Figure 2 As shown, the automatic combustion adjustment method for a 6FA gas turbine of the present invention includes the following steps: Obtain key data for gas turbine operation, including: load "DWATT", compressor inlet temperature "ATID", total fuel flow rate "FQG", fuel temperature "FTG", NOx emission value "AFPPMVD", and PM1 distribution ratio "f". FSRPM1 PM3 allocation ratio FSRPM3 ", Quaternary allocation ratio" f FSRPMQ ".

[0018] Each combustion chamber is equipped with a pressure sensor. The pressure signal is acquired by the data acquisition system, and the signal is processed by FFT to obtain the pressure pulsation amplitude in four frequency bands: B, L, M, and H, covering pressure signals above 250Hz (10Hz-60Hz, 60Hz-130Hz, 130Hz-250Hz, and above 250Hz), respectively. The maximum amplitude in each frequency band of the six combustion chambers is taken and denoted as P. B P L P M P H These four values ​​can reflect the combustion stability of a gas turbine.

[0019] Create a key historical data table for the gas turbine, recording data at intervals of one second (the time interval can be defined, but should not exceed 10 seconds). The recorded data includes "DWATT", "ATID", "FQG", "FTG", "AFPPMVD", "FSRPM1", "FSRPM3", "FSRPMQ", and P. B P L P M P H .

[0020] Develop a general gas turbine fuel distribution strategy under which the flow rate percentage of each nozzle group changes with the gas turbine load and compressor inlet temperature.

[0021] According to the above scheme, the fuel flow rate formula for the PM3 nozzle is: Q PM3 =FQG×(f FSRPM3 (DWATT, ATID)-B PM3 ) The fuel flow rate formula for PM1 nozzles is: Q PM1 =(FQG-Q PM3 )×(f FSRPM1 (DWATT, ATID)-B PM1 ) The fuel flow rate formula for a quaternary nozzle is: Q quaternary =(FQG-Q PM1 -Q PM3 )×(f FSRPMQ (DWATT, ATID)-B PMQ ) The fuel flow rate formula for a PM2 nozzle is: Q PM2 =(FQG-Q PM3 -Q PM1 -Q quaternary ); Calculate the Pearson correlation coefficient for each parameter in the table at regular intervals (e.g., once a month). (Other correlation coefficients can be selected, such as Kendall correlation coefficient or Spearman correlation coefficient.)

[0022] Record the correlation coefficient R as follows PM1,PB R PM1,PL R PM1,PM R PM1,PH R PM3,PB R PM3,PL R PM3,PM R PM3,PH R PMQ,PB R PMQ,PL R PMQ,PM R PMQ,PH .

[0023] When the system detects P B If the value exceeds the alarm threshold of 0.65, execute: B PM3= O PM3 ×R PM3,PB B PM1= O PM1 ×R PM1,PB B PMQ= O PMQ ×R PMQ,PB .

[0024] When the system detects P L If the value exceeds the alarm threshold of 0.55, execute: B PM3= O PM3 ×R PM3,PL B PM1= O PM1 ×R PM1,PL B PMQ= O PMQ ×R PMQ,PL .

[0025] When the system detects P M If the value exceeds the alarm threshold of 0.45, execute: B PM3= O PM3 ×R PM3,PM BPM1= O PM1 ×R PM1,PM B PMQ= O PMQ ×R PMQ,PM .

[0026] When the system detects P H If the value exceeds the alarm threshold of 0.35, execute: B PM3= O PM3 ×R PM3,PH B PM1= O PM1 ×R PM1,PH B PMQ= O PMQ ×R PMQ,PH .

[0027] The above O PM3 O PM1 O PMQ It is the baseline value for each adjustment step, which can be set freely; B PM3 It is the offset of the PM3 nozzle, B PM1 It is the offset of the PM1 nozzle, B PMQ This is the offset of the Quaternary nozzle. The offset is used to adjust the fuel flow rate of the nozzle in the aforementioned fuel distribution strategy until the pressure in each combustion chamber falls below the alarm value.

[0028] Adjust the parameter settings as follows: Automatic adjustment is allowed when DWATT > 30MW. O PM3 O PM1 O PMQ The recommended baseline value is 0.03. When an alarm is detected in a certain frequency band, an adjustment procedure is executed every 10 seconds until the pressure amplitude of the certain frequency band falls below the alarm value.

[0029] B PM3 The absolute value of B > 0.05 PM1 The absolute value of B is greater than 0.04. PMQ If the absolute value is greater than 0.04, the program exits and displays the message "Adjustment invalid".

[0030] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0031] A computer-readable storage medium storing one or more programs, the programs including instructions that, when executed by a computing device, cause the computing device to perform an automatic combustion adjustment method for a 6FA gas turbine.

[0032] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing an automatic combustion adjustment method for a 6FA gas turbine.

[0033] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0034] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0035] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0036] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0037] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. An automatic combustion adjustment method for a 6FA gas turbine, characterized in that: Obtain pressure values ​​at different frequency bands in each combustion chamber of the gas turbine; If the pressure value is higher than the alarm value, calculate the offset amount used to adjust the pressure value each time; Determine if the bias is higher than the preset value; if it is, switch to manual adjustment. If the pressure is lower than the preset value, the offset is added to the pre-built fuel distribution model, and the fuel flow rate of the nozzle is adjusted until the pressure value of different frequency bands in each combustion chamber is lower than the alarm value.

2. The automatic combustion adjustment method for a 6FA gas turbine according to claim 1, characterized in that: Methods for obtaining pressure values ​​at different frequency bands in each combustion chamber of a gas turbine include: Pressure sensors are installed in each combustion chamber to collect pressure signals. The signals are then processed using FFT to obtain pressure pulsation amplitudes in four frequency bands: B, L, M, and H, covering 10Hz-60Hz, 60Hz-130Hz, 130Hz-250Hz, and pressure signals above 250Hz, respectively. The maximum amplitude in each frequency band from all six combustion chambers is taken and denoted as P. B P L P M P H .

3. The automatic combustion adjustment method for a 6FA gas turbine according to claim 2, characterized in that: If the pressure value is higher than the alarm value, the method for calculating the offset amount used to adjust the pressure value each time includes: P B The value is 0.65 higher than the alarm value, B PM3= O PM3 ×R PM3,PB B PM1= O PM1 ×R PM1,PB B PMQ= O PMQ ×R PMQ,PB ; P L The value is 0.55 higher than the alarm value, B PM3= O PM3 ×R PM3,PL B PM1= O PM1 ×R PM1,PL B PMQ= O PMQ ×R PMQ,PL ; P M The value is 0.45 higher than the alarm value, B PM3= O PM3 ×R PM3,PM B PM1= O PM1 ×R PM1,PM B PMQ= O PMQ ×R PMQ,PM ; P H The value is 0.35 higher than the alarm value, B PM3= O PM3 ×R PM3,PH B PM1= O PM1 ×R PM1,PH B PMQ= O PMQ ×R PMQ,PH ; Among them, O PM3 O PM1 O PMQ This is the baseline value for each adjustment step; B PM3 It is the bias of the PM3 nozzle, B PM1 It is the offset of the PM1 nozzle, B PMQ It is the offset of the Quaternary nozzle, R PM1,PB R PM1,PL R PM1,PM R PM1,PH R PM3,PB R PM3,PL R PM3,PM R PM3,PH R PMQ,PB R PMQ,PL R PMQ,PM R PMQ,PH All are correlation coefficients.

4. The automatic combustion adjustment method for a 6FA gas turbine according to claim 3, characterized in that, The fuel distribution model includes: Fuel flow rate Q of PM3 nozzle PM3 =FQG×(f FSRPM3 (DWATT, ATID)-B PM3 ); The fuel flow rate Q of the PM1 nozzle PM1 =(FQG-Q PM3 )×(f FSRPM1 (DWATT, ATID)-B PM1 ); Fuel flow rate Q of the Quaternary nozzle quaternary =(FQG-Q PM1 -Q PM3 )×(f FSRPMQ (DWATT, ATID)-B PMQ ); Fuel flow rate Q of PM2 nozzle PM2 =(FQG-Q PM3 -Q PM1 -Q quaternary ); Where FQG is the total fuel flow rate, f FSRPM3 This refers to the PM3 distribution ratio, DWATT is the load, ATID is the compressor inlet temperature, and f FSRPM1 It is the PM1 allocation ratio, f FSRPMQ It is the Quaternary allocation ratio.

5. The automatic combustion adjustment method for a 6FA gas turbine according to claim 3, characterized in that, Methods for determining that the bias is higher than the preset value include: B PM3 The absolute value of B > 0.05 PM1 The absolute value of B is greater than 0.

04. PMQ The absolute value is greater than 0.

04.

6. The automatic combustion adjustment method for a 6FA gas turbine according to claim 3, characterized in that, O PM3 O PM1 O PMQ The baseline value is set to 0.

03.

7. The automatic combustion adjustment method for a 6FA gas turbine according to claim 4, characterized in that, Automatic adjustment is allowed when DWATT > 30MW.

8. An automatic combustion adjustment system for a 6FA gas turbine, characterized in that: The pressure monitoring module is used to acquire pressure values ​​at different frequency bands in each combustion chamber of the gas turbine; The bias calculation module is used to calculate the bias amount used to adjust the pressure value each time when the pressure value is higher than the alarm value. The bias determination module is used to determine whether the bias is higher than the preset value. If it is higher than the preset value, it will switch to manual adjustment. The fuel distribution module is used to adjust the fuel flow of the nozzle by adding offset when the offset is lower than the preset value, until the pressure value of different frequency bands in each combustion chamber is lower than the alarm value.

9. A computer-readable storage medium for storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 7.

10. A computing device, characterized in that, include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1 to 7.

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