A method for controlling exhaust pressure based on a gas turbine booster spool valve and a return valve

Abstract

This application relates to a method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger. It employs a decoupled control architecture of "pressure deviation as the primary factor and PID control of the return valve as the secondary factor," and develops an intelligent control algorithm with adaptive pulse limiting to achieve precise pressure regulation under both steady-state and dynamic conditions. In terms of parameter optimization, a multi-objective PID parameter optimization model is established using the response surface methodology to determine the optimal parameter combination, improving the system's robustness and regulation performance. Regarding system logic design, the original complex coupled logic is replaced with single-loop PID control of the return valve and direct control of the slide valve pressure deviation, supplemented by dead-zone control and pulse time limiting, effectively reducing the problem of frequent valve actuation. Furthermore, a real-time valve position compensation mechanism is designed, and a one-button emergency intervention system is developed, enabling seamless switching between automatic and manual control modes. This ensures that manual signals are prioritized in emergency situations, greatly enhancing emergency response capabilities.

Description

Technical Field

[0001] This application relates to the field of gas turbine control and gas turbine auxiliary system optimization, and in particular to a method for controlling exhaust pressure based on the gas turbine turbocharger slide valve and return valve. Background Technology

[0002] As a key component in the gas turbine supply system, the stability of the outlet pressure of the natural gas booster directly affects the safe and economical operation of the gas turbine. However, in actual operation, the gas turbines currently in operation are GE LM6000 aero-derivative gas turbines. The booster system frequently experiences problems such as excessive outlet pressure fluctuations (>±0.05MPa), pressure runaway, and abnormal valve regulation, leading to shortened equipment lifespan and reduced efficiency. The existing control strategy, employing a coupled control method of slide valves and return valves, suffers from drawbacks such as dynamic response lag, increased oscillation risk, and a lack of effective manual intervention. There is an urgent need to research and optimize control methods to solve the problems of outlet pressure fluctuations and control oscillations, improve the stability and reliability of the booster system, and thus ensure the safe and stable operation of the aero-derivative gas turbine units. Summary of the Invention

[0003] The technical problem this application aims to solve is that the existing control strategy of the GE LM6000 aero-derivative gas turbine adopts a coupled control method of slide valve and return valve, which has defects such as dynamic response lag, increased oscillation risk and lack of effective manual intervention.

[0004] To address the aforementioned technical problems, this application provides a method for controlling exhaust pressure based on a gas turbine turbocharger slide valve and a return valve, comprising the following steps:

[0005] S1: Single-loop PID fine-tuning of the reflux valve:

[0006] 1) Real-time data acquisition: Continuously acquire the actual outlet pressure P of the booster compressor. 实际 , and the set pressure P 设定 In comparison, the pressure deviation e=P is calculated. 设定 -P 实际 ;

[0007] 2) PID calculation: Substitute the parameters to perform PID calculation and output the reflux valve opening adjustment command;

[0008] 3) Opening adjustment: The opening of the return valve is linearly adjusted according to the PID output signal. The larger the deviation, the larger the opening adjustment range; the smaller the deviation, the fine adjustment.

[0009] 4) Stable maintenance: when |P 实际 -P 设定 When | approaches 0, the PID integral element eliminates the residual, the reflux valve maintains a stable opening, and the pressure remains constant;

[0010] 5) Mode switching: When switching to manual mode, the human-machine interface locks the PLC output, and the opening of the return valve can be directly adjusted manually, while the automatic control logic is locked.

[0011] S2: Coarse pressure adjustment of the slide valve:

[0012] S21: Loading of the slide valve:

[0013] 1) Deviation determination: Real-time calculation of current pressure deviation e k =P 设定 -P 实际 The loading logic is initiated only when the current deviation reaches the loading trigger threshold;

[0014] 2) Incremental calculation: Substitute the values ​​into the incremental algorithm to calculate the valve opening adjustment increment Δu, and determine the loading amplitude;

[0015] 3) Loading execution: Output loading command, slide valve executes loading action, booster compressor displacement increases, outlet pressure rises;

[0016] 4) Action interlock: After a single loading is completed, a short-term interlock is triggered to avoid continuous loading and control the frequency to 5-8 times / hour;

[0017] 5) Stop loading: When P 实际 Approaching P 设定 When the deviation is below the threshold, loading stops, the slide valve maintains its current opening, and subsequent fine adjustment is made by the return valve.

[0018] 6) Emergency manual intervention: In an emergency, the manual loading button is triggered. The loading button signal is directly connected to the relay, bypassing the PLC output, and manual loading is executed first. The automatic loading logic is automatically locked during manual operation.

[0019] S22: Unloading of the slide valve:

[0020] 1) Dead zone determination: First, determine the pressure deviation; when |P 实际 -P 设定 When |≤0.05MPa, the load reduction logic is directly blocked, and no action is triggered;

[0021] 2) Deviation trigger: Only when |P 实际 -P 设定 |>0.05MPa and P 实际 >P 设定 When this happens, the load reduction logic is initiated;

[0022] 3) Load reduction execution: Output load reduction command, slide valve executes load reduction action, pulse time is fixed at 1.5s to ensure that a single load reduction action is completed, the compressor displacement is reduced and the outlet pressure drops;

[0023] 4) Action Interlock: After a single load reduction is completed, a short-term interlock is triggered to prevent repeated load reduction in a short period of time;

[0024] 5) Stop unloading: When P 实际 When the load drops back to near the set value and the deviation enters the 0.05MPa dead zone, the unloading stops, the slide valve maintains the current opening, and subsequent fine adjustment is made by the return valve;

[0025] 6) Emergency manual intervention: In an emergency, triggering the manual load reduction button will directly connect the load reduction button signal to the relay, forcibly executing the load reduction, bypassing the PLC and PID output, and locking the automatic load reduction logic in manual mode;

[0026] The slide valve and the return valve work together: 1) Normal operating condition: When the pressure deviation is small, only the return valve is finely adjusted by the single-loop PID, and the slide valve does not move, ensuring stable pressure without fluctuation; 2) When the pressure deviation is large and exceeds the adjustment range of the return valve: the slide valve is first triggered to load / unload coarsely adjust and pull the pressure back to near the set value; after the slide valve moves, the return valve is finely adjusted by the PID to eliminate residual deviation and achieve precise pressure stabilization; 3) Emergency operating condition: switch to manual mode, and the slide valve opening and the return valve opening are directly controlled by the operator. All automatic control logic is locked, and manual signals take priority.

[0027] According to an embodiment of this application, the opening adjustment in step S1 includes the following specific steps: If P 实际 <P 设定 This indicates low pressure. Reduce the opening of the reflux valve to decrease natural gas reflux and increase the outlet pressure. If P... 实际 >P 设定 This indicates that the pressure is too high. Increase the opening of the reflux valve to increase the natural gas reflux and reduce the outlet pressure.

[0028] According to an embodiment of this application, in manual mode, the human-machine interface locks the PLC output, which can be directly adjusted manually with an accuracy of ±1%.

[0029] According to an embodiment of this application, in step S1, the parameters substituted into the PID calculation include: P=19, to reduce steady-state error; I=8, to accelerate integration and eliminate residuals; and D=0, to suppress noise.

[0030] According to an embodiment of this application, the calculation formula for the incremental algorithm is Δu=K p *(e k -e k-1 )+K i *e k e k e represents the current pressure deviation. k-1 K represents the pressure deviation from the previous moment. p For proportional gain, K i This is the integral gain.

[0031] According to an embodiment of this application, the control algorithm for the reflux valve uses the Ziegler-Nichols critical proportional method to tune the parameters of the single-loop PID.

[0032] According to an embodiment of this application, during the single-loop PID fine-tuning process of the reflux valve, the adjustment time is 1 second, the overshoot is <5%, and the phase margin is 60°.

[0033] According to an embodiment of this application, during the loading process of the slide valve, the loading pulse time is set to 2 seconds to ensure that each loading action is completed, and the frequency is reduced to 5 to 8 times per hour.

[0034] According to an embodiment of this application, during the loading process of the slide valve, emergency manual intervention is performed, with the manual signal taking precedence over the PLC output and a response time of <0.5s.

[0035] According to an embodiment of this application, in the unloading process of the slide valve, the unloading pulse time is fixed at 1.5s to avoid short-term repetitive actions.

[0036] Compared with the prior art, the technical solution of this application achieves the following beneficial effects:

[0037] 1. In this application, the original coupled control of the slide valve and the return valve is optimized so that the slide valve is directly controlled by the pressure deviation, and the return valve is used as the main regulation method. The control logic of the return valve has been changed from the original complex and redundant control to the existing single-loop PID control. The control idea is clearer and simpler. The core of this architecture is to completely decouple the slide valve control dominated by the pressure deviation of the natural gas booster from the single-loop PID control of the return valve, eliminate the oscillation caused by traditional coupling, and combine it with an adaptive pulse limiting algorithm and manual priority mode to take into account stability, energy efficiency and emergency response.

[0038] 2. In this application, a pressure deviation direct pulse control slide valve is used in conjunction with a single-loop PID fine-tuning return valve, with a phase margin of 50°, 1s adjustment and 5% overshoot, to achieve oscillation-free, low-frequency and highly robust decoupled control of the natural gas booster.

[0039] 3. The control method of this application is the first to adopt a decoupled architecture of "pressure deviation as the main factor + PID assistance of return valve", and develops an intelligent control algorithm with adaptive pulse limitation; parameter optimization innovation: a multi-objective optimization model is established by applying the response surface method, and the optimal parameter combination (P=19, I=8) is determined through 200 sets of simulations; human-computer interaction innovation: a real-time valve position compensation mechanism is designed and a one-click emergency intervention system is developed. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Based on the described embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0041] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the field to which this application pertains. The terms "first," "second," and similar terms used in the patent application specification and claims of this application do not denote any order, quantity, or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "one" do not denote a quantity limitation, but indicate that there is at least one.

[0042] A method for controlling the exhaust pressure based on the slide valve and reflux valve of a gas turbine booster according to an example of this application includes the following steps:

[0043] S1: Single-loop PID fine tuning of the reflux valve:

[0044] 1) Real-time acquisition: Continuously obtain the actual pressure P at the outlet of the booster 实际 , compare it with the set pressure P 设定 , and calculate the pressure deviation e = P 设定 - P 实际 ;

[0045] 2) PID operation: Substitute the parameters to perform PID operation and output the opening adjustment instruction for the reflux valve;

[0046] 3) Opening adjustment: According to the PID output signal, linearly adjust the opening of the reflux valve. If the deviation is large, the opening adjustment amplitude is large; if the deviation is small, it is fine-tuned;

[0047] 4) Stable holding: When |P 实际 - P 设定 | tends to 0, the PID integral link eliminates the residual error, and the reflux valve maintains a stable opening to keep the pressure constant;

[0048] 5) Mode switching: When switching to the manual mode, the human-machine interface locks the PLC output, and the operator directly adjusts the opening of the reflux valve, and the automatic control logic is locked.

[0049] Specifically, the opening adjustment in step S1 includes the following specific steps: If P actual < P set, it means the pressure is low, then reduce the opening of the reflux valve, reduce the natural gas reflux, and increase the outlet pressure; If P 实际 > P 设定This indicates that the pressure is too high. Increase the opening of the reflux valve to increase the natural gas reflux and reduce the outlet pressure.

[0050] Specifically, the control algorithm for the reflux valve uses the Ziegler-Nichols critical proportional method to tune the parameters of the single-loop PID controller. Preferably, in step S1, the parameters substituted into the PID calculation include: P=19 to reduce steady-state error; I=8 to accelerate integration and eliminate residuals; and D=0 to suppress noise.

[0051] Specifically, during the single-loop PID fine-tuning process of the reflux valve, the adjustment time is 1 second, the overshoot is <5%, and the phase margin is 60°.

[0052] S2: Coarse pressure adjustment of the slide valve:

[0053] S21: Loading of the slide valve:

[0054] 1) Deviation determination: Real-time calculation of current pressure deviation e k =P 设定 -P 实际 The loading logic is only initiated when the deviation reaches the loading trigger threshold;

[0055] 2) Incremental calculation: Substitute the values ​​into the incremental algorithm to calculate the valve opening adjustment increment Δu, and determine the loading amplitude;

[0056] 3) Loading execution: Output loading command, slide valve executes loading action, booster compressor displacement increases, outlet pressure rises;

[0057] 4) Action interlock: After a single loading is completed, a short-term interlock is triggered to avoid continuous loading and control the frequency to 5-8 times / hour;

[0058] 5) Stop loading: When P 实际 Approaching P 设定 When the deviation is below the threshold, loading stops, the slide valve maintains its current opening, and subsequent fine adjustment is made by the return valve.

[0059] 6) Emergency Manual Intervention: In an emergency, the manual loading button is triggered. The loading button signal is directly connected to the relay, bypassing the PLC output, and manual loading is executed first. The automatic loading logic is automatically locked during manual operation.

[0060] Specifically, the calculation formula for the incremental algorithm is Δu=K p *(e k -e k−1 )+K i *e k e k e represents the current pressure deviation. k-1 K represents the pressure deviation from the previous moment. p For proportional gain, K iThis is the integral gain.

[0061] Specifically, during the loading process of the slide valve, the loading pulse time is set to 2 seconds to ensure that each loading action is completed, and the frequency is reduced to 5 to 8 times per hour.

[0062] Specifically, during the loading process of the slide valve, emergency manual intervention is required, with the manual signal taking priority over the PLC output and a response time of <0.5s.

[0063] S22: Unloading of the slide valve:

[0064] 1) Dead zone determination: First, determine the pressure deviation; when |P 实际 -P 设定 When |≤0.05MPa, the load reduction logic is directly blocked, and no action is triggered;

[0065] 2) Deviation trigger: Only when |P 实际 -P 设定 |>0.05MPa and P 实际 >P 设定 When this happens, the load reduction logic is initiated;

[0066] 3) Load reduction execution: Output load reduction command, slide valve executes load reduction action, pulse time is fixed at 1.5s to ensure that a single load reduction action is completed, the compressor displacement is reduced and the outlet pressure drops;

[0067] 4) Action Interlock: After a single load reduction is completed, a short-term interlock is triggered to prevent repeated load reduction in a short period of time;

[0068] 5) Stop unloading: When P actually falls back to near the set value and the deviation enters the 0.05MPa dead zone, stop unloading, the slide valve maintains the current opening, and subsequent fine adjustment is made by the return valve;

[0069] 6) Emergency manual intervention: In an emergency, triggering the manual load reduction button will directly connect the load reduction button signal to the relay, forcibly executing the load reduction, bypassing the PLC and PID output, and locking the automatic load reduction logic in manual mode;

[0070] The slide valve and the return valve work together: 1) Normal operating condition: When the pressure deviation is small, only the return valve is finely adjusted by the single-loop PID, and the slide valve does not move, ensuring stable pressure without fluctuation; 2) When the pressure deviation is large and exceeds the adjustment range of the return valve: the slide valve is first triggered to load / unload coarsely adjust and pull the pressure back to near the set value; after the slide valve moves, the return valve is finely adjusted by the PID to eliminate residual deviation and achieve precise pressure stabilization; 3) Emergency operating condition: switch to manual mode, and the slide valve opening and the return valve opening are directly controlled by the operator. All automatic control logic is locked, and manual signals take priority.

[0071] Specifically, in manual mode, the human-machine interface locks the PLC output, which can be directly adjusted manually with an accuracy of ±1%.

[0072] Specifically, in the unloading process of the slide valve, the unloading pulse time is fixed at 1.5 s to avoid short-term repeated actions.

[0073] Example 1 Optimization of the control system for the reflux valve and slide valve supporting the GE LM6000PFSprint gas turbine

[0074] Original logic problems of the reflux valve: Complex redundant control: Multiple condition cross-judgments lead to response delays (measured adjustment time ≥ 2 s); Unoptimized parameters: The proportional gain P = 71 is too high, prone to oscillation (overshoot reaches 12%). The optimization of the reflux valve control logic changed from the original complex redundant control to the existing single-loop PID control, with a clearer and simpler control idea, and the three parameters P, I, and D inside were optimized according to the debugging. P was changed from 71 to 19, I was changed from 6.7 to 8, and D remained unchanged. Optimization technology and effects: Single-loop PID control: Re-tune the parameters using the Ziegler-Nichols critical ratio method, P = 19 (reduce the steady-state error), I = 8 (accelerate integration to eliminate residuals), D = 0 (maintain differentiation to suppress noise); The step response shows that the adjustment time is shortened to 1 s, and the overshoot < 5%; Robustness verification: Through Bode plot analysis, the phase margin is increased from 40° to 60°, enhancing the anti-interference ability.

[0075] Original logic problems of the slide valve loading: RS flip-flop defect: Harsh conditions (need to meet 4 conditions simultaneously), resulting in a lag in the loading action (delay ≥ 1.5 s); No pulse control, frequent loading (measured to trigger 20 - 25 times per hour). The slide valve loading control logic changed from the original RS flip-flop control, with the conditions being (local non-manual state) AND (slide valve loading allowed) AND (reflux valve position feedback < 4.2%) AND (no unloading instruction), to direct pressure deviation control, and a loading pulse time was set, effectively reducing the loading frequency, and a manual control button was added, allowing manual intervention in case of emergency.

[0076] Original logic problems of the slide valve unloading: Single condition: Only relying on the reflux valve position feedback (> 6%), prone to mis-triggering unloading; No pulse limit: Leading to frequent valve actions and increased mechanical wear. The slide valve unloading control logic also changed from the original RS flip-flop control, with the conditions being (local non-manual state) AND (reflux valve position feedback > 6%), to direct pressure deviation control, and an unloading pulse time was set, effectively reducing the unloading frequency, and a manual control button was also added, allowing manual intervention in case of emergency.

[0077] After optimizing the control logic, the fluctuations in the slide valve and return valve were significantly smaller than before optimization, and the pressure control was basically stable within ±0.05 MPa of the set value. Operators can also manually add or remove loads in emergencies, and the DCS will issue an alarm when the slide valve exceeds 70%. All results met expectations. Overall benefits: Improved stability: Surge-related actions reduced by 50%, extending equipment lifespan; Improved energy efficiency: Reduced ineffective loading / unloading, saving approximately 32,000 kWh of electricity annually; Enhanced emergency response: Manual mode enables "one-click intervention," reducing MTTR (Mean Time To Repair) by 60%.

[0078] In summary, the technical solution of this application has the following beneficial effects:

[0079] 1. In this application, the original coupled control of the slide valve and the return valve is optimized so that the slide valve is directly controlled by the pressure deviation, and the return valve is used as the main regulation method. The control logic of the return valve has been changed from the original complex and redundant control to the existing single-loop PID control. The control idea is clearer and simpler. The core of this architecture is to completely decouple the slide valve control dominated by the pressure deviation of the natural gas booster from the single-loop PID control of the return valve, eliminate the oscillation caused by traditional coupling, and combine it with an adaptive pulse limiting algorithm and manual priority mode to take into account stability, energy efficiency and emergency response.

[0080] 2. In this application, a pressure deviation direct pulse control slide valve is used in conjunction with a single-loop PID fine-tuning return valve, with a phase margin of 50°, 1s adjustment and 5% overshoot, to achieve oscillation-free, low-frequency and highly robust decoupled control of the natural gas booster.

[0081] 3. The control method of this application is the first to adopt a decoupled architecture of "pressure deviation as the main factor + PID assistance of return valve", and develops an intelligent control algorithm with adaptive pulse limitation; parameter optimization innovation: a multi-objective optimization model is established by applying the response surface method, and the optimal parameter combination (P=19, I=8) is determined through 200 sets of simulations; human-computer interaction innovation: a real-time valve position compensation mechanism is designed and a one-click emergency intervention system is developed.

[0082] The above description is merely an exemplary embodiment of this application and is not intended to limit the scope of protection of this application. The scope of protection of this application is determined by the appended claims.

Claims

1. A method for controlling exhaust pressure based on a gas turbine turbocharger slide valve and a return valve, characterized in that, Includes the following steps: S1: Single-loop PID fine-tuning of the reflux valve: 1) Real-time data acquisition: Continuously acquire the actual outlet pressure P of the booster compressor. 实际 , and the set pressure P 设定 In comparison, the pressure deviation e=P is calculated. 设定 -P 实际 ; 2) PID calculation: Substitute the parameters to perform PID calculation and output the reflux valve opening adjustment command; 3) Opening adjustment: The opening of the return valve is linearly adjusted according to the PID output signal. The larger the deviation, the larger the opening adjustment range; the smaller the deviation, the fine adjustment. 4) Stable maintenance: when |P 实际 -P 设定 When | approaches 0, the PID integral element eliminates the residual, the reflux valve maintains a stable opening, and the pressure remains constant; 5) Mode switching: When switching to manual mode, the human-machine interface locks the PLC output, and the opening of the return valve can be directly adjusted manually, while the automatic control logic is locked. S2: Coarse pressure adjustment of the slide valve: S21: Loading of the slide valve: 1) Deviation determination: Real-time calculation of current pressure deviation e k =P 设定 -P 实际 The loading logic is initiated only when the current deviation reaches the loading trigger threshold; 2) Incremental calculation: Substitute the values ​​into the incremental algorithm to calculate the valve opening adjustment increment Δu, and determine the loading amplitude; 3) Loading execution: Output loading command, slide valve executes loading action, booster compressor displacement increases, outlet pressure rises; 4) Action interlock: After a single loading is completed, a short-term interlock is triggered to avoid continuous loading and control the frequency to 5-8 times / hour; 5) Stop loading: When P 实际 Approaching P 设定 When the deviation is below the threshold, loading stops, the slide valve maintains its current opening, and subsequent fine adjustment is made by the return valve. 6) Emergency manual intervention: In an emergency, the manual loading button is triggered. The loading button signal is directly connected to the relay, bypassing the PLC output, and manual loading is executed first. The automatic loading logic is automatically locked during manual operation. S22: Unloading of the slide valve: 1) Dead zone determination: First, determine the pressure deviation; when |P 实际 -P 设定 When |≤0.05MPa, the load reduction logic is directly blocked, and no action is triggered; 2) Deviation trigger: Only when |P 实际 -P 设定 |>0.05MPa and P 实际 >P 设定 When this happens, the load reduction logic is initiated; 3) Load reduction execution: Output load reduction command, slide valve executes load reduction action, pulse time is fixed at 1.5s to ensure that a single load reduction action is completed, the compressor displacement is reduced and the outlet pressure drops; 4) Action Interlock: After a single load reduction is completed, a short-term interlock is triggered to prevent repeated load reduction in a short period of time; 5) Stop unloading: When P 实际 When the load drops back to near the set value and the deviation enters the 0.05MPa dead zone, the unloading stops, the slide valve maintains the current opening, and subsequent fine adjustment is made by the return valve; 6) Emergency manual intervention: In an emergency, triggering the manual load reduction button will directly connect the load reduction button signal to the relay, forcibly executing the load reduction, bypassing the PLC and PID output, and locking the automatic load reduction logic in manual mode; The slide valve and the return valve work together: 1) Normal operating condition: When the pressure deviation is small, only the return valve is finely adjusted by the single-loop PID, and the slide valve does not move, ensuring stable pressure without fluctuation; 2) When the pressure deviation is large and exceeds the adjustment range of the return valve: the slide valve is first triggered to load / unload coarsely adjust and pull the pressure back to near the set value; after the slide valve moves, the return valve is finely adjusted by the PID to eliminate residual deviation and achieve precise pressure stabilization; 3) Emergency operating condition: switch to manual mode, and the slide valve opening and the return valve opening are directly controlled by the operator. All automatic control logic is locked, and manual signals take priority.

2. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, The opening adjustment in step S1 includes the following specific steps: If P 实际 <P 设定 This indicates low pressure. Reduce the opening of the reflux valve to decrease natural gas reflux and increase the outlet pressure. If P... 实际 >P 设定 This indicates that the pressure is too high. Increase the opening of the reflux valve to increase the natural gas reflux and reduce the outlet pressure.

3. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, In manual mode, the PLC output is locked by the human-machine interface and can be directly adjusted manually with an accuracy of ±1%.

4. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, In step S1, the parameters obtained by performing PID calculation include: P=19, to reduce steady-state error; I=8, to accelerate integration and eliminate residuals; and D=0, to suppress noise.

5. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, The incremental algorithm yields the calculation formula Δu=K p ⋅(e k -e k-1 )+K i ⋅e k e k e represents the current pressure deviation. k-1 K represents the pressure deviation from the previous moment. p For proportional gain, K i This is the integral gain.

6. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, The control algorithm for the reflux valve uses the Ziegler-Nichols critical proportional method to tune the parameters of the single-loop PID.

7. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, During the single-loop PID fine-tuning process of the reflux valve, the adjustment time is 1 second, the overshoot is <5%, and the phase margin is 60°.

8. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, During the loading process of the slide valve, the loading pulse time is set to 2 seconds to ensure that each loading action is completed, and the frequency is reduced to 5-8 times per hour.

9. A method for controlling exhaust pressure based on a gas turbine turbocharger slide valve and a return valve according to claim 1, characterized in that, During the loading process of the slide valve, emergency manual intervention is required. The manual signal takes priority over the PLC output, and the response time is <0.5s.

10. The method for controlling exhaust pressure based on the slide valve and return valve of a gas turbine turbocharger according to claim 1, characterized in that, In the unloading process of the slide valve, the unloading pulse time is fixed at 1.5s to avoid short-term repetitive actions.