Gas turbine performance improvement control method and system under deep peak regulation working condition

Abstract

The invention discloses a gas turbine performance improvement control method and system under a deep peak shaving working condition, the system comprises an AUMA motor, an IGV connecting rod, an IGV ring mechanical limit, an IGV execution mechanism limit switch and an IGV angle transmitter, the adjustable range of the IGV is improved, and the IGV can be closed to an opening IGVmin1 smaller than the original design 0%. After the transformation is completed, after the load instruction of the gas turbine is gradually reduced and the IGV is reduced to 0%, if the AGC load instruction still requires further reduction of the load of the gas turbine, the IGV can continue to be reduced, and along with reduction of the amount of air entering a combustion chamber, the turbine outlet temperature correction value OTC is still expected to be maintained within the designed temperature range. According to the method, hardware and control logic of an existing IGV and a deicing valve are transformed, the method for improving the low-load performance of a Siemens gas turbine is provided, the lower limit of peak-load operation load of a unit is increased, heat consumption in the low-load operation period is reduced, combustion stability is improved, NOx emission is continuously improved, and safe and efficient operation of the unit is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine performance improvement optimization control, and in particular to a gas turbine performance improvement control method and system under deep peak load conditions. Background Art

[0002] Since the "dual carbon" goal was proposed, the installed capacity of new energy (wind power, solar energy, etc.) has grown rapidly, and gas turbine combined cycle units mainly used for heating must also participate in grid peak regulation; statistical data show that in recent years, the peak-shaving operating load range of gas turbine units has increased significantly, and the cumulative low-load operation time has increased year by year, which has put higher requirements on the flexible peak-shaving capabilities of gas turbine units. Usually, gas turbines adjust power output by adjusting the input of fuel quantity and adjusting the compressor inlet guide vanes (IGV). Taking a certain type of Siemens gas turbine as an example, when the IGV has been closed to 0% opening, if the AGC instruction from the power grid requires the load to continue to be reduced, the turbine outlet temperature will continue to drop until the load drops to the lower limit of the design load of this type of gas turbine (Note: when the turbine outlet temperature correction value is lower than a certain value, it will cause premixed combustion to switch to diffusion combustion). Under winter conditions, when the gas turbine operates at the lower limit of the design load, the turbine outlet temperature is low, which will correspondingly cause the heating steam parameters to fail to meet the needs of heat users. In addition, since the unit has a high heat consumption when operating at low load, the economy of the unit operation will deteriorate.

[0003] In order to deal with the above problems in the operation of the unit, the usual solution is to artificially increase the load limit of the AGC operation, which will cause the unit to face the strict assessment of the "Two Detailed Rules" of the power grid. In order to meet the assessment requirements of the "Two Detailed Rules" and improve the performance of the gas turbine under low load, the present invention proposes a method to improve the low-load performance of a certain type of Siemens gas turbine by transforming the hardware and control logic of the existing IGV and de-icing valve, increasing the load limit of the unit's peak-shaving operation, reducing heat consumption during low-load operation, improving combustion stability, and continuously improving NOx emissions to ensure safe and efficient operation of the unit. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a control method and system for improving the performance of a gas turbine under deep peak-shaving conditions, thereby ensuring that a certain type of Siemens gas turbine improves the performance of the unit while meeting the lower limit of the grid AGC load and the steam parameters of the thermal users, thereby ensuring efficient, stable and environmentally friendly operation of the unit.

[0005] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is: a gas turbine performance improvement control system under deep peak load regulation conditions, comprising an IGV actuator; the IGV actuator comprises an IGV ring mechanical limit, an IGV actuator mechanical limit, an IGV connecting rod, an AUMA motor and an IGV transmitter; the IGV actuator is used to control the opening of the intake guide vane, thereby affecting the amount and speed of air flowing into the gas turbine;

[0006] The IGV ring mechanical limit is used to provide a physical limit for the opening of the IGV, ensuring that the guide vanes operate within a safe range and preventing damage caused by excessive opening;

[0007] The mechanical limit of the IGV actuator is used to further ensure the motion range of the actuator and protect the overall stability of the system;

[0008] The IGV connecting rod connects the IGV and the actuator to transmit the movement of the actuator to the IGV;

[0009] The AUMA motor: as a driving element, is responsible for controlling the opening of the IGV and driving the connecting rod through rotational motion;

[0010] The IGV transmitter is used to monitor the opening of the IGV in real time and feed the data back to the control system for real-time adjustment.

[0011] A method for improving the performance of a gas turbine under deep peak load conditions is provided, and the specific steps are as follows:

[0012] Step S1: establishing a compressor flow and pressure ratio model within the operating range of the diffusion IGV, determining a surge boundary curve and a margin value; and establishing a relationship between the compressor flow and the airflow attack angle;

[0013] Step S2: Establishing a calculation model and a multivariable function for the minimum IGV opening that can avoid surface airflow separation and surge of the compressor blades under specific boundary conditions, that is, IGVmin2 = f(x1, x2, x3...);

[0014] Step S3: Determine the minimum opening function that the IGV can actually reach, IGVmin=MAX(IGVmin1,IGVmin2).

[0015] Step S4: Optimizing the IGV temperature control logic, specifically including: IGV feedforward control function, IGV flow and IGV opening function, etc., so that the IGV has the ability to participate in the automatic adjustment control of the turbine outlet temperature within the extended range; optimizing the primary frequency modulation control, so that the gas turbine has the primary frequency modulation function within the extended IGV adjustment range;

[0016] Step S5: Add deep peak-shaving switching logic, that is, when the deep peak-shaving function is activated, the adjustment range of IGV is IGVmin-100%; when the deep peak-shaving function is exited, IGV returns to the original adjustment range, that is, 0-100%;

[0017] Step S6: Add deep peak load regulation input condition judgment logic and abnormal working condition protection exit deep peak load regulation function related logic to ensure the safe and reliable operation of deep peak load regulation function;

[0018] Step S7: Optimizing the IGV switch rate and the engine load setting value change rate under different working conditions to ensure that no abnormal fluctuation of the turbine outlet temperature correction value OTC is caused;

[0019] Step S8: Add de-icing valve related control logic. When the IGV is closed to the IGVmin position and no longer has the function of adjusting the turbine outlet temperature, the closed-loop control of the de-icing valve can take over and participate in the deep peak regulation control, thereby expanding the deep peak regulation capability of the gas turbine.

[0020] Step S9: Add an operation screen to facilitate power plant operators to confirm whether the deep peak-shaving function meets the regulation requirements, activate and deactivate the deep peak-shaving function, and judge the operation status of the deep peak-shaving regulation.

[0021] Furthermore, in step S2, the extreme boundary conditions include factors such as atmospheric temperature and humidity, compressor airflow angle of attack, compressor flow and pressure ratio, compressor surge boundary, etc., and the minimum opening of the IGV that can be adjusted with an appropriate safety margin is calculated. min2 .

[0022] Furthermore, in step S8, in order to further improve the deep peak regulation range of the gas turbine, the anti-icing valve control logic needs to be optimized; under specific operating conditions (such as the ambient temperature is below 0°C), due to the decrease in the AGC load command, the IGV has been closed to the IGV min Position, if the load command continues to decrease, the turbine outlet temperature will gradually decrease because the IGV can no longer regulate the air entering the combustion chamber; in order to avoid or reduce the decrease in turbine outlet temperature to a certain extent, under the premise of not affecting the compressor surge boundary, a part of the compressor outlet air is diverted to the compressor inlet to reduce the amount of air entering the combustion chamber; specifically, the anti-icing valve issues an opening command α% through closed-loop control to heat the compressor inlet air temperature to 2k higher than the corresponding dew point temperature under the ambient temperature at that time; at the same time, the anti-icing valve issues an opening command β% through the added control closed-loop logic, and also participates in adjusting the turbine outlet temperature to the set value, and the final command output comes from the larger value of α% and β%.

[0023] Furthermore, the method for extending the IGV adjustment range is specifically as follows:

[0024] S1: Adjustment Figure 1 The IGV ring in the middle is mechanically limited to ensure that the IGV can participate in the adjustment within an extended range.

[0025] S2: Adjustment Figure 1 The mechanical limit of the IGV actuator ensures that the IGV connecting rod can participate in the adjustment within the extended stroke range.

[0026] S3: Transformation Figure 1 The IGV connecting rod in the middle is optimized in length to ensure that the IGV extends the adjustment angle range and moves as a whole in the closing direction by a certain angle.

[0027] S4: Adjustment Figure 1 The limit switch of the AUMA motor and the screw limit of the AUMA motor ensure that the AUMA motor can drive the connecting rod and adjust the IGV to the extended angle range.

[0028] S5: Adjust the configuration parameters of the IGV transmitter so that it can display the expanded IGV opening value (%).

[0029] S6: Determine the minimum opening IGVmin1 that the IGV can achieve on the machine.

[0030] The beneficial effects of the present invention are as follows: by transforming the hardware and control logic of the existing IGV and de-icing valve, the present invention proposes a method for improving the low-load performance of a certain type of Siemens gas turbine, increasing the lower limit of the peak-shaving operation load of the unit, reducing the heat consumption during low-load operation, improving combustion stability, continuously improving NOx emissions, and ensuring safe and efficient operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the hardware structure of the present invention.

[0032] In the figure: 1. IGV ring mechanical limit, 2. IGV actuator mechanical limit, 3. IGV connecting rod, 4. AUMA motor, 5. IGV transmitter. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0035] like Figure 1 As shown, a control method and system for improving the performance of a gas turbine under deep peak load conditions, including: studying the hardware structure of an IGV actuator, and improving the adjustable range of the IGV by modifying a certain type of Siemens gas turbine IGV actuator, including its AUMA motor electric limit switch, effective stroke of the motor screw, IGV connecting rod, IGV ring mechanical limit, IGV actuator limit switch and IGV angle transmitter, so that the IGV can be closed to an opening IGVmin1 that is smaller than the original design of 0%;

[0036] After the above transformation is completed, when the gas turbine load command gradually decreases and the IGV is closed to 0%, if the AGC load command still requires a further decrease in the gas turbine load, the IGV can continue to be closed. As the amount of air entering the combustion chamber decreases, the turbine outlet temperature correction value OTC is expected to remain within the design temperature range. This can improve the thermal efficiency of the gas turbine at low load, effectively expand the gas turbine load operating range and primary frequency regulation operating range, achieve deep peak regulation, and also help the steam parameters generated by the waste heat boiler to meet the requirements of the steam turbine and heat users;

[0037] The above transformation provides hardware capability guarantee for further closing of IGV, but under actual operating conditions, the lower limit of IGV adjustable opening is a dynamic value, which is determined by many factors and needs to be calculated. As a preferred solution for optimizing the control logic of IGV described in the present invention, the study is conducted to calculate the minimum opening of IGV that can be adjusted under the premise of appropriate safety margin under extreme boundary conditions including atmospheric temperature and humidity, compressor airflow angle of attack, compressor flow and pressure ratio, compressor surge boundary and other factors. min2 ;

[0038] After the transformation is completed, the lower limit value that IGV can actually adjust is the above IGV min1 and IGV min2 The larger value of the two is defined as IGV min , which is a dynamically calculated value that changes with boundary conditions.

[0039] After the above transformation is completed, in order to further improve the deep peak regulation range of the gas turbine, the anti-icing valve control logic needs to be optimized. Under certain operating conditions (such as ambient temperature below 0°C), due to the decrease in AGC load command, the IGV has been closed to IGVmin Position, if the load command continues to decrease, the turbine outlet temperature will gradually decrease because the IGV can no longer regulate the air entering the combustion chamber.

[0040] The present invention utilizes an anti-freezing valve and a corresponding system for modification. Under the premise of not affecting the compressor surge boundary, a portion of the compressor outlet air is diverted to the compressor inlet to reduce the amount of air entering the combustion chamber. When the engine load continues to decrease, the decrease in turbine outlet temperature can be avoided or reduced to a certain extent.

[0041] Among them, the anti-icing valve issues an opening command α% through closed-loop control, heating the compressor inlet air temperature to a dew point temperature 2k higher than the corresponding ambient temperature and humidity at that time; at the same time, the anti-icing valve issues an opening command β% through the added closed-loop control logic, and also participates in adjusting the turbine outlet temperature to the set value. The final command output comes from the larger value of α% and β%.

[0042] An embodiment of the present invention provides a method for controlling gas turbine performance improvement under deep peak load conditions, and the specific steps are as follows:

[0043] Step S1: establishing a compressor flow and pressure ratio model within the operating range of the diffusion IGV, determining a surge boundary curve and a margin value; and establishing a relationship between the compressor flow and the airflow attack angle;

[0044] Step S2: Establishing a calculation model and a multivariable function for the minimum IGV opening that can avoid surface airflow separation and surge of the compressor blades under specific boundary conditions, that is, IGVmin2 = f(x1, x2, x3...);

[0045] Step S3: Determine the minimum opening function that the IGV can actually achieve.

[0046] IGVmin=MAX(IGVmin1,IGVmin2).

[0047] Step S4: Optimizing the IGV temperature control logic, specifically including: IGV feedforward control function, IGV flow and IGV opening function, etc., so that the IGV has the ability to participate in the automatic adjustment control of the turbine outlet temperature within the extended range; optimizing the primary frequency modulation control, so that the gas turbine has the primary frequency modulation function within the extended IGV adjustment range;

[0048] Step S5: Add deep peak-shaving switching logic, that is, when the deep peak-shaving function is activated, the adjustment range of IGV is IGVmin-100%; when the deep peak-shaving function is exited, IGV returns to the original adjustment range, that is, 0-100%;

[0049] Step S6: Add deep peak load regulation input condition judgment logic and abnormal working condition protection exit deep peak load regulation function related logic to ensure the safe and reliable operation of deep peak load regulation function;

[0050] Step S7: Optimizing the IGV switch rate and the engine load setting value change rate under different working conditions to ensure that no abnormal fluctuation of the turbine outlet temperature correction value OTC is caused;

[0051] Step S8: Add de-icing valve related control logic. When the IGV is closed to the IGVmin position and no longer has the function of adjusting the turbine outlet temperature, the closed-loop control of the de-icing valve can take over and participate in the deep peak regulation control, thereby expanding the deep peak regulation capability of the gas turbine.

[0052] Step S9: Add an operation screen to facilitate power plant operators to confirm whether the deep peak-shaving function meets the regulation requirements, activate and deactivate the deep peak-shaving function, and judge the operation status of the deep peak-shaving regulation.

[0053] The method for extending the IGV adjustment range is specifically as follows:

[0054] S1: Adjustment Figure 1 The IGV ring mechanical limit 1 ensures that the IGV can participate in the adjustment within the extended range.

[0055] S2: Adjustment Figure 1 The IGV actuator mechanical limit 2 ensures that the IGV connecting rod can participate in the adjustment within the extended stroke range.

[0056] S3: Transformation Figure 1 The IGV connecting rod 3 in the middle is optimized in length to ensure that the IGV extends the adjustment angle range and moves as a whole in the closing direction by a certain angle.

[0057] S4: Adjustment Figure 1 The limit switch of the AUMA motor 4 and the screw limit of the AUMA motor ensure that the AUMA motor can drive the connecting rod to adjust the IGV to the extended angle range.

[0058] S5: Adjust the configuration parameters of the IGV transmitter 5 so that it can display the expanded IGV opening value (%).

[0059] S6: Determine the minimum opening IGVmin1 that the IGV can achieve on the machine.

[0060] The present invention proposes a method for improving the low-load performance of a certain type of Siemens gas turbine by transforming the hardware and control logic of the existing IGV and de-icing valve, increasing the lower limit of the peak-shaving operation load of the unit, reducing the heat consumption during low-load operation, improving combustion stability, continuously improving NOx emissions, and ensuring safe and efficient operation of the unit.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas turbine performance improvement control system under deep peak load conditions, characterized in that: The invention comprises an IGV actuator; the IGV actuator comprises an IGV ring mechanical limiter (1), an IGV actuator mechanical limiter (2), an IGV connecting rod (3), an AUMA motor (4) and an IGV transmitter (5); the IGV actuator is used to control the opening of the intake guide vane, thereby affecting the volume flow rate and flow velocity of air flowing into the gas turbine; The IGV ring mechanical limiter (1) is used to provide a physical limit for the opening of the IGV, ensuring that the guide vanes operate within a safe range and preventing damage caused by excessive opening; The IGV actuator mechanical limiter (2) is used to further ensure the motion range of the actuator and protect the overall stability of the system; The IGV connecting rod (3) connects the IGV and the actuator to transmit the movement of the actuator to the IGV; The AUMA motor (4) is a driving element responsible for controlling the opening of the IGV and driving the connecting rod through rotational motion; The IGV transmitter (5) is used to measure the opening of the IGV in real time and feed the data back to the control system for real-time adjustment.

2. A method for improving the performance of a gas turbine under deep peak load conditions, characterized in that: The specific steps are as follows: Step S1: establishing a compressor flow and pressure ratio model within the operating range of the diffusion IGV, determining a surge boundary curve and a margin value; and establishing a relationship between the compressor flow and the airflow attack angle; Step S2: Establishing a calculation model and a multivariable function for the minimum IGV opening that can avoid surface airflow separation and surge of the compressor blades under specific boundary conditions, that is, IGVmin2 = f(x1, x2, x3...); Step S3: Determine the minimum opening function that the IGV can actually reach, IGVmin=MAX(IGVmin1,IGVmin2). Step S4: Optimizing the IGV temperature control logic, specifically including: IGV feedforward control function, IGV flow and IGV opening function, etc., so that the IGV has the ability to participate in the automatic adjustment control of the turbine outlet temperature within the extended range; optimizing the primary frequency modulation control, so that the gas turbine has the primary frequency modulation function within the extended IGV adjustment range; Step S5: Add deep peak-shaving switching logic, that is, when the deep peak-shaving function is activated, the adjustment range of IGV is IGVmin-100%; when the deep peak-shaving function is exited, IGV returns to the original adjustment range, that is, 0-100%; Step S6: Add deep peak load regulation input condition judgment logic and abnormal working condition protection exit deep peak load regulation function related logic to ensure the safe and reliable operation of deep peak load regulation function; Step S7: Optimizing the IGV switch rate and the engine load setting value change rate under different working conditions to ensure that no abnormal fluctuation of the turbine outlet temperature correction value OTC is caused; Step S8: Add de-icing valve related control logic. When the IGV is closed to the IGVmin position and no longer has the function of adjusting the turbine outlet temperature, the closed-loop control of the de-icing valve can take over and participate in the deep peak regulation control, thereby expanding the deep peak regulation capability of the gas turbine. Step S9: Add an operation screen to facilitate power plant operators to confirm whether the conditions for putting the deep peak-shaving function into use are met, to put the deep peak-shaving function into or out of use, and to monitor the operation of the deep peak-shaving regulation.

3. The method for improving the performance of a gas turbine under deep peak load conditions according to claim 2, characterized in that: In step S2, the extreme boundary conditions include factors such as atmospheric temperature and humidity, compressor airflow angle of attack, compressor flow and pressure ratio, compressor surge boundary, etc., and the minimum opening IGV that can be adjusted with an appropriate safety margin is calculated. min2 .

4. The method for improving the performance of a gas turbine under deep peak load conditions according to claim 2, characterized in that: In step S8, in order to further improve the deep peak regulation range of the gas turbine, the anti-icing valve control logic needs to be optimized; under specific operating conditions (such as ambient temperature below 0°C), due to the decrease in AGC load command, the IGV has been closed to IGV min Position, if the load command continues to decrease, the turbine outlet temperature will gradually decrease because the IGV can no longer regulate the air entering the combustion chamber; in order to avoid or reduce the decrease in turbine outlet temperature to a certain extent, without affecting the compressor surge boundary, a part of the compressor outlet air is diverted to the compressor inlet to reduce the amount of air entering the combustion chamber; specifically, the anti-icing valve issues an opening command α% through closed-loop control to heat the compressor inlet air temperature to a dew point temperature of more than 2k higher than the corresponding ambient temperature and humidity; at the same time, the anti-icing valve issues an opening command β% through the added closed-loop control logic, and also participates in adjusting the turbine outlet temperature to the set value, and the final command output comes from the larger value of α% and β%.

5. The method for improving the performance of a gas turbine under deep peak load conditions according to claim 2, characterized in that: The method for extending the IGV adjustment range is specifically as follows: S1: Adjust the IGV ring mechanical limit (1) in Figure 1 to ensure that the IGV can participate in the regulation within the extended range; S2: Adjust the mechanical limit (2) of the IGV actuator in FIG1 to ensure that the IGV connecting rod can participate in the adjustment within the extended travel range; S3: Modify the IGV connecting rod (3) in Figure 1 and optimize its length to ensure that the IGV expands the adjustment angle range and moves in the closing direction as a whole by a certain angle; S4: Adjust the limit switch of the AUMA motor (4) in FIG. 1 and the screw limit of the AUMA motor to ensure that the AUMA motor can drive the connecting rod and adjust the IGV to the extended angle range; S5: adjusting the configuration parameters of the IGV transmitter (5) so that it can display the expanded IGV opening value (%); S6: Determine the minimum opening IGVmin1 that the IGV can achieve on the machine.

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