A CO2 capture control method and device, electronic equipment and storage medium

Abstract

The application provides a CO2 capture control method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a CO2 capture concentration in amine liquid at an outlet of an absorption section; and when a deviation between the CO2 capture concentration and a target capture concentration exceeds a preset deviation range, adjusting a condensation temperature of a condensation section by using a pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration. Compared with a traditional method of adjusting amine liquid flow, the application establishes a coupling relationship between condensation dewatering and carbon capture absorption collaborative control, adjusts the CO2 capture concentration of the absorption section by adjusting the condensation section temperature, and improves the accuracy of CO2 capture.

Description

Technical Field

[0001] This invention relates to the field of CO2 capture technology, and more specifically, to a CO2 capture control method, apparatus, electronic device, and storage medium. Background Technology

[0002] With the acceleration of global industrialization, emissions of greenhouse gases such as carbon dioxide (CO2) have increased dramatically, leading to global warming and more frequent extreme weather events. Therefore, it is necessary to separate CO2 from the flue gas after fuel combustion.

[0003] Currently, chemical absorption methods (such as amine absorption) are mainly used to separate CO2. However, since the flue gas contains water vapor, it will dilute the amine solution, resulting in unsatisfactory collection accuracy. Existing technologies often directly adjust the flow rate or concentration of the amine solution, which is not only slow to respond but also has high energy consumption. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a CO2 capture and control method, apparatus, electronic device and storage medium to improve the accuracy of CO2 capture.

[0005] In a first aspect, a CO2 capture and control method is provided, applied to a capture tower comprising a condensation section and an absorption section; flue gas enters the absorption section after being cooled and dehydrated in the condensation section, and CO2 in the flue gas is captured by an amine solution; the method includes: Obtain the CO2 capture concentration in the amine solution at the outlet of the absorption section; When the deviation between the CO2 capture concentration and the target capture concentration exceeds the preset deviation range, the condensation temperature of the condensation section is adjusted by utilizing the pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration.

[0006] Optionally, the condensation temperature of the condensation section can be adjusted by utilizing a pre-established coupling relationship between condensation temperature and carbon capture concentration, including: Obtain the concentration deviation of external interference caused by the amount of external interference; The effective concentration deviation is obtained by removing the external interference concentration deviation from the deviation between the CO2 capture concentration and the target capture concentration; Based on the effective concentration deviation and the pre-constructed coupling relationship between condensation temperature and carbon capture concentration, the corresponding condensation temperature adjustment parameters are calculated. The condensing temperature of the condensing section is adjusted based on the condensing temperature adjustment parameters.

[0007] Optionally, obtaining the external interference concentration deviation caused by the external interference amount includes: Collect external disturbance quantities, including at least the flue gas flow rate fluctuation and flue gas temperature fluctuation at the inlet of the capture tower; The first concentration deviation component is determined based on the product of the flue gas flow fluctuation value and the static flow gain coefficient. The second concentration deviation component is determined based on the product of the flue gas temperature fluctuation value and the temperature static gain coefficient. The external interference concentration deviation is obtained by superimposing the first concentration deviation component and the second concentration deviation component.

[0008] Optionally, adjusting the condensing temperature of the condensing section based on the condensing temperature adjustment parameters includes: Analyze the condensation temperature adjustment parameters to obtain the adjustment direction and adjustment range; Based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy, the target adjustment strategy under the adjustment direction is determined; and the condensation temperature of the condensation section is adjusted according to the target adjustment strategy.

[0009] Optionally, based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy, the target adjustment strategy under the adjustment direction is determined as follows: If the adjustment range is less than the preset adjustment threshold, the target adjustment strategy is determined to be a single-variable adjustment strategy, which is used to adjust the first adjustment parameter. If the adjustment range is greater than the preset adjustment threshold, the target adjustment strategy is determined to be a multivariate collaborative adjustment strategy. The multivariate collaborative adjustment strategy is used to simultaneously adjust the first adjustment parameter and the second adjustment parameter; the first adjustment parameter is the heat exchange fan speed; the second adjustment parameter is the heat exchange cooling medium flow rate.

[0010] Optionally, when the target regulation strategy is a multivariate coordinated regulation strategy; adjusting the condensation temperature of the condensation section according to the target regulation strategy includes: Based on the adjustment range of the current condensation temperature and the preset static gain coefficient, the adjustment amount of the second adjustment parameter is calculated using a proportional control algorithm. The rate of change of the adjustment range of the condensing temperature over time is obtained, and combined with the preset dynamic response coefficient, the adjustment amount of the first adjustment parameter is calculated using a differential control algorithm. During the adjustment process, the adjustment amount of the second adjustment parameter and the ratio of the adjustment amount of the second adjustment parameter are dynamically adjusted, and the parameters of the corresponding actuator are adjusted based on the adjusted ratio.

[0011] Optionally, before adjusting the condensation temperature of the condensing section, the method further includes: Real-time monitoring of the current condensation temperature in the condensation section; If the current condensing temperature exceeds the preset safety limit, the adjustment of the condensing temperature will stop and the backup control strategy will be triggered. The backup control strategy includes adjusting the amine liquid circulation flow rate in the absorption section or changing the opening of the intake bypass valve.

[0012] Secondly, a CO2 capture and control device is provided, applied to a capture tower including a condensation section and an absorption section; the flue gas enters the absorption section after being cooled and dehydrated in the condensation section, and CO2 in the flue gas is captured by amine liquid; comprising: The acquisition unit is used to acquire the CO2 capture concentration in the amine solution at the outlet of the absorption section; The adjustment unit is used to adjust the condensation temperature of the condensation section by utilizing the pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration when the deviation between the CO2 capture concentration and the target capture concentration exceeds the preset deviation range.

[0013] Thirdly, an electronic device is provided, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements any of the methods of the first aspect.

[0014] Fourthly, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when the computer program is executed by a processor, it implements any of the methods of the first aspect.

[0015] This invention provides a CO2 capture control method, apparatus, electronic device, and storage medium. It acquires the CO2 capture concentration in the amine solution at the outlet of the absorption section. When the deviation between the CO2 capture concentration and the target capture concentration exceeds a preset deviation range, the condensation temperature of the condensation section is adjusted using a pre-established coupling relationship between condensation temperature and carbon capture concentration. Compared to traditional methods of adjusting the amine solution flow rate, this invention establishes a coupling relationship between condensation dehydration and carbon capture absorption for coordinated control. By adjusting the condensation section temperature, the CO2 capture concentration in the absorption section is adjusted, thus improving the accuracy of CO2 capture.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the trapping tower provided in an embodiment of the present invention is shown; Figure 2A flowchart of a CO2 capture and control method provided by an embodiment of the present invention is shown; Figure 3 This diagram illustrates the structure of a CO2 capture and control device provided in an embodiment of the present invention. Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present invention is shown. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] Currently, chemical absorption methods (such as amine absorption) are mainly used to separate CO2. However, since the flue gas contains water vapor, it will dilute the amine solution, resulting in unsatisfactory collection accuracy. Existing technologies often directly adjust the flow rate or concentration of the amine solution, which not only has a slow response but also high energy consumption.

[0021] Based on this, embodiments of the present invention provide a CO2 capture and control method and apparatus, which are described below through embodiments.

[0022] This invention provides a CO2 capture and control method, applied to a capture tower including a condensation section and an absorption section; such as... Figure 1 As shown, the flue gas enters the absorption section after being cooled and dehydrated in the condensation section, and CO2 in the flue gas is captured by amine solution.

[0023] Specifically, the capture tower, as a gas phase resource recovery coupling device, integrates a deep condensation unit and a chemical absorption unit in series from bottom to top along the gas flow path. The condensation section is located at the bottom of the tower, and the absorption section is located at the top of the tower. That is, along the flow direction of the flue gas, the flue gas first enters the condensation section.

[0024] Within the condensation section, a condensing heat exchange coil (or cooling medium channel) is installed. High-temperature, high-humidity flue gas (e.g., flue gas from a gas-fired power plant at approximately 90-110°C) enters from the bottom and undergoes counter-current or cross-current heat exchange with the cooling medium within the coil. By controlling the coil temperature, the flue gas is cooled below its dew point, causing most of the water vapor in the flue gas to undergo a phase change and condense into liquid water, which is then discharged through the drain outlet at the bottom. This process achieves the recovery of high-purity water and preliminary dehydration and cooling of the flue gas.

[0025] After dehydration and cooling, the dry, cold flue gas flows upward into the absorption section, which is filled with absorbent packing to increase the gas-liquid contact area. Simultaneously, lean amine solution is sprayed down from the top of the tower, passing through the packing layer under gravity and forming a counter-current contact with the rising flue gas. During this process, the amine solution reacts chemically with CO2 in the flue gas, achieving efficient CO2 capture. The resulting rich amine solution collects at the bottom of the tower and is then drawn off.

[0026] After CO2 capture, the gas continues to flow upwards into the water washing and demisting section at the top of the tower. This area is typically equipped with a demister or spray scrubbing device to further remove trace amounts of amine liquid droplets and dust entrained in the gas, preventing amine liquid from escaping and contaminating subsequent environments. Finally, the purified and dehydrated clean gas is discharged from the top of the tower as purified and dehydrated tail gas.

[0027] It should be understood that although this embodiment uses amine liquid as the absorbent, in other embodiments, the absorbent may be other solvents that can physically or chemically absorb CO2, and this embodiment does not limit this.

[0028] This pre-condensation design effectively avoids the problems of amine dilution and increased heat load caused by high-temperature and high-humidity flue gas directly entering the absorption section.

[0029] like Figure 2 As shown, the method includes the following steps: Step S201: Obtain the CO2 capture concentration in the amine solution at the outlet of the absorption section.

[0030] Specifically, an online concentration detection device, such as an infrared gas analyzer or a conductivity sensor, can be installed at the outlet pipe of the absorption section.

[0031] This sensor monitors the molar concentration or mass fraction of CO2 in the amine solution (i.e., the rich solution) flowing out of the absorption section in real time. This concentration value directly reflects the absorption efficiency of the trapping tower at the current moment and is a key indicator for determining whether the system's operating status meets the standards.

[0032] For example, if the target capture concentration is 3.5 mol / L, the data collected by the sensor in real time is the current actual capture concentration.

[0033] Step S202: When the deviation between the CO2 capture concentration and the target capture concentration exceeds the preset deviation range, the condensation temperature of the condensation section is adjusted by utilizing the pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration.

[0034] The control system has a preset target concentration value and an allowable deviation range. It calculates the difference between the actual concentration value collected by the sensor and the target value in real time.

[0035] The preset deviation range is set according to the control accuracy required by the process, for example, it can be set to ±0.2mol / L.

[0036] When the calculated absolute value of the deviation is less than or equal to the preset deviation range, the current acquisition state is determined to be stable and no intervention or adjustment is required; when the absolute value of the deviation exceeds the preset deviation range, subsequent adjustment steps are triggered.

[0037] Traditional control methods often directly adjust the amine flow rate or regeneration parameters in the absorption section, which results in a lag. This embodiment, however, influences the absorption efficiency at the downstream end by adjusting the condensation temperature at the front end.

[0038] The physical mechanism is that changes in condensation temperature directly alter the moisture content and temperature of the flue gas. Lowering the condensation temperature further reduces the moisture content in the flue gas, lowers the partial pressure of water vapor entering the absorption section, thereby reducing the dilution effect of the amine solution. At the same time, the low temperature flue gas increases the driving force for gas-liquid mass transfer, thus improving the CO2 absorption efficiency and increasing the CO2 concentration in the outlet amine solution; conversely, the opposite is also true.

[0039] Therefore, a coupling model or data table of the "temperature-concentration" relationship is pre-stored in the experiment. When an excessive concentration deviation is detected, the target condensation temperature required to eliminate the deviation is calculated based on this coupling relationship, and an adjustment command is output.

[0040] There are several ways to adjust the condensing temperature, such as adjusting the speed of the heat exchange fan in the condensing section to change the heat exchange rate, or adjusting the flow rate of the cooling medium (such as cooling water) introduced into the condensing section.

[0041] It should be understood that although this embodiment is illustrated by adjusting the condensation temperature, any means that can change the heat exchange efficiency of the condensation section and thus affect the flue gas outlet state parameters should be included within the scope of protection of this invention.

[0042] This embodiment establishes a coupling relationship between condensation dehydration and carbon capture and absorption synergistic control. Compared with the traditional method of adjusting the amine liquid flow rate, this invention improves the CO2 capture accuracy by adjusting the temperature of the condensation section. This not only has a fast adjustment response speed and eliminates control lag, but also significantly reduces system energy consumption and improves the overall energy efficiency and operational stability of CO2 capture.

[0043] In real-world industrial scenarios, flue gas parameters at the inlet of the capture tower are often unstable. For example, load changes in gas-fired power plants can cause fluctuations in flue gas flow and temperature. If adjustments are made directly based on detected concentration deviations, these temporary external disturbances may be misinterpreted as a decrease in the system's internal absorption efficiency, leading to unnecessary adjustments or even system oscillations.

[0044] Therefore, based on the above embodiments, this embodiment introduces an external interference decoupling mechanism. When it is determined that the deviation between the CO2 capture concentration and the target capture concentration exceeds a preset deviation range, this embodiment does not immediately perform temperature adjustment, but further performs the following refined steps: Step S202A: Obtain the external interference concentration deviation caused by the external interference amount.

[0045] In one feasible implementation, obtaining the external interference concentration deviation caused by the external interference amount includes: Step S202A1: Collect external interference quantities. The external interference variables include at least the flue gas flow rate fluctuation value and flue gas temperature fluctuation value at the inlet of the capture tower.

[0046] In this embodiment, flow sensors and temperature sensors installed at the inlet pipe can be used to collect the current flue gas flow rate and temperature data in real time, and calculate the difference between these values ​​and the baseline operating conditions, which are recorded as flue gas flow rate fluctuation values. and flue gas temperature fluctuation value .

[0047] Step S202A2: Determine the first concentration deviation component based on the product of the flue gas flow fluctuation value and the flow static gain coefficient.

[0048] Among them, the static gain coefficient of flow rate This is a parameter characterizing the system's properties, reflecting the degree of steady-state impact of a unit change in flue gas flow rate on the outlet CO2 concentration. For example, when the flue gas flow rate suddenly increases, the gas-liquid contact time shortens, leading to a decrease in the outlet concentration. This coefficient describes the slope of this change and can be derived through regression analysis of historical operating data or mechanistic models.

[0049] Specifically, the first concentration deviation component The calculation formula is: .

[0050] in, This indicates the change in CO2 concentration caused by a unit fluctuation in flue gas flow rate, expressed as concentration / flow rate.

[0051] Step S202A3: Determine the second concentration deviation component based on the product of the flue gas temperature fluctuation value and the temperature static gain coefficient.

[0052] Similarly, the temperature static gain coefficient This reflects the effect of changes in the unit temperature of the inlet flue gas on the absorption reaction rate.

[0053] The formula for calculating the second concentration deviation component is:

[0054] in, This indicates the change in CO2 concentration caused by a unit change in flue gas temperature, expressed as concentration / temperature.

[0055] Step S202A4: Superimpose the first concentration deviation component and the second concentration deviation component to obtain the external interference concentration deviation.

[0056] Assuming they are linearly independent, the external disturbance concentration deviation is: .

[0057] It should be understood that linear superposition is a preferred calculation method here, designed to meet the speed requirements of real-time control; in other complex operating conditions, nonlinear superposition models can also be used.

[0058] Step S202B: Remove the external interference concentration deviation from the deviation between the CO2 capture concentration and the target capture concentration to obtain the effective concentration deviation.

[0059] In this step, the calculated external interference concentration deviation is subtracted from the total deviation, and the remaining part is the effective concentration deviation truly caused by changes in absorption efficiency or insufficient condensation effect. .

[0060] For example, if the total deviation is 0.5 mol / L and the calculated deviation caused by external interference is 0.3 mol / L, then the effective deviation is only 0.2 mol / L.

[0061] Step S202C: Based on the effective concentration deviation and the pre-constructed coupling relationship between condensation temperature and carbon capture concentration, calculate the corresponding condensation temperature adjustment parameters.

[0062] Specifically, using the coupling relationship model established in step S202A, the following steps are taken: Substitute the inverse function to solve.

[0063] Assuming the coupling relationship is approximately linear, then the adjustment range of the condensation temperature... It can be represented as:

[0064] in, This is the sensitivity coefficient of condensation temperature to the collection concentration (i.e., the slope of the coupling relationship).

[0065] If the model is nonlinear, the target temperature can be solved using Newton's iteration method or table lookup interpolation method. This allows us to obtain the adjustment range of the condensation temperature:

[0066] in, This is the current condensation temperature.

[0067] In this embodiment, since interference factors are eliminated, the adjustment parameters here only respond to the internal state of the system, which greatly improves the accuracy of control.

[0068] Step S202D: Adjust the condensing temperature of the condensing section based on the condensing temperature adjustment parameters.

[0069] This embodiment, through the aforementioned interference decoupling logic, can intelligently identify and compensate for fluctuations in external operating conditions, avoiding increased energy consumption and system instability caused by blind adjustments, and significantly improving the robustness of the control algorithm.

[0070] Based on the above embodiments, adjusting the condensation temperature of the condensation section based on the condensation temperature adjustment parameters includes: Step S202D1: Analyze the condensing temperature adjustment parameters to obtain the adjustment direction and adjustment range.

[0071] The adjustment direction indicates whether the condensation temperature needs to be increased or decreased. For example, when the effective concentration deviation is negative (i.e. the actual concentration is lower than the target value), the condensation temperature usually needs to be decreased to improve the absorption efficiency. In this case, the adjustment direction is to decrease the temperature.

[0072] The adjustment range refers to the absolute value of the temperature change, which directly reflects the degree to which the current system deviates from the ideal state and the magnitude of the demand for heat exchange load adjustment.

[0073] Step S202D2: Based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy, determine the target adjustment strategy under the adjustment direction.

[0074] As a specific implementation method, based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy, the target adjustment strategy under the adjustment direction is determined as follows: Step A: If the adjustment range is less than the preset adjustment threshold, then the target adjustment strategy is determined to be a single-variable adjustment strategy.

[0075] The preset adjustment threshold can be set to, for example, 2°C. When the adjustment range is small, it indicates that the system is only slightly disturbed, and only fine-tuning is required.

[0076] The single-variable adjustment strategy is used to adjust the first adjustment parameter, which is the heat exchange fan speed. By adjusting the fan speed alone, the airflow disturbance intensity or heat transfer coefficient in the condensing section can be changed, thus achieving fine-tuning of the temperature.

[0077] The advantage of this method is that it has a very fast response speed and minimal increase in energy consumption. It can smoothly eliminate small deviations and avoid system lag and additional energy consumption caused by starting the cooling medium flow regulating valve.

[0078] Step B: If the adjustment range is greater than the preset adjustment threshold, then the target adjustment strategy is determined to be a multivariate collaborative adjustment strategy.

[0079] When the adjustment range is large, it means that the system is facing significant changes in operating conditions (such as a sudden increase in load), and simply adjusting the fan speed is no longer sufficient to provide enough heat exchange to reach the target temperature. In this case, a multi-variable coordinated adjustment strategy is used to simultaneously adjust the first and second adjustment parameters. The first adjustment parameter is the heat exchange fan speed; the second adjustment parameter is the heat exchange cooling medium flow rate.

[0080] By simultaneously increasing the cooling medium flow rate and adjusting the fan speed, the system can quickly change the heat transfer temperature difference and heat transfer coefficient, providing a significant cooling output and thus rapidly pulling back from the deviated operating conditions.

[0081] It should be understood that the specific value of the preset adjustment threshold can be set according to the heat capacity of the collection tower and the accuracy of the actuator, and is not limited to 2°C in this embodiment.

[0082] The system has a preset adjustment threshold, which is a critical value determined based on the response characteristics of the actuator and the thermal inertia of the system.

[0083] This embodiment compares the adjustment range with the threshold and selects a matching control strategy, thus avoiding the limitations of a single control mode under a wide range of operating conditions.

[0084] Step S202D3: Adjust the condensation temperature of the condensation section according to the target adjustment strategy.

[0085] Based on the determined strategy and the adjustment range of the condensing temperature, the control system calculates the operating parameters by utilizing the mapping relationship between the condensing temperature and the operating parameters of the actuators in the condensing section, and sends commands to the corresponding actuators (frequency converters, flow regulating valves) to complete the temperature regulation.

[0086] This embodiment performs fine-tuning for small deviations and aggressive adjustments for large deviations, ensuring both control accuracy and the system's ability to cope with extreme conditions. It effectively prevents system oscillations or response lags caused by mismatches between control methods and adjustment requirements.

[0087] In one specific implementation, when the target regulation strategy is a multivariate coordinated regulation strategy, adjusting the condensation temperature of the condensation section according to the target regulation strategy includes: Step S202D301: Based on the adjustment range of the current condensing temperature and the preset static gain coefficient, calculate the adjustment amount of the second adjustment parameter using a proportional control algorithm.

[0088] The second regulating parameter is the flow rate of the heat exchange cooling medium. Specifically, the flow rate of the cooling medium is usually adjusted by regulating the valve opening, and its relationship with the heat exchange is approximately linear under steady state. A proportional control algorithm (P-algorithm) is used to linearly output valve regulation commands based on the magnitude of the effective concentration deviation.

[0089] The calculation formula can be, for example:

[0090] in, The amount of adjustment for the cooling medium flow rate. The static gain coefficient for the cooling medium flow rate is... This represents the adjustment range of the condensation temperature at the current moment.

[0091] The main function of this step is to provide basic cooling capacity regulation to eliminate steady-state errors in the system. When the concentration deviation persists, the proportional action will continuously increase the cooling medium flow rate until the deviation returns to zero.

[0092] It should be understood that the static gain coefficient The value needs to be calibrated according to the heat exchange characteristics of the condenser to ensure that the adjustment process is neither too slow nor too sensitive.

[0093] Step S202D302: Obtain the rate of change of the adjustment amplitude of the condensing temperature over time, and calculate the adjustment amount of the first adjustment parameter using a differential control algorithm in combination with the preset dynamic response coefficient.

[0094] The first adjustable parameter is the heat exchange fan speed. Unlike the cooling medium flow rate, changes in fan speed can rapidly alter the disturbance intensity and heat transfer coefficient on the flue gas side, exhibiting an extremely fast response.

[0095] Therefore, this embodiment utilizes a differential control algorithm (D algorithm) to capture the changing trend of concentration deviation. The calculation formula can be, for example:

[0096] Where ΔN is the adjustment amount of the fan speed. For dynamic response coefficients, This represents the rate of change of the adjustment range of the condensation temperature over time.

[0097] When the system detects that the concentration deviation is increasing rapidly (i.e., the rate of change is large), even if the current absolute value of the deviation has not yet reached its maximum, the differential term will immediately output a large adjustment amount to suppress this trend by quickly adjusting the fan speed, thus playing a damping role and effectively preventing the system from overshooting or oscillating during large-scale adjustments.

[0098] Step S202D303: During the adjustment process, the adjustment amount of the second adjustment parameter and the ratio of the adjustment amount of the second adjustment parameter are dynamically adjusted, and the parameters of the corresponding actuator are adjusted based on the adjusted ratio.

[0099] Specifically, in the initial stage of adjustment, in order to quickly pull back to the operating condition, the weight of the derivative term can be appropriately increased, that is, the adjustment range of the fan speed can be increased to take advantage of its rapid response characteristics; while in the later stage of adjustment, when the system approaches the target state, the weight of the proportional term is gradually increased, that is, the steady-state effect is locked by fine adjustment of the cooling medium flow rate.

[0100] This dynamic proportional adjustment mechanism essentially adaptively allocates control weights for fast variables (fan speed) and slow variables (cooling medium flow rate) according to different adjustment stages.

[0101] Ultimately, the control system converts the calculated adjustment values ​​of the first and second parameters into specific execution commands, such as sending an opening command to the flow regulating valve of the cooling water pump and a frequency adjustment command to the frequency converter of the heat exchange fan, thereby achieving precise, rapid, and stable control of the condensing temperature.

[0102] This embodiment solves the problems of easy oscillation and slow response of a single control method under large deviation conditions, and significantly improves the dynamic quality of the system.

[0103] In actual industrial operation, situations may occur such as cooling system failure, abnormal rise in flue gas temperature, or scaling on the heat exchange surface leading to a sharp drop in heat exchange efficiency. If the condensing temperature is forcibly adjusted according to the above control logic, it may cause the condensing section equipment to operate at overheating, resulting in equipment damage or safety accidents.

[0104] Therefore, based on the above embodiments, before adjusting the condensation temperature of the condensation section, the method further includes: Step S203: Monitor the current condensation temperature of the condensation section in real time.

[0105] High-precision temperature sensors are installed at key locations in the condensation section (such as the heat exchanger outlet or the bottom of the condensation section). These sensors collect the current condensation temperature data in real time at a frequency of milliseconds and transmit it to the safety monitoring module of the control system.

[0106] This data serves as the direct basis for determining whether security protection has been triggered.

[0107] Step S204: If the current condensing temperature exceeds the preset safety limit, stop adjusting the condensing temperature and trigger the backup control strategy.

[0108] The preset safety upper limit is a critical temperature value set comprehensively based on the temperature resistance limit of the collection tower material, the stability of the amine solution, and process safety specifications.

[0109] For example, for conventional carbon steel collection towers and amine absorbents, the preset safety upper limit can be set to 60°C. When the monitored current condensation temperature is lower than this upper limit, the system determines it to be a safe operating condition and allows the execution of the conventional adjustment logic described in the above embodiment; when the monitored current condensation temperature is higher than this upper limit, the system determines it to be a dangerous operating condition and immediately triggers a safety response.

[0110] If the current condensing temperature exceeds the preset safety limit, all control commands related to the condensing temperature (such as fan speed adjustment and cooling medium flow rate adjustment) will be locked first to prevent further increase in equipment heat load due to continued execution of control commands. At the same time, the backup control strategy will be immediately activated to quickly reduce the system heat load or enhance heat dissipation capacity.

[0111] As one specific implementation method, the backup control strategy includes adjusting the amine solution circulation flow rate in the absorption section.

[0112] Specifically, the system controls the lean solution pump in the absorption section to increase its rotation speed and improve the amine solution circulation flow rate.

[0113] The physical mechanism is that increasing the amine liquid flow rate can enhance the gas-liquid mass transfer efficiency in the absorption section. At the same time, the lower temperature of the amine liquid can remove more reaction heat and sensible heat brought in by the flue gas, thereby helping to reduce the heat load in the entire tower and playing a role in liquid phase cooling.

[0114] As another specific implementation, the backup control strategy includes changing the opening of the intake bypass valve. A bypass pipe and bypass valve are installed on the inlet flue of the capture tower.

[0115] When the condensing temperature exceeds the limit, the system controls to increase the opening of the inlet bypass valve, directly leading some of the high-temperature flue gas out through the bypass pipeline, preventing it from entering the condensing and absorption sections. This action can quickly reduce the total amount of heat source entering the capture tower, thereby reducing the heat load on the condensing section and preventing equipment damage due to overheating.

[0116] It should be understood that the two backup strategies mentioned above can be used individually or in combination depending on the severity of the overheating. For example, the amine flow rate can be increased when there is a slight overheating, and the bypass valve can be opened simultaneously when there is a severe overheating.

[0117] This embodiment adds an extra layer of safety protection beyond the conventional control logic. When the system faces uncontrollable external thermal interference or internal heat exchange failure, it prioritizes the intrinsic safety of the equipment, avoids the risks of blind adjustments, and significantly improves the operational reliability of the CO2 capture system.

[0118] The application effects of the above CO2 capture and control methods will be explained in detail below, taking into account specific gas-fired power plant application scenarios.

[0119] Specifically, the application scenario is set as the flue gas treatment system of a gas-fired power plant.

[0120] The original flue gas parameters are as follows: flue gas temperature is 95℃, moisture content is approximately 9% (by volume), and CO2 volume fraction is 4%. The design target collection concentration of the trap is 3.5 mol / L (referring to the CO2 concentration in the amine solution at the outlet of the absorption section).

[0121] The initial operating state of the system is as follows: the condensation temperature of the condensation section is controlled at 40℃. After the flue gas passes through the condensation section for dehydration, the temperature of the flue gas entering the absorption section drops to 42℃, the moisture content is significantly reduced, the system operates stably, and the actual collection concentration is maintained at about 3.48 mol / L, which is within the preset deviation range.

[0122] To verify the dynamic response performance of the control method of the present invention, a simulated operating condition fluctuation event was conducted: due to the adjustment of the power plant load, the flue gas flow rate at the inlet of the capture tower suddenly increased by 15% in a short period of time, while the flue gas temperature fluctuated from 95°C to 98°C.

[0123] At this time, the following control procedure is executed: The first step is to obtain the CO2 capture concentration in the amine solution at the outlet of the absorption section.

[0124] As the increased flue gas flow rate led to a shorter gas-liquid contact time, and the increased inlet temperature increased the desorption tendency of the amine liquid, the sensor detected that the CO2 concentration in the outlet amine liquid rapidly decreased to 3.2 mol / L.

[0125] The second step is for the system to determine the concentration deviation.

[0126] The calculated total deviation was 0.3 mol / L, exceeding the preset deviation range (±0.2 mol / L). Using conventional control, this would likely result in a significant increase in the amine circulation volume, leading to a surge in energy consumption. However, this invention triggers an interference decoupling mechanism.

[0127] The third step is to obtain the concentration deviation of external interference.

[0128] The system collected flue gas flow rate fluctuations of +15% and flue gas temperature fluctuations of +3℃. This is based on pre-stored gain coefficients (assuming a static flow gain coefficient). The static gain coefficient at temperature is 0.008 mol / (L·%). Given a concentration of 0.015 mol / (L·℃), the first concentration deviation component is calculated to be 0.12 mol / L, and the second concentration deviation component is 0.045 mol / L. The sum of these components yields an external interference concentration deviation of approximately 0.165 mol / L.

[0129] The fourth step is to calculate the effective concentration deviation.

[0130] After removing the external interference concentration deviation from the total deviation, the effective concentration deviation is approximately 0.135 mol / L.

[0131] This result indicates that the actual decrease in absorption efficiency is far less than the total detected deviation, with most of the deviation being caused by fluctuations in external load.

[0132] The fifth step is to calculate the adjustment parameters and perform tiered adjustments.

[0133] Based on the effective concentration deviation, it was calculated that the condensation temperature needs to be reduced by 3℃ (i.e., the adjustment range is 3℃) to improve the absorption efficiency.

[0134] Since the adjustment range (3℃) is greater than the preset adjustment threshold (2℃), the target adjustment strategy is determined to be a multivariate collaborative adjustment strategy.

[0135] Step 6: Perform multivariate collaborative regulation.

[0136] The control system uses a proportional control algorithm to increase the second adjustment parameter (heat exchange cooling medium flow rate), while using a derivative control algorithm to quickly adjust the first adjustment parameter (heat exchange fan speed).

[0137] Specifically, the cooling water valve opening is increased, the fan speed is increased, and the heat exchange capacity of the condensing section is rapidly enhanced.

[0138] After the above adjustments, the temperature of the condensing section dropped from 40°C to 37°C within 2 minutes. As the condensing temperature decreased, the dew point of the flue gas also decreased, resulting in more water vapor condensing and precipitating in the condensing section. This not only reduced the moisture content of the flue gas entering the absorption section, preventing the amine solution from being diluted, but also significantly increased the driving force for gas-liquid mass transfer due to the low temperature of the flue gas.

[0139] Final result display: After the adjustment took effect, the CO2 capture concentration at the outlet of the absorption section gradually rose and stabilized at 3.45 mol / L after 5 minutes, returning to the target deviation range.

[0140] Meanwhile, due to the enhanced dehydration effect caused by the reduction in condensation temperature, the recovery rate of condensate increased by approximately 8% during this adjustment process.

[0141] Statistics show that during the stable operation phase following fluctuations in operating conditions, the gas-fired power plant's carbon capture system recovers an additional 1.2 tons of high-quality condensate per hour, achieving the goal of maximizing water resource recovery while ensuring carbon capture efficiency meets standards.

[0142] This embodiment fully demonstrates that the method provided by the present invention has strong anti-interference ability and resource recovery benefits under complex working conditions.

[0143] Based on the same inventive concept, this invention provides a CO2 capture and control device applied to a capture tower comprising a condensation section and an absorption section; flue gas enters the absorption section after being cooled and dehydrated in the condensation section, and CO2 in the flue gas is captured by amine solution; as shown... Figure 3 As shown, it includes: Acquisition unit 301 is used to acquire the CO2 capture concentration in the amine solution at the outlet of the absorption section.

[0144] The adjustment unit 302 is used to adjust the condensation temperature of the condensation section by utilizing the pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration when the deviation between the CO2 capture concentration and the target capture concentration exceeds a preset deviation range.

[0145] Based on the same technical concept, embodiments of the present invention also provide an electronic device, such as... Figure 4 As shown, it includes a processor 401, a communication interface 402, a memory 403, and a communication bus 404, wherein the processor 401, the communication interface 402, and the memory 403 communicate with each other through the communication bus 404.

[0146] Memory 403 is used to store computer programs; The processor 401, when executing the program stored in the memory 403, implements the steps of the method embodiment.

[0147] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0148] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0149] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0150] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0151] In another embodiment of the present invention, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of any of the CO2 capture and control methods described above. Specific implementation details can be found in the method embodiments and will not be repeated here.

[0152] The CO2 capture and control device provided in this embodiment of the invention can be specific hardware on a device or software or firmware installed on the device. The implementation principle and technical effects of the device provided in this embodiment of the invention are the same as those in the foregoing method embodiments. For the sake of brevity, any parts not mentioned in the device embodiments can be referred to the corresponding content in the foregoing method embodiments. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can all be referred to the corresponding processes in the above method embodiments, and will not be repeated here.

[0153] In the embodiments provided by this invention, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0154] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0155] In addition, the functional units in the embodiments provided by the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0156] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0157] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0158] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. All should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A CO2 capture and control method, characterized in that, A capture tower comprising a condensation section and an absorption section; flue gas, after being cooled and dehydrated in the condensation section, enters the absorption section, where CO2 is captured by an amine solution; the method includes: Obtain the CO2 capture concentration in the amine solution at the outlet of the absorption section; When the deviation between the CO2 capture concentration and the target capture concentration exceeds a preset deviation range, the condensation temperature of the condensation section is adjusted by utilizing the pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration.

2. The method according to claim 1, characterized in that, The method of adjusting the condensation temperature of the condensation section by utilizing the pre-established coupling relationship between condensation temperature and carbon capture concentration includes: Obtain the concentration deviation of external interference caused by the amount of external interference; The effective concentration deviation is obtained by removing the external interference concentration deviation from the deviation between the CO2 capture concentration and the target capture concentration; Based on the effective concentration deviation and the pre-constructed coupling relationship between condensation temperature and carbon capture concentration, the corresponding condensation temperature adjustment parameters are calculated. The condensing temperature of the condensing section is adjusted based on the condensing temperature adjustment parameters.

3. The method according to claim 2, characterized in that, The method of obtaining the external interference concentration deviation caused by the external interference amount includes: Collect external disturbance quantities, including at least the flue gas flow rate fluctuation and flue gas temperature fluctuation at the inlet of the capture tower; The first concentration deviation component is determined based on the product of the flue gas flow fluctuation value and the flow static gain coefficient. The second concentration deviation component is determined based on the product of the flue gas temperature fluctuation value and the temperature static gain coefficient. The first concentration deviation component and the second concentration deviation component are superimposed to obtain the external interference concentration deviation.

4. The method according to claim 2, characterized in that, The adjustment of the condensing temperature of the condensing section based on the condensing temperature adjustment parameters includes: The condensation temperature adjustment parameters are analyzed to obtain the adjustment direction and adjustment range; Based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy, the target adjustment strategy under the adjustment direction is determined; and the condensation temperature of the condensation section is adjusted according to the target adjustment strategy.

5. The method according to claim 4, characterized in that, The determination of the target adjustment strategy under the adjustment direction based on the adjustment range and the preset mapping relationship between the adjustment range and the adjustment strategy includes: If the adjustment range is less than the preset adjustment threshold, then the target adjustment strategy is determined to be a single-variable adjustment strategy, which is used to adjust the first adjustment parameter. If the adjustment range is greater than the preset adjustment threshold, the target adjustment strategy is determined to be a multivariate collaborative adjustment strategy. The multivariate collaborative adjustment strategy is used to simultaneously adjust the first adjustment parameter and the second adjustment parameter; the first adjustment parameter is the heat exchange fan speed; and the second adjustment parameter is the heat exchange cooling medium flow rate.

6. The method according to claim 5, characterized in that, When the target regulation strategy is a multivariate collaborative regulation strategy; adjusting the condensation temperature of the condensation section according to the target regulation strategy includes: Based on the adjustment range of the current condensation temperature and the preset static gain coefficient, the adjustment amount of the second adjustment parameter is calculated using a proportional control algorithm. The rate of change of the adjustment range of the condensation temperature over time is obtained, and the adjustment amount of the first adjustment parameter is calculated using a differential control algorithm in combination with a preset dynamic response coefficient. During the adjustment process, the ratio of the adjustment amount of the second adjustment parameter to the adjustment amount of the second adjustment parameter is dynamically adjusted, and the parameters of the corresponding actuator are adjusted based on the adjusted ratio.

7. The method according to claim 1, characterized in that, Before adjusting the condensation temperature of the condensation section, the method further includes: Real-time monitoring of the current condensation temperature of the condensation section; If the current condensation temperature exceeds the preset safety limit, the adjustment of the condensation temperature will be stopped and a backup control strategy will be triggered. The backup control strategy includes adjusting the amine liquid circulation flow rate in the absorption section or changing the opening of the intake bypass valve.

8. A CO2 capture and control device, characterized in that, A collection tower comprising a condensation section and an absorption section; flue gas, after being cooled and dehydrated in the condensation section, enters the absorption section, where CO2 is captured by amine solution; the device includes: The acquisition unit is used to acquire the CO2 capture concentration in the amine solution at the outlet of the absorption section; The adjustment unit is used to adjust the condensation temperature of the condensation section by utilizing a pre-constructed coupling relationship between the condensation temperature and the carbon capture concentration when the deviation between the CO2 capture concentration and the target capture concentration exceeds a preset deviation range.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; The memory is used to store computer programs; When the processor executes the program stored in the memory, it implements the method described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-7.

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