Gas capture system control methods, devices, electronic equipment and readable storage media

Abstract

This disclosure relates to a control method, apparatus, electronic device, and readable storage medium for a gas capture system. The method includes: using lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data for the gas capture system, and using gas capture rate and reboiler temperature as output step response signal data for the gas capture system; constructing an open-loop transfer function matrix for the gas capture system, where the gas includes CO2; determining the corresponding eigenvector and characteristic transfer function based on the open-loop transfer function matrix; determining the stability and correlation of the gas capture system based on the characteristic equation and characteristic transfer function; and adjusting the multi-frequency domain controller of the gas capture system based on the stability and correlation until the stability and correlation of the gas capture system meet preset requirements. This method can effectively improve the stability and response speed of the post-combustion CO2 capture system and has a strong setpoint tracking capability.

Description

Technical Field

[0001] This disclosure relates to the field of thermal control technology, and more specifically, to a gas capture system control method, apparatus, electronic device, and readable storage medium. Background Technology

[0002] In related technologies, with the greenhouse effect and related climate and ecological problems becoming increasingly severe, reducing carbon dioxide (CO2) emissions has gradually become an important task in the process of industrialization and urbanization. Coal-fired power generation units are one of the largest sources of CO2 emissions, and equipping coal-fired power generation units with CO2 capture systems is one of the main means to achieve low-carbon emission goals.

[0003] Among existing CO2 capture technologies in coal-fired power generation systems, post-combustion CO2 capture technology based on ethanolamine (MEA) chemical absorption is relatively mature. This method directly separates CO2 from flue gas, has good inheritance of existing generator units and good technical applicability, and many pilot coal-fired power plants in the industry have put this technology into operation. At the same time, because the CO2 capture process involves many chemical changes and different equipment, there is strong coupling and a lot of inertia among the variables of the CO2 capture system, and changes in flue gas flow can also have a significant impact on the operation of the CO2 capture system. Therefore, how to achieve flexible and effective operation of the CO2 capture system places high demands on the control system design. Summary of the Invention

[0004] The purpose of this disclosure is to provide a gas capture system control method, apparatus, electronic device, and readable storage medium, wherein the gas capture system control method is used to make the operation of the CO2 capture system more flexible and efficient.

[0005] To achieve the above objectives, according to a first aspect of the present disclosure, a gas capture system control method is provided, comprising: using lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data of the gas capture system, using gas capture rate and reboiler temperature as output step response signal data of the gas capture system, and constructing an open-loop transfer function matrix of the gas capture system; wherein the gas includes carbon dioxide;

[0006] The corresponding eigenvectors and eigentransfer functions are determined based on the open-loop transfer function matrix.

[0007] The stability and correlation of the gas capture system are determined based on the characteristic equation and the characteristic transfer function.

[0008] The multi-frequency domain controller of the gas capture system is adjusted according to the stability and correlation until the stability and correlation of the gas capture system meet the preset requirements.

[0009] Optionally, determining the stability and correlation of the gas capture system based on the feature vector and the feature transfer function includes:

[0010] Based on the feature vector and the feature transfer function, draw the feature trajectory and mismatch angle curve;

[0011] The stability of the gas capture system is determined based on the characteristic trajectory, and the correlation of the gas capture system is determined based on the mismatch angle curve.

[0012] Optionally, the multi-frequency domain controller includes a high-frequency controller, a medium-frequency controller, and a low-frequency controller; adjusting the multi-frequency domain controller of the gas capture system according to the stability and correlation until the stability and correlation of the gas capture system meet preset requirements includes:

[0013] If the stability or correlation does not meet the preset requirements, adjust the high-frequency controller; and / or adjust the intermediate-frequency controller; and / or adjust the low-frequency controller;

[0014] Plot the current characteristic trajectory and current mismatch angle curve of the open-loop transfer function matrix of the current gas capture system;

[0015] The current stability and current correlation of the gas capture system are determined based on the current characteristic trajectory and the current mismatch angle curve;

[0016] If the current stability and current correlation do not meet the preset requirements, the multi-frequency domain controller is readjusted until the stability and correlation of the gas capture system meet the preset requirements.

[0017] Optionally, the characteristic equation of the open-loop transfer function matrix includes:

[0018] det[q(s)I m -Q(s)]=0

[0019]

[0020] Where Q(s) is the open-loop transfer function matrix, the det[] function is used to obtain the determinant value of the matrix, q(s) is the characteristic transfer function, and I m Let m be the identity matrix and m be the matrix order.

[0021] Optionally, determining the stability and correlation of the gas capture system based on the characteristic equation and the characteristic transfer function includes:

[0022] The characteristic trajectory of the open-loop transfer function matrix satisfies

[0023]

[0024] Under these circumstances, it is determined that the stability of the gas capture system meets the preset requirements;

[0025] Where n0 is the number of unstable poles in the gas capture system, n i Let m be the number of times the characteristic trajectory of the gas trapping system surrounds the point (-1, j0), and m be the matrix order.

[0026] When the mismatch angle is less than a specified threshold, the correlation of the gas capture system meets the preset requirements; the formula for calculating the mismatch angle includes:

[0027]

[0028] Wherein, θ(jω) is the mismatch angle, and the mismatch angle is the feature vector w. i (jω) and the natural basis vector e i The angle between them.

[0029] Optionally, the gas capture system is equipped with a constant gain pre-compensator K1, and adjusting the high-frequency controller includes:

[0030] Select the high-frequency point ω h The high-frequency controller K is determined using the approximate matching method. h The value of (s) is G -1 (jω h );

[0031] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0032] Q1(s)=K1K h (s)G(s)

[0033] Where Q1(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h G(s) is the high-frequency controller, and G(s) is the object transfer function.

[0034] Optionally, adjusting the intermediate frequency controller includes:

[0035] Select the mid-frequency point ω m The intermediate frequency controller K is determined using the approximate alignment method. m The value of (s) is G -1 (jω m );

[0036] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0037] Q2(s)=K1K h (s)K m (s)G(s)

[0038] Where Q2(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is the high-frequency controller, K m G(s) is the intermediate frequency controller, and G(s) is the object transfer function.

[0039] Optionally, adjusting the low-frequency controller includes:

[0040] Select the low-frequency point ω l The low-frequency controller K is determined using the approximate matching method. l The value of (s) is G -1 (jω l );

[0041] Introducing an integral term, the low-frequency controller is obtained as follows:

[0042]

[0043] Where β is used to simultaneously correct the control gain of each loop, α i This is used to adjust the integral action strength of each loop, A l B l To calculate Q(ω) using the approximate alignment method described above l The eigenvector W(ω) of j) l ) and V(ω l The approximate real matrix of ), where s is in transfer function form;

[0044] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0045] Q3(s)=K1K h (s)K m (s)K l (s)G(s)

[0046] Where Q3(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is the high-frequency controller, K m (s) is the intermediate frequency controller, K l G(s) is the low-frequency controller, and G(s) is the object transfer function.

[0047] According to a second aspect of the present disclosure, a gas capture system control device is provided, comprising: a construction module, configured to use lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data of the gas capture system, and use gas capture rate and reboiler temperature as output step response signal data of the gas capture system, to construct an open-loop transfer function matrix of the gas capture system; wherein the gas includes carbon dioxide;

[0048] The processing module is used to determine the corresponding eigenvector and eigentransfer function based on the open-loop transfer function matrix;

[0049] The processing module is also used to determine the stability and correlation of the gas capture system based on the characteristic equation and the characteristic transfer function;

[0050] An adjustment module is used to adjust the multi-frequency domain controller of the gas capture system according to the stability and correlation, until the stability and correlation of the gas capture system meet the preset requirements.

[0051] According to a third aspect of the present disclosure, an electronic device is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to execute the executable instructions to implement the steps of the aforementioned gas capture system control method.

[0052] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement the steps of the gas capture system control method provided in the first aspect of the present disclosure.

[0053] The above technical solution uses lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data for the gas capture system, and gas capture rate and reboiler temperature as output step response signal data. An open-loop transfer function matrix is ​​constructed for the gas capture system, including CO2. Based on the open-loop transfer function matrix, the corresponding eigenvector and characteristic transfer function are determined. The stability and correlation of the gas capture system are determined based on the characteristic equation and characteristic transfer function. The multi-frequency domain controller of the gas capture system is adjusted based on the stability and correlation until the stability and correlation of the gas capture system meet the preset requirements. This effectively improves the stability and response speed of the post-combustion CO2 capture system and has strong setpoint tracking capability.

[0054] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0055] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0056] Figure 1 A flowchart illustrating a gas capture system control method for exemplary embodiments of this disclosure.

[0057] Figure 2 This is a schematic diagram of an open-loop transfer function as an exemplary embodiment of the present disclosure.

[0058] Figure 3 This is a control block diagram of a CO2 capture system shown as an exemplary embodiment of the present disclosure.

[0059] Figure 4 This is a schematic diagram illustrating a characteristic trajectory and mismatch angle curve for an exemplary embodiment of the present disclosure.

[0060] Figure 5 This is a schematic diagram illustrating a characteristic trajectory and mismatch angle curve for an exemplary embodiment of the present disclosure.

[0061] Figure 6 This is a schematic diagram illustrating a characteristic trajectory and mismatch angle curve for an exemplary embodiment of the present disclosure.

[0062] Figure 7 This is a schematic diagram of an open-loop zero-pole distribution diagram, illustrating an exemplary embodiment of the present disclosure.

[0063] Figure 8 This is a schematic diagram illustrating the changes in input and output of a CO2 capture system as an exemplary embodiment of the present disclosure.

[0064] Figure 9 This is a schematic diagram illustrating the changes in input and output of another CO2 capture system as an exemplary embodiment of this disclosure.

[0065] Figure 10 This is a block diagram of a gas capture system control device shown as an exemplary embodiment of the present disclosure.

[0066] Figure 11 This is a block diagram illustrating an electronic device according to an exemplary embodiment. Detailed Implementation

[0067] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0068] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0069] It is further understood that although operations are described in a specific order in the accompanying drawings in the embodiments of this disclosure, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the shown operations to be performed to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0070] Figure 1 A flowchart illustrating a gas capture system control method as an exemplary embodiment of this disclosure is shown below. Figure 1 As shown, the control method for this gas capture system is executed by computer equipment such as desktop computers, laptops, or servers, and includes the following steps.

[0071] In step S11, the lean liquid flow rate and the turbine extraction steam flow rate are used as the input step excitation signal data of the gas capture system, and the gas capture rate and the reboiler temperature are used as the output step response signal data of the gas capture system to construct the open-loop transfer function matrix of the gas capture system.

[0072] For example, the gas capture system control method can be, but is not limited to, a capture system for capturing carbon dioxide (CO2) after chemical absorption combustion, referred to as a CO2 capture system; for the purpose of illustrating the gas capture system control method proposed in this disclosure, the following description will use a CO2 capture system as an example.

[0073] CO2 capture systems are used to remove CO2 from gas streams or separate CO2 as a gaseous product. Capture is the first step in carbon capture and storage (CCS) technology. CO2 needs to be present in high purity during transportation and storage, but in most cases, the concentration of CO2 in industrial exhaust gas does not meet this requirement. Therefore, CO2 must be separated from the exhaust gas; this process is called CO2 capture. CO2 capture systems can be classified into several categories, including chemical absorption, physical absorption, physical adsorption, membrane separation, and cryogenic separation. The selection of capture method and equipment needs to be based on the actual characteristics and parameters of the CO2 emission source. This disclosure focuses on a chemical absorption post-combustion CO2 capture system as the controlled object.

[0074] Taking the post-combustion CO2 capture system of chemical absorption as the controlled object, two control variables, lean liquid flow rate u1 and turbine extraction steam flow rate u2, are selected as input step excitation signal data to obtain two controlled variables, CO2 capture rate y1 and reboiler temperature y2, as output step response data. Through the actual data generated by the step response experiment of the input variables, the input step excitation signal data and the output step response data are identified and used as the open-loop transfer function matrix Q(s) of the system. Based on the open-loop transfer function matrix, a control method for the post-combustion CO2 capture system based on the characteristic trajectory method is established.

[0075] Figure 2 This is a schematic diagram illustrating an open-loop transfer function as an exemplary embodiment of the present disclosure. Figure 3 A control block diagram of a CO2 capture system is shown as an exemplary embodiment of this disclosure, such as Figure 2 and Figure 3 As shown, the obtained open-loop transfer function is:

[0076]

[0077]

[0078]

[0079]

[0080] In the above formula, each parameter represents the steady-state and dynamic characteristics of the open-loop transfer function. Figure 2 Zhong K l (s) is a low-frequency controller, K h G(s) is the high-frequency controller, K1 is the constant gain pre-compensator of the CO2 capture system, G(s) is the object transfer function, and f1 and f2 are the feedback quantities input to the multi-frequency domain controller, which are the output quantities of the controlled object.

[0081] In step S12, the corresponding eigenvectors and eigentransfer functions are determined based on the open-loop transfer function matrix.

[0082] Based on the existing controlled open-loop transfer function matrix Q(s), the characteristic equation of Q(s) can be solved to obtain the corresponding characteristic transfer function q. i (s) and determine the corresponding feature vector w i (s),

[0083] For example, the characteristic equation of the modified open-loop transfer function matrix Q(s) includes:

[0084] det[q(s)I m -Q(s)]=0

[0085]

[0086] Where Q(s) is the open-loop transfer function matrix, the det[] function is used to obtain the determinant value of the matrix, q(s) is the eigenfunction transfer function, and I m Let m be the identity matrix and m be the matrix order.

[0087] It should be noted that the open-loop transfer function refers to the functional relationship between the output-to-input ratio of an open-loop system, such as a filter, and the frequency; that is, the frequency domain characteristic of the system. It is commonly represented by the amplitude and phase frequency characteristics. The transfer function expresses the inherent characteristics of the system and is independent of the input quantity.

[0088] In step S13, the stability and correlation of the gas capture system are determined based on the characteristic equation and characteristic transfer function.

[0089] In the preceding steps, the characteristic equation and characteristic transfer function were obtained. In this step, the characteristic trajectory and mismatch angle curve can be plotted based on the characteristic vector and characteristic transfer function. Then, the stability of the gas capture system is determined based on the characteristic trajectory, and the correlation of the gas capture system is determined based on the mismatch angle curve.

[0090] For example, based on the feature transfer function and the feature vector w i (s) Plot the characteristic trajectory and mismatch angle curve respectively. The characteristic trajectory is the Nyquist curve of the characteristic transfer function. Therefore, the stability of the CO2 capture system can be judged according to the Nyquist stability criterion.

[0091] It should be noted that the Nyquist curve is a graph plotting the gain and phase of the frequency response of a continuous-time linear time-invariant system in polar coordinates. Each point on the curve corresponds to the frequency response at a specific frequency, the angle of that point relative to the origin represents the phase, and the distance from the origin represents the gain. This curve provides information about the transfer function and can be used to determine whether a system with feedback is stable. Therefore, the stability of a CO2 trapping system can be determined based on the Nyquist curve.

[0092] In one implementation, the characteristic trajectory of the open-loop transfer function matrix satisfies

[0093]

[0094] Under the condition that the stability of the CO2 capture system meets the preset requirements; where n0 is the number of unstable poles in the CO2 capture system, n i Let m be the number of times the characteristic trajectory of the CO2 trapping system surrounds the point (-1, j0), and m be the matrix order.

[0095] Mismatched angle refers to the eigenvector w i (jω) and the natural basis vector ei The angle between the two values ​​is generally required to be as small as possible within the operating frequency range to reduce the correlation of the CO2 capture system. Therefore, when the mismatch angle is less than a specified threshold, the correlation of the CO2 capture system meets the preset requirements. The formula for calculating the mismatch angle includes:

[0096]

[0097] Where θ(jω) is the mismatch angle, and the mismatch angle is the eigenvector w. i (jω) and the natural basis vector e i The angle between them, the specified threshold can be determined based on empirical data or other feasible methods, and this disclosure does not limit it.

[0098] In step S14, the multi-frequency domain controller of the gas capture system is adjusted according to stability and correlation until the stability and correlation of the gas capture system meet the preset requirements.

[0099] In the preceding steps, the stability and correlation of the current CO2 capture system were determined. In this step, it is determined whether the stability and correlation of the current CO2 capture system meet the preset requirements. If the stability and / or correlation do not meet the preset requirements, the multi-frequency domain controller of the CO2 capture system is adjusted until the stability and correlation of the CO2 capture system meet the preset requirements.

[0100] The multi-frequency domain controller includes a high-frequency controller, a medium-frequency controller, and a low-frequency controller. Adjusting the multi-frequency domain controller of the gas capture system based on stability and correlation until the stability and correlation of the gas capture system meet preset requirements includes: adjusting the high-frequency controller if stability or correlation does not meet preset requirements; and / or adjusting the medium-frequency controller; and / or adjusting the low-frequency controller. Specifically, first, the high-frequency controller is adjusted and designed; then, the characteristic trajectory and mismatch angle curve of the open-loop transfer function matrix of the current CO2 capture system are plotted. The stability and correlation of the current CO2 capture system are determined based on the characteristic trajectory and mismatch angle curve. If the stability and correlation of the current CO2 capture system do not meet preset requirements, the medium-frequency controller is adjusted and designed. Then, the aforementioned steps of plotting the characteristic trajectory and mismatch angle curve are repeated, and the stability and correlation of the current CO2 capture system are determined based on the characteristic trajectory and mismatch angle curve. If the stability and correlation of the current CO2 capture system do not meet preset requirements, the low-frequency controller is adjusted and designed. After designing the low-frequency controller, the aforementioned steps of plotting the characteristic trajectory and mismatch angle curve are repeated, and the stability and correlation of the current CO2 capture system are determined based on the characteristic trajectory and mismatch angle curve. The stability and correlation of the CO2 capture system are made to meet preset requirements by adjusting the design of the high-frequency, medium-frequency, and low-frequency controllers. It should be noted that the preset requirements can be determined based on empirical data or other feasible methods, and this disclosure does not impose any restrictions on this.

[0101] To ensure good control performance of the multi-frequency domain controller over a wide frequency range, a constant gain pre-compensator K1 is pre-configured. K1 can be expressed as:

[0102]

[0103] In one implementation,

[0104]

[0105] The characteristic trajectory and mismatch angle curve of Q(s) at this time are obtained as follows: Figure 4 As shown. Figure 4 This is a schematic diagram illustrating a characteristic trajectory and a mismatch angle curve, as shown in an exemplary embodiment of the present disclosure. Figure 4 The figure shows the frequency domain characteristics of the two output quantities, CO2 capture rate and reboiler temperature. The frequency domain characteristics are also known as the characteristic trajectory, and the mismatch angle curves of CO2 capture rate and reboiler temperature.

[0106] For example, a high-frequency controller is designed based on the stability and correlation of the CO2 capture system. If the mismatch angle of the eigenvector is large, it indicates that the CO2 capture system has strong correlation. To reduce the correlation of the CO2 capture system, an appropriate high-frequency point ω is selected. hG was calculated using the approximate alignment (ALIGN) method. -1 (jω h Take the high-frequency controller K. h (s) is G -1 (jω h In one implementation method,

[0107]

[0108] Then the open-loop transfer function matrix of the CO2 capture system is:

[0109] Q1(s)=K1K h (s)G(s)

[0110] Where Q1(s) is the open-loop transfer function matrix of the current CO2 capture system, K1 is the constant gain pre-compensator, and K h G(s) is the high-frequency controller, and G(s) is the object transfer function. Figure 5 A schematic diagram of a characteristic trajectory and mismatch angle curve shown as an exemplary embodiment of this disclosure, such as... Figure 5 As shown, K h The introduction of (s) reduces the correlation of the CO2 capture system without compromising its stability.

[0111] If the stability and correlation of the CO2 capture system still do not meet the preset requirements after designing the high-frequency controller, then design the medium-frequency controller K. m (s) ensures that the CO2 capture system meets the preset stability requirements. The purpose of intermediate frequency controller compensation is to obtain a closed-loop stable CO2 capture system with sufficient stability margin to guarantee satisfactory dynamic quality. To reduce the correlation of the CO2 capture system, the intermediate frequency point ω is selected. m G was calculated using the approximate alignment (ALIGN) method. -1 (jω m Take the intermediate frequency controller K. m (s) is G -1 (jω m If the open-loop transfer function matrix of the CO2 capture system is then:

[0112] Q2(s)=K1K h (s)K m (s)G(s)

[0113] Where Q2(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is a high-frequency controller, K m G(s) is the intermediate frequency controller, and G(s) is the object transfer function.

[0114] If the stability and correlation of the CO2 capture system still do not meet the preset requirements after designing the intermediate frequency controller, then design a low frequency controller K. l (s). For example, select the low-frequency band frequency point ω. l The low-frequency controller K is determined using the approximate matching method. l The value of (s) is G -1 (jω l );

[0115] Introducing an integral term yields the following low-frequency controller:

[0116]

[0117] Where β is used to simultaneously correct the control gain of each loop, α i This is used to adjust the integral action strength of each loop, A l B l To calculate Q(ω) using the approximate alignment method l The eigenvector W(ω) of j) l ) and V(ω l The approximate real matrix of ), where s is in transfer function form;

[0118] The formulas for calculating the open-loop transfer function matrix of current gas capture systems include:

[0119] Q3(s)=K1K h (s)K m (s)K l (s)G(s)

[0120] Where Q3(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is a high-frequency controller, K m (s) is the intermediate frequency controller, K l G(s) is the low-frequency controller, and G(s) is the object transfer function.

[0121] After adjusting the high-frequency, medium-frequency, and low-frequency controllers of the multi-frequency domain controller, the characteristic trajectory and mismatch angle curve of the open-loop transfer function matrix of the CO2 capture system are plotted. The stability and correlation of the CO2 capture system are determined based on the characteristic trajectory and mismatch angle curve. If the stability and correlation do not meet the preset requirements, the multi-frequency domain controller is readjusted until the stability and correlation of the CO2 capture system meet the preset requirements.

[0122] In one implementation, the design of the intermediate frequency controller primarily considers the stability of the CO2 capture system while also taking into account the correlation between variables. Since the CO2 capture system has a low order, the intermediate frequency controller and the low-frequency controller are designed together. The selected frequency point ω... l =0.004 rad / s, design a low-frequency controller. Calculate Q(ω) using ALIGN. l The approximate real matrix A of the eigenvectors of (j) l B l ,have to:

[0123]

[0124] Take α i =0.008, therefore the low-frequency controller is:

[0125]

[0126] At this point, the open-loop transfer function matrix of the CO2 capture system is:

[0127] Q2(s)=K1K h (s)K m (s)K l (s)G(s)

[0128] Plot the characteristic trajectory and mismatch angle curve of the open-loop transfer function matrix Q2(s) of the CO2 capture system at this point, as shown below. Figure 6 and Figure 7 As shown, the stability and correlation of the CO2 capture system are checked by plotting the step response curve. The characteristic trajectory surrounds the point (-1,j0) once in both clockwise and counterclockwise directions. At this time, Q2(s) has no poles in the right half-closed plane of s, so the closed-loop control system is stable. Figure 6 This is a schematic diagram illustrating a characteristic trajectory and a mismatch angle curve, as shown in an exemplary embodiment of the present disclosure. Figure 7 This is a schematic diagram of an open-loop pole-zero distribution diagram shown as an exemplary embodiment of the present disclosure. Figure 7 The horizontal axis is the real axis (Re), and the vertical axis is the imaginary axis (Im).

[0129] To verify the control effect of the post-combustion CO2 capture system control method based on the characteristic trajectory method disclosed in this invention, two sets of simulation experiments were conducted: Simulation Experiment 1: The initial capture rate of the CO2 capture system was stabilized at 60%. At t=1000s, the capture rate was set to change stepwise to 70%. The actual changes in CO2 capture rate, reboiler temperature, lean liquor flow rate, and extraction steam flow rate under the adopted control method were observed. Simulation Experiment 2: The initial reboiler temperature of the CO2 capture system was stabilized at 388.2K. At t=1000s, the reboiler temperature was set to change stepwise to 389.2K. The actual changes in CO2 capture rate, reboiler temperature, lean liquor flow rate, and extraction steam flow rate under the adopted CO2 capture system control method were observed.

[0130] Figure 8 This is a schematic diagram illustrating the changes in input and output of a CO2 capture system as an exemplary embodiment of the present disclosure. Figure 9 This is a schematic diagram illustrating the input and output changes of another CO2 capture system as an exemplary embodiment of this disclosure, wherein the change in carbon capture rate is the same as the change in CO2 capture rate. Figure 8 , Figure 9 As shown, when the CO2 capture rate undergoes a step change, from 50% to 60% at t = 1000 s, the post-combustion CO2 capture system control method based on the characteristic trajectory method can quickly track the CO2 capture rate to the set value by rapidly changing the lean liquor flow rate and the extraction steam flow rate. Similarly, when the reboiler temperature undergoes a step change, from 388.2 K to 389.2 K at t = 1000 s, the post-combustion CO2 capture system control method based on the characteristic trajectory method can also quickly track the reboiler temperature to the set value by rapidly changing the lean liquor flow rate and the extraction steam flow rate.

[0131] In summary, the post-combustion CO2 capture system control method based on the characteristic trajectory method disclosed herein effectively reduces the correlation between various variables within the CO2 capture system while ensuring the stability of the CO2 capture system, enabling the system to quickly and smoothly achieve the ability to track the setpoint.

[0132] This disclosure presents a control method for a post-combustion CO2 capture system based on the characteristic trajectory method. This method takes the chemical absorption post-combustion CO2 capture system as the controlled object, selecting lean liquid flow rate and turbine extraction steam flow rate as controlled variables, and CO2 capture rate and reboiler temperature as controlled variables. The open-loop transfer function model of the post-combustion CO2 capture system is identified through step response experiments. Based on this, the stability and correlation of the CO2 capture system are determined using the characteristic trajectory and mismatch angle of the open-loop transfer function, based on the characteristic analysis of the system transfer function, thereby guiding the design of a multi-frequency domain controller. Results show that this controller designed based on the characteristic trajectory method effectively reduces the correlation between variables within the CO2 capture system while ensuring its stability, enabling the CO2 capture system to quickly and smoothly achieve setpoint tracking capability.

[0133] In summary, the gas capture system control method provided in this disclosure includes: using lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data for the gas capture system, using gas capture rate and reboiler temperature as output step response signal data for the gas capture system, constructing an open-loop transfer function matrix for the gas capture system (gas including CO2), determining the corresponding eigenvector and characteristic transfer function based on the open-loop transfer function matrix, determining the stability and correlation of the gas capture system based on the characteristic equation and characteristic transfer function, and adjusting the multi-frequency domain controller of the gas capture system based on the stability and correlation until the stability and correlation of the gas capture system meet the preset requirements; it can effectively improve the stability and response speed of the post-combustion CO2 capture system and has a strong setpoint tracking capability.

[0134] Figure 10 This is a block diagram of a gas capture system control device illustrated as an exemplary embodiment of the present disclosure. (Refer to...) Figure 10 The gas capture system control device 20 includes a construction module 201, a processing module 202, and an adjustment module 203.

[0135] The construction module 201 is used to construct the open-loop transfer function matrix of the gas capture system by using lean liquid flow rate and turbine extraction steam flow rate as input step excitation signal data of the gas capture system, and gas capture rate and reboiler temperature as output step response signal data of the gas capture system; the gas includes carbon dioxide.

[0136] The processing module 202 is used to determine the corresponding eigenvector and eigentransfer function based on the open-loop transfer function matrix;

[0137] The processing module 202 is also used to determine the stability and correlation of the gas capture system based on the characteristic equation and the characteristic transfer function;

[0138] The adjustment module 203 is used to adjust the multi-frequency domain controller of the gas capture system according to the stability and the correlation, until the stability and correlation of the gas capture system meet the preset requirements.

[0139] The processing module 202 is also used to draw feature trajectories and mismatch angle curves based on the feature vector and the feature transfer function;

[0140] The stability of the gas capture system is determined based on the characteristic trajectory, and the correlation of the gas capture system is determined based on the mismatch angle curve.

[0141] The adjustment module 203 is also used to adjust the high-frequency controller, and / or adjust the intermediate-frequency controller, and / or adjust the low-frequency controller when the stability or correlation does not meet the preset requirements;

[0142] Plot the current characteristic trajectory and current mismatch angle curve of the open-loop transfer function matrix of the current gas capture system;

[0143] The current stability and current correlation of the gas capture system are determined based on the current characteristic trajectory and the current mismatch angle curve;

[0144] If the current stability and current correlation do not meet the preset requirements, the multi-frequency domain controller is readjusted until the stability and correlation of the gas capture system meet the preset requirements.

[0145] Optionally, the characteristic equation of the open-loop transfer function matrix includes:

[0146] det[q(s)I m -Q(s)]=0

[0147]

[0148] Where Q(s) is the open-loop transfer function matrix, the det[] function is used to obtain the determinant value of the matrix, q(s) is the characteristic transfer function, and I m Let m be the identity matrix and m be the matrix order.

[0149] Optionally, the characteristic trajectory of the open-loop transfer function matrix satisfies

[0150]

[0151] Under these circumstances, it is determined that the stability of the gas capture system meets the preset requirements;

[0152] Where n0 is the number of unstable poles in the gas capture system, n iLet m be the number of times the characteristic trajectory of the gas trapping system surrounds the point (-1, j0), and m be the matrix order.

[0153] When the mismatch angle is less than a specified threshold, the correlation of the gas capture system meets the preset requirements; the formula for calculating the mismatch angle includes:

[0154]

[0155] Wherein, θ(jω) is the mismatch angle, and the mismatch angle is the feature vector w. i (jω) and the natural basis vector e i The angle between them.

[0156] The adjustment module 203 is also used to select the high-frequency point ω in the high-frequency band. h The high-frequency controller K is determined using the approximate matching method. h The value of (s) is G -1 (jω h );

[0157] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0158] Q1(s)=K1K h (s)G(s)

[0159] Where Q1(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h G(s) is the high-frequency controller, and G(s) is the object transfer function.

[0160] The adjustment module 203 is also used to select the mid-frequency point ω. m The intermediate frequency controller K is determined using the approximate alignment method. m The value of (s) is G -1 (jω m );

[0161] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0162] Q2(s)=K1K h (s)K m (s)G(s)

[0163] Where Q2(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is the high-frequency controller, K m G(s) is the intermediate frequency controller, and G(s) is the object transfer function.

[0164] The adjustment module 203 is also used to select the low-frequency point ω. l The low-frequency controller K is determined using the approximate matching method. l The value of (s) is G -1 (jω l );

[0165] Introducing an integral term, the low-frequency controller is obtained as follows:

[0166]

[0167] Where β is used to simultaneously correct the control gain of each loop, α i This is used to adjust the integral action strength of each loop, A l B l To calculate Q(ω) using the approximate alignment method described above l The eigenvector W(ω) of j) l ) and V(ω l The approximate real matrix of ), where s is in transfer function form;

[0168] The formula for calculating the open-loop transfer function matrix of the current gas capture system includes:

[0169] Q3(s)=K1K h (s)K m (s)K l (s)G(s)

[0170] Where Q3(s) is the open-loop transfer function matrix of the current gas capture system, K1 is the constant gain pre-compensator, and K h (s) is the high-frequency controller, K m (s) is the intermediate frequency controller, K l G(s) is the low-frequency controller, and G(s) is the object transfer function.

[0171] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0172] Figure 11 This is a block diagram illustrating an electronic device 700 according to an exemplary embodiment. Figure 11 As shown, the electronic device 700 can be Figure 1 The computer device 700 shown, including desktop computers, laptops, or servers, may include: a processor 701 and a memory 702. The electronic device 700 may also include one or more of a multimedia component 703, an input / output (I / O) interface 704, and a communication component 705.

[0173] The processor 701 controls the overall operation of the electronic device 700 to complete all or part of the steps in the gas capture system control method described above. The memory 702 stores various types of data to support the operation of the electronic device 700. This data may include, for example, instructions for any application or method operating on the electronic device 700, and application-related data such as contact data, sent and received messages, pictures, audio, video, etc. The memory 702 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Multimedia component 703 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 702 or transmitted via communication component 705. The audio component also includes at least one speaker for outputting audio signals. I / O interface 704 provides an interface between processor 701 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 705 is used for wired or wireless communication between the electronic device 700 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IoT, eMTC, or other 5G technologies, or combinations thereof, is not limited here. Therefore, the corresponding communication component 705 may include: a Wi-Fi module, a Bluetooth module, an NFC module, etc.

[0174] In an exemplary embodiment, the electronic device 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the gas capture system control method described above.

[0175] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the gas capture system control method described above. For example, the computer-readable storage medium may be the memory 702 including program instructions described above, which may be executed by the processor 701 of the electronic device 700 to complete the gas capture system control method described above.

[0176] In another exemplary embodiment, a computer program product is also provided, the computer program product comprising a computer program executable by a programmable device, the computer program having a code portion for performing the gas capture system control method described above when executed by the programmable device.

[0177] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure. It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not further describe the various possible combinations.

[0178] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A gas capture system control method, characterized by, The method comprises the following steps: determining a corresponding eigenvector and an eigen-transfer function according to the open-loop transfer function matrix; determining stability and relevance of the gas capture system according to the eigen-equation and the eigen-transfer function; adjusting a multi-frequency domain segment controller of the gas capture system according to the stability and the relevance until the stability and the relevance of the gas capture system meet preset requirements; the multi-frequency domain segment controller comprises a high-frequency controller, a medium-frequency controller and a low-frequency controller; adjusting the multi-frequency domain segment controller of the gas capture system according to the stability and the relevance until the stability and the relevance of the gas capture system meet preset requirements comprises: adjusting the high-frequency controller; and / or adjusting the medium-frequency controller; and / or adjusting the low-frequency controller in the case that the stability or the relevance does not meet the preset requirements; drawing a current eigen-trajectory and a current mismatch angle curve of the current open-loop transfer function matrix of the gas capture system; determining current stability and current relevance of the gas capture system according to the current eigen-trajectory and the current mismatch angle curve; re-adjusting the multi-frequency domain segment controller until the stability and the relevance of the gas capture system meet preset requirements in the case that the current stability and the current relevance do not meet the preset requirements; G(s) The gas capture system is equipped with a constant gain pre-compensator. The adjustment of the high-frequency controller includes: selecting a high-frequency band frequency point. The high-frequency controller is determined using an approximate matching method. The value is The open-loop transfer function matrix of the current gas capture system The calculation formulas include: wherein determining the stability and the relevance of the gas capture system according to the eigen-vector and the eigen-transfer function comprises: is the object transfer function; The adjusting the intermediate frequency controller comprises: selecting an intermediate frequency band frequency point , and determining the value of the intermediate frequency controller by using the approximate matching method ; and a calculation formula of a current open-loop transfer function matrix of the gas trapping system comprises: The adjusting the low-frequency controller comprises: selecting a low-frequency point , determining the value of the low-frequency controller by using the approximate compensation method ; and introducing an integral element to obtain the low-frequency controller​ in, Used to simultaneously correct the control gain of each loop. This is used to adjust the intensity of the integral action of each loop. To calculate using the approximate alignment method eigenvectors and Approximate real matrix, s It is in transfer function form; The open loop transfer function matrix of the current gas capture system The computational formula includes: 。 2. The method of claim 1, wherein, drawing an eigen-trajectory and a mismatch angle curve according to the eigen-vector and the eigen-transfer function; determining the stability of the gas capture system according to the eigen-trajectory and determining the relevance of the gas capture system according to the mismatch angle curve. determining the stability and the relevance of the gas capture system according to the eigen-equation and the eigen-transfer function comprises:

3. The method of claim 1, wherein, determining that the stability of the gas capture system meets the preset requirements in the case that the eigen-trajectory of the open-loop transfer function matrix meets determining that the relevance of the gas capture system meets the preset requirements in the case that the mismatch angle is less than a specified threshold; the calculation formula of the mismatch angle comprises: The method comprises the following steps: wherein, the number of unstable poles of the gas capture system, the number of times the characteristic trajectory of the gas capture system encloses the (-1, ) point, m is the matrix rank; a construction module is configured to construct an open-loop transfer function matrix of a gas capture system by taking lean liquid flow and steam turbine extraction flow as input step excitation signal data of the gas capture system and taking gas capture rate and reboiler temperature as output step response signal data of the gas capture system; the gas comprises carbon dioxide; wherein, is the mismatch angle, which is the angle between the eigenvector and the natural basis vector .

4. A gas capture system control device characterized by, a processing module is configured to determine a corresponding eigenvector and an eigen-transfer function according to the open-loop transfer function matrix; the processing module is further configured to determine stability and relevance of the gas capture system according to an eigen-equation and the eigen-transfer function; the processing module is further configured to adjust a multi-frequency domain segment controller of the gas capture system according to the stability and the relevance until the stability and the relevance of the gas capture system meet preset requirements. ​ an adjusting module, configured to adjust a multi-frequency-domain segment controller of the gas trapping system according to the stability and the correlation until the stability and the correlation of the gas trapping system meet preset requirements; the multi-frequency-domain segment controller comprises a high-frequency controller, a medium-frequency controller and a low-frequency controller; and the adjusting the multi-frequency-domain segment controller of the gas trapping system according to the stability and the correlation until the stability and the correlation of the gas trapping system meet preset requirements comprises: adjusting the high-frequency controller; and / or adjusting the medium-frequency controller; and / or adjusting the low-frequency controller, when the stability or the correlation does not meet the preset requirements; drawing a current characteristic trajectory and a current mismatch angle curve of an open-loop transfer function matrix of the current gas trapping system; determining a current stability and a current correlation of the gas trapping system according to the current characteristic trajectory and the current mismatch angle curve; re-adjusting the multi-frequency-domain segment controller until the stability and the correlation of the gas trapping system meet preset requirements, when the current stability and the current correlation do not meet the preset requirements; The gas capture system is equipped with a constant gain pre-compensator. The adjustment of the high-frequency controller includes: selecting a high-frequency band frequency point. The high-frequency controller is determined using an approximate matching method. The value is The open-loop transfer function matrix of the current gas capture system The calculation formulas include: wherein G(s) is the object transfer function; The adjusting the intermediate frequency controller comprises: selecting an intermediate frequency band frequency point , and determining the value of the intermediate frequency controller by using the approximate matching method ; and a calculation formula of a current open-loop transfer function matrix of the gas trapping system comprises: The adjusting the low-frequency controller comprises: selecting a low-frequency point , determining the value of the low-frequency controller by using the approximate compensation method is ; introducing an integral element to obtain the low-frequency controller wherein for simultaneously correcting the control gains of the respective loops, for adjusting the strength of the integral action of the respective loops, are calculated using the approximate pole placement method the eigenvectors and the approximate real matrices, s are in the form of transfer functions; The open loop transfer function matrix of the current gas capture system The computational formula includes: 。 5. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1-3.

6. An electronic device, comprising: comprise: a memory having a computer program stored thereon; a processor configured to execute the computer program in the memory to implement the steps of the method in any one of claims 1-3.

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