Waste heat utilization and regeneration system and method based on carbon capture system

Abstract

The invention provides a waste heat utilization and regeneration system and method based on a carbon capture system, and relates to the technical field of carbon capture and heat exchange, the system comprises an absorption tower, a lean and rich liquid heat exchanger, a regeneration tower and a rich liquid storage tank which are connected in sequence; the rich liquid storage tank is communicated with the regeneration tower through a circulation loop containing a driving unit; the system is further provided with a waste heat utilization device and a controller, and the controller responds to a signal indicating that the system enters an abnormal operation working condition, controls the storage tank to receive the rich liquid, synchronously starts the waste heat utilization device and the driving unit, and drives the rich liquid to flow through the regeneration tower through the circulation loop to complete regeneration. The system waste heat can be effectively utilized, deep regeneration of the solvent under the abnormal operation working condition is achieved, the system restart time is remarkably shortened, the operation flexibility is improved, and solvent degradation loss can be reduced.

Description

Technical Field

[0001] This invention relates to the field of carbon capture and heat exchange technology, and more specifically, to a waste heat utilization and regeneration system and method based on a carbon capture system. Background Technology

[0002] In the field of carbon capture, chemical absorption has become the mainstream technology for CO2 emission reduction from large stationary sources such as coal-fired power plants due to its high maturity and adaptability. This process typically relies on a closed-loop system consisting of an absorption tower and a regeneration tower, selectively capturing CO2 from flue gas using organic solvents such as amines, and achieving rich-liquid desorption and lean-liquid regeneration through thermal drive. To improve energy efficiency, existing systems generally employ rich-lean-lean heat exchangers to recover sensible heat and reboilers to provide the heat energy required for desorption. With the advancement of "dual carbon" targets and the increasing demand for power system flexibility, carbon capture devices are increasingly facing non-steady-state operating conditions such as frequent peak shaving and periodic shutdowns. Against this backdrop, ensuring the safety, economy, and recoverability of the system during periods of significant load fluctuations or interruptions has become a common challenge in engineering practice.

[0003] However, current technologies primarily focus on optimizing steady-state continuous operation, lacking a systematic mechanism for managing energy dynamics and regulating solvent status under abnormal operating conditions. On one hand, the sensible heat carried by the remaining high-temperature rich solution and related components after equipment shutdown is gradually dissipated due to the interruption of the heat source, failing to create a cascaded utilization path and failing to support subsequent regeneration needs. On the other hand, the rich solution is prone to irreversible thermal / oxidative degradation under high-temperature stagnation, leading to solvent performance degradation, increased corrosion risk, and the need to re-establish a complete thermal balance and concentration gradient during restart, significantly extending the commissioning preparation time. Although some studies have attempted to introduce auxiliary heat sources or protective additives, these often focus on single aspects (such as antioxidant storage or top gas waste heat recovery), resulting in technical problems such as wasted residual heat, insufficient solvent regeneration leading to slow restarts, and insufficient operational flexibility. Summary of the Invention

[0004] The purpose of this invention is to provide a waste heat utilization and regeneration system and method based on a carbon capture system, so as to alleviate the technical problems of system heat waste, insufficient solvent regeneration leading to slow restart and insufficient operational flexibility in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a waste heat utilization and regeneration system based on a carbon capture system, comprising: an absorption tower, a lean-rich liquid heat exchanger, a regeneration tower, and a rich liquid storage tank connected sequentially via related pipelines; the rich liquid storage tank and the regeneration tower are connected via a circulation loop, the circulation loop including a drive unit; the system further comprises: a waste heat utilization device for recovering and utilizing the residual heat of the system; and a controller for responding to a signal indicating that the system has entered an abnormal operating condition, controlling the rich liquid storage tank to receive rich liquid, and activating the waste heat utilization device and the drive unit to drive the rich liquid in the storage tank to flow through the circulation loop and through the regeneration tower for regeneration treatment.

[0006] In some alternative implementations, the aforementioned circulation loop further includes a rich liquid transfer pipeline and a circulation regeneration pipeline; the inlet of the rich liquid storage tank is connected to the regeneration tower via the rich liquid transfer pipeline, and the outlet of the rich liquid storage tank is connected to the regeneration tower via the circulation regeneration pipeline.

[0007] In some alternative implementations, the waste heat utilization device includes: a waste heat switching valve group, which is connected to a high-grade waste heat source and a medium- and low-grade waste heat source respectively; and an auxiliary heater, which is located on the above-mentioned circulating regeneration pipeline and connected to the above-mentioned medium- and low-grade waste heat source.

[0008] In some optional implementations, the above-mentioned rich liquid storage tank is equipped with a zoned heating coil, which is connected to the above-mentioned waste heat switching valve group.

[0009] In some optional implementations, the controller is also configured to: acquire absorbent type identification information for the rich liquid, and when the type identification information corresponds to a pre-stored heat-sensitive absorbent, adjust the output power of the partitioned heating coil to reduce the local heating temperature.

[0010] In some alternative implementations, the regeneration tower is equipped with a high-efficiency mass transfer component, and the connection end between the regeneration pipeline and the regeneration tower is an adjustable reflux port that can be switched to different positions at the top of the tower or in the tower.

[0011] Secondly, embodiments of the present invention provide a waste heat utilization and regeneration method based on a carbon capture system, applied to the system described in any one of the first aspects above. The method includes: in response to the system entering an abnormal operating condition, introducing the rich liquid in the system into the rich liquid storage tank; and using the residual heat of the system to drive the rich liquid in the storage tank to flow through the circulation loop and through the regeneration tower for regeneration treatment.

[0012] In some alternative implementations, utilizing the residual heat of the system includes: using high-grade waste heat to heat the rich liquid in the aforementioned storage tank, and using medium- and low-grade waste heat to heat the rich liquid flowing in the aforementioned circulation loop.

[0013] In some optional implementations, the above method further includes: monitoring the CO2 load of the rich liquid, and stopping the regeneration process when the CO2 load drops to a preset threshold.

[0014] In some optional implementations, the aforementioned abnormal operating conditions include system shutdown or load falling below a preset threshold.

[0015] This invention provides a waste heat utilization and regeneration system and method based on a carbon capture system. The system includes an absorption tower, a lean-rich liquor heat exchanger, a regeneration tower, and a rich liquor storage tank connected in sequence. The rich liquor storage tank and the regeneration tower are connected via a circulation loop containing a drive unit. The system also includes a waste heat utilization device and a controller. In response to a signal indicating that the system has entered an abnormal operating condition, the controller controls the storage tank to receive the rich liquor and simultaneously activates the waste heat utilization device and the drive unit, driving the rich liquor to flow through the circulation loop into the regeneration tower to complete regeneration. This invention can effectively utilize the system's waste heat, achieve deep regeneration of the solvent under abnormal operating conditions, significantly shorten the system restart time, improve operational flexibility, and help reduce solvent degradation losses. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention 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.

[0017] Figure 1 A schematic diagram of a waste heat utilization and regeneration system based on a carbon capture system is provided in an embodiment of the present invention. Figure 2 A schematic flowchart of a waste heat utilization and regeneration method based on a carbon capture system provided in an embodiment of the present invention; Figure 3 A schematic diagram of another waste heat utilization and regeneration system based on a carbon capture system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In traditional chemical absorption carbon capture systems, the rich solution after CO2 capture in the absorption tower is heated and desorbed in the regeneration tower by hot steam provided by the reboiler, desorbing high-purity CO2. The regenerated lean solution is then returned to the absorption tower for recycling.

[0020] When the system stops supplying flue gas for any reason (such as power plant peak shaving, equipment maintenance, or process fluctuations), a large amount of high-temperature rich liquid and sensible heat remain in the regeneration tower, its reboiler, and the rich-lean liquid heat exchanger. This residual heat encompasses different grades, and current technologies lack both a targeted tiered utilization mechanism and an effective means of recovering it for solvent regeneration. It dissipates as the system cools, resulting in energy waste. Furthermore, immediately stopping the capture system without promptly reducing the tower temperature can create a negative pressure condition within the regeneration tower, causing equipment damage. During shutdown, if the rich liquid remaining in the regeneration tower and pipelines cannot be regenerated promptly and sufficiently, it will remain in a high-temperature environment for an extended period, exacerbating thermal and oxidative degradation of the solvent. Simultaneously, existing protection technologies often focus only on single-aspect oxidation prevention or liquid storage, which can easily lead to solvent failure, increased costs, and potential equipment corrosion. Because the solvent state within the system is poor after shutdown (partially consisting of unregenerated rich liquid), and current technologies lack advance prediction and thermal maintenance mechanisms, restarting requires longer time and more energy to restore the entire system's solvent to its optimal lean state, affecting the system's rapid response capability. Even though some solutions attempt to utilize waste heat, the lack of a targeted mass transfer enhancement structure in the regeneration tower results in insufficient contact between the rich liquid and heat, leading to a low CO2 desorption rate and a significant reduction in waste heat utilization efficiency.

[0021] Therefore, there is an urgent need for a new technology that can achieve efficient utilization of waste heat in stages, deep regeneration and protection of solvents, enhanced mass transfer efficiency, and intelligent control under abnormal system operating conditions, so as to improve the overall performance and flexibility of carbon capture systems.

[0022] Based on this, the present invention provides a waste heat utilization and regeneration system and method based on a carbon capture system to solve the technical problems of system heat waste, insufficient solvent regeneration leading to slow restart and insufficient operational flexibility in the prior art.

[0023] To facilitate understanding of this embodiment, a waste heat utilization and regeneration system based on a carbon capture system disclosed in this embodiment of the invention will be described in detail first. This waste heat utilization and regeneration system can serve as a functionally enhanced auxiliary subsystem of the main system of chemical absorption carbon capture. It is physically integrated in parallel within the conventional carbon capture process flow and establishes controllable flow path connections with key nodes such as the lean liquid outlet of the absorption tower, the rich liquid outlet of the regeneration tower, and the hot side outlet of the lean and rich liquid heat exchanger. It does not change the equipment configuration, material flow direction, and control logic of the main system under steady-state conditions.

[0024] See Figure 1The diagram shows a waste heat utilization and regeneration system based on a carbon capture system. The system mainly includes an absorption tower 110, a lean and rich liquid heat exchanger 120, a regeneration tower 130, and a rich liquid storage tank 140 connected in sequence through relevant pipelines. The rich liquid storage tank 140 and the regeneration tower 130 are connected by a circulation loop 150, which includes a drive unit.

[0025] In this embodiment, the absorption tower 110 is used to absorb carbon dioxide; the lean-rich liquid heat exchanger 120 can be used to recover the sensible heat of the rich liquid to preheat the lean liquid under normal operating conditions, and in conjunction with the waste heat utilization device under abnormal operating conditions, to directionally transfer residual heat energy to the rich liquid storage tank 140 and the circulation loop, realizing dynamic redistribution and cascade utilization of heat; the regeneration tower 130 is used to desorb and regenerate the rich liquid; the rich liquid storage tank 140 is used to receive and store the rich liquid from the regeneration tower 130 or related pipelines. The absorption tower 110, lean-rich liquid heat exchanger 120, regeneration tower 130 and rich liquid storage tank 140 are connected sequentially through corresponding pipelines.

[0026] The system also includes a waste heat recovery device for recovering and utilizing the system's residual heat. The controller is used to respond to a signal indicating that the system has entered an abnormal operating condition, control the rich liquid storage tank 140 to receive rich liquid, and start the waste heat utilization device and drive unit to drive the rich liquid in the storage tank to flow through the regeneration tower 130 for regeneration treatment via the circulation loop.

[0027] In one embodiment, the circulation loop 150 may further include a rich liquid transfer pipeline and a circulation regeneration pipeline; the inlet of the rich liquid storage tank 140 is connected to the regeneration tower 130 through the rich liquid transfer pipeline, and the outlet of the rich liquid storage tank 140 is connected to the regeneration tower 130 through the circulation regeneration pipeline.

[0028] In one embodiment, the waste heat utilization device includes: a waste heat switching valve group, which is connected to a high-grade waste heat source and a medium- and low-grade waste heat source respectively; and an auxiliary heater, which is located on the circulating regeneration pipeline and connected to the medium- and low-grade waste heat source.

[0029] High-grade waste heat sources can be used to provide the heat required for rapid heating to support the initial desorption and activation of the rich liquid in the storage tank, for example: reboiler condensate, high-temperature sensible heat recovery end of equipment (regeneration tower bottom, hot side shell surface of lean and rich liquid heat exchanger, etc.).

[0030] Low- to medium-grade waste heat sources can be used to maintain a stable heat input required for the continuous desorption of rich liquid, in order to compensate for the heat loss of the system and extend the effective regeneration time. Examples include: low-pressure steam condensate (temperature 60-85℃), pipeline cooling water, waste hot water at the cold side outlet of the rich and lean liquid heat exchanger, and cooling water in the equipment insulation layer.

[0031] Auxiliary heaters can serve as an enhancement structure for low- to medium-grade waste heat sources. When combined with low- to medium-grade waste heat sources, they can raise the temperature of recovered low- to medium-grade heat energy to improve local heat transfer efficiency and CO2 desorption driving force, such as absorption heat pumps or electric-driven heat pumps.

[0032] In other words, the waste heat switching valve group enables the graded use of high / medium-low grade waste heat. High-grade waste heat is prioritized for the initial heating of the rich liquid in the storage tank, resulting in rapid start-up and temperature rise. Medium- and low-grade waste heat is compensated by auxiliary heaters and sent to the circulating regeneration pipeline, ensuring stable response and good continuity. The two work together to achieve the appropriate utilization of waste heat of different grades, ensuring sufficient and controllable desorption of the rich liquid in the regeneration tower.

[0033] In one embodiment, the rich liquid storage tank 140 is equipped with a zoned heating coil, which is connected to the waste heat switching valve group in the above embodiment.

[0034] As a specific example, the zoned heating coils can be independently arranged in three zones—upper, middle, and lower—along the 140mm height of the rich liquid storage tank. Each zone is connected to different branches of the waste heat switching valve group to achieve spatially directional heat injection and controllable temperature gradient construction. The upper zone coils are preferentially connected to high-grade waste heat sources to suppress gas entrainment and volatilization losses, while the middle and lower zone coils are linked to medium and low-grade waste heat sources to ensure overall temperature uniformity and avoid overheating and degradation of the rich liquid at the bottom or localized vaporization of the solvent at the top.

[0035] As a specific example, the zoned heating coils can be radially distributed along the horizontal cross-section of the rich liquid storage tank 140, dividing it into three concentric ring heating zones: an inner ring zone, a middle ring zone, and an outer ring zone. Each ring zone coil is independently connected to different control branches of the waste heat switching valve group and is equipped with corresponding temperature sensors and flow regulating valves.

[0036] As another concrete example, this radial partition structure is adapted to the mixed flow state of natural convection and forced circulation in the rich liquid within the storage tank: the inner ring coil is close to the center of the tank, has a small heat capacity and fast response, and is used to receive pulsed energy supply from high-grade waste heat sources to achieve rapid activation and heating of the core area of ​​the rich liquid; the outer ring coil is close to the tank wall, has a short heat conduction path and fast heat dissipation, and is preferentially connected to medium and low-grade waste heat sources to compensate for heat loss on the tank surface and suppress local overheating of the wall; the middle ring coil serves as a transition modulation zone, and its heat supply is dynamically adjusted by the controller according to the overall temperature field uniformity index in the tank (such as the temperature difference between the inner and outer rings not exceeding 5℃), ensuring that the temperature rise gradient of the rich liquid in the entire tank is gentle and without significant hot spots.

[0037] In one embodiment, the controller can also be used to: acquire absorbent type identification information of the rich liquid, and when the type identification information corresponds to a pre-stored heat-sensitive absorbent, adjust the output power of the zone heating coil to reduce the local heating temperature.

[0038] The rich liquid absorbent refers to the liquid medium used in a chemical absorption carbon capture system to selectively undergo a reversible chemical reaction with CO2 in flue gas, form a stable adduct, and achieve CO2 enrichment. It is preferably a water-based organic amine solution, including but not limited to monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), piperazine (PZ), and their modified composite systems.

[0039] Heat-sensitive absorbents can refer to absorbents with poor thermal stability (e.g., when the temperature exceeds the preset safe regeneration temperature threshold, they are prone to irreversible chemical degradation, resulting in a significant decrease in CO2 absorption capacity).

[0040] Furthermore, in another embodiment, in addition to acquiring the type identification information of the rich liquid, the controller can also acquire the current temperature in the storage tank. When the type identification information corresponds to a pre-stored heat-sensitive absorbent and the current temperature is higher than the preset safe regeneration temperature threshold corresponding to the absorbent, the output power of the partition heating coil is adjusted to reduce the local heating temperature.

[0041] The preset safe regeneration temperature threshold can be pre-calibrated according to the type of absorbent, for example: 82℃ for MEA solution, 105℃ for MDEA solution, and 88℃ for PZ solution; the type identification information can be obtained by reading the process formula number entered in the DCS system or the solvent label set on the inlet pipeline of the storage tank.

[0042] In another embodiment, the strategy for adjusting the output power of the zone heating coil may specifically include: determining the thermal stability threshold (i.e., the preset safe regeneration temperature threshold) based on the absorbent type, and dynamically allocating the heating power of each zone coil in combination with the real-time monitored temperature distribution in the storage tank, the rich liquid CO2 load, and the duration of the abnormal operating conditions of the system.

[0043] As a specific example, the zoned heating coils are independently arranged in three zones—upper, middle, and lower—along the 140mm height of the rich liquid storage tank. The principle for the distribution of heating power in each zone coil is as follows: when a high CO2 load is detected in the rich liquid, the power in the lower zone is increased to accelerate the desorption and activation of the rich liquid at the bottom; when it is identified as a heat-sensitive absorbent and the upper temperature is close to its safety threshold, the power in the upper zone is actively reduced and the heating in the middle zone is increased simultaneously to suppress gas phase volatilization and interface degradation; the entire process is continuously calibrated by the controller based on real-time temperature feedback to ensure a gradually increasing regeneration temperature potential from top to bottom, which drives the effective release of CO2 from the liquid phase to the gas phase while avoiding irreversible solvent loss caused by local overheating.

[0044] As another concrete example, the zoned heating coils are radially distributed along the horizontal cross-section of the rich liquid storage tank 140, dividing it into three concentric annular heating zones: an inner ring zone, a middle ring zone, and an outer ring zone. The principle for allocating the heating power of each zoned coil is as follows: priority is given to ensuring that the inner ring zone meets the basic activation temperature rise requirements, while the outer ring zone is simultaneously regulated to suppress wall overheating, and then the power of the middle ring zone is finely adjusted to achieve overall temperature field homogenization. This adjustment process forms a closed-loop feedback: temperature data drives power adjustment, and the adjusted heat distribution in turn affects the subsequent degradation rate and regeneration efficiency, thereby ensuring deep solvent regeneration while controlling the risk of local high temperatures within a preset safety boundary.

[0045] In one embodiment, the regeneration tower 130 is equipped with a high-efficiency mass transfer component, and the connection end between the circulating regeneration pipeline and the regeneration tower 130 is an adjustable reflux port that can be switched to different positions at the top of the tower or in the middle of the tower.

[0046] Among them, the high-efficiency mass transfer component is a functional internal component used to enhance the dispersion of the rich liquid during the flow process in the tower, prolong the effective contact time, and promote the transfer of heat to the depth of the liquid phase. Preferably, it can be corrugated packing, porous guide plate or combined vortex turbulence structure.

[0047] Specifically, the adjustable reflux port is set at the top of the regeneration tower 130, so that the rich liquid flows down along the surface of the packing in a lower temperature zone (e.g., 80-90℃), preferentially releasing physically dissolved CO2, and using the residual sensible heat in the upper part of the tower to achieve mild desorption, reducing the risk of degradation of heat-sensitive components; or, the adjustable reflux port is set in the middle of the regeneration tower 130, so that the rich liquid directly enters the high-temperature core zone (≥95℃) inside the tower, accelerating the breakage and desorption of chemically bound CO2 under strong heat drive, improving the regeneration intensity and depth per unit time, which is suitable for high-load rich liquid or emergency restart scenarios.

[0048] Based on this, the controller can further determine the optimal reflux position dynamically according to the real-time data of the rich liquid CO2 load, the tank outlet temperature and the regeneration tower wall temperature distribution: when the load is high, it can be switched to the middle of the tower to enhance the desorption power; when the load is low or the absorbent is identified as heat-sensitive, it can be switched to the top of the tower to match the low temperature regeneration window, so as to achieve on-demand energy supply.

[0049] In one embodiment, abnormal operating conditions include system shutdown or load falling below a preset threshold.

[0050] The preset threshold is dynamically set by the controller based on the operating characteristics of the carbon capture system and the current thermal stability of the absorbent. For example, when key parameters such as flue gas flow rate, boiler load, or CO2 concentration at the absorber inlet are continuously below this threshold for a preset time window (e.g., 5-15 minutes), the controller determines that the system has entered an abnormal operating condition and simultaneously triggers rich liquid transfer, waste heat start-up and shutdown, and regeneration cycle initiation. This determination logic is linked with the rich liquid CO2 load, tank temperature, and waste heat status of the regeneration tower: high-load rich liquid prioritizes deep regeneration, while low-load and high-temperature rich liquid focuses on maintaining thermal stability and inhibiting degradation, thereby ensuring precise matching between the regeneration strategy and the system's energy and solvent states under different operating conditions.

[0051] As a preferred example, the aforementioned drive unit includes a circulating pump; the controller is electrically connected to the waste heat switching valve group, the circulating pump, and the auxiliary heater, and is configured to: receive an external shutdown or low load trigger signal, control the rich liquid transfer pipeline to introduce rich liquid into the rich liquid storage tank, and start the waste heat switching valve group, the circulating pump, and the auxiliary heater to construct an independent circulating regeneration loop from the rich liquid storage tank through the circulating regeneration pipeline to the regeneration tower.

[0052] Under normal operating conditions, the system is in standby mode, with all control valves closed, the circulating pump stopped, the waste heat switching valve group disconnected, and the rich liquid storage tank not participating in the main circulation. When an abnormal operating condition signal is detected, the system automatically starts, guiding the high-temperature rich liquid retained in the regeneration tower and its associated pipelines to the rich liquid storage tank for temporary storage through the rich liquid transfer pipeline. Relying on the waste heat switching valve group to match residual heat sources of different grades, and through the coordinated energy supply of the zoned heating coil and auxiliary heater, the rich liquid is driven to continuously circulate in the closed loop formed between the rich liquid storage tank and the regeneration tower. This allows the rich liquid to complete deep CO2 desorption in the regeneration tower with the help of the tower's waste heat and external heating, ultimately achieving in-situ regeneration and thermal maintenance of the solvent.

[0053] In summary, this invention provides a waste heat utilization and regeneration system based on a carbon capture system. The system includes an absorption tower, a lean-rich liquor heat exchanger, a regeneration tower, and a rich liquor storage tank connected in sequence. The rich liquor storage tank and the regeneration tower are connected via a circulation loop containing a drive unit. The system also includes a waste heat utilization device and a controller. In response to a signal indicating that the system is entering an abnormal operating condition, the controller controls the storage tank to receive the rich liquor and simultaneously activates the waste heat utilization device and the drive unit, driving the rich liquor to flow through the circulation loop into the regeneration tower to complete regeneration. This invention effectively utilizes system waste heat, achieving deep regeneration of the solvent under abnormal operating conditions, significantly shortening system restart time, improving operational flexibility, and helping to reduce solvent degradation losses.

[0054] Based on the same inventive concept, this invention also provides a method for waste heat utilization and regeneration based on a carbon capture system, applicable to the system described in any of the above embodiments. See [link to relevant documentation]. Figure 2As shown, the method includes: S220, in response to the system entering an abnormal operating condition, introduces the rich liquid in the system into the rich liquid storage tank; When the system enters an abnormal operating condition, it can be triggered by the flue gas parameters, load signals or equipment status signals monitored in real time by the main system DCS controller or the power plant coordinated control system. These signals are then transmitted to the controller of the waste heat utilization and regeneration system in the above embodiment via the communication interface. The controller then immediately opens the control valve of the rich liquid transfer pipeline and starts the drive unit to guide the high-temperature rich liquid retained in the regeneration tower and its downstream pipeline to the rich liquid storage tank for temporary storage, thus laying the foundation for subsequent regeneration.

[0055] Specifically, abnormal operating conditions can include system shutdown or load falling below a preset threshold. As a concrete example, when an abnormal operating condition is a system shutdown, the lean solution in the storage tank can be used to restart the system after regeneration is completed.

[0056] S240 utilizes the residual heat of the system to drive the rich liquid in the storage tank to flow through the regeneration tower via a circulation loop for regeneration treatment.

[0057] In one embodiment, the use of residual heat in step S240 may specifically include: using high-grade waste heat to heat the rich liquid in the storage tank, and using medium- and low-grade waste heat to heat the rich liquid flowing in the circulation loop.

[0058] Furthermore, the controller can coordinate the power distribution of the waste heat switching valve group and the zone heating coil according to the current CO2 load of the rich liquid and the heat sensitivity characteristics corresponding to the absorbent type. For example, for high-load rich liquid, high-grade waste heat is used first to quickly raise the temperature inside the tank to the desorption and activation range, while medium and low-grade waste heat is used to continuously compensate for heat loss during the circulation process. For heat-sensitive absorbents, the high-grade heat input intensity is actively reduced, and the uniform supply of medium and low-grade heat in the circulation pipeline is enhanced to maintain a stable and mild regeneration temperature.

[0059] In one embodiment, the method may further include: monitoring the CO2 load of the rich solution, and stopping the regeneration process when the CO2 load drops to a preset threshold. Specifically, the preset threshold can be set according to the absorbent type and matches the lean solution quality requirements required for system restart. For example, MEA solution corresponds to 0.02-0.03 mol CO2 / mol absorbent, and PZ solution corresponds to 0.01-0.025 mol CO2 / mol absorbent; when the feedback value from the online CO2 load sensor is continuously and stably lower than the threshold for a preset time (e.g., 3-5 minutes), and the tank outlet temperature is still higher than the safe regeneration lower limit temperature, the controller determines that regeneration is complete, and simultaneously shuts down the drive unit, waste heat switching valve group, and auxiliary heater, switching to hot standby mode.

[0060] To facilitate understanding of this embodiment, this invention also provides an application example of a waste heat utilization and regeneration system and method based on a carbon capture system, see [link to relevant documentation]. Figure 3 The diagram shows another waste heat utilization and regeneration system based on a carbon capture system. The system mainly includes an absorption tower 110, a lean and rich liquid heat exchanger 120, a regeneration tower 130 and a rich liquid storage tank 140 connected in sequence through pipelines, so as to realize the capture of carbon dioxide in flue gas and efficient regeneration of solvent.

[0061] The absorber tower 110 has a flue gas inlet 111 on its lower side, which is connected to the pipeline (solid line) for rich liquid transmission at its bottom; and a clean flue gas outlet 112 on its top, which is connected to the pipeline (dashed line) for lean liquid transmission at its upper side. The rich liquid output from the absorber tower 110 is preheated by the lean-rich liquid heat exchanger 120 and then enters the regeneration tower 130 for desorption and regeneration.

[0062] The regeneration tower 130 is connected to the reboiler 100, the core heating component, at its lower side, and has a product gas CO2 outlet 131 at its top. The reboiler 100 includes a steam inlet 132 and a steam outlet 133. External steam enters the reboiler 100 through the steam inlet 132, releasing its latent heat to heat the carbon dioxide-rich liquid at the bottom of the regeneration tower 130. The heated rich liquid desorbs carbon dioxide gas at high temperature and is discharged through the product gas CO2 outlet 131. The steam that has released all its heat condenses into hydrophobic condensate and is discharged through the steam outlet 133. The reboiler 100, as the main heat source in the solvent regeneration process, can be used to separate CO2 from the rich liquid, i.e., to promote the release of CO2 from the rich liquid through steam heating.

[0063] The inlet of the rich liquid storage tank 140 is connected to the rich liquid side of the regeneration tower 130 through a rich liquid transfer pipeline 310, which is equipped with a control valve; its outlet is connected to the rich liquid side or the upper part of the regeneration tower 130 through a circulation regeneration pipeline 320.

[0064] The rich liquor, after being treated by the regeneration tower 130, is transported to the rich liquor storage tank 140 via the rich liquor transfer pipeline 310, which is equipped with a control valve to regulate the flow rate. The rich liquor storage tank 140 has a spiral heating coil running through it, which is connected to the heat source inlet 141 and heat source outlet 142 at the top of the tank. It can be connected to waste heat sources of different grades to achieve cascade heating of the rich liquor inside the tank. The outlet of the rich liquor storage tank 140 is connected to the regeneration tower 130 via a circulation regeneration pipeline 320, forming a circulation regeneration path for the rich liquor.

[0065] Specifically, the rich liquid storage tank 140 has a built-in zoned heating coil, which is connected to the high-grade waste heat source 330 (reboiler condensate, high-temperature sensible heat recovery end of the equipment) and the medium- and low-grade waste heat source 340 (low-pressure steam condensate, pipeline heat dissipation water) through a waste heat switching valve group, so as to realize the adaptive utilization of waste heat of different grades; the rich liquid storage tank 140 is also equipped with a temperature sensor and a CO2 load detector to provide real-time feedback on the liquid status.

[0066] Preferably, a circulating pump and an auxiliary heater can be sequentially installed on the circulating regeneration pipeline; the auxiliary heater is connected to a medium- or low-grade waste heat source to supplement the heat during the circulation process; temperature and pressure sensors are arranged along the pipeline, and a linkage control system is used to achieve precise regulation.

[0067] In one embodiment, the system may further include a regeneration tower enhancement structure. Preferably, a high-efficiency mass transfer component (corrugated packing layer and guide plate) may be added in the middle of the regeneration tower 130 to extend the residence time of the rich liquid and enhance heat exchange. An adjustable reflux port (top / middle switching) is provided at the top of the regeneration tower 130 to adapt to different temperature gradients in the tower.

[0068] In one embodiment, the system may further include an intelligent control component: including a controller (linking with the original distributed control DCS system) electrically connected to each sensor, control valve, circulating pump, and heater, with a built-in regeneration termination determination algorithm and low load prediction logic to achieve automated process control.

[0069] In the system provided in this embodiment of the invention, the bottom of the lean liquor self-regeneration tower 130 is cooled by the lean-rich liquor heat exchanger 120 and then returned to the absorption tower 110, forming a complete solvent cycle. Through multi-stage utilization of waste heat, zoned heating within the storage tank, and enhanced structural design within the regeneration tower, the system significantly improves the energy efficiency and operational stability of the carbon capture system.

[0070] Accordingly, the method applied to the waste heat utilization and regeneration system based on the carbon capture system can achieve the following modes: (1) Normal operation mode: Flue gas is introduced into the system through the flue gas inlet 111 of the absorption tower 110. The rich liquid enters the regeneration tower 130 after passing through the lean and rich liquid heat exchanger 120 along the original path. It is desorbed under the heating of the main steam of the reboiler, and the lean liquid returns to the absorption tower 110. At this time, the waste heat switching valve group is in the closed state, and the rich liquid storage tank 140 is on standby.

[0071] (2) Shutdown switching / low load prediction mode: When the controller receives a warning signal of "boiler load reduced to below 30%" or a shutdown signal of "flue gas shut-off valve closed" through the DCS, it immediately performs the following operations: Open the control valve on the rich liquid transfer pipeline 310 to guide the high temperature rich liquid in the regeneration tower 130 and pipeline to the rich liquid storage tank 140 for storage; start the waste heat switching valve group, give priority to connecting the high-grade waste heat source 330, and preheat the rich liquid through the built-in coil of the storage tank; start the circulation pump to preheat the circulation pipeline.

[0072] (3) Deep regeneration cycle mode: 1. Heat supply and matching: The controller automatically adjusts the waste heat switching valve group based on the temperature data of the storage tank temperature sensor and the heat source. High-grade waste heat is given priority for heating the rich liquid in the storage tank, while medium and low-grade waste heat is supplied to the auxiliary heater to maintain the heat demand in the circulation process. When the heat of a certain heat source is exhausted, it automatically switches to the next heat source to maximize the utilization rate of waste heat.

[0073] 2. High-efficiency circulation and regeneration: Start the circulation pump to pump out the rich liquid from the rich liquid storage tank 140. After being heated by the auxiliary heater, it returns to the top or middle of the tower through the adjustable reflux port according to the temperature gradient in the regeneration tower. The rich liquid flows from top to bottom along the mass transfer components in the regeneration tower, making full use of the sensible heat of the tower body and the heat it brings in for desorption reaction.

[0074] 3. Intelligent circulation control: The controller collects parameters such as the CO2 load of the rich liquid, the wall temperature of the regeneration tower, and the liquid temperature in the storage tank in real time, and executes the regeneration termination judgment algorithm. When it is detected that the CO2 load of the rich liquid drops to the preset lean liquid standard (e.g., ≤0.02mol CO2 / mol absorbent, the target value can also be flexibly adjusted according to the type of absorbent and operating requirements), or the temperature of the waste heat source is lower than the regeneration critical temperature (e.g., ≤80℃, the critical temperature is different for different absorbents and can be flexibly adjusted), the circulation pump, heater and inert gas supply are automatically stopped, and all control valves are closed.

[0075] 4. Solvent adaptation optimization: For heat-sensitive absorbents (such as MEA solution), the controller adjusts the output power of the heating coils in the storage tank zones to reduce the local heating temperature and avoid local overheating that could accelerate degradation.

[0076] (4) Restart preparation mode: After deep regeneration is completed, the solvent in the rich liquid storage tank 140 is in a qualified lean liquid state, and the system is kept in a hot standby state; when starting, the lean liquid is directly pumped back to the absorption tower 110 and quickly enters the normal operation state.

[0077] This invention provides a waste heat utilization and regeneration system and method based on a carbon capture system. The system, in addition to a main process including an absorption tower, a lean-rich liquor heat exchanger, and a regeneration tower, adds a rich liquor storage tank, a circulation loop connecting the storage tank and the regeneration tower, a waste heat utilization device for recovering residual heat from the system, and a controller. When the controller responds to a signal indicating that the system has entered an abnormal operating condition (such as shutdown or low load), it controls the transfer of rich liquor to the storage tank and activates the drive units of the waste heat utilization device and the circulation loop, driving the rich liquor in the storage tank to flow through the regeneration tower for regeneration. This invention can effectively recover and utilize system waste heat, achieve deep regeneration of solvents during shutdown or low load periods, significantly shorten system restart time, improve operational flexibility, and help reduce solvent degradation losses.

[0078] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, specifically, the electronic device includes a processor and a storage device; the storage device stores a computer program, and the computer program, when run by the processor, executes the method described in any of the above embodiments.

[0079] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. The electronic device 400 includes: a processor 410, a memory 420, a communication interface 430, and a bus 440. The memory 420 stores machine-readable instructions that can be executed by the processor 410. When the electronic device is running, the processor 410 communicates with the memory 420 through the bus 440. The processor 410 executes the machine-readable instructions to perform the steps of the method described above.

[0080] Specifically, the memory 420 and processor 410 can be general-purpose memory and processor, without any specific limitations. When the processor 410 runs the computer program stored in the memory 420, it can execute the above method.

[0081] Processor 410 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 410 or by instructions in software form. The processor 410 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 420, and processor 410 reads the information from memory 420 and, in conjunction with its hardware, completes the steps of the above method.

[0082] Corresponding to the above method, this embodiment of the invention also provides a computer-readable storage medium storing machine-executable instructions. When the computer-executable instructions are called and run by a processor, the computer-executable instructions cause the processor to perform the steps of the above method.

[0083] 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.

[0084] Furthermore, 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.

[0085] Furthermore, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0086] It should be noted that if the functionality is implemented as a software module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part 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.

[0087] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0088] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A waste heat utilization and regeneration system based on a carbon capture system, characterized in that, include: The absorption tower, lean and rich liquid heat exchanger, regeneration tower and rich liquid storage tank are connected in sequence through relevant pipelines. The rich liquid storage tank and the regeneration tower are connected by a circulation loop, which includes a drive unit. The system also includes: a waste heat recovery device for recovering and utilizing the residual heat of the system; The controller is used to respond to a signal indicating that the system has entered an abnormal operating condition, control the rich liquid storage tank to receive rich liquid, and start the waste heat utilization device and the drive unit to drive the rich liquid in the storage tank to flow through the circulation loop through the regeneration tower for regeneration treatment.

2. The system according to claim 1, characterized in that, The circulation loop also includes a rich liquid transfer pipeline and a circulation regeneration pipeline; the inlet of the rich liquid storage tank is connected to the regeneration tower through the rich liquid transfer pipeline, and the outlet of the rich liquid storage tank is connected to the regeneration tower through the circulation regeneration pipeline.

3. The system according to claim 2, characterized in that, The waste heat recovery device includes: The waste heat switching valve assembly is connected to a high-grade waste heat source and a medium- and low-grade waste heat source, respectively. An auxiliary heater is installed on the circulating regeneration pipeline and connected to the medium- and low-grade waste heat source.

4. The system according to claim 3, characterized in that, The rich liquid storage tank is equipped with a zoned heating coil, which is connected to the waste heat switching valve group.

5. The system according to claim 4, characterized in that, The controller is also configured to: acquire absorbent type identification information of the rich liquid; and when the type identification information corresponds to a pre-stored heat-sensitive absorbent, adjust the output power of the partitioned heating coil to reduce the local heating temperature.

6. The system according to claim 2, characterized in that, The regeneration tower is equipped with a high-efficiency mass transfer component, and the connection end between the circulating regeneration pipeline and the regeneration tower is an adjustable reflux port that can be switched to different positions at the top of the tower or in the middle of the tower.

7. A method for waste heat utilization and regeneration based on a carbon capture system, characterized in that, The method, applied to the system according to any one of claims 1 to 6, comprises: In response to the system entering an abnormal operating condition, the rich liquid in the system is introduced into the rich liquid storage tank; The residual heat of the system is used to drive the rich liquid in the storage tank to flow through the circulation loop and through the regeneration tower for regeneration treatment.

8. The method according to claim 7, characterized in that, The utilization of residual heat in the system includes: using high-grade waste heat to heat the rich liquid in the storage tank, and using medium- and low-grade waste heat to heat the rich liquid flowing in the circulation loop.

9. The method according to claim 7, characterized in that, The method further includes: monitoring the CO2 load of the rich liquid, and stopping the regeneration process when the CO2 load drops to a preset threshold.

10. The method according to claim 7, characterized in that, The abnormal operating conditions include system shutdown or load below a preset threshold.

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