Method and system for participating in thermal power generating unit coordination control based on high-pressure heater steam extraction throttling

Abstract

The invention discloses a method and system for participating in thermal power generating unit coordination control based on high-pressure heater steam extraction throttling, and relates to the technical field of thermal power generating unit coordination control. Obtaining a main steam pressure deviation value; the main steam pressure deviation value is input into a PID control module to be adjusted, and a steam turbine adjusting valve opening degree instruction, a No.7 high-pressure heater steam inlet adjusting valve opening degree instruction and a boiler fuel quantity instruction are generated; and coordination control of the unit load is carried out. Through high-pressure heater steam extraction throttling and PID adjustment, quick response and accurate adjustment of unit loads are achieved, the requirement for flexibility of a power grid is met, accurate adjustment of main steam pressure is ensured through real-time monitoring and feedback control, load fluctuation is reduced, system stability is improved, meanwhile, energy utilization is optimized through accurate fuel control, waste is avoided, and the energy consumption is reduced. An amplitude limiting and high-low speed limiting module is introduced to guarantee equipment safety, load fluctuation is rapidly adapted, and system flexibility and power supply stability are improved.

Description

Technical Field

[0001] This invention relates to the field of coordinated control technology for thermal power units, specifically to a method and system for coordinated control of thermal power units based on high-pressure heater extraction steam throttling. Background Technology

[0002] As the global energy structure transitions towards cleaner and lower-carbon energy, the installed capacity and grid-connected scale of renewable energy continue to expand. However, renewable energy power generation is significantly affected by natural conditions, and its output power is intermittent and fluctuating, posing a severe challenge to the stable operation of the power grid. As the core supporting power source of the power grid, thermal power units are shifting from traditional baseload power sources to peak-shaving power sources, facing the dual tasks of improving flexibility and ensuring safety. The flexibility of thermal power units is mainly reflected in two aspects: rapid load change and deep peak shaving. The former requires the units to have a faster load adjustment rate and higher adjustment accuracy to smooth out the fluctuations of renewable energy. The latter requires the units to reduce the load lower limit from the traditional 45% rated load to 30% or even lower to meet the load demand of the power grid during off-peak periods. To achieve this goal, the industry has explored various technical approaches, such as adjusting boiler feedwater flow, utilizing turbine bypass systems, condensate throttling, and low-pressure heater extraction steam control. However, these methods all have significant limitations, including: boiler-side adjustment limitations: while rapid adjustments to feedwater flow or desuperheating water volume can utilize boiler heat storage, they easily lead to drastic fluctuations in main steam temperature, which, in the long run, will exacerbate wear and corrosion of boiler heating surfaces and shorten equipment life; adjusting unit load by changing condensate flow can easily cause large fluctuations in deaerator water level, requiring a complex water level control system, and the adjustment response speed is slow; changes in low-pressure heater extraction steam flow have a small adjustment range on unit load, making it difficult to meet the grid's requirements for rapid load changes; adjusting the deaerator extraction steam volume can easily cause insufficient deoxygenation of boiler feedwater, leading to pipeline oxygen corrosion, and also causing fluctuations in deaerator water level, increasing the difficulty of system control.

[0003] Therefore, existing technologies struggle to balance rapid load changes, deep peak shaving, and equipment safety. There is an urgent need for a coordinated control technology for thermal power units that can efficiently utilize the unit's heat storage, improve regulation response speed, avoid equipment damage, and ensure system stability. Summary of the Invention

[0004] To address the aforementioned technical problems, a method and system for coordinated control of thermal power units based on high-pressure steam extraction throttling is provided. This technical solution solves the problems mentioned above.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for coordinated control of thermal power units based on high-pressure steam extraction throttling includes: Based on the thermal power unit operation monitoring equipment, the actual value of the turbine power, the actual value of the main steam pressure, the design value of the turbine power and the design value of the main steam pressure are obtained, and the unit operation dataset is generated. Based on the unit operation dataset, the design value of main steam pressure and the actual value of main steam pressure are input into the difference calculation module to obtain the main steam pressure deviation value. The main steam pressure deviation value is input into the PID control module for adjustment. After the amplitude limiting module limits the adjustment range and the high and low speed limiting module controls the adjustment rate, the turbine regulating valve opening command, the No. 7 high-pressure heater inlet steam regulating valve opening command and the boiler fuel quantity command are generated respectively. Based on the generated turbine regulating valve opening command, No. 7 high-pressure heater steam inlet regulating valve opening command, and boiler fuel quantity command, the turbine regulating valve, No. 7 high-pressure heater steam inlet regulating valve, and boiler fuel supply device are controlled respectively to achieve coordinated control of unit load and improve the unit's ability to quickly change load.

[0006] Preferably, the step of acquiring the actual value of the turbine power, the actual value of the main steam pressure, the design value of the turbine power, and the design value of the main steam pressure based on the thermal power unit operation monitoring equipment, and generating the unit operation dataset specifically includes: The actual power values ​​of the steam turbine at different operating times are obtained based on the power sensor of the thermal power unit, with the sampling interval set to 1 to 5 seconds; The actual value of the main steam pressure in the main steam pipeline at different operating times is obtained based on the main steam pressure sensor, and the sampling accuracy is controlled within ±0.05MPa; Retrieve the turbine power design value and main steam pressure design value that match the current unit model from the unit design parameter database. The design values ​​must meet the operating standards of the unit under rated operating conditions. The actual values ​​of turbine power, main steam pressure, turbine power design value, and main steam pressure design value are obtained and stored in a time series to generate a unit operation dataset.

[0007] Preferably, the step of inputting the design value of the main steam pressure and the actual value of the main steam pressure into the difference calculation module to obtain the deviation value of the main steam pressure specifically includes: The main steam pressure deviation value is obtained by subtracting the actual main steam pressure value from the design main steam pressure value. The units of the main steam pressure deviation value, the design main steam pressure value, and the actual main steam pressure value are all MPa. When the calculated main steam pressure deviation value is positive, it indicates that the actual main steam pressure value is lower than the design value. When the calculated main steam pressure deviation value is negative, it indicates that the actual main steam pressure value is higher than the design value.

[0008] Preferably, the step of inputting the main steam pressure deviation value into the PID control module for adjustment, and then limiting the adjustment range through the amplitude limiting module and controlling the adjustment rate through the high and low speed limiting modules, respectively generating the turbine regulating valve opening command, the No. 7 high-pressure heater inlet steam regulating valve opening command, and the boiler fuel quantity command specifically includes: The proportional coefficient of the PID control module is set between 0.5 and 2.0, the integral time is set between 10 and 30 seconds, and the derivative time is set between 1 and 5 seconds. The PID control module is used to adjust the main steam pressure deviation value and output the basic control signal. The limiting module restricts the control signal range of the turbine regulating valve opening to 20% to 100%, the control signal range of the No. 7 high-pressure heater steam inlet regulating valve opening to 0% to 100%, and the control signal range of the boiler fuel quantity to 30% to 100% of the rated fuel quantity. The high and low speed limiting module controls the rate of change of the turbine regulating valve opening to between 0.5% and 2% per second, the rate of change of the No. 7 high-pressure steam inlet regulating valve opening to between 1% and 3% per second, and the rate of change of the boiler fuel quantity to between 0.3% and 1.5% of the rated fuel quantity per second. Based on the control signals after the amplitude and speed limits are set, corresponding steam turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands are generated respectively.

[0009] Preferably, the step of controlling the turbine regulating valve, the No. 7 high-pressure heater inlet steam regulating valve, and the boiler fuel supply device respectively according to the generated turbine regulating valve opening command, the No. 7 high-pressure heater inlet steam regulating valve opening command, and the boiler fuel quantity command, to achieve coordinated control of the unit load and improve the unit's rapid load change capability, specifically includes: After receiving the opening command, the steam turbine regulating valve adjusts the valve opening through the electric actuator, thereby changing the steam flow rate entering the high-pressure cylinder of the steam turbine and thus adjusting the steam turbine output power. After receiving the opening command, the No. 7 high-pressure heater inlet steam regulating valve adjusts the steam extraction flow rate into the No. 7 high-pressure heater, thereby adjusting the effective enthalpy drop of the steam turbine by changing the steam extraction flow rate. After receiving the fuel quantity command, the boiler fuel supply device adjusts the coal feeder or the gas supply of the burner to change the boiler's heat load and provide stable steam support for unit load changes. Through the coordinated control of these three systems, the load change rate of the unit can be increased to between 2% and 5% of the rated load per minute when the load changes, and the load regulation accuracy can be controlled within ±1% of the rated load, thus meeting the grid's requirements for the unit's flexibility.

[0010] Preferably, the adjustment process of the No. 7 high-pressure heater steam inlet regulating valve also includes a step of monitoring and compensating for the feedwater temperature of the No. 7 high-pressure heater, specifically including: Based on the feedwater temperature sensor at the outlet of the No. 7 high-pressure heater, the actual value of the feedwater temperature is obtained in real time. Compare the actual water temperature with the design temperature. If the deviation between the two exceeds ±3℃, a compensation adjustment signal is sent to the No. 7 high-pressure steam inlet regulating valve. The compensation adjustment signal adjusts the opening of the No. 7 high-pressure steam inlet regulating valve proportionally according to the size of the temperature deviation. The larger the temperature deviation, the larger the opening adjustment range, and the maximum adjustment range does not exceed 10%, so as to ensure that the feedwater temperature is stable within the design range.

[0011] A coordinated control system for thermal power units based on high-pressure steam extraction throttling, comprising: The data acquisition module is used to obtain the actual value of turbine power, the actual value of main steam pressure, the design value of turbine power, and the design value of main steam pressure, and generate the unit operation dataset; The deviation calculation module is electrically connected to the data acquisition module. It is used to calculate the difference between the design value and the actual value of the main steam pressure to obtain the deviation value of the main steam pressure. The control command generation module is electrically connected to the deviation calculation module. The control command generation module includes a PID control unit, a limiting unit, and a high and low speed limiting unit. It is used to process the main steam pressure deviation value and generate turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands. The execution control module is electrically connected to the control command generation module. The execution control module includes a turbine valve control unit, a high-pressure heater inlet valve control unit, and a boiler fuel control unit. It is used to control the operation of relevant equipment according to the corresponding control commands to achieve coordinated control of unit load.

[0012] Preferably, the data acquisition module includes: The power acquisition unit is connected to the power sensor at the turbine shaft end. It uses the Hall effect principle to acquire the turbine power signal. The sampling frequency is set between 50 and 100 Hz. The acquired analog signal is converted into a digital signal and then transmitted to the data storage unit. The pressure acquisition unit is connected to the pressure sensor on the main steam pipeline. It uses piezoelectric sensing technology to acquire the main steam pressure signal. The measurement range covers 0 to 25 MPa. The acquired data is filtered and then transmitted to the data storage unit. The design parameter retrieval unit connects to the unit design parameter database via Ethernet and retrieves the corresponding turbine power design value and main steam pressure design value based on the unit's unique equipment number. The data storage unit uses a solid-state drive to store the data obtained by the power acquisition unit, pressure acquisition unit, and design parameter retrieval unit in association with timestamps, forming a unit operation dataset with a storage capacity of not less than 1TB and a data retention period of not less than 1 year.

[0013] Preferably, the control command generation module includes: The PID control unit receives the main steam pressure deviation value output by the deviation calculation module, has built-in adjustable proportional, integral, and derivative parameters, calculates the deviation value through the PID algorithm, and outputs the basic control signal. The limiting unit is connected to the PID control unit. It presets a range of values ​​for different controlled objects and limits the range of the basic control signal to prevent the equipment from operating outside the range. High and low speed limiting unit, which is connected to the amplitude limiting unit, sets the maximum rate of change of different control signals to prevent sudden changes in control signals from causing equipment damage or unstable unit operation. The command distribution unit is connected to the high and low speed limiting unit. It distributes the processed control signals into turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands, and sends them to the corresponding execution units.

[0014] Preferably, the execution control module includes: The turbine valve control unit is connected to the electric actuator of the turbine regulating valve. After receiving the opening command, it drives the valve core to move through the servo motor and feeds back the actual valve opening to the control command generation module in real time to form a closed-loop control. The high-pressure heater steam inlet valve control unit is connected to the pneumatic actuator of the No. 7 high-pressure heater steam inlet regulating valve. After receiving the opening command, it adjusts the compressed air pressure to control the valve opening. At the same time, it receives the feed water temperature deviation signal through the temperature compensation subunit and compensates and adjusts the valve opening. The boiler fuel control unit is connected to the control module of the coal feeder or gas burner. After receiving the fuel quantity command, it adjusts the speed of the coal feeder or the opening of the gas valve of the burner to control the fuel supply and ensure the stability of the boiler heat load. The operation monitoring subunit is connected to each control unit and collects turbine power, main steam pressure and feedwater temperature parameters in real time. If the parameters exceed the safe range, an alarm signal is immediately sent and an emergency shutdown procedure is triggered.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes to achieve rapid response and precise regulation of unit load through high-pressure steam extraction throttling and PID control, with a maximum regulation rate of 2% to 5% of rated load, meeting the grid flexibility requirements. Real-time monitoring and feedback control ensure precise regulation of main steam pressure, reducing load fluctuations and improving system stability. At the same time, precise fuel control optimizes energy utilization and avoids waste. The introduction of limiting and high / low speed modules ensures equipment safety, quickly adapts to load fluctuations, and improves system flexibility and power supply stability. Based on data-driven decision support, the system's intelligence level is further enhanced. Attached Figure Description

[0016] Figure 1 This is a flowchart of the steps of the present invention; Figure 2 This is a system framework diagram of the present invention. Detailed Implementation

[0017] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0018] Reference Figure 1 As shown, a method for coordinated control of thermal power units based on high-pressure steam extraction throttling includes: Based on the thermal power unit operation monitoring equipment, the actual value of the turbine power, the actual value of the main steam pressure, the design value of the turbine power and the design value of the main steam pressure are obtained, and the unit operation dataset is generated. Based on the unit operation dataset, the design value of main steam pressure and the actual value of main steam pressure are input into the difference calculation module to obtain the main steam pressure deviation value. The main steam pressure deviation value is input into the PID control module for adjustment. After the amplitude limiting module limits the adjustment range and the high and low speed limiting module controls the adjustment rate, the turbine regulating valve opening command, the No. 7 high-pressure heater inlet steam regulating valve opening command and the boiler fuel quantity command are generated respectively. Based on the generated turbine regulating valve opening command, No. 7 high-pressure heater steam inlet regulating valve opening command, and boiler fuel quantity command, the turbine regulating valve, No. 7 high-pressure heater steam inlet regulating valve, and boiler fuel supply device are controlled respectively to achieve coordinated control of unit load and improve the unit's ability to quickly change load.

[0019] The process of acquiring actual turbine power, actual main steam pressure, design turbine power, and design main steam pressure values ​​from the thermal power unit operation monitoring equipment, and generating a unit operation dataset specifically includes: The actual power values ​​of the steam turbine at different operating times are obtained based on the power sensor of the thermal power unit, with the sampling interval set to 1 to 5 seconds; The actual value of the main steam pressure in the main steam pipeline at different operating times is obtained based on the main steam pressure sensor, and the sampling accuracy is controlled within ±0.05MPa; Retrieve the turbine power design value and main steam pressure design value that match the current unit model from the unit design parameter database. The design values ​​must meet the operating standards of the unit under rated operating conditions. The actual values ​​of turbine power, main steam pressure, turbine power design value, and main steam pressure design value are obtained and stored in a time series to generate a unit operation dataset. A multi-dimensional data fusion mechanism combining real-time acquisition, design parameter retrieval, and time-series correlation was established, and quantitative standards for power sampling intervals and pressure sampling accuracy were defined to ensure data timeliness and accuracy. By binding and storing dynamic operating data with the unit's rated operating condition design values, a standardized data foundation was provided for subsequent deviation calculations and control adjustments, avoiding the blind control caused by the lack of design benchmarks in traditional data acquisition. The step of inputting the design value of the main steam pressure and the actual value of the main steam pressure into the difference calculation module to obtain the deviation value of the main steam pressure specifically includes: The main steam pressure deviation value is obtained by subtracting the actual main steam pressure value from the design main steam pressure value. The units of the main steam pressure deviation value, the design main steam pressure value, and the actual main steam pressure value are all MPa. When the calculated main steam pressure deviation value is positive, it indicates that the actual main steam pressure value is lower than the design value. When the calculated main steam pressure deviation value is negative, it indicates that the actual main steam pressure value is higher than the design value. By adopting the calculation rule of the difference between the design value and the actual value, and clarifying the pressure state judgment criteria corresponding to the positive and negative values ​​of the deviation, the physical meaning of the pressure deviation is made more intuitive. This design abandons the traditional fuzzy deviation description and provides a clear and quantifiable input signal for the PID control module, ensuring the accuracy of the control direction.

[0020] The process of inputting the main steam pressure deviation value into the PID control module for adjustment, then limiting the adjustment range through the amplitude limiting module and controlling the adjustment rate through the high and low speed limiting modules, and generating turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands, specifically includes: The proportional coefficient of the PID control module is set between 0.5 and 2.0, the integral time is set between 10 and 30 seconds, and the derivative time is set between 1 and 5 seconds. The PID control module is used to adjust the main steam pressure deviation value and output the basic control signal. The limiting module restricts the control signal range of the turbine regulating valve opening to 20% to 100%, the control signal range of the No. 7 high-pressure heater steam inlet regulating valve opening to 0% to 100%, and the control signal range of the boiler fuel quantity to 30% to 100% of the rated fuel quantity. The high and low speed limiting module controls the rate of change of the turbine regulating valve opening to between 0.5% and 2% per second, the rate of change of the No. 7 high-pressure steam inlet regulating valve opening to between 1% and 3% per second, and the rate of change of the boiler fuel quantity to between 0.3% and 1.5% of the rated fuel quantity per second. Based on the control signals after the amplitude and speed limits are set, corresponding steam turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands are generated respectively.

[0021] The process of controlling the turbine regulating valve, the No. 7 high-pressure heater inlet steam regulating valve, and the boiler fuel quantity command based on the generated commands to achieve coordinated control of the unit load and improve the unit's ability to rapidly change load specifically includes: After receiving the opening command, the steam turbine regulating valve adjusts the valve opening through the electric actuator, thereby changing the steam flow rate entering the high-pressure cylinder of the steam turbine and thus adjusting the steam turbine output power. After receiving the opening command, the No. 7 high-pressure heater inlet steam regulating valve adjusts the steam extraction flow rate into the No. 7 high-pressure heater, thereby adjusting the effective enthalpy drop of the steam turbine by changing the steam extraction flow rate. After receiving the fuel quantity command, the boiler fuel supply device adjusts the coal feeder or the gas supply of the burner to change the boiler's heat load and provide stable steam support for unit load changes. Through the coordinated control of these three systems, the load change rate of the unit can be increased to between 2% and 5% of the rated load per minute when the load changes, and the load regulation accuracy can be controlled within ±1% of the rated load, thus meeting the grid's requirements for the unit's flexibility.

[0022] The adjustment process of the No. 7 high-pressure heater steam inlet regulating valve also includes the monitoring and compensation steps for the feedwater temperature of the No. 7 high-pressure heater, specifically including: Based on the feedwater temperature sensor at the outlet of the No. 7 high-pressure heater, the actual value of the feedwater temperature is obtained in real time. Compare the actual water temperature with the design temperature. If the deviation between the two exceeds ±3℃, a compensation adjustment signal is sent to the No. 7 high-pressure steam inlet regulating valve. The compensation adjustment signal adjusts the opening of the No. 7 high-pressure steam inlet regulating valve proportionally according to the size of the temperature deviation. The larger the temperature deviation, the larger the opening adjustment range, and the maximum adjustment range does not exceed 10%, so as to ensure that the feedwater temperature is stable within the design range.

[0023] Reference Figure 2 As shown, a coordinated control system for thermal power units based on high-pressure steam extraction throttling includes: The data acquisition module is used to obtain the actual value of turbine power, the actual value of main steam pressure, the design value of turbine power, and the design value of main steam pressure, and generate the unit operation dataset; The deviation calculation module is electrically connected to the data acquisition module. It is used to calculate the difference between the design value and the actual value of the main steam pressure to obtain the deviation value of the main steam pressure. The control command generation module is electrically connected to the deviation calculation module. The control command generation module includes a PID control unit, a limiting unit, and a high and low speed limiting unit. It is used to process the main steam pressure deviation value and generate turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands. The execution control module is electrically connected to the control command generation module. The execution control module includes a turbine valve control unit, a high-pressure heater inlet valve control unit, and a boiler fuel control unit. It is used to control the operation of relevant equipment according to the corresponding control commands to achieve coordinated control of unit load.

[0024] The data acquisition module includes: The power acquisition unit is connected to the power sensor at the turbine shaft end. It uses the Hall effect principle to acquire the turbine power signal. The sampling frequency is set between 50 and 100 Hz. The acquired analog signal is converted into a digital signal and then transmitted to the data storage unit. The pressure acquisition unit is connected to the pressure sensor on the main steam pipeline. It uses piezoelectric sensing technology to acquire the main steam pressure signal. The measurement range covers 0 to 25 MPa. The acquired data is filtered and then transmitted to the data storage unit. The design parameter retrieval unit connects to the unit design parameter database via Ethernet and retrieves the corresponding turbine power design value and main steam pressure design value based on the unit's unique equipment number. The data storage unit uses a solid-state drive to store the data obtained by the power acquisition unit, pressure acquisition unit, and design parameter retrieval unit in association with timestamps, forming a unit operation dataset with a storage capacity of not less than 1TB and a data retention period of not less than 1 year.

[0025] The control command generation module includes: The PID control unit receives the main steam pressure deviation value output by the deviation calculation module, has built-in adjustable proportional, integral, and derivative parameters, calculates the deviation value through the PID algorithm, and outputs the basic control signal. The limiting unit is connected to the PID control unit. It presets a range of values ​​for different controlled objects and limits the range of the basic control signal to prevent the equipment from operating outside the range. High and low speed limiting unit, which is connected to the amplitude limiting unit, sets the maximum rate of change of different control signals to prevent sudden changes in control signals from causing equipment damage or unstable unit operation. The instruction distribution unit is connected to the high and low speed limiting unit. It distributes the processed control signals into turbine regulating valve opening instructions, No. 7 high-pressure heater steam inlet regulating valve opening instructions, and boiler fuel quantity instructions, and sends them to the corresponding execution units. Based on traditional PID control, three processing units—amplitude limiting, high and low speed limiting, and command distribution—are added to form a complete signal processing chain encompassing deviation adjustment, range constraint, rate control, and command distribution. The command distribution unit design enables precise distribution of a single basic control signal to three types of objects, solving the problem of coarse signal processing and easy equipment malfunction caused by traditional control modules.

[0026] The execution control module includes: The turbine valve control unit is connected to the electric actuator of the turbine regulating valve. After receiving the opening command, it drives the valve core to move through the servo motor and feeds back the actual valve opening to the control command generation module in real time to form a closed-loop control. The high-pressure heater steam inlet valve control unit is connected to the pneumatic actuator of the No. 7 high-pressure heater steam inlet regulating valve. After receiving the opening command, it adjusts the compressed air pressure to control the valve opening. At the same time, it receives the feed water temperature deviation signal through the temperature compensation subunit and compensates and adjusts the valve opening. The boiler fuel control unit is connected to the control module of the coal feeder or gas burner. After receiving the fuel quantity command, it adjusts the speed of the coal feeder or the opening of the gas valve of the burner to control the fuel supply and ensure the stability of the boiler heat load. The operation monitoring subunit is connected to each control unit and collects turbine power, main steam pressure and feedwater temperature parameters in real time. If the parameters exceed the safe range, an alarm signal is immediately sent and an emergency shutdown procedure is triggered.

[0027] In summary, the advantages of this invention are: Through high-pressure steam extraction throttling control and PID regulation, the unit load can be rapidly responded to in a short time. The maximum load regulation rate can reach 2% to 5% of the rated load per minute, meeting the grid's requirements for unit flexibility. By real-time monitoring and feedback control of the main steam pressure, combined with PID algorithm regulation control, the precise regulation of the main steam pressure deviation is ensured, the fluctuations that may occur during load changes are reduced, and the stability of the system is guaranteed. By precisely controlling the boiler fuel quantity command, the fuel supply can be adjusted, making the boiler load adjustment more refined, avoiding unnecessary fuel waste, and improving energy utilization efficiency. The present invention also introduces a limiting module and a high and low speed limiting module, which effectively avoid overload or instability caused by excessively fast adjustment of the equipment by limiting the adjustment range and adjustment rate, thus ensuring the safety and reliability of the equipment. The coordinated control method of the present invention can adapt to different load fluctuations, especially when the power grid load demand fluctuates greatly, it can quickly adjust the operating status of the unit and ensure the stability of power supply. By using high-pressure heater extraction steam throttling and real-time temperature compensation, the No. 7 high-pressure heater inlet steam regulating valve can be compensated and adjusted according to the actual operating conditions, thereby improving the overall operational flexibility of the unit. Based on the data acquisition and storage of thermal power unit operation monitoring equipment, rich real-time data support is provided for subsequent load regulation, enabling the system to make optimized decisions under different operating conditions and further improving the system's intelligence level.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for coordinated control of thermal power units based on high-pressure steam extraction throttling, characterized in that, include: Based on the thermal power unit operation monitoring equipment, the actual value of the turbine power, the actual value of the main steam pressure, the design value of the turbine power and the design value of the main steam pressure are obtained, and the unit operation dataset is generated. Based on the unit operation dataset, the design value of main steam pressure and the actual value of main steam pressure are input into the difference calculation module to obtain the main steam pressure deviation value. The main steam pressure deviation value is input into the PID control module for adjustment. After the amplitude limiting module limits the adjustment range and the high and low speed limiting module controls the adjustment rate, the turbine regulating valve opening command, the No. 7 high-pressure heater inlet steam regulating valve opening command and the boiler fuel quantity command are generated respectively. Based on the generated turbine regulating valve opening command, No. 7 high-pressure heater steam inlet regulating valve opening command, and boiler fuel quantity command, the turbine regulating valve, No. 7 high-pressure heater steam inlet regulating valve, and boiler fuel supply device are controlled respectively to coordinate the load control of the unit.

2. The method for coordinated control of thermal power units based on high-pressure steam extraction throttling according to claim 1, characterized in that, The process of acquiring actual turbine power, actual main steam pressure, design turbine power, and design main steam pressure values ​​from the thermal power unit operation monitoring equipment, and generating a unit operation dataset specifically includes: The actual power value of the steam turbine at different operating times is obtained based on the power sensor of the thermal power unit; The actual values ​​of the main steam pressure at different operating times in the main steam pipeline are obtained based on the main steam pressure sensor. Retrieve the turbine power design value and main steam pressure design value that match the current unit model from the unit design parameter database. The design values ​​must meet the operating standards of the unit under rated operating conditions. The actual values ​​of turbine power, main steam pressure, turbine power design value, and main steam pressure design value are obtained and stored in a time series to generate a unit operation dataset.

3. The method for coordinated control of thermal power units based on high-pressure steam extraction throttling according to claim 2, characterized in that, The step of inputting the design value of the main steam pressure and the actual value of the main steam pressure into the difference calculation module to obtain the deviation value of the main steam pressure specifically includes: The main steam pressure deviation value is obtained by subtracting the actual main steam pressure value from the design value. When the calculated main steam pressure deviation value is positive, it indicates that the actual main steam pressure value is lower than the design value. When the calculated main steam pressure deviation value is negative, it indicates that the actual main steam pressure value is higher than the design value.

4. The method for coordinated control of thermal power units based on high-pressure steam extraction throttling according to claim 3, characterized in that, The process of inputting the main steam pressure deviation value into the PID control module for adjustment, then limiting the adjustment range through the amplitude limiting module and controlling the adjustment rate through the high and low speed limiting modules, and generating turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands, specifically includes: The main steam pressure deviation is adjusted by the PID control module, and a basic control signal is output. The limiting module restricts the control signal range of the turbine regulating valve opening to 20% to 100%, the control signal range of the No. 7 high-pressure heater steam inlet regulating valve opening to 0% to 100%, and the control signal range of the boiler fuel quantity to 30% to 100% of the rated fuel quantity. The high and low speed limiting module controls the rate of change of the turbine regulating valve opening to between 0.5% and 2% per second, the rate of change of the No. 7 high-pressure steam inlet regulating valve opening to between 1% and 3% per second, and the rate of change of the boiler fuel quantity to between 0.3% and 1.5% of the rated fuel quantity per second. Based on the control signals after the amplitude and speed limits are set, corresponding steam turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands are generated respectively.

5. The method for coordinated control of thermal power units based on high-pressure steam extraction throttling according to claim 4, characterized in that, The process of controlling the turbine regulating valve, the No. 7 high-pressure heater inlet steam regulating valve, and the boiler fuel quantity command based on the generated commands to achieve coordinated control of the unit load and improve the unit's ability to rapidly change load specifically includes: After receiving the opening command, the steam turbine regulating valve adjusts the valve opening through the electric actuator, thereby changing the steam flow rate entering the high-pressure cylinder of the steam turbine and thus adjusting the steam turbine output power. After receiving the opening command, the No. 7 high-pressure heater inlet steam regulating valve adjusts the steam extraction flow rate into the No. 7 high-pressure heater, thereby adjusting the effective enthalpy drop of the steam turbine by changing the steam extraction flow rate. After receiving the fuel quantity command, the boiler fuel supply device adjusts the coal feeder or the gas supply of the burner to change the boiler's heat load and provide stable steam support for unit load changes. Through the coordinated control of these three systems, the load change rate of the unit can be increased to between 2% and 5% of the rated load per minute when the load changes, and the load regulation accuracy can be controlled within ±1% of the rated load.

6. The method for coordinated control of thermal power units based on high-pressure steam extraction throttling according to claim 5, characterized in that, The adjustment process of the No. 7 high-pressure heater steam inlet regulating valve also includes the monitoring and compensation steps for the feedwater temperature of the No. 7 high-pressure heater, specifically including: Based on the feedwater temperature sensor at the outlet of the No. 7 high-pressure heater, the actual value of the feedwater temperature is obtained in real time. Compare the actual water temperature with the design temperature. If the deviation between the two exceeds ±3℃, a compensation adjustment signal is sent to the No. 7 high-pressure steam inlet regulating valve. The compensation adjustment signal adjusts the opening of the No. 7 high-pressure steam inlet regulating valve proportionally according to the size of the temperature deviation. The larger the temperature deviation, the larger the opening adjustment range, and the maximum adjustment range does not exceed 10%.

7. A coordinated control system for thermal power units based on high-pressure heater extraction steam throttling, used to implement the coordinated control method for thermal power units based on high-pressure heater extraction steam throttling as described in claims 1-6, comprising: The data acquisition module is used to obtain the actual value of turbine power, the actual value of main steam pressure, the design value of turbine power, and the design value of main steam pressure, and generate the unit operation dataset; The deviation calculation module is electrically connected to the data acquisition module. It is used to calculate the difference between the design value and the actual value of the main steam pressure to obtain the deviation value of the main steam pressure. The control command generation module is electrically connected to the deviation calculation module. The control command generation module includes a PID control unit, a limiting unit, and a high and low speed limiting unit. It is used to process the main steam pressure deviation value and generate turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands. The execution control module is electrically connected to the control command generation module. The execution control module includes a turbine valve control unit, a high-pressure heater inlet valve control unit, and a boiler fuel control unit. It is used to control the operation of relevant equipment according to the corresponding control commands to achieve coordinated control of unit load.

8. A coordinated control system for thermal power units based on high-pressure steam extraction throttling as described in claim 7, characterized in that, The data acquisition module includes: The power acquisition unit is connected to the power sensor at the turbine shaft end. It uses the Hall effect principle to acquire the turbine power signal, converts the acquired analog signal into a digital signal, and then transmits it to the data storage unit. The pressure acquisition unit is connected to the pressure sensor on the main steam pipeline. It uses piezoelectric sensing technology to acquire the main steam pressure signal. The acquired data is filtered and then transmitted to the data storage unit. The design parameter retrieval unit connects to the unit design parameter database via Ethernet and retrieves the corresponding turbine power design value and main steam pressure design value based on the unit's unique equipment number. The data storage unit uses a solid-state drive to store data acquired by the power acquisition unit, pressure acquisition unit, and design parameter retrieval unit in association with timestamps, forming a unit operation dataset.

9. A coordinated control system for thermal power units based on high-pressure steam extraction throttling as described in claim 8, characterized in that, The control command generation module includes: The PID control unit receives the main steam pressure deviation value output by the deviation calculation module, has built-in adjustable proportional, integral, and derivative parameters, calculates the deviation value through the PID algorithm, and outputs the basic control signal. The limiting unit is connected to the PID control unit. It presets a range of values ​​for different controlled objects and limits the range of the basic control signal to prevent the equipment from operating outside the range. High and low speed limiting unit, which is connected to the amplitude limiting unit, sets the maximum rate of change of different control signals to prevent sudden changes in control signals from causing equipment damage or unstable unit operation. The command distribution unit is connected to the high and low speed limiting unit. It distributes the processed control signals into turbine regulating valve opening commands, No. 7 high-pressure heater inlet steam regulating valve opening commands, and boiler fuel quantity commands, and sends them to the corresponding execution units.

10. A coordinated control system for thermal power units based on high-pressure steam extraction throttling as described in claim 9, characterized in that, The execution control module includes: The turbine valve control unit is connected to the electric actuator of the turbine regulating valve. After receiving the opening command, it drives the valve core to move through the servo motor and feeds back the actual valve opening to the control command generation module in real time to form a closed-loop control. The high-pressure heater steam inlet valve control unit is connected to the pneumatic actuator of the No. 7 high-pressure heater steam inlet regulating valve. After receiving the opening command, it adjusts the compressed air pressure to control the valve opening. At the same time, it receives the feed water temperature deviation signal through the temperature compensation subunit and compensates and adjusts the valve opening. The boiler fuel control unit is connected to the control module of the coal feeder or gas burner. After receiving the fuel quantity command, it adjusts the speed of the coal feeder or the opening of the gas valve of the burner to control the fuel supply. The operation monitoring subunit is connected to each control unit and collects turbine power, main steam pressure and feedwater temperature parameters in real time. If the parameters exceed the safe range, an alarm signal is immediately sent and an emergency shutdown procedure is triggered.

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