CN-121995888-A - Multi-mode coordination PID control method and system for coal-fired unit coupling carbon capture system

CN121995888ACN 121995888 ACN121995888 ACN 121995888ACN-121995888-A

Abstract

The invention discloses a multi-mode coordination PID control method and system for a coal-fired unit coupled carbon capture system, and belongs to the technical field of thermal power generation system control. The method comprises the steps of determining different control modes according to different scene demands, wherein the control modes comprise a rapid power response mode, a power-carbon trapping compatible mode and a strict carbon trapping mode, performing online setting on PID controller parameters in a current control mode by adopting a particle swarm algorithm to obtain an optimal PID controller parameter combination in the current control mode, controlling a coal-fired unit coupled carbon trapping system based on the optimal PID controller parameter combination, and switching the different control modes by adopting a weighted mixing control strategy to realize smooth transition of the different control modes. According to the invention, various control modes are flexibly switched according to different scene demands, so that the load response speed of the coal-fired unit can be effectively improved, and the stable operation effect of the carbon capture system can be maintained.

Inventors

ZHANG ZITENG
WANG HAITAO
QIAN FENGLEI
TANG WEIJIE
ZHU YING

Assignees

中国能源建设集团江苏省电力设计院有限公司

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (10)

1. A multi-mode coordination PID control method for a coal-fired unit coupled carbon capture system is characterized by comprising the following steps: Determining different control modes according to different scene demands, wherein the control modes comprise a rapid power response mode, a power-carbon trapping compatible mode and a strict carbon trapping mode; Performing online setting on the PID controller parameters in the current control mode by adopting a particle swarm algorithm to obtain an optimal PID controller parameter combination in the current control mode, and controlling a coupled carbon capture system of the coal-fired unit based on the optimal PID controller parameter combination; and switching different control modes by adopting a weighted mixed control strategy to realize smooth transition of the different control modes.
2. The coal-fired unit coupled carbon capture system multi-mode coordinated PID control method of claim 1, wherein the determining different control modes according to different scenario requirements comprises: under the condition of requiring the rapid tracking of the generated power, a rapid power response mode is adopted; Under the condition of considering both the generated power tracking and the carbon trapping system stabilization, a power-carbon trapping mode is adopted; Under the condition of strictly requiring the stable operation of the carbon capture system, a strict carbon capture mode is adopted.
3. The multi-mode coordinated PID control method of the coal-fired unit coupling carbon capture system according to claim 1, wherein the rapid power response mode comprises control of a coal-fired unit and control of a carbon capture system, the control of the coal-fired unit comprises regulation and control of power generation, the regulation and control of power generation adopts a parallel PID control structure, the parallel PID control structure comprises a first power PID controller and a second power PID controller, deviation of a power generation actual value of the coal-fired unit side from a set value is input into the first power PID controller and the second power PID controller at the same time, the first power PID controller realizes long-term accurate maintenance of the power generation by adjusting a coal quantity according to the deviation of the power generation actual value from the set value, the second power PID controller realizes rapid preliminary tracking of the power generation by adjusting a steam extraction flow of a reboiler according to the deviation of the power generation actual value and the set value, and the control of the carbon capture system comprises a single-loop carbon capture rate PID controller, and the carbon capture rate PID controller controls a carbon capture rate by adjusting a liquid flow according to the deviation of the actual value and the set value.
4. The coal-fired unit coupled carbon capture system multi-mode coordinated PID control method of claim 3, characterized in that the fast power response mode comprises: When the power generation power set value is reduced, the second power PID controller stores reboiler extraction steam into the carbon capture system by increasing the opening of the reboiler extraction steam valve so as to realize power quick response; when the power generation power reaches the vicinity of the set value, the second power PID controller slowly reduces the steam extraction flow of the reboiler to enable the temperature of the reboiler to return to the set value; when the power set value rises, the second power PID controller reduces the steam extraction flow of the reboiler, and uses the heat energy of the steam extraction flow of the reboiler for power generation, so that the power generation power can be tracked quickly.
5. The multi-feature coordinated PID control method of the coal-fired unit coupling carbon capture system according to claim 1 is characterized in that the power-carbon capture compatible mode comprises control of a coal-fired unit and control of a carbon capture system, the control of the coal-fired unit comprises regulation and control of power generation, the regulation and control of the power generation adopts a cascade PID control structure, the cascade PID control structure comprises a power PID controller and a steam extraction PID controller, the power PID controller realizes preliminary tracking of power generation by adjusting steam extraction flow of a reboiler according to deviation of actual power generation value and set value of a coal-fired unit side power generation, the steam extraction PID controller ensures steam extraction flow of the reboiler to track set value of the reboiler by adjusting coal extraction flow according to deviation of actual steam extraction flow of the reboiler, the control of the carbon capture system comprises a single-loop carbon capture rate PID controller, and the carbon capture rate PID controller controls the carbon capture rate by adjusting lean liquid flow according to deviation of actual carbon capture rate and set value.
6. The multi-feature coordinated PID control method of the coal-fired unit coupling carbon capture system according to claim 1, wherein the strict carbon capture mode comprises control of a coal-fired unit and control of a carbon capture system, the control of the coal-fired unit comprises regulation and control of power generation, the regulation and control of power generation adopts a single-loop power PID controller, the power PID controller tracks a set value of the power generation through adjusting fuel quantity according to deviation of actual power generation on the coal-fired unit side from the set value, the control of the carbon capture system comprises a single-loop carbon capture rate PID controller and a single-loop reboiler temperature PID controller, the carbon capture rate PID controller controls the carbon capture rate through adjusting lean liquid flow according to deviation of actual value and set value of the carbon capture rate, and the reboiler temperature PID controller controls the reboiler temperature through adjusting reboiler steam extraction flow according to deviation of actual value and set value of reboiler temperature.
7. The method for multi-feature coordinated PID control of a coal-fired unit coupled carbon capture system according to claim 1, wherein the performing on-line tuning of the PID controller parameters in the current control mode by using a particle swarm algorithm to obtain an optimal PID controller parameter combination in the current control mode comprises: Initializing particle swarm, including initializing particle swarm position Particle velocity Population size Position range [ , Sum of speed ranges , Each particle represents a candidate control sequence , , In the formula, 、、 The proportional coefficient, the integral coefficient and the differential coefficient of the nth PID controller are respectively; in the minimum position of the device, In the position of the maximum of the two positions, At the minimum of the speed of the vehicle, Is the maximum speed; defining a fitness function: , Where MSE is the mean square error, For the actual output of the system at the kth sampling instant, Setting a system value for the kth sampling time, wherein N is the total number of samples; updating the particle position and speed, and iteratively optimizing to gradually approach a global optimal value: , in the formula, 、 The individual extremum and the global extremum are respectively; Is the updated particle velocity; For the particle velocity before update, w is the inertial weight, 、 Are learning factors; The updated particle position; For the particle location before update; As a function of random numbers; and when the convergence condition is met, outputting the optimal PID controller parameter combination.
8. The multi-feature coordinated PID control method of a coal-fired unit coupled carbon capture system according to claim 1, wherein the switching between different control modes by using a weighted hybrid control strategy is specifically: setting the current control mode as i, setting the target control mode as j, and mixing the output as follows: , in the formula, The total control amount is output for the time k, The control quantity is output for the current control mode i at the time k, The control amount is output for the target control pattern j at the time k, The weight of the current control mode i at time k, The weight occupied by the target control pattern j at time k, + =1, 、 Dynamic adjustment is performed by adopting a Sigmoid function, so that the control quantity changes smoothly during transition.
9. The multi-feature coordinated PID control method of a coal-fired unit coupled carbon capture system according to any one of claims 3 to 6, wherein the control of the coal-fired unit further comprises regulation and control of an outlet steam enthalpy value of the steam-water separator and a main steam pressure, the regulation and control of the outlet steam enthalpy value of the steam-water separator adopts a single-loop enthalpy value PID controller, the enthalpy value PID controller controls the outlet steam enthalpy value of the steam-water separator by adjusting a water supply flow rate according to deviation of an actual steam-water separation outlet enthalpy value and a set value, and the regulation and control of the main steam pressure adopts a single-loop pressure PID controller, and the pressure PID controller controls the main steam pressure by adjusting a main steam valve opening according to deviation of the actual main steam pressure value and the set value.
10. The utility model provides a coal-fired unit coupling carbon entrapment system multimode cooperation PID control system which characterized in that includes: The control mode determining module is used for determining different control modes according to different scene demands, wherein the control modes comprise a rapid power response mode, a power-carbon trapping compatible mode and a strict carbon trapping mode; The control parameter adjusting module is used for carrying out online setting on the PID controller parameters in the current control mode by adopting a particle swarm algorithm to obtain an optimal PID controller parameter combination in the current control mode, and controlling the coupled carbon capture system of the coal-fired unit based on the optimal PID controller parameter combination; And the control mode switching module is used for switching different control modes by adopting a weighted mixed control strategy so as to realize smooth transition of the different control modes.

Description

Multi-mode coordination PID control method and system for coal-fired unit coupling carbon capture system Technical Field The invention relates to a multi-mode PID (proportion integration differentiation) coordination control method of a coal-fired unit coupled carbon capture system, and belongs to the technical field of thermal power generation system control. Background The coal-fired generator set is an important support in an energy supply system, and is a key facility for peak regulation, frequency modulation, renewable energy source compensation and stable load fluctuation of a power grid. The boiler-steam turbine coordination control system is used as a core component of the coal-fired power generation unit, and the performance quality of the boiler-steam turbine coordination control system directly determines whether the unit can respond to a power grid load instruction rapidly and accurately, and meanwhile, the safe and efficient operation of the boiler-steam turbine coordination control system is maintained. Meanwhile, along with the proposal of a national 'double carbon' target, a coal-fired generator set needs to be matched with a carbon trapping system to meet emission reduction requirements, the coal-fired generator set is coupled with the carbon trapping system to form a strong-coupling and multivariable system, and the application of the system not only faces instability caused by renewable energy grid connection, but also faces changing carbon emission requirements. In the system, the steam extraction flow of the reboiler is a key variable for connecting the coal-fired unit and the carbon capture system, and the dynamic response speed of the power generation power and the carbon capture rate is obviously different. The difference makes the coordinated control of the system have great challenges (1) the traditional single PID control strategy is difficult to meet the control requirements of multiple modes and multiple targets, (2) the requirements of different operation scenes on the control strategy are obviously contradictory, and (3) the multivariable coupling characteristic of the system aggravates the control difficulty. Disclosure of Invention The invention aims to provide a multi-mode coordinated PID control method and system for a coal-fired unit coupled carbon capture system, which can flexibly switch control modes according to different operation scenes, realize multi-mode control of the coal-fired unit coupled carbon capture system, effectively improve the load response speed of the coal-fired unit and maintain the stable operation of the carbon capture system. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme. In a first aspect, the invention provides a multi-mode coordination PID control method for a coal-fired unit coupled carbon capture system, comprising the following steps: Determining different control modes according to different scene demands, wherein the control modes comprise a rapid power response mode, a power-carbon trapping compatible mode and a strict carbon trapping mode; Performing online setting on the PID controller parameters in the current control mode by adopting a particle swarm algorithm to obtain an optimal PID controller parameter combination in the current control mode, and controlling a coupled carbon capture system of the coal-fired unit based on the optimal PID controller parameter combination; and switching different control modes by adopting a weighted mixed control strategy to realize smooth transition of the different control modes. Further, the method is characterized in that the determining of different control modes according to different scene requirements includes: under the condition of requiring the rapid tracking of the generated power, a rapid power response mode is adopted; Under the condition of considering both the generated power tracking and the carbon trapping system stabilization, a power-carbon trapping mode is adopted; Under the condition of strictly requiring the stable operation of the carbon capture system, a strict carbon capture mode is adopted. Further, the rapid power response mode comprises control of a coal-fired unit and control of a carbon capture system, wherein the control of the coal-fired unit comprises regulation and control of generating power; the control of the power generation power adopts a parallel PID control structure, the parallel PID control structure comprises a first power PID controller and a second power PID controller, the deviation of the actual value and the set value of the power generation power at the coal-fired unit side is input into the first power PID controller and the second power PID controller at the same time, the first power PID controller realizes the long-term accurate maintenance of the power generation power by adjusting the coal burning quantity according to the deviation of the actual value and the set value of the power