Control method for starting optimization of 9H gas unit

Abstract

The invention discloses a control method for starting optimization of a 9H gas turbine unit, which belongs to the technical field of heavy gas turbines of electric power systems and comprises the following steps: setting the rotating speed of a high disc of a 9H gas turbine as 735RPM, collecting the air quantity of an outlet of a gas compressor at the rotating speed, calculating the air quantity of the outlet of the gas compressor according to a conversion relation, air density and a time conversion coefficient, and calculating the starting optimization of the 9H gas turbine unit. After the 9H fuel gas-steam combined cycle unit is started and optimized, the starting time is shortened to 158 minutes from original 533 minutes, the gas consumption of natural gas is reduced to 0.164 Nm / kwh from original 0.181 Nm / kwh, and the heat efficiency of combined cycle is improved; the dual-carbon emission reduction effect is remarkable, the qualified emission time of pollutants is shortened to 2 hours from original 6 hours of cold-state starting, and the qualified emission time of pollutants is shortened to 1 hour from 4 hours of warm-state starting; the 9H fuel gas-steam combined cycle unit is excellent in operation condition, and a typical demonstration effect is achieved for transformation and upgrading of clean energy.

Description

Technical Field

[0001] This invention belongs to the field of heavy-duty gas turbine technology in power systems, specifically referring to a control method for optimizing the start-up of a 9H gas turbine unit. Background Technology

[0002] The 9H gas turbine unit aims to support national actions to address climate change and facilitate the transformation and upgrading of clean energy. Through in-depth analysis, scientific judgment, and innovative inventions based on relevant data from the world's first microporous premixed gas turbine, the startup optimization of the first 9H gas turbine unit in China has been completed.

[0003] A control method for optimizing the startup of a 9H gas turbine unit has achieved remarkable results through practical application in production sites. It not only significantly shortens the unit's startup time and enables economical operation, but also breaks the national record for natural gas consumption. Furthermore, it achieves the national strategic goal of dual carbon emission reduction, with carbon emissions only 85% of those of a 9F gas turbine, and CO emissions as low as below 14 PPM. Its flexible load response meets the needs of the power grid, enabling rapid startup and contributing to the transformation and upgrading of clean energy.

[0004] In the background of this method, many difficulties and challenges were encountered, including a lack of understanding of the characteristics of the first 9H gas turbine in China, and logical and technical difficulties in its operation. In particular, the gas turbine fire protection system, fuel control system, and fire protection system were all used for the first time. In response to these technical bottlenecks, through invention and innovation, and through in-depth analysis and judgment of the technical difficulties, a control method for optimizing the start-up of 9H gas turbine units was proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for optimizing the startup of a 9H gas turbine unit, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a control method for optimizing the startup of a 9H gas turbine unit, comprising the following steps:

[0007] S1.1 Set the high-disk speed of the 9H gas turbine to 735 RPM, collect the compressor outlet air volume at the speed, and calculate the compressor outlet air volume based on the conversion relationship, air density and time conversion factor.

[0008] S1.2 Confirm the total volume of the hot passage of the 9H gas turbine, and set the minimum threshold for the cleaning air volume to 5 times the volume of the hot passage and the minimum threshold for the cleaning time.

[0009] S1.3 Install a CEMS online monitoring device at the boiler outlet. Use the recovery of the oxygen content at the exhaust outlet to the normal air oxygen content as the criterion for completion of purging. Determine the optimal purging time through test verification.

[0010] Preferably, it further includes a seamless combustion mode switching step, wherein the seamless combustion mode switching step specifically comprises:

[0011] S2.1 Analyze the characteristics of combustion modes: Clarify the load range and combustion parameter requirements of modes M3, M4, M6, and M6A of the 9H microporous fully premixed combustion system, and determine that the switching control target is low-stability combustion with no load fluctuation;

[0012] S2.2 Pre-parameter acquisition: Before switching, collect the current fuel flow rate, air flow rate, combustion temperature, unit load and GCV opening to establish a parameter comparison benchmark;

[0013] S2.3 Adjusting the GCV air-fuel ratio: Keeping the CRT combustion baseline unchanged, calculate the adjustment amount of each GCV opening offset according to the target mode parameter requirements, and adjust the fuel adjustment valve opening offset through the control module to optimize the air-fuel ratio;

[0014] S2.4 Real-time monitoring and fine-tuning: During the switching process, the system monitors load changes, flame stability, and vibration values. When fluctuations occur, it automatically fine-tunes the GCV opening offset to achieve seamless switching.

[0015] Preferably, in S2.4, flame stability monitoring uses no flameout and no flashback as the criteria, and vibration values ​​are controlled within the safe operating threshold of the unit to ensure that the unit has no abnormal operating conditions during the switching process.

[0016] Preferably, it also includes a step for early commissioning and control of the performance heater, wherein the step for early commissioning and control of the performance heater specifically includes:

[0017] S3.1, Pre-pressure safety control: Before the gas turbine is ignited, start the frequency converter of the medium-pressure feedwater pump to adjust the water-side outlet pressure of the medium-pressure economizer.

[0018] S3.2 Determine the heat source and control logic: The water source for the performance heater is taken from the hot water outlet of the medium-pressure economizer. Construct the feedforward and feedback control logic for the temperature control valve. The feedforward link calculates the initial opening degree based on the hot water parameters and fuel flow rate, and the feedback link corrects the opening degree based on the change in natural gas temperature.

[0019] S3.3, Advance commissioning and parameter control: The performance heater is put into operation in advance before ignition, the hot water flow is adjusted to heat the natural gas temperature to the target value, and the combined cycle output is monitored;

[0020] S3.4 Efficiency Verification: Through performance testing and calculation, it was confirmed that the combined cycle efficiency improved after the performance heater was put into operation.

[0021] Preferably, in S3.2, the hot water parameters include hot water temperature, pressure and flow rate. Feedforward and feedback control logic is used to reduce natural gas temperature fluctuations and avoid the RB phenomenon caused by excessively low temperature.

[0022] Preferably, it further includes a temperature matching optimization step, wherein the temperature matching optimization step specifically includes:

[0023] S4.1 Clarify the allowable conditions for temperature matching: Set the temperature matching logic condition to be greater than 100.63% when the speed control reference TNR is greater than 100.63%, at which time the gas turbine load is about 80MW;

[0024] S4.2 Conduct temperature rise rate test: Set the temperature rise rate gradient to 0.1°F / S to 2°F / S, and record the turbine cylinder temperature rise rate, vibration value and thermal stress during the test;

[0025] S4.3 Determine the optimal temperature matching rate: Through experimental verification, the optimal temperature matching rate was determined to be 2°F / S, at which the unit operates stably and has the shortest start-up time;

[0026] S4.4 Dynamic adjustment mechanism: During operation, if the cylinder temperature rise rate exceeds the safe range, the temperature rise rate will be automatically reduced; if the cylinder temperature rises slowly, the temperature rise rate will be appropriately increased.

[0027] Preferably, in S4.1, the temperature matching conditions must simultaneously meet the speed control reference TNR > 100.63% and the load of approximately 80MW to avoid the turbine thermal stress exceeding the standard when the temperature matching is activated during the low load stage.

[0028] Preferably, it also includes a step for real-time monitoring and adjustment of exhaust system parameters, wherein the real-time monitoring and adjustment of exhaust system parameters specifically comprises:

[0029] S5.1 Sensor Placement and Calibration: Install temperature, pressure, and oxygen content sensors at key locations in the exhaust system, and calibrate the sensors before startup to ensure data accuracy;

[0030] S5.2 Parameter Threshold Setting and Early Warning: Based on the emission requirements of CO≤14PPM and the unit's safety parameters, set the normal range of exhaust parameters, and automatically issue an early warning when the range is exceeded;

[0031] S5.3 Automatic adjustment under abnormal operating conditions: When the oxygen content is too low, increase the compressor intake air volume; when the temperature is too high, adjust the combustion ratio; when CO exceeds the standard, optimize fuel control; and ensure that the pollutant emission compliance time is ≤2 hours for cold start and ≤1 hour for warm start.

[0032] S5.4 Data Recording and Analysis: Establish a historical database of parameters and analyze data patterns regularly.

[0033] Preferably, it also includes a variable frequency drive (VFD) coordinated control step for the medium-pressure feedwater pump, wherein the VFD coordinated control step for the medium-pressure feedwater pump specifically comprises:

[0034] S6.1 Initial frequency conversion setting: During the initial startup, the initial frequency conversion of the medium-pressure feedwater pump is set according to the heat exchange requirements of the medium-pressure economizer.

[0035] S6.2 Pressure Coordination Regulation: Real-time monitoring of the pressure difference between the water-side outlet pressure of the medium-pressure economizer and the natural gas pressure; when the pressure difference approaches the 0.35MPa threshold, the frequency converter frequency is adjusted to maintain a stable pressure difference.

[0036] S6.3 Flow matching control: Establish the correlation between the frequency of the variable frequency and the hot water flow of the performance heater, and dynamically adjust the frequency according to the hot water demand;

[0037] S6.4, Start-up mode switching: After the unit load reaches a certain level, the frequency converter control will be switched to automatic stabilization mode.

[0038] Preferably, the process also includes an environmental monitoring step during startup, which specifically includes:

[0039] S7.1 Carbon Emission Monitoring: Carbon emissions are collected through carbon emission monitoring equipment to ensure that the optimized carbon emissions are 85% of those of the 9F gas turbine, which is 30% lower than that of traditional coal-fired power plants;

[0040] S7.2 CO emission monitoring: Monitor CO emissions in real time to ensure they are below 14 PPM;

[0041] S7.3 Environmental data review: After each startup, compare the environmental indicators with the target values, and adjust the control parameters if there is a deviation to ensure that the environmental benefits meet the standards.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] 1. After optimizing the startup of the 9H gas-steam combined cycle unit, the startup time was shortened from 533 minutes to 158 minutes, natural gas consumption was reduced from 0.181 Nm³ / kWh to 0.164 Nm³ / kWh, and the combined cycle thermal efficiency was increased from 61.35% to 63.36%. The dual carbon emission reduction effect is significant, reducing carbon emissions by 30% compared to traditional coal-fired power plants and by 85% compared to F-class gas turbines. The emission compliance time for pollutants was shortened from 6 hours for cold startup to 2 hours, and from 4 hours for warm startup to 1 hour. The 9H gas-steam combined cycle unit operates well, providing a typical demonstration effect for the transformation and upgrading of clean energy.

[0044] 2. This invention saves 72,000 Nm³ of natural gas per start-up. Calculated at a price of 3.5 yuan / Nm³, the natural gas cost saved per start-up is 252,000 yuan. With 50 start-ups and shutdowns for peak shaving throughout the year, the cost savings can reach 252,000 x 50 = 12.6 million yuan. Natural gas consumption is reduced to 0.164 Nm³ / kWh, with the optimal value for the 9FB gas turbine being 0.173 Nm³ / kWh. 1 m³ of natural gas can generate 6 kWh of electricity. Attached Figure Description

[0045] Figure 1 This is a schematic diagram illustrating the effect of natural gas temperature on combined cycle efficiency in a control method for optimizing the start-up of a 9H gas turbine unit according to the present invention.

[0046] Figure 2 This is a schematic diagram of the gas turbine purge time test verification of the control method for optimizing the start-up of a 9H gas turbine unit according to the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] Please see Figures 1-2 As shown, the present invention provides a technical solution comprising the following steps:

[0050] S1.1 Set the high-disk speed of the 9H gas turbine to 735 RPM, collect the compressor outlet air volume at the speed, and calculate the compressor outlet air volume based on the conversion relationship, air density and time conversion factor.

[0051] S1.2 Confirm the total volume of the hot passage of the 9H gas turbine, and set the minimum threshold for the cleaning air volume to 5 times the volume of the hot passage and the minimum threshold for the cleaning time.

[0052] S1.3 Install a CEMS online monitoring device at the boiler outlet. Use the recovery of the oxygen content at the exhaust outlet to the normal air oxygen content as the criterion for completion of purging. Determine the optimal purging time through test verification.

[0053] In this embodiment, a seamless switching step for combustion modes is also included, which specifically involves:

[0054] S2.1 Analyze the characteristics of combustion modes: Clarify the load range and combustion parameter requirements of modes M3, M4, M6, and M6A of the 9H microporous fully premixed combustion system, and determine that the switching control target is low-stability combustion with no load fluctuation;

[0055] S2.2 Pre-parameter acquisition: Before switching, collect the current fuel flow rate, air flow rate, combustion temperature, unit load and GCV opening to establish a parameter comparison benchmark;

[0056] S2.3 Adjusting the GCV air-fuel ratio: Keeping the CRT combustion baseline unchanged, calculate the adjustment amount of each GCV opening offset according to the target mode parameter requirements, and adjust the fuel adjustment valve opening offset through the control module to optimize the air-fuel ratio;

[0057] S2.4 Real-time monitoring and fine-tuning: During the switching process, the system monitors load changes, flame stability, and vibration values. When fluctuations occur, it automatically fine-tunes the GCV opening offset to achieve seamless switching.

[0058] In this embodiment, in S2.4, flame stability monitoring is based on the criteria of no flameout and no flashback, and the vibration value is controlled within the safe operating threshold of the unit to ensure that the unit has no abnormal operating conditions during the switching process.

[0059] This embodiment also includes a step for the early commissioning and control of the performance heater, which specifically involves:

[0060] S3.1, Pre-pressure safety control: Before the gas turbine is ignited, start the frequency converter of the medium-pressure feedwater pump to adjust the water-side outlet pressure of the medium-pressure economizer.

[0061] S3.2 Determine the heat source and control logic: The water source for the performance heater is taken from the hot water outlet of the medium-pressure economizer. Construct the feedforward and feedback control logic for the temperature control valve. The feedforward link calculates the initial opening degree based on the hot water parameters and fuel flow rate, and the feedback link corrects the opening degree based on the change in natural gas temperature.

[0062] S3.3, Advance commissioning and parameter control: The performance heater is put into operation in advance before ignition, the hot water flow is adjusted to heat the natural gas temperature to the target value, and the combined cycle output is monitored;

[0063] S3.4 Efficiency Verification: Through performance testing and calculation, it was confirmed that the combined cycle efficiency improved after the performance heater was put into operation.

[0064] In this embodiment, in step S3.2, the hot water parameters include hot water temperature, pressure, and flow rate. Feedforward and feedback control logic is used to reduce natural gas temperature fluctuations and avoid the RB phenomenon caused by excessively low temperatures.

[0065] In this embodiment, a temperature matching optimization step is also included, which specifically includes:

[0066] S4.1 Clarify the allowable conditions for temperature matching: Set the temperature matching logic condition to be greater than 100.63% when the speed control reference TNR is greater than 100.63%, at which time the gas turbine load is about 80MW;

[0067] S4.2 Conduct temperature rise rate test: Set the temperature rise rate gradient to 0.1°F / S to 2°F / S, and record the turbine cylinder temperature rise rate, vibration value and thermal stress during the test;

[0068] S4.3 Determine the optimal temperature matching rate: Through experimental verification, the optimal temperature matching rate was determined to be 2°F / S, at which the unit operates stably and has the shortest start-up time;

[0069] S4.4 Dynamic adjustment mechanism: During operation, if the cylinder temperature rise rate exceeds the safe range, the temperature rise rate will be automatically reduced; if the cylinder temperature rises slowly, the temperature rise rate will be appropriately increased.

[0070] In this embodiment, in S4.1, the temperature matching conditions must simultaneously meet the speed control benchmark TNR > 100.63% and the load of approximately 80MW to avoid the turbine thermal stress exceeding the standard when the temperature matching is activated during the low load stage.

[0071] This embodiment also includes a step for real-time monitoring and adjustment of exhaust system parameters, which specifically involves:

[0072] S5.1 Sensor Placement and Calibration: Install temperature, pressure, and oxygen content sensors at key locations in the exhaust system, and calibrate the sensors before startup to ensure data accuracy;

[0073] S5.2 Parameter Threshold Setting and Early Warning: Based on the emission requirements of CO≤14PPM and the unit's safety parameters, set the normal range of exhaust parameters, and automatically issue an early warning when the range is exceeded;

[0074] S5.3 Automatic adjustment under abnormal operating conditions: When the oxygen content is too low, increase the compressor intake air volume; when the temperature is too high, adjust the combustion ratio; when CO exceeds the standard, optimize fuel control; and ensure that the pollutant emission compliance time is ≤2 hours for cold start and ≤1 hour for warm start.

[0075] S5.4 Data Recording and Analysis: Establish a historical database of parameters and analyze data patterns regularly.

[0076] This embodiment also includes a variable frequency coordinated control step for the medium-pressure feedwater pump, which specifically involves:

[0077] S6.1 Initial frequency conversion setting: During the initial startup, the initial frequency conversion of the medium-pressure feedwater pump is set according to the heat exchange requirements of the medium-pressure economizer.

[0078] S6.2 Pressure Coordination Regulation: Real-time monitoring of the pressure difference between the water-side outlet pressure of the medium-pressure economizer and the natural gas pressure; when the pressure difference approaches the 0.35MPa threshold, the frequency converter frequency is adjusted to maintain a stable pressure difference.

[0079] S6.3 Flow matching control: Establish the correlation between the frequency of the variable frequency and the hot water flow of the performance heater, and dynamically adjust the frequency according to the hot water demand;

[0080] S6.4, Start-up mode switching: After the unit load reaches a certain level, the frequency converter control will be switched to automatic stabilization mode.

[0081] This embodiment also includes an environmental monitoring step during startup, which specifically includes:

[0082] S7.1 Carbon Emission Monitoring: Carbon emissions are collected through carbon emission monitoring equipment to ensure that the optimized carbon emissions are 85% of those of the 9F gas turbine, which is 30% lower than that of traditional coal-fired power plants;

[0083] S7.2 CO emission monitoring: Monitor CO emissions in real time to ensure they are below 14 PPM;

[0084] S7.3 Environmental data review: After each startup, compare the environmental indicators with the target values, and adjust the control parameters if there is a deviation to ensure that the environmental benefits meet the standards.

[0085] Example 2

[0086] 1. According to NFPA 85, "Explosion Protection Rules for Boilers and Combustion Systems," the purging time for waste heat boilers and gas turbine exhaust systems is specified as follows: the purging air volume for the hot passage of the gas turbine should be 5 times its volume, and the purging time should not be less than 5 minutes. When the 9H gas turbine is in high-disk mode, the speed is 735 RPM, and the air volume is 640 lbs. 1 lbs = 0.454 kg / s, therefore 640 x 0.454 ÷ 1.293 ÷ (1 / 3600) = 808984 m³ / h. Before optimization, the purging time was 19.5 minutes, and the volume of the entire hot passage of the 9H gas turbine was 16432 m³. Therefore, the air volume flowing through the airflow passage in 19.5 minutes is:

[0087] 808984 x 19.5 ÷ 60 = 262919.8 m³, 262919.8 ÷ 16432 = 15.9 (times). The amount of air during the cleaning process is greater than the specified 5 times the volume of the hot channel, which indicates that the time set for the cleaning stage in the logic is too long.

[0088] Research experiment: Through online monitoring of the boiler outlet CEMS, when the oxygen content at the exhaust outlet reaches the normal oxygen content value, it indicates that the purging is completed. Using the equivalent substitution method, when the oxygen content reaches the normal level, it indicates that the natural gas, which is the substitute variable, has been completely discharged from the unit. Therefore, the purging time is 6.4 minutes.

[0089] 2. The 9H micro-orifice fully premixed combustion system, during the switching between different modes (M3, M4, M6, and M6A), achieves seamless switching of the gas turbine load while maintaining relatively stable combustion through adjustments to the GCV combustion ratio, thus shortening the load ramp-up time. The adjustment process involves changing the air-fuel ratio in each GCV (fuel control valve) to alter the opening offset of each fuel adjustment valve, while keeping the CRT combustion baseline unchanged, thereby correspondingly changing the combustion conditions.

[0090] 3. Before the gas turbine is ignited, the medium-pressure feedwater pump is started via frequency converter to adjust the water-side outlet pressure of the medium-pressure economizer, ensuring that the water-side pressure is at least 0.35 MPa higher than the natural gas pressure. Before the gas turbine is ignited, the performance heater is put into operation in advance to prevent the natural gas temperature from being too low and causing RB (reverse burner) and to shorten the start-up time.

[0091] System Flow: The water source is hot water from the outlet of the medium-pressure economizer. The control logic calculates the feedforward setting of the temperature control valve based on the hot water parameters and fuel flow rate to adjust the hot water flow rate. Further adjustments are made based on temperature changes to reduce the impact of temperature variations on combustion stability. Implementation Results: Performance tests show that by activating the performance heater before unit startup to heat the natural gas to 130°C, the combined cycle output decreases by approximately 0.3MW, a relatively small impact on output, while the combined cycle efficiency increases by approximately 0.34%. In other words, by activating the performance heater in advance, a significant improvement in combined cycle efficiency is achieved at the cost of a very small reduction in output.

[0092] 4. Temperature matching optimization: After numerous tests and repeated verifications, the optimal temperature matching rate was determined, ranging from 0.1°F / s to 2°F / s. This ensures gas turbine stability while shortening the start-up time of the split-shaft unit. The permissible condition for engaging gas turbine temperature matching is that the speed control reference TNR is greater than 100.63%, at which point the gas turbine load is approximately 80MW. The temperature matching rate was adjusted from the original 0.2°F / s to 2°F / s to control the rate of cylinder temperature rise in the turbine.

[0093] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their likenesses.

[0094] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A control method for optimizing the start-up of a 9H gas turbine unit, characterized in that, Includes the following steps: S1.1 Set the high-disk speed of the 9H gas turbine to 735 RPM, collect the compressor outlet air volume at the speed, and calculate the compressor outlet air volume based on the conversion relationship, air density and time conversion factor. S1.2 Confirm the total volume of the hot passage of the 9H gas turbine, and set the minimum threshold for the cleaning air volume to 5 times the volume of the hot passage and the minimum threshold for the cleaning time. S1.3 Install a CEMS online monitoring device at the boiler outlet. Use the recovery of the oxygen content at the exhaust outlet to the normal air oxygen content as the criterion for completion of purging. Determine the optimal purging time through test verification.

2. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes a seamless switching step for combustion modes, which specifically includes: S2.1 Analyze the characteristics of combustion modes: Clarify the load range and combustion parameter requirements of modes M3, M4, M6, and M6A of the 9H microporous fully premixed combustion system, and determine that the switching control target is low-stability combustion with no load fluctuation; S2.2 Pre-parameter acquisition: Before switching, collect the current fuel flow rate, air flow rate, combustion temperature, unit load and GCV opening to establish a parameter comparison benchmark; S2.3 Adjusting the GCV air-fuel ratio: Keeping the CRT combustion baseline unchanged, calculate the adjustment amount of each GCV opening offset according to the target mode parameter requirements, and adjust the fuel adjustment valve opening offset through the control module to optimize the air-fuel ratio; S2.4 Real-time monitoring and fine-tuning: During the switching process, the system monitors load changes, flame stability, and vibration values. When fluctuations occur, it automatically fine-tunes the GCV opening offset to achieve seamless switching.

3. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 2, characterized in that: In S2.4, flame stability monitoring is based on the criteria of no flameout and no flashback, and the vibration value is controlled within the safe operating threshold of the unit.

4. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes a step for the early commissioning and control of the performance heater, which specifically includes: S3.1, Pre-pressure safety control: Before the gas turbine is ignited, start the frequency converter of the medium-pressure feedwater pump to adjust the water-side outlet pressure of the medium-pressure economizer. S3.2 Determine the heat source and control logic: The water source for the performance heater is taken from the hot water outlet of the medium-pressure economizer. Construct the feedforward and feedback control logic for the temperature control valve. The feedforward link calculates the initial opening degree based on the hot water parameters and fuel flow rate, and the feedback link corrects the opening degree based on the change in natural gas temperature. S3.3, Advance commissioning and parameter control: The performance heater is put into operation in advance before ignition, the hot water flow is adjusted to heat the natural gas temperature to the target value, and the combined cycle output is monitored; S3.4 Efficiency Verification: Through performance testing and calculation, it was confirmed that the combined cycle efficiency improved after the performance heater was put into operation.

5. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 4, characterized in that: In S3.2, the hot water parameters include hot water temperature, pressure and flow rate. Feedforward and feedback control logic is used to reduce natural gas temperature fluctuations and avoid the RB phenomenon caused by excessively low temperature.

6. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes a temperature matching optimization step, which specifically includes: S4.1 Clarify the allowable conditions for temperature matching: Set the temperature matching logic condition to be greater than 100.63% when the speed control reference TNR is greater than 100.63%, at which time the gas turbine load is about 80MW; S4.2 Conduct temperature rise rate test: Set the temperature rise rate gradient to 0.1°F / S to 2°F / S, and record the turbine cylinder temperature rise rate, vibration value and thermal stress during the test; S4.3 Determine the optimal temperature matching rate: Through experimental verification, the optimal temperature matching rate was determined to be 2°F / S, at which the unit operates stably and has the shortest start-up time; S4.4 Dynamic adjustment mechanism: During operation, if the cylinder temperature rise rate exceeds the safe range, the temperature rise rate will be automatically reduced; if the cylinder temperature rises slowly, the temperature rise rate will be appropriately increased.

7. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 6, characterized in that: In S4.1, the temperature matching conditions must simultaneously meet the speed control benchmark TNR > 100.63% and the load of approximately 80MW to avoid the turbine thermal stress exceeding the standard when the temperature matching is activated during the low load phase.

8. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes a real-time monitoring and adjustment procedure for exhaust system parameters, which specifically includes: S5.1 Sensor Placement and Calibration: Install temperature, pressure, and oxygen content sensors at key locations in the exhaust system, and calibrate the sensors before startup to ensure data accuracy; S5.2 Parameter Threshold Setting and Early Warning: Based on the emission requirements of CO≤14PPM and the unit's safety parameters, set the normal range of exhaust parameters, and automatically issue an early warning when the range is exceeded; S5.3 Automatic adjustment under abnormal operating conditions: When the oxygen content is too low, increase the compressor intake air volume; when the temperature is too high, adjust the combustion ratio; when CO exceeds the standard, optimize fuel control; and ensure that the pollutant emission compliance time is ≤2 hours for cold start and ≤1 hour for warm start. S5.4 Data Recording and Analysis: Establish a historical database of parameters and analyze data patterns regularly.

9. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes a variable frequency drive (VFD) coordinated control step for the medium-pressure feedwater pump, which specifically includes: S6.1 Initial frequency conversion setting: During the initial startup, the initial frequency conversion of the medium-pressure feedwater pump is set according to the heat exchange requirements of the medium-pressure economizer. S6.2 Pressure Coordination Regulation: Real-time monitoring of the pressure difference between the water-side outlet pressure of the medium-pressure economizer and the natural gas pressure; when the pressure difference approaches the 0.35MPa threshold, the frequency converter frequency is adjusted to maintain a stable pressure difference. S6.3 Flow matching control: Establish the correlation between the frequency of the variable frequency and the hot water flow of the performance heater, and dynamically adjust the frequency according to the hot water demand; S6.4, Start-up mode switching: After the unit load reaches a certain level, the frequency converter control will be switched to automatic stabilization mode.

10. The control method for optimizing the start-up of a 9H gas turbine unit according to claim 1, characterized in that: It also includes an environmental monitoring step during startup, which specifically includes: S7.1 Carbon Emission Monitoring: Collect carbon emissions through carbon emission monitoring equipment; S7.2 CO emission monitoring: Real-time monitoring of CO emissions; S7.3 Environmental data review: After each startup, compare the environmental indicators with the target values, and adjust the control parameters if there is a deviation.

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