Carbon capture system combined with multi-flow state deployment and heat pump waste heat recovery

Abstract

The present application relates to the technical field of carbon capture, and particularly discloses a carbon capture system combined with multi-flow state adjustment and heat pump waste heat recovery. The system comprises an absorption tower, a mixer, a heat pump system and a desorption tower. The absorption tower is used for forming rich liquid by absorbing carbon dioxide in flue gas and discharging the rich liquid. The mixer comprises a first chamber, a second chamber, a third chamber and a mixing chamber. Liquid media of different temperatures in single chambers are mixed in the mixing chamber and then output. The mixed liquid is heated by the heat pump system and then transported to the desorption tower. The mixed liquid enters the upper chamber of the desorption tower, is heated and desorbs part of carbon dioxide, and then separates the first lean liquid. The first lean liquid is transported to the third chamber and / or the lower chamber. The second lean liquid is separated from the lower chamber and then transported to the absorption tower. High-temperature carbon dioxide gas output from the desorption tower is input to the heat pump system, so that the heat pump system utilizes the waste heat of carbon dioxide. The present application ensures stable operation of the heat pump system and improves the utilization rate of heat energy.

Description

Technical Field

[0001] This invention belongs to the field of carbon capture technology, specifically relating to a carbon capture system that combines multi-flow regulation with heat pump waste heat recovery. Background Technology

[0002] In related technologies, carbon capture systems directly send rich or reflux lean liquid into heat exchangers, or the rich and lean liquids simply exchange heat through a heat pump system. This lack of a buffer for decoupling and redistribution of the liquid flow hinders the full utilization of the heat pump's advantages. In particular, the waste heat from the desorption tower and the heat load of the reboiler frequently fluctuate with changes in fluctuating flue gas volume and carbon dioxide concentration, making the heat pump system prone to deviating from its design operating conditions, leading to efficiency reduction or even shutdown. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a carbon capture system combining multi-flow mixing and heat pump waste heat recovery. This system can mix various liquids at different temperatures before inputting them into the heat pump system, ensuring stable operation of the system. Simultaneously, the coordination between the heat pump system and components such as heat exchangers improves the utilization rate of thermal energy.

[0004] This invention discloses a carbon capture system combining multi-flow regulation and heat pump waste heat recovery, comprising an absorption tower, a mixer, a heat pump system, and a desorption tower. The absorption tower introduces flue gas and an absorbent, which absorbs carbon dioxide from the flue gas to form a rich solution, which is then discharged. The mixer includes a first chamber, a second chamber, a third chamber, and a mixing chamber. The first chamber is connected to the absorption tower and stores the rich solution. The second chamber stores fresh absorbent or water. The third chamber is connected to the middle section of the desorption tower and stores the first lean solution output from the middle section of the desorption tower. The first chamber is connected to the mixing chamber via a first valve, and the second chamber is connected to the mixing chamber via a second valve. The third chamber... The mixing chamber is connected to the mixing chamber via a third valve. The mixing chamber is used to output the mixture from the three chambers. The heat pump system is located between the mixer and the desorption tower. The mixture is heated by the heat pump system and then transported to the desorption tower. The desorption tower includes an upper chamber and a lower chamber. The mixture enters the upper chamber, is heated and desorbs some carbon dioxide, and then separates the first lean liquid. Part of the first lean liquid is transported to the third chamber, and part of the first lean liquid enters the lower chamber to be heated and desorbed again, separating the second lean liquid. The second lean liquid is transported to the absorption tower. The high-temperature carbon dioxide gas output from the desorption tower is input to the heat pump system so that the heat pump system can utilize the waste heat of the carbon dioxide.

[0005] This invention employs a mixer with first, second, and third chambers, as well as a mixing chamber. The rich solution from the absorber, fresh absorbent or water, and the first lean solution from the middle section of the desorption tower are buffered in different chambers, then mixed as needed and heated by a heat pump before being fed into the desorption tower. Simultaneously, the high-temperature gas from the top of the desorption tower serves as the heat source for the heat pump. This structure provides the heat pump with a relatively stable inlet temperature and flow rate, mitigating the impact of upstream fluctuations on heat pump operation and improving the system's operational stability under varying conditions.

[0006] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a first storage tank and a second storage tank, wherein the first storage tank is used to store fresh absorbent and the second storage tank is used to store water, and the first and second storage tanks are respectively connected to the second chamber via pipelines.

[0007] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a heat exchanger having a first flow channel and a second flow channel. The first flow channel connects the rich liquid outlet of the absorption tower to the first chamber for the flow of rich liquid output from the absorption tower. The second flow channel connects the second lean liquid outlet of the desorption tower to the absorbent inlet of the absorption tower for the flow of second lean liquid output from the desorption tower, so that the second lean liquid exchanges heat with the rich liquid in the first flow channel.

[0008] In some embodiments, the heat pump system includes an evaporator, a compressor, a condenser, an expansion valve, and a heat exchange medium connected in sequence. The heat exchange medium circulates within the heat pump system. The heat exchange side of the condenser is connected to the mixed liquid outlet of the mixing chamber and the inlet of the upper chamber for heating the mixed liquid output from the mixing chamber. The heat exchange side of the evaporator is connected to the carbon dioxide gas outlet of the desorption tower for recovering the waste heat of the high-temperature carbon dioxide gas output from the desorption tower.

[0009] In some embodiments, the mixer includes an inner cylinder and an outer cylinder, the center of the inner cylinder forming the mixing chamber, and three first partitions provided in the region between the inner cylinder and the outer cylinder, the first partitions dividing the region between the inner cylinder and the outer cylinder into a first chamber, a second chamber and a third chamber, wherein a stirrer is provided in the mixing chamber.

[0010] In some embodiments, the mixer includes an upper chamber and a lower chamber, the interior of the lower chamber forming the mixing chamber, and the interior of the upper chamber having three second partitions that divide the interior of the upper chamber into a first chamber, a second chamber, and a third chamber, wherein a stirrer is provided in the mixing chamber.

[0011] In some embodiments, the desorption tower is provided with a partition plate in the middle, which divides the interior of the desorption tower into an upper chamber and a lower chamber. The upper chamber is provided with a microwave heating component, and the lower chamber is provided with a flash evaporation component. A liquid channel connecting the upper chamber and the lower chamber may be provided on the partition plate.

[0012] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a reboiler. The bottom outlet of the upper chamber and the bottom outlet of the lower chamber are respectively connected to the corresponding inlet of the reboiler via independent outlet pipes. The bottom outlet of the reboiler is connected to the lower part of the lower chamber via a pipe. This allows the first lean liquid output from the upper chamber to be heated by the reboiler and enter the lower chamber to form an intermediate lean liquid. The liquid output from the lower chamber is heated by the reboiler and returns to the lower chamber to form a reflux liquid. The lower chamber heats the intermediate lean liquid and / or the reflux liquid to form a second lean liquid.

[0013] In some embodiments, the top gas outlets of the upper chamber and the lower chamber merge and are connected via a pipe to the evaporator of the heat pump system.

[0014] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a valve assembly, a pump, a sensor, and a controller electrically connected to the valve assembly, the pump, the sensor, the first valve, the second valve, and the third valve. The controller is used to control the opening and closing of the valve assembly, the first valve, the second valve, and the third valve, as well as the operating status of the pump, based on data from the sensor. The valve assembly, the pump, and the sensor are installed on pipelines on any one of the absorption tower, the mixer, the heat pump system, the desorption tower, the first storage tank, the second storage tank, the heat exchanger, and the reboiler, or between any two of them, according to process requirements.

[0015] The carbon capture system combining multi-flow blending and heat pump waste heat recovery in this invention deeply couples a multi-chamber blending tank with a heat pump, providing a buffer and redistribution hub for liquid streams in the carbon capture system. On one hand, by mixing chamber liquids at different temperature levels as needed, the heat pump condenser side obtains relatively stable heat; on the other hand, the heat pump evaporator side continuously recovers waste heat from the top of the desorption tower. The combination of these two aspects reduces steam consumption in the external reboiler and enables the system to better adapt to complex industrial scenarios such as flue gas load variations. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the present invention.

[0017] Figure 2This is a top cross-sectional view of the mixer in one embodiment of the present invention.

[0018] Figure label:

[0019] 1. Absorption tower; 2. Mixer; 21. First chamber; 22. Second chamber; 23. Third chamber; 24. Mixing chamber; 25. Stirrer; 3. Heat pump system; 31. Evaporator; 32. Compressor; 33. Condenser; 34. Expansion valve; 4. Desorption tower; 41. Upper chamber; 42. Lower chamber; 43. Baffle plate; 5. First storage tank; 6. Second storage tank; 7. Heat exchanger; 8. Reboiler. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] like Figures 1-2 As shown, the carbon capture system combining multi-flow blending and heat pump waste heat recovery according to an embodiment of the present invention includes an absorption tower 1, a mixer 2, a heat pump system 3, and a desorption tower 4. The absorption tower 1 is used to introduce flue gas and absorbent. The absorbent absorbs carbon dioxide from the flue gas to form a rich liquid and then discharges it. The mixer 2 includes a first chamber 21, a second chamber 22, a third chamber 23, and a mixing chamber 24. The first chamber 21 is connected to the absorption tower 1 and is used to store the rich liquid. The second chamber 22 is used to store fresh absorbent or water. The third chamber 23 is connected to the middle section of the desorption tower 4 and is used to store the first lean liquid output from the middle section of the desorption tower 4. The first chamber 21 is connected to the mixing chamber 24 via a first valve, and the second chamber 22 is connected to the mixing chamber 24 via a second valve. The mixing chamber 24 is connected to the third chamber 23, which is connected to the mixing chamber 24 via a third valve. The mixing chamber 24 is used to output the mixture from the three chambers. The heat pump system 3 is located between the mixer 2 and the desorption tower 4. The mixture is heated by the heat pump system 3 and then transported to the desorption tower 4. The desorption tower 4 includes an upper chamber 41 and a lower chamber 42. The mixture enters the upper chamber 41, is heated and desorbs some carbon dioxide, and then separates into a first lean liquid. Part of the first lean liquid is transported to the third chamber 23, and part of the first lean liquid enters the lower chamber 42 to continue to be heated and desorbed, separating into a second lean liquid. The second lean liquid is transported to the absorption tower 1. The high-temperature carbon dioxide gas output from the desorption tower 4 is input to the heat pump system 3 so that the heat pump system 3 can utilize the waste heat of the carbon dioxide.

[0022] The carbon capture system combining multi-flow distribution and heat pump waste heat recovery in this embodiment uses a multi-chamber mixer 2 as a material buffer and distribution hub, and provides a stable heat source and heat sink for the heat pump system 3. This mitigates the impact of changes in the heat load of the desorption tower 4 caused by upstream flue gas fluctuations on the operating efficiency of the heat pump, and improves the operational stability of the entire carbon capture system.

[0023] Specifically, the system includes an absorption tower 1, a mixer 2, a heat pump system 3, and a desorption tower 4. The absorption tower 1 is used to introduce the flue gas to be treated and a chemical absorbent (e.g., an organic amine solution). The absorbent can be introduced directly from the outside, or typically, a lean solution desorbed by the desorption tower 4 can be introduced, serving as a second lean solution in this system. Inside the absorption tower 1, the flue gas flows from bottom to top, and the absorbent flows from top to bottom, ensuring full contact between the two. Carbon dioxide in the flue gas is absorbed by the absorbent, and the carbon dioxide-rich absorbent forms a rich solution, which is discharged from the bottom of the absorption tower 1.

[0024] Mixer 2, as a key buffer and mixing unit in the system, is internally constructed with multiple independent chambers, including a first chamber 21, a second chamber 22, a third chamber 23, and a mixing chamber 24. The inlet of the first chamber 21 is connected to the rich liquid outlet at the bottom of the absorption tower 1 via a pipe, and is used to receive and temporarily store the rich liquid discharged from the absorption tower 1. The second chamber 22 is used to store fresh absorbent or process water to replenish consumption during system operation. The inlet of the third chamber 23 is connected to the middle section of the desorption tower 4 via a pipe, and is used to receive and store the first lean liquid, which has undergone partial desorption, drawn from the middle section of the desorption tower 4.

[0025] Each of the first chamber 21, the second chamber 22, and the third chamber 23 has a discharge port at its bottom or lower part. Each discharge port is connected to the lower inlet of the mixing chamber 24 via an independent discharge pipe. Specifically, a first valve is installed on the pipe between the first chamber 21 and the mixing chamber 24, a second valve is installed on the pipe between the second chamber 22 and the mixing chamber 24, and a third valve is installed on the pipe between the third chamber 23 and the mixing chamber 24. By adjusting the opening of these three valves, the rich liquid from the first chamber 21, the fresh absorbent or water from the second chamber 22, and the first lean liquid from the third chamber 23 can be introduced into the mixing chamber 24 in any proportion. Within the mixing chamber 24, these liquids from different chambers are thoroughly stirred and mixed to form a mixture with specific temperature, load, and flow rate. This mixture is then discharged from the outlet of the mixing chamber 24.

[0026] A heat pump system 3 is located on the connection path between the mixer 2 and the desorption tower 4. The mixture discharged from the mixing chamber 24 of the mixer 2 is first sent to the heat pump system 3 for heating, and then sent to the desorption tower 4, thus achieving preheating of the mixture. The internal space of the desorption tower 4 is divided into an upper chamber 41 and a lower chamber 42. The high-temperature mixture heated by the heat pump enters the upper chamber 41 of the desorption tower 4. In the upper chamber 41, the mixture is further heated, and the carbon dioxide absorbed inside begins to desorb. After the desorption treatment in the upper chamber 41, part of the carbon dioxide is separated from the mixture and converted into the aforementioned first lean liquid. Part of this first lean liquid is drawn out from the middle or bottom of the upper chamber 41 and sent back to the third chamber 23 of the mixer 2 to form a cycle. Another part of the first lean liquid enters the lower chamber 42. In the lower chamber 42, the first lean liquid is further heated, causing the residual carbon dioxide in it to be further desorbed, and finally converted into a second lean liquid with a very low carbon dioxide loading. The second lean solution is discharged from the bottom of the desorption tower 4 and transported back to the top of the absorption tower 1 through a pipeline for recycling as an absorbent.

[0027] On the other hand, the high-temperature carbon dioxide gas generated during the desorption process in the upper chamber 41 and lower chamber 42 of the desorption tower 4 is collected from the top of the upper chamber 41 and lower chamber 42 and then discharged. This portion of high-temperature gas is guided to the heat pump system 3 as a low-grade heat source for the heat pump system 3. The heat pump system 3 absorbs the waste heat of these gases through its evaporator 31, thereby realizing the recovery and utilization of waste heat within the system.

[0028] In some embodiments, the carbon capture system combining multi-flow conditioning and heat pump waste heat recovery further includes a first storage tank 5 and a second storage tank 6. The first storage tank 5 is used to store fresh absorbent, and the second storage tank 6 is used to store water. The first storage tank 5 and the second storage tank 6 are respectively connected to the second chamber 22 via pipelines.

[0029] Specifically, the first storage tank 5 is used to store fresh absorbent, such as a high-concentration organic amine solution, to compensate for absorbent losses due to degradation or escape during system operation. The second storage tank 6 is used to store process water to replenish the water carried away by the exhaust gas from the top of the tower. The outlet of the first storage tank 5 is connected to the inlet of the second chamber 22 of the mixer 2 via a pipeline, and the outlet of the second storage tank 6 is also connected to the inlet of the second chamber 22 of the mixer 2 via a pipeline. In actual operation, fresh absorbent or water can be selectively added to the second chamber 22 from the first storage tank 5 and / or the second storage tank 6, based on the liquid level in the second chamber 22 of the mixer 2 or the calculation results of the overall water balance of the system. These added materials are mixed with the original liquid in the second chamber 22, and then mixed with the liquids in the first chamber 21 and the third chamber 23 as needed.

[0030] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a heat exchanger 7, which has a first flow channel and a second flow channel. The first flow channel connects the rich liquid outlet of the absorption tower 1 with the first chamber 21 for the flow of rich liquid output from the absorption tower 1. The second flow channel connects the second lean liquid outlet of the desorption tower 4 with the absorbent inlet of the absorption tower 1 for the flow of second lean liquid output from the desorption tower 4, so that the second lean liquid exchanges heat with the rich liquid in the first flow channel.

[0031] Specifically, heat exchanger 7 can be a plate heat exchanger 7 or a shell-and-tube heat exchanger 7. The inlet of its first flow channel is connected to the rich liquid outlet at the bottom of absorption tower 1 via a pipe, and the outlet of the first flow channel is connected to the feed inlet of the first chamber 21 of mixer 2 via a pipe. The low-temperature rich liquid from absorption tower 1 first flows through the first flow channel and then enters the first chamber 21 for storage. The inlet of the second flow channel of heat exchanger 7 is connected to the second lean liquid outlet at the bottom of desorption tower 4 via a pipe, and the outlet of the second flow channel is connected to the absorbent inlet at the top of absorption tower 1 via a pipe. The high-temperature second lean liquid (typically at a high temperature, such as above 100°C) discharged from desorption tower 4 flows through the second flow channel and exchanges heat with the rich liquid in the first flow channel. In this process, the rich liquid is preheated, and its temperature increases; while the second lean liquid is cooled, and its temperature decreases. After heat exchange, the second lean liquid is then sent to the top of the absorption tower 1 to participate in the absorption reaction again, while the preheated rich liquid enters the first chamber 21 of the mixer 2, waiting to be mixed with the liquids in other chambers for the next step.

[0032] In some embodiments, the heat pump system 3 includes an evaporator 31, a compressor 32, a condenser 33, an expansion valve 34, and a heat exchange medium connected in sequence. The heat exchange medium circulates within the heat pump system 3. The heat exchange side of the condenser 33 is connected to the outlet of the mixture in the mixing chamber 24 and the inlet of the upper chamber 41 for heating the mixture output from the mixing chamber 24. The heat exchange side of the evaporator 31 is connected to the outlet of the carbon dioxide gas in the desorption tower 4 for recovering the waste heat of the high-temperature carbon dioxide gas output from the desorption tower 4.

[0033] Specifically, the heat pump system 3 uses high-boiling-point working fluids such as R134a or R245fa as the heat exchange medium. The condenser 33 has a first heat exchange side and a second heat exchange side that are isolated from each other. The first heat exchange side is the heat exchange medium channel, and the second heat exchange side is the heated fluid channel. The outlet of the mixing chamber 24 of the mixer 2 is connected to the inlet of the second heat exchange side of the condenser 33 via a pipe, and the outlet of the second heat exchange side of the condenser 33 is connected to the feed inlet of the upper chamber 41 of the desorption tower 4 via a pipe. The mixed liquid discharged from the mixing chamber 24 absorbs heat released by the condensation of the high-temperature heat exchange medium from the first heat exchange side as it flows through the second heat exchange side of the condenser 33, raising its temperature to near the desorption temperature (e.g., above 100°C), and then enters the upper chamber 41 of the desorption tower 4.

[0034] Evaporator 31 also has a first heat exchange side and a second heat exchange side that are isolated from each other. The first heat exchange side is a heat exchange medium channel, and the second heat exchange side is a channel for the cooled fluid. The carbon dioxide gas outlet at the top of desorption tower 4 is connected to the inlet of the second heat exchange side of evaporator 31 via a pipe, and the outlet of the second heat exchange side of evaporator 31 is connected to a subsequent gas-liquid separation or carbon dioxide collection device. The high-temperature carbon dioxide and water vapor mixture (e.g., about 90°C) collected and discharged from the top of the upper chamber 41 and lower chamber 42 of desorption tower 4 enters the second heat exchange side of evaporator 31, transferring heat to the low-temperature, low-pressure liquid or gas-liquid two-phase heat exchange medium flowing in the first heat exchange side. After releasing the latent heat of vaporization, the mixture is condensed and cooled, and the water vapor in it condenses and precipitates out, thereby achieving preliminary dehydration of carbon dioxide.

[0035] The inlet of compressor 32 is connected to the first heat exchange side outlet of evaporator 31, and the outlet of compressor 32 is connected to the first heat exchange side inlet of condenser 33. The heat exchange medium, after absorbing heat from evaporator 31 and becoming a low-pressure gaseous state, is drawn into compressor 32, compressed into high-temperature, high-pressure superheated vapor, and then sent to condenser 33. The inlet of expansion valve 34 is connected to the first heat exchange side outlet of condenser 33, and the outlet of expansion valve 34 is connected to the first heat exchange side inlet of evaporator 31. The medium-temperature, high-pressure heat exchange medium, after releasing heat and liquefying in condenser 33, is adiabatically throttled and depressurized when flowing through expansion valve 34, becoming a low-temperature, low-pressure gas-liquid two-phase mixture again, returning to evaporator 31 to begin the next cycle. The entire heat pump system 3 operates continuously in this closed-loop manner, continuously pumping the waste heat from the top of desorption tower 4 to the mixed liquid entering desorption tower 4.

[0036] In some embodiments, the mixer 2 includes an inner cylinder and an outer cylinder, with a mixing chamber 24 formed at the center of the inner cylinder. Three first partitions are provided in the area between the inner cylinder and the outer cylinder, which divide the area between the inner cylinder and the outer cylinder into a first chamber 21, a second chamber 22 and a third chamber 23. An agitator 25 is provided in the mixing chamber 24.

[0037] In some embodiments, the mixer 2 includes an upper housing and a lower housing. The interior of the lower housing forms a mixing chamber 24, and the interior of the upper housing is provided with three second partitions, which divide the interior of the upper housing into a first chamber 21, a second chamber 22, and a third chamber 23. A stirrer 25 is provided in the mixing chamber 24.

[0038] The mixer 2 can have various forms. For example, in the first structural form, the mixer 2 includes an inner cylinder and an outer cylinder. The outer cylinder is fitted over the inner cylinder, forming an annular space between them. The inner cylinder is hollow, and its central area constitutes the mixing chamber 24. Three first baffles are arranged within the annular space between the inner and outer cylinders. These three first baffles are evenly distributed along the circumference of the inner cylinder, and each first baffle is sealed to the outer wall of the inner cylinder and the inner wall of the outer cylinder on both sides, respectively. The three first baffles divide the annular space into three independent sector-shaped chambers, namely the first chamber 21, the second chamber 22, and the third chamber 23. Each chamber has an independent inlet and outlet. Inside the mixing chamber 24, an agitator 25 is installed along the axial direction of the inner cylinder. This agitator 25 can be a stirring shaft with double-layered blades, its top end extending beyond the top of the mixer 2 and connected to a variable frequency motor. When the liquids from different chambers flow into the mixing chamber 24 in a set ratio, the stirrer 25 rotates under the drive of the motor to forcibly agitate the mixture, making its temperature and composition distribution uniform. Then the mixture is discharged from the overflow port at the top or the outlet at the bottom of the mixing chamber 24.

[0039] For example, in the second structural form, the mixer 2 includes an upper chamber and a lower chamber. The upper chamber is stacked on top of the lower chamber, and the two are connected by a pipe with a valve or a direct connection port. The interior of the lower chamber forms a mixing chamber 24, the volume of which is generally larger than the volume of any chamber in the upper chamber. The mixing chamber 24 also contains a stirrer 25, the structure of which is similar to the stirrer 25 in the first form described above. The interior of the upper chamber has three second partitions, dividing the interior of the upper chamber into three independent chambers, namely the first chamber 21, the second chamber 22, and the third chamber 23. Each chamber has a discharge port at its bottom, which is connected to the inlet of the mixing chamber 24 in the lower chamber via a pipe, and a valve is installed on each pipe to control the flow rate. In actual operation, the liquids in the first chamber 21, the second chamber 22, and the third chamber 23 flow into the mixing chamber 24 of the lower tank by gravity or through an additional small transfer pump. After being mixed evenly by the agitator 25, they are discharged. Both of these structures can achieve the physical buffering and precise mixing functions of multi-flow liquids, and can be flexibly selected according to the site space layout and processing costs.

[0040] In some embodiments, a partition plate 43 is provided in the middle of the desorption tower 4, which divides the interior of the desorption tower 4 into an upper chamber 41 and a lower chamber 42. A microwave heating component is provided in the upper chamber 41, and a flash evaporation component is provided in the lower chamber 42. A liquid channel connecting the upper chamber 41 and the lower chamber 42 can be provided on the partition plate 43.

[0041] In some embodiments, the carbon capture system combining multi-flow regulation and heat pump waste heat recovery further includes a reboiler 8. The bottom outlet of the upper chamber 41 and the bottom outlet of the lower chamber 42 are respectively connected to the corresponding inlet of the reboiler 8 via independent outlet pipes. The bottom outlet of the reboiler 8 is connected to the lower part of the lower chamber 42 via a pipe. This allows the first lean liquid output from the upper chamber 41 to enter the lower chamber 42 after being heated by the reboiler 8 to form an intermediate lean liquid. The liquid output from the lower chamber 42 is heated by the reboiler 8 and returns to the lower chamber 42 to form a reflux liquid. The lower chamber 42 heats the intermediate lean liquid and / or the reflux liquid to form a second lean liquid.

[0042] In some embodiments, the top gas outlets of the upper chamber 41 and the lower chamber 42 merge and are connected via a pipe to the evaporator 31 of the heat pump system 3.

[0043] Specifically, the partition plate 43 is fixed horizontally or slightly inclined to the middle of the inner wall of the desorption tower 4, dividing the space inside the tower into an upper chamber 41 and a lower chamber 42. In some specific embodiments, one or more liquid channels connecting the upper chamber 41 and the lower chamber 42 can be provided on the partition plate 43, for example, by opening a through hole in the center of the partition plate 43, or by installing a short pipe with a valve. The first lean liquid generated by desorption in the upper chamber 41 can enter the lower chamber 42 through this liquid channel.

[0044] In some specific embodiments, the upper part of the first chamber 21 is provided with a liquid distribution assembly, such as a plate body with through holes evenly distributed on the plate body.

[0045] A microwave heating assembly is installed inside the upper chamber 41. This assembly includes several microwave generators and their waveguides, which are arranged on the side walls or end caps of the upper chamber 41. The microwaves generated directly act on the mixture inside the upper chamber 41, causing the water and amine molecules inside the mixture to vibrate violently, thus rapidly raising the temperature and causing carbon dioxide to desorb quickly. Microwave heating can achieve rapid start-up and precise temperature control for mixtures with high loads in the upper chamber 41. A flash evaporation assembly is installed inside the lower chamber 42. This flash evaporation assembly can be one or more flash baffles, flash plates, or an expanded flash space. The first lean solution entering the lower chamber 42 (at which point the load has been reduced) stays on the flash evaporation assembly. Because the lower chamber 42 maintains a lower pressure or higher temperature than the upper chamber 41, the residual carbon dioxide in the first lean solution is rapidly flashed out, further reducing the carbon dioxide load of the solution, and finally forming a second lean solution.

[0046] This embodiment also includes a reboiler 8. The reboiler 8 can be a kettle-type or vertical thermosiphon heat exchanger 7, with its heat source coming from external steam or heat transfer oil. The bottom of the upper chamber 41 of the desorption tower 4 is provided with a first liquid outlet for drawing out a portion of the first lean liquid; the bottom of the lower chamber 42 is provided with a second liquid outlet for drawing out the second lean liquid. The first and second liquid outlets are respectively connected to the corresponding inlets of the reboiler 8 through independent liquid outlet pipes. A heating flow channel can be provided inside the reboiler 8 to allow liquids from the upper chamber 41 and the lower chamber 42 to enter simultaneously. Alternatively, two independent heating flow channels can be provided to receive liquids from the upper chamber 41 and the lower chamber 42 respectively. The bottom of the reboiler 8 is provided with a total liquid outlet, which is connected to the lower part of the lower chamber 42 (e.g., the side wall of the lower chamber 42 near the bottom) through a pipe. During operation, the first lean liquid drawn from the upper chamber 41 enters the reboiler 8 and is heated to a higher temperature. It then exits from the bottom of the reboiler 8 and enters the lower chamber 42, becoming the intermediate lean liquid in the lower chamber 42, which continues to participate in flash desorption. Simultaneously, the second lean liquid drawn from the bottom of the lower chamber 42 enters the reboiler 8 and is heated. The heated liquid returns from the bottom of the reboiler 8 to the lower part of the lower chamber 42, forming reflux liquid to maintain thermal circulation within the lower chamber 42. By continuously receiving the heated intermediate lean liquid and reflux liquid from the reboiler 8, the lower chamber 42 maintains a high-temperature state, thereby promoting further flash desorption of residual carbon dioxide.

[0047] In addition, gas outlets are provided at the top of the upper chamber 41 and the lower chamber 42, respectively. These two gas outlets are connected to the evaporator 31 of the heat pump system 3 via a confluence of pipes. The high-temperature carbon dioxide gas (usually carrying water vapor) generated by desorption in the upper chamber 41 mixes with the carbon dioxide gas generated by flash evaporation in the lower chamber 42 in the confluence pipe and enters the evaporator 31 together. These mixed gases release their latent heat of vaporization in the evaporator 31, which is absorbed by the heat pump working fluid. Simultaneously, the gas temperature decreases, and water vapor condenses, facilitating subsequent carbon dioxide purification and compression. By confluencing the gas outlets of the two chambers, it can be ensured that all waste heat generated by desorption can be effectively captured by the heat pump system 3, regardless of the load distribution within the desorption tower 4.

[0048] In some embodiments, the carbon capture system combining multi-flow modulation and heat pump waste heat recovery further includes valve assemblies, pumps, sensors, and a controller electrically connected to the valve assemblies, pumps, sensors, a first valve, a second valve, and a third valve. The controller is used to control the opening and closing of the valve assemblies, the first valve, the second valve, and the third valve, as well as the operating status of the pump, based on data from the sensors. The valve assemblies, pumps, and sensors are installed on any one of the absorption tower 1, the mixer 2, the heat pump system 3, the desorption tower 4, the first storage tank 5, the second storage tank 6, the heat exchanger 7, and the reboiler 8, or on pipelines between any two of them, according to process requirements.

[0049] Specifically, the valve assembly includes all regulating valves, shut-off valves, or solenoid valves in the system other than the first, second, and third valves already mentioned, such as flow regulating valves installed on various fluid pipelines. Pumps include all power equipment in the system used for transporting liquids, such as the rich liquid pump connected between the absorption tower 1 and the first chamber 21 of the mixer 2, the interstage suction pump connected between the middle section of the desorption tower 4 and the third chamber 23 of the mixer 2, and the booster pump located between the outlet of the mixing chamber 24 of the mixer 2 and the heat pump condenser 33. Sensors are distributed at key nodes of the system according to process monitoring needs, including but not limited to temperature sensors, flow sensors, and carbon dioxide load analyzers installed at each chamber and outlet of the mixer 2, pressure sensors and superheat monitors installed on the working fluid loop of the heat pump system 3, and online component analyzers installed at the inlet and outlet of the desorption tower 4.

[0050] The controller employs a distributed control system (DCS) or a programmable logic controller (PLC). Its signal input terminals are electrically connected to the signal output terminals of various sensors, and its control output terminals are electrically connected to the actuators of each valve in the valve assembly and the frequency converters of each pump. The controller has multiple preset control modes, including at least one liquid flow feedforward distribution mode and one heat pump load adaptive tracking mode.

[0051] In the liquid feedforward distribution mode, when the sensor detects a sudden change in flow rate or temperature at the inlet of desorber 4 (e.g., an increase in the required regeneration heat load due to an increase in upstream flue gas volume), the controller first calculates the adjustment amount of the liquid output ratio from the first chamber 21 and the second chamber 22 of mixer 2. The controller then outputs a command to increase the opening of the third valve to increase the inflow of the medium-temperature semi-lean liquid from the third chamber 23, while simultaneously decreasing the opening of the first valve to reduce the inflow of the low-temperature rich liquid from the first chamber 21. This adjustment raises the average temperature of the liquid entering the mixing chamber 24, allowing the mixed liquid to enter desorber 4 at a higher temperature after flowing through the heat pump condenser 33, thereby quickly responding to the instantaneous heat load demand of desorber 4 without significantly increasing the power of the heat pump compressor 32.

[0052] In the heat pump load adaptive tracking mode, the controller collects data from the pressure and temperature sensors installed on the heat pump evaporator 31 and condenser 33 in real time to calculate the real-time energy efficiency ratio and superheat of the heat pump. When the flow rate or temperature of the high-temperature gas discharged from the top of the desorption tower 4 fluctuates, the controller dynamically adjusts the operating frequency of the variable frequency compressor 32 according to the change in evaporation pressure, thereby changing the circulation volume of the heat exchange medium. At the same time, the controller fine-tunes the opening of the expansion valve 34 to maintain the superheat at the outlet of the evaporator 31 within the set range. These two adjustment actions work together to achieve a dynamic balance between the heat absorption rate and the heat release rate of the heat pump system 3, thereby preventing a significant drop in heat pump energy efficiency due to operating conditions deviating from the design point.

[0053] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0057] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A carbon capture system combined with a multi-flow state deployment and heat pump waste heat recovery, characterized in that, This includes absorption towers, mixers, heat pump systems, and desorption towers; The absorption tower is used to introduce flue gas and absorbent. The absorbent absorbs carbon dioxide in the flue gas to form a rich liquid and then discharges it. The mixer includes a first chamber, a second chamber, a third chamber, and a mixing chamber. The first chamber is connected to the absorption tower and is used to store the rich solution. The second chamber is used to store fresh absorbent or water. The third chamber is connected to the middle section of the desorption tower and is used to store the first lean solution output from the middle section of the desorption tower. The first chamber is connected to the mixing chamber via a first valve, the second chamber is connected to the mixing chamber via a second valve, and the third chamber is connected to the mixing chamber via a third valve. The mixing chamber is used to output the mixture from the three chambers. The heat pump system is located between the mixer and the desorption tower. The mixture is heated by the heat pump system and then transported to the desorption tower. The desorption tower includes an upper chamber and a lower chamber. The mixture enters the upper chamber, is heated and desorbs some carbon dioxide, and then separates into the first lean liquid. Part of the first lean liquid is transported to the third chamber, and part of the first lean liquid enters the lower chamber to be heated and desorbed again, separating into the second lean liquid. The second lean liquid is then transported to the absorption tower. The high-temperature carbon dioxide gas output from the desorption tower is input to the heat pump system so that the heat pump system can utilize the waste heat of the carbon dioxide.

2. The carbon capture system combining multi-flow regulation and heat pump waste heat recovery according to claim 1, characterized in that, It also includes a first storage tank and a second storage tank. The first storage tank is used to store fresh absorbent, and the second storage tank is used to store water. The first storage tank and the second storage tank are respectively connected to the second chamber via pipelines.

3. The carbon capture system combining multi-flow regulation and heat pump waste heat recovery according to claim 1, characterized in that, It also includes a heat exchanger having a first flow channel and a second flow channel, the first flow channel connecting the rich liquid outlet of the absorption tower with the first chamber for circulating the rich liquid output from the absorption tower. The second flow channel connects the second lean liquid outlet of the desorption tower with the absorbent inlet of the absorption tower, and is used to circulate the second lean liquid output from the desorption tower, so that the second lean liquid exchanges heat with the rich liquid in the first flow channel.

4. The multi-flow regime integrated carbon capture system with heat pump waste heat recovery of claim 1, wherein, The heat pump system includes an evaporator, a compressor, a condenser, an expansion valve, and a heat exchange medium connected in sequence. The heat exchange medium circulates within the heat pump system. The heat exchange side of the condenser is connected to the mixed liquid outlet of the mixing chamber and the inlet of the upper chamber for heating the mixed liquid output from the mixing chamber. The heat exchange side of the evaporator is connected to the carbon dioxide gas outlet of the desorption tower for recovering the waste heat of the high-temperature carbon dioxide gas output from the desorption tower.

5. The multi-flow regime integrated carbon capture system with heat pump waste heat recovery of claim 1, wherein, The mixer includes an inner cylinder and an outer cylinder. The mixing chamber is formed at the center of the inner cylinder. Three first partitions are provided in the area between the inner cylinder and the outer cylinder. The first partitions divide the area between the inner cylinder and the outer cylinder into a first chamber, a second chamber, and a third chamber. A stirrer is provided in the mixing chamber.

6. The multi-flow regime integrated carbon capture system with heat pump waste heat recovery of claim 1, wherein, The mixer includes an upper chamber and a lower chamber. The lower chamber forms the mixing chamber. The upper chamber has three second partitions that divide the interior of the upper chamber into a first chamber, a second chamber, and a third chamber. A stirrer is provided in the mixing chamber.

7. The multi-flow regime integrated carbon capture system with heat pump waste heat recovery of claim 1, wherein, The desorption tower is provided with a partition plate in the middle, which divides the interior of the desorption tower into an upper chamber and a lower chamber. The upper chamber is provided with a microwave heating component, and the lower chamber is provided with a flash evaporation component. A liquid channel connecting the upper chamber and the lower chamber can be provided on the partition plate.

8. The multi-flow regime integrated carbon capture system with heat pump waste heat recovery of claim 1, wherein, It also includes a reboiler, wherein the bottom outlet of the upper chamber and the bottom outlet of the lower chamber are respectively connected to the corresponding inlet of the reboiler via independent outlet pipes, and the bottom outlet of the reboiler is connected to the lower part of the lower chamber via a pipe; so that the first lean liquid output from the upper chamber is heated by the reboiler and enters the lower chamber to form an intermediate lean liquid, the liquid output from the lower chamber is heated by the reboiler and returns to the lower chamber to form a reflux liquid, and the lower chamber heats the intermediate lean liquid and / or the reflux liquid to form a second lean liquid.

9. The carbon capture system combining multi-flow regulation and heat pump waste heat recovery according to claim 1, characterized in that, The gas outlets at the top of the upper chamber and the lower chamber merge and are then connected to the evaporator of the heat pump system via a pipeline.

10. The carbon capture system combining multi-flow regulation and heat pump waste heat recovery according to any one of claims 1-9, characterized in that, It also includes valve assemblies, pumps, sensors, and a controller electrically connected to the valve assemblies, pumps, sensors, the first valve, the second valve, and the third valve. The controller is used to control the opening and closing of the valve assemblies, the first valve, the second valve, and the third valve, as well as the operating status of the pump, based on data from the sensors. The valve assemblies, pumps, and sensors are installed on pipelines on any one of the absorption tower, the mixer, the heat pump system, the desorption tower, the first storage tank, the second storage tank, the heat exchanger, and the reboiler, or between any two of them, according to process requirements.

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