Carbon dioxide capture device and capture process

Abstract

The present application provides a carbon dioxide capture device and capture process, which relate to the field of carbon dioxide capture and recovery technology. The device includes a dust removal mechanism, a pre-storage mechanism, an air inlet end of which is connected to the air outlet end of the dust removal mechanism through a first pipe; a capture mechanism, an air inlet end of which is connected to the air outlet end of the pre-storage mechanism through a second pipe, wherein the pre-storage mechanism has a straight-through state and a cache state. In the straight-through state, industrial exhaust gas directly enters the second pipe through the pre-storage mechanism; in the cache state, industrial exhaust gas is temporarily stored in the pre-storage mechanism; a control module is configured to control the pre-storage mechanism to enter the straight-through state when the real-time exhaust gas flow rate is greater than or equal to a first preset flow rate; when the real-time exhaust gas flow rate is less than the first preset flow rate, control the pre-storage mechanism to enter the cache state, and switch to the straight-through state after the cached gas volume in the pre-storage mechanism reaches the first preset capacity, thereby avoiding ineffective contact between small-flow gas and solvent, and significantly saving energy consumption.

Description

Technical Field

[0001] The present application relates to the technical field of carbon dioxide capture and recovery, and in particular to a carbon dioxide capture device and capture process. Background Art

[0002] It is impossible to completely reduce carbon emissions from current manufacturing and daily life to zero. Relevant technologies are needed to absorb, fix, and utilize the emitted carbon dioxide. Carbon dioxide can be separated from emission sources such as industrial exhaust through carbon dioxide capture devices for long-term storage or reuse.

[0003] In existing industrial carbon dioxide capture devices, such as the invention patent with application number 202510428300.8, entitled "A Carbon Dioxide Capture and Recovery System," it is disclosed that dust-laden exhaust gas is usually directly introduced into the reaction chamber of the capture mechanism after dust removal. In this design, when the exhaust gas flow rate is lower than the optimal processing threshold of the reaction chamber, the capture solvent cannot fully contact the gas, resulting in low solvent utilization, increased unit capture energy consumption, and increased risk of solvent degradation. Therefore, under low flow conditions, it will cause serious waste of resources. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present application aims to provide a carbon dioxide capture device and capture process to achieve energy saving and consumption reduction.

[0005] In a first aspect, the present application proposes a carbon dioxide capture device, comprising:

[0006] Dust removal mechanism, used for dust removal of industrial exhaust gas containing carbon dioxide;

[0007] A pre-storage mechanism, the air inlet of which is connected to the air outlet of the dust removal mechanism via a first pipe; the first pipe or the air outlet of the dust removal mechanism is provided with a flow detection unit for monitoring the real-time exhaust flow;

[0008] A capture mechanism, the gas inlet of which is connected to the gas outlet of the pre-storage mechanism via a second pipe, wherein the capture mechanism is provided with a solvent distributor and a reaction chamber for providing a reaction space for carbon dioxide and the capture solvent;

[0009] The pre-storage mechanism has a straight-through state and a buffer state. In the straight-through state, the industrial exhaust gas directly enters the second pipeline through the pre-storage mechanism; in the buffer state, the industrial exhaust gas is temporarily stored in the pre-storage mechanism.

[0010] A control module is electrically connected to the flow detection unit and is configured to:

[0011] When the real-time exhaust gas flow rate is greater than or equal to a first preset flow rate, controlling the pre-storage mechanism to enter the direct-flow state;

[0012] When the real-time exhaust gas flow rate is less than a first preset flow rate, the pre-storage mechanism is controlled to enter the cache state, and after the cache gas volume in the pre-storage mechanism reaches a first preset capacity, it is switched to the through state.

[0013] According to the technical solution provided in the present application, the pre-storage mechanism includes a storage shell having a storage space therein, a storage tank body is provided in the storage space, the air inlet end of the pre-storage mechanism is the air inlet of the storage tank body, and the air outlet end is the air outlet of the storage tank body, and a first switch is provided at the air outlet of the storage tank body, and the first switch is used to control the connection and disconnection between the storage tank body and the second pipeline to realize the straight-through state and the cache state of the pre-storage mechanism.

[0014] According to the technical solution provided in this application, in the storage space, a first heat exchange component is provided outside the storage tank body, the first heat exchange component has a heat exchange cavity, a spiral guide baffle is provided in the heat exchange cavity, and the heat exchange cavity is connected to the waste heat recovery unit.

[0015] According to the technical solution provided in this application, the capture mechanism has a rich liquid outlet; the rich liquid outlet is connected to a solvent regeneration mechanism via a rich liquid delivery pipeline, and the solvent regeneration mechanism includes:

[0016] a regeneration tower including a reboiler for heating the rich liquid to release carbon dioxide;

[0017] a lean liquid circulation component, wherein the inlet of the lean liquid circulation component is connected to the lean liquid outlet of the regeneration tower, and the outlet of the lean liquid circulation component is connected to the solvent distributor via a second heat exchange component;

[0018] Wherein, the primary side channel of the second heat exchange component is connected to the outlet of the lean liquid circulation component, and the secondary side channel is connected to the waste heat recovery unit.

[0019] According to the technical solution provided in this application, the dust removal mechanism is connected to the cooling mechanism through a third pipe, and the cooling mechanism includes a third heat exchange component. The primary side inlet of the third heat exchange component is connected to the original exhaust gas inlet pipe, and the primary side outlet of the third heat exchange component is connected to the dust removal mechanism.

[0020] According to the technical solution provided in this application, the waste heat recovery unit includes:

[0021] The heat storage box is equipped with temperature stratification partitions inside to form high temperature zone and medium temperature zone;

[0022] The heat medium circulation main line is connected in series with the heat storage tank outlet and the diversion controller;

[0023] Heat medium input assembly, including:

[0024] a first input pipe connecting the secondary side outlet of the third heat exchange component and the high temperature zone inlet of the heat storage tank;

[0025] a second input pipe connecting the secondary side outlet of the second heat exchange component and the medium temperature zone inlet of the heat storage tank;

[0026] Heat medium output assembly, including:

[0027] a first output pipe extending from the flow diversion controller and connected to an inlet of a heat exchange chamber of the first heat exchange component to input the heat medium of the medium temperature zone into the heat exchange chamber;

[0028] a second output pipe, led out from the split flow controller and connected to the heat medium inlet of the reboiler, so as to input the heat medium of the high temperature zone into the reboiler;

[0029] Heat transfer return assembly, including:

[0030] a first reflux pipe connecting the heat exchange cavity outlet of the first heat exchange assembly with the medium temperature zone inlet of the heat storage tank;

[0031] The second reflux pipe is connected to the heat medium outlet of the reboiler and the secondary side inlet of the third heat exchange component.

[0032] According to the technical solution provided in this application, the waste heat recovery unit further includes an emergency branch in the high temperature zone of the heat storage tank that is independent of the heat medium output component, and the emergency branch includes:

[0033] A heat extraction pipe, the inlet of which is connected to the auxiliary outlet of the high temperature zone of the heat storage tank, and the auxiliary outlet is isolated from the main outlet space supplying heat to the reboiler;

[0034] The heat exchange enhancement unit has a primary side inlet connected to the heat extraction pipe outlet, and the primary side outlet is connected to the auxiliary inlet of the high temperature zone of the heat storage tank through a high temperature return pipe;

[0035] The secondary side channel of the heat exchange enhancement unit is sleeved outside the storage tank body to form a high-temperature heat exchange flow channel independent of the medium-temperature heat medium flow channel.

[0036] In a second aspect, the present application proposes a carbon dioxide capture process, which is implemented based on the carbon dioxide capture device as described above, and includes the following steps:

[0037] Real-time monitoring of industrial exhaust gas flow;

[0038] If the industrial tail gas flow rate is less than or equal to the first preset flow rate, the first switch is closed, and the amount of buffered gas in the storage tank is monitored in real time;

[0039] If the amount of buffered gas is greater than or equal to a first preset value, the first heat exchange component is turned on to call the heat medium in the medium temperature zone of the heat storage tank to preheat the buffered gas;

[0040] If the amount of buffered gas is greater than or equal to a first preset capacity, turning on the first switch to input the preheated buffered gas into the capture mechanism; the first preset capacity is greater than the first preset value;

[0041] Controlling the solvent distributor to spray the solvent into the reaction chamber at a target spraying amount that matches the real-time air intake amount, and inputting the generated rich liquid into the solvent regeneration mechanism through the rich liquid outlet;

[0042] monitoring the rich liquid level in the regeneration tower of the solvent regeneration mechanism in real time, and starting the reboiler when the rich liquid level reaches a second preset value to call the heat medium in the high temperature zone of the heat storage tank to heat the rich liquid;

[0043] The second heat exchange component is turned on to cool the lean liquid returned to the solvent distributor, so that the lean liquid after cooling can re-participate in the capture reaction in the reaction chamber.

[0044] According to the technical solution provided in this application, the process of opening the first heat exchange component to call upon the heat medium in the medium temperature zone of the heat storage tank to preheat the buffered gas includes the following steps:

[0045] Real-time monitoring of a first real-time temperature and a first real-time flow rate of the heat medium in the heat exchange cavity to obtain available heat;

[0046] Obtaining a target heat requirement based on the amount of buffered gas in the storage tank and the buffered gas temperature;

[0047] If the target heat requirement is less than or equal to the available heat, the heat medium in the medium temperature zone of the thermal storage tank is continuously called at the first real-time flow rate.

[0048] According to the technical solution provided in this application, after obtaining the target heat requirement, the following steps are also included:

[0049] If the target heat requirement is greater than the available heat, the heat to be compensated is obtained, where the heat to be compensated is the difference between the target heat requirement and the available heat;

[0050] Determine whether the heat to be compensated is reliable and increase the compensation strategy of calling the heat medium in the medium temperature zone;

[0051] If so, the heat medium in the medium temperature zone of the heat storage tank is called at a second real-time flow rate, where the second real-time flow rate is obtained by adding the first real-time flow rate to the flow rate increment corresponding to the heat to be compensated;

[0052] If not, open the emergency branch of the high temperature zone of the thermal storage tank that is independent of the heat medium output component to call the heat medium in the high temperature zone of the thermal storage tank to preheat the buffer gas.

[0053] Compared with the prior art, the beneficial effects of the present application are as follows: the present application achieves energy conservation and consumption reduction by introducing a pre-storage mechanism and a flow response control strategy: switching to a cache state at low flow, accumulating gas to a preset capacity and then processing it centrally, avoiding ineffective contact between small-flow gas and solvent, reducing solvent circulation volume, and significantly saving energy consumption. At the same time, it can also improve the capture efficiency: the gas flow released after caching is stable, ensuring that the solvent distributor forms a uniform liquid film, increasing the gas-liquid reaction surface area, and improving the carbon dioxide absorption rate. In addition, it can also extend the life of the solvent: avoiding ineffective circulation oxidation of the solvent under low-flow conditions, and extending the solvent replacement cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic structural diagram of the carbon dioxide capture device provided in this application;

[0055] Figure 2 This is a flow chart of the steps of the carbon dioxide capture process provided in this application.

[0056] The text annotations in the figure represent:

[0057] 1. Cooling mechanism; 2. Third heat exchange component; 3. Dust removal mechanism; 4. Pre-storage mechanism; 41. Storage tank; 42. Heat exchange enhancement unit; 43. First heat exchange component; 5. Capturing mechanism; 51. Solvent distributor; 6. Solvent regeneration mechanism; 61. Lean liquid circulation component; 7. Second heat exchange component; 8. Heat storage tank; 81. High temperature zone; 82. Medium temperature zone. DETAILED DESCRIPTION

[0058] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0059] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0060] Example 1

[0061] As mentioned in the background technology, in order to solve the problems in the prior art, this application proposes a carbon dioxide capture device, such as Figure 1 Shown, including:

[0062] Dust removal mechanism 3, used for dust removal of industrial exhaust gas containing carbon dioxide;

[0063] The pre-storage mechanism 4 has an air inlet end connected to the air outlet end of the dust removal mechanism 3 through a first pipe; the first pipe or the air outlet end of the dust removal mechanism 3 is provided with a flow detection unit for monitoring the real-time exhaust gas flow;

[0064] The capture mechanism 5 has an air inlet connected to the air outlet of the pre-storage mechanism 4 via a second pipe, and the capture mechanism 5 is provided with a solvent distributor 51 and a reaction chamber for providing a reaction space for carbon dioxide and the capture solvent;

[0065] The pre-storage mechanism 4 has a straight-through state and a buffer state. In the straight-through state, the industrial exhaust gas directly enters the second pipeline through the pre-storage mechanism 4; in the buffer state, the industrial exhaust gas is temporarily stored in the pre-storage mechanism 4.

[0066] A control module is electrically connected to the flow detection unit and is configured to:

[0067] When the real-time exhaust gas flow rate is greater than or equal to a first preset flow rate, controlling the pre-storage mechanism 4 to enter the straight-through state;

[0068] When the real-time exhaust gas flow rate is less than the first preset flow rate, the pre-storage mechanism 4 is controlled to enter the cache state, and after the cache gas volume in the pre-storage mechanism 4 reaches the first preset capacity, it is switched to the through state.

[0069] Furthermore, the pre-storage mechanism 4 includes a storage shell having a storage space therein, a storage tank body 41 is provided in the storage space, the air inlet end of the pre-storage mechanism 4 is the air inlet of the storage tank body 41, and the air outlet end is the air outlet of the storage tank body 41, and a first switch is provided at the air outlet of the storage tank body 41, and the first switch is used to control the connection and disconnection between the storage tank body 41 and the second pipeline to realize the straight-through state and the cache state of the pre-storage mechanism 4.

[0070] Furthermore, in the storage space, a first heat exchange component 43 is provided on the outer shell of the storage tank body 41. The first heat exchange component 43 has a heat exchange cavity. A spiral guide baffle is provided in the heat exchange cavity. The heat exchange cavity is connected to the waste heat recovery unit.

[0071] Specifically, the pre-storage mechanism 4 acts as an intelligent gas cabinet, switching between two states through the first switch: straight-through state: the gas directly passes through the storage tank body 41 and enters the capture mechanism 5 (high flow condition); cache state: the gas outlet is closed to intercept the gas, and the gas is released after accumulating to a preset volume (low flow condition). The control module dynamically decides on the state switching based on the real-time flow to ensure that the gas flow entering the capture mechanism 5 is always stable in the optimal reaction range, wherein the flow threshold is set based on: the first preset flow Q1 is the minimum gas flow rate for the solvent distributor 51 to form a uniform liquid film (optionally 1000m³ / h).

[0072] The working process is described as follows: System startup and initial state: dust removal mechanism 3 introduces dust-laden tail gas (initial flow rate 1500m³ / h, temperature 200°C), the control module detects the flow rate > Q1 (1000m³ / h), the output signal turns on the first switch, and the pre-storage mechanism 4 enters the straight-through state; tail gas flow path: industrial tail gas → dust removal mechanism 3 → pre-storage mechanism 4 → reaction chamber of capture mechanism 5 → countercurrent contact with the solvent sprayed by solvent distributor 51 → purified gas is discharged. In the straight-through state, the first heat exchange component 43 is not started (gas Short gas residence time); low flow rate conditions (<1000 m³ / h) enter a buffer state: the control module closes the first switch, the gas path: dust removal mechanism 3 → first pipeline → storage tank 41 (temporary gas storage), and heat exchange is initiated: heat medium is introduced into the heat exchange chamber, and the gas spirally flows along the spiral guide baffle to cool down. When the buffer volume is greater than or equal to the first preset capacity (the first preset capacity can be understood as the amount of gas that can be stably maintained for a certain period of time to allow the solvent distributed by the solvent distributor 51 to fully react), the system switches to a straight-through state to release gas. Gas-liquid reaction occurs within the capture mechanism 5: Gas enters the reaction chamber from the bottom inlet, and the solvent distributor 51 sprays and captures the solvent at the top of the reaction chamber. The gas flows from bottom to top, undergoing countercurrent mass transfer with the solvent flowing from top to bottom in the packing layer. The purified gas is discharged from the top of the reaction chamber, and the CO2-enriched solvent (referred to as rich liquid) flows from the bottom for recovery and regeneration.

[0073] In a preferred embodiment, the capture mechanism 5 has a rich liquid outlet; the rich liquid outlet is connected to a solvent regeneration mechanism 6 via a rich liquid delivery pipeline, and the solvent regeneration mechanism 6 includes:

[0074] a regeneration tower including a reboiler for heating the rich liquid to release carbon dioxide;

[0075] a lean liquid circulation component 61, wherein the inlet of the lean liquid circulation component 61 is connected to the lean liquid outlet of the regeneration tower, and the outlet of the lean liquid circulation component 61 is connected to the solvent distributor 51 via a second heat exchange component 7;

[0076] The primary side channel of the second heat exchange component 7 is connected to the outlet of the lean liquid circulation component 61 , and the secondary side channel is connected to the waste heat recovery unit.

[0077] In a preferred embodiment, the dust removal mechanism 3 is connected to the cooling mechanism 1 through a third pipe, and the cooling mechanism 1 includes a third heat exchange component 2, the primary side inlet of the third heat exchange component 2 is connected to the original exhaust gas inlet pipe, and the primary side outlet of the third heat exchange component 2 is connected to the dust removal mechanism 3.

[0078] In a preferred embodiment, the waste heat recovery unit comprises:

[0079] The heat storage tank 8 is provided with temperature stratification partitions inside, forming a high temperature zone 81 and a medium temperature zone 82;

[0080] The heat medium circulation main line is connected in series with the outlet of the heat storage tank 8 and the diversion controller;

[0081] Heat medium input assembly, including:

[0082] A first input pipe connects the secondary side outlet of the third heat exchange component 2 with the inlet of the high temperature zone 81 of the heat storage tank 8;

[0083] The second input pipe connects the secondary side outlet of the second heat exchange component 7 with the inlet of the medium temperature zone 82 of the heat storage tank 8;

[0084] Heat medium output assembly, including:

[0085] a first output pipe extending from the flow diversion controller and connected to the heat exchange chamber inlet of the first heat exchange assembly 43 to input the heat medium of the medium temperature zone 82 into the heat exchange chamber;

[0086] A second output pipe is led out from the split flow controller and connected to the heat medium inlet of the reboiler to input the heat medium of the high temperature zone 81 into the reboiler;

[0087] Heat transfer return assembly, including:

[0088] A first return pipe, connecting the heat exchange cavity outlet of the first heat exchange component 43 and the inlet of the medium temperature zone 82 of the heat storage tank 8;

[0089] The second reflux pipe connects the heat medium outlet of the reboiler with the secondary side inlet of the third heat exchange component 2 .

[0090] Specifically, this solution provides an ingenious waste heat cascade recovery and reuse system, including a high-temperature heat recovery circuit, the path of which is: the third heat exchange component 2 → the first input pipe → the high-temperature zone 81 of the heat storage tank 8 → the second output pipe → the reboiler, which is used to recover the original tail gas waste heat (250°C → 150°C) for use in the regeneration tower. It also includes a medium-temperature heat recovery circuit, the path of which is: the second heat exchange component 7 → the second input pipe → the medium-temperature zone 82 of the heat storage tank 8 → the first output pipe → the first heat exchange component 43, which is used to recover the lean liquid waste heat (102°C → 80°C) for preheating the cache gas in the pre-storage mechanism 4. The diversion controller serves as the heat medium distribution center, intelligently adjusts the flow of the first / second output pipe, and distributes high / medium-temperature heat medium on demand. The first return pipe and the second return pipe → return to the heat storage tank 8 to maintain a closed heat medium circulation loop.

[0091] The working process of heat recovery and reuse is described as follows: exhaust gas pretreatment and high-temperature heat recovery: the original exhaust gas (250°C) enters the primary side of the third heat exchange component 2, exchanges heat with the secondary side circulating water and cools it down to 150°C (meeting the upper limit of dust removal temperature); high-temperature heat medium generation: the water temperature at the secondary side outlet rises to 150°C → pumped into the high-temperature area 81 of the heat storage tank 8 through the first input pipe (the temperature stratification partition maintains the water temperature > 140°C); dynamic control of dust removal and pre-storage mechanism 4: the same as the aforementioned flow adaptive logic, with the addition of a heat medium Enter: When the pre-storage mechanism 4 enters the cache state and the cached gas needs to be heated (the gas drops to room temperature (25°C) after a long period of caching → needs to be heated to 40-60°C (to maintain CO2 absorption dynamics)): the control module sends a signal to the diversion controller, the first output pipe is opened, and the heat medium in the medium temperature zone 82 (90°C) flows to the first heat exchange component 43; the heat medium flows in the spiral guide baffle channel, raising the temperature of the cached gas from 25°C to 50°C; after heat exchange, the heat medium returns to the medium temperature zone 82 of the heat storage tank 8 through the first reflux pipe. CO2 capture and medium-temperature heat recovery: After the gas reacts in the capture mechanism 5, a rich liquid (40°C) is generated, and the rich liquid is pumped into the regeneration tower and heated by the reboiler to desorb CO2; lean liquid waste heat recovery: 102°C lean liquid flows out from the bottom of the regeneration tower → enters the primary side of the second heat exchange component 7, and exchanges heat with the secondary side circulating water to cool it down to 40°C (suitable for spraying);

[0092] The secondary outlet water temperature rises to 90°C and enters the medium-temperature zone 82 of the heat storage tank 8 via the second input pipe. Regeneration tower heat supply and heat medium intelligent allocation: Reboiler heat medium supply: The diversion controller monitors the regeneration tower temperature demand in real time. When the reboiler requires 170°C heat medium, the second output pipe is opened to extract heat medium from the high-temperature zone 81 (150°C). The heat medium enters the reboiler and releases heat (150°C → 120°C). The cooled heat medium returns to the secondary inlet of the third heat exchange component 2 via the second return pipe. The cooled heat medium cools the incoming raw high-temperature industrial exhaust gas, improving heat recovery efficiency. It should be noted that the reboiler in the regeneration tower has its own heat source, and the third heat exchange component 2 in this embodiment is only an auxiliary heat source. Because the heat required for solvent recovery is relatively high, the third heat exchange component 2 may sometimes be unable to meet all the heat requirements. Therefore, the auxiliary heat source can reuse the recovered heat, reducing the energy consumption of the original heat source.

[0093] In a preferred embodiment, the waste heat recovery unit further includes an emergency branch in the high temperature zone 81 of the heat storage tank 8 that is independent of the heat medium output component, and the emergency branch includes:

[0094] A heat-extraction pipe, the inlet of which is connected to the auxiliary outlet of the high-temperature zone 81 of the heat storage tank 8, the auxiliary outlet being isolated from the main outlet space supplying heat to the reboiler;

[0095] The heat exchange enhancement unit 42 has a primary side inlet connected to the heat extraction pipe outlet, and the primary side outlet is connected to the auxiliary inlet of the high temperature zone 81 of the heat storage tank 8 through a high temperature return pipe;

[0096] The secondary side channel of the heat exchange enhancement unit 42 is sleeved outside the storage tank body 41 to form a high-temperature heat exchange flow channel independent of the medium-temperature heat medium flow channel.

[0097] Specifically, the heat extraction conduit is made of high-temperature resistant material, with a diameter matching that of the main heat medium pipeline. Its inlet is connected to the auxiliary outlet of the high-temperature zone 81 of the thermal storage tank 8. This auxiliary outlet is located at the lower side of the thermal storage tank 8 and is spatially isolated from the main outlet (located at the bottom of the thermal storage tank 8) that supplies heat to the reboiler. This ensures independent access to the high-temperature heat medium and prevents mixing with the main output flow channel. The outlet is flanged to the primary inlet of the heat exchange enhancement unit 42. The heat exchange enhancement unit 42 is a shell-and-tube heat exchanger with a primary channel: the inlet is connected to the outlet of the heat extraction conduit, and the outlet is connected to the auxiliary inlet of the high-temperature zone 81 of the thermal storage tank 8 via a high-temperature return pipe, forming an independent circulation loop for the high-temperature heat medium. A flow control valve (electrically controlled) is installed within the primary channel and managed by the control module. It should be noted that the medium-temperature heat medium flow channel is the flow channel within the heat exchange chamber, circulating the medium-temperature heat medium within the medium-temperature zone 82 of the thermal storage tank 8. The spiral piping formed by the secondary channel of the heat exchange enhancement unit 42 in this embodiment is a completely independent flow channel from the medium-temperature heat medium flow channel, a parallel coil. The secondary channel is physically isolated from the original medium-temperature heat medium flow channel, forming an independent high-temperature heat exchange flow channel. The auxiliary inlet and auxiliary outlet of the high-temperature zone 81 of the thermal storage tank 8 are equipped with temperature sensors and pressure gauges, which are integrated into the monitoring system of the control module.

[0098] Example 2

[0099] On the basis of Example 1, this example proposes a carbon dioxide capture process, which is implemented based on the carbon dioxide capture device as described in Example 1. Figure 2 As shown, the following steps are included:

[0100] S1. Real-time monitoring of industrial exhaust gas flow;

[0101] S2. If the industrial exhaust gas flow rate is less than or equal to the first preset flow rate, the first switch is closed, and the amount of buffered gas in the storage tank 41 is monitored in real time;

[0102] S3. If the amount of cached gas is greater than or equal to a first preset value, the first heat exchange component 43 is turned on to call the heat medium in the medium temperature zone 82 of the heat storage tank 8 to preheat the cached gas;

[0103] S4. If the amount of buffered gas is greater than or equal to a first preset capacity, turning on the first switch to input the preheated buffered gas into the capture mechanism 5; the first preset capacity is greater than the first preset value;

[0104] S5, controlling the solvent distributor 51 to spray the solvent into the reaction chamber at a target spraying amount that matches the real-time air intake amount, and the generated rich liquid is input into the solvent regeneration mechanism 6 through the rich liquid outlet;

[0105] S6, monitoring the rich liquid level in the regeneration tower of the solvent regeneration mechanism 6 in real time, and when the rich liquid level reaches a second preset value, starting the reboiler to call the heat medium in the high temperature zone 81 of the heat storage tank 8 to heat the rich liquid;

[0106] S7, turning on the second heat exchange component 7 to cool the lean liquid returned to the solvent distributor 51, so that the lean liquid after cooling can re-participate in the capture reaction in the reaction chamber.

[0107] Specifically, the industrial exhaust gas flow rate is monitored in real time: a flow detection unit (e.g., a vortex flowmeter) at the outlet of the first pipeline or dust removal mechanism 3 continuously collects the real-time exhaust gas flow rate Q (unit: m³ / h). The control module dynamically compares Q with a first preset flow rate Q1. Buffer status determination and gas storage: If the industrial exhaust gas flow rate is less than or equal to the first preset flow rate, the control module closes the first switch (e.g., a solenoid valve), disconnecting the outlet of the storage tank 41 from the second pipeline. The pre-storage mechanism 4 enters a buffer state, and exhaust gas continuously flows into the storage tank 41. The volume of the buffered gas V in the tank is monitored in real time (calculated using a pressure sensor or a volume integration algorithm). Preheating start condition judgment: When the first preset value V ≥ the first preset value (for example, 60% of the tank volume, to ensure that there is enough gas to start preheating): turn on the first heat exchange component 43: the control module sends a command to the diversion controller to open the first output pipe, calling the heat medium in the medium temperature zone 82 (about 90°C) of the heat storage tank 8 to flow into the heat exchange cavity. The heat medium flows along the spiral guide baffle to heat the cached gas (for example, from 25°C to 50°C), thereby improving the efficiency of subsequent capture reactions. Cache gas release: When the first preset capacity V ≥ the first preset capacity (for example, 90% of the tank volume, to ensure that the amount of gas released in a single time meets the requirements of sufficient reaction, and the capacity>preset value>preset value): turn on the first switch, and the preheated gas enters the reaction chamber of the capture mechanism 5 through the second pipe. Switch the pre-storage mechanism 4 to the straight-through state until the next low flow triggers the cache. Solvent Spray and Capture Reaction: The solvent distributor 51 is controlled to adjust the spray rate based on the real-time air intake. Based on data from the gas flow sensor, the target solvent flow rate (e.g., a gas-liquid ratio of 1:3 L / m³) is calculated to ensure countercurrent mass transfer efficiency. Gas flows upward through the packing layer, reacting with the solvent to produce a rich liquid, which is then discharged from the bottom rich liquid outlet. Rich liquid regeneration control: The rich liquid is piped to the regeneration tower of the solvent regeneration mechanism 6. The rich liquid level H within the tower is monitored in real time. If the rich liquid level H ≥ a second preset value (e.g., 80% of the tower volume), the reboiler is activated. The control module instructs the flow splitter controller to open the second output pipe, drawing heat medium from the high-temperature zone 81 (>140°C) of the thermal storage tank 8 to heat the rich liquid and release CO2. Simultaneously, the second heat exchanger 7 is activated. After the lean liquid exits the regeneration tower, it undergoes heat exchange with the intermediate-temperature heat medium on the secondary side of the second heat exchanger 7, cooling it down (e.g., from 102°C to 40°C) before returning it to the solvent distributor 51 for recycling.

[0108] In a preferred embodiment, the process of opening the first heat exchange component 43 to call upon the heat medium in the medium temperature zone 82 of the heat storage tank 8 to preheat the buffer gas includes the following steps:

[0109] Real-time monitoring of a first real-time temperature and a first real-time flow rate of the heat medium in the heat exchange cavity to obtain available heat;

[0110] Obtaining a target heat requirement based on the amount of buffered gas and the buffered gas temperature in the storage tank 41;

[0111] If the target heat requirement is less than or equal to the available heat, the heat medium in the medium temperature zone 82 of the heat storage tank 8 is continuously called at the first real-time flow rate.

[0112] Specifically, heat medium parameter monitoring: real-time collection of the first real-time temperature T1 (thermocouple monitoring) and the first real-time flow F1 (flow meter monitoring) of the heat medium in the heat exchange cavity. Calculation of available heat , where c represents the specific heat capacity of the heat medium, T 回流 Indicates the first return pipe temperature, T1 indicates the first real-time temperature, and F1 indicates the first real-time flow rate. Target heat demand calculation: Based on the buffered gas volume V and the current temperature T 气 (Temperature sensor monitoring), set the target temperature rise value ΔT (for example, 25℃→50℃, ΔT=25℃): target heat requirement , where ρ represents the gas density, c1 represents the gas specific heat capacity, and V represents the amount of buffered gas. Heat matching decision: If the target heat requirement is less than or equal to the available heat, continue to introduce the medium-temperature heat medium at the current flow rate until the gas temperature reaches the target.

[0113] In a preferred embodiment, after obtaining the target heat requirement, the method further comprises the following steps:

[0114] If the target heat requirement is greater than the available heat, the heat to be compensated is obtained, where the heat to be compensated is the difference between the target heat requirement and the available heat;

[0115] Determine whether the heat to be compensated is reliable and increase the compensation strategy of calling the heat medium in the medium temperature zone 82;

[0116] If yes, the heat medium in the medium temperature zone 82 of the heat storage tank 8 is called at a second real-time flow rate, where the second real-time flow rate is obtained by adding the first real-time flow rate to the flow rate increment corresponding to the heat to be compensated;

[0117] If not, open the emergency branch of the high temperature zone 81 of the thermal storage tank 8 which is independent of the heat medium output component to call the heat medium of the high temperature zone 81 of the thermal storage tank 8 to preheat the buffer gas.

[0118] Specifically, the method for judging whether the flow rate of the heat medium in the medium temperature zone 82 can be increased is as follows: if the residual heat in the medium temperature zone 82 of the heat storage tank 8 is sufficient (temperature>85℃ and liquid level>safety threshold), it is determined that the strategy compensation for increasing the call for the heat medium in the medium temperature zone 82 is reliable; if the temperature 85℃ or liquid level If the safety threshold, or the heat to be compensated, cannot be reached when the corresponding control valve body is at its maximum opening, it is determined to be unreliable and the strategic compensation of calling the heat medium in the medium temperature zone 82 is increased.

[0119] Specifically, if the strategy compensation for calling the medium temperature zone 82 heat medium is reliably increased, the flow increment is calculated , where T 中温 The second real-time flow rate represents the temperature of the heat medium in the medium-temperature zone 82. The second real-time flow rate is the first real-time flow rate plus the flow increment. The medium-temperature heat medium is called at the second real-time flow rate (the shunt controller adjusts the opening of the first output pipe). Otherwise (insufficient heat medium in the medium-temperature zone 82): the emergency branch is opened: the primary-side flow control valve of the heat exchange enhancement unit 42 is activated, and high-temperature heat medium (>140°C) is drawn from the auxiliary outlet of the high-temperature zone 81 of the thermal storage tank 8. The high-temperature heat medium enters the primary side of the heat exchange enhancement unit 42 through the heat extraction pipe. The high-temperature heat medium directly heats the storage tank 41 through an independent coil (physically isolated from the medium-temperature heat medium flow channel). The cooled heat medium then returns to the auxiliary inlet of the high-temperature zone 81 of the thermal storage tank 8 through the high-temperature return pipe.

[0120] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present invention, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A carbon dioxide capture device, characterized in that: include: A dust removal mechanism (3) is used for removing dust from industrial exhaust gas containing carbon dioxide; A pre-storage mechanism (4) has an air inlet end connected to the air outlet end of the dust removal mechanism (3) via a first pipe; the first pipe or the air outlet end of the dust removal mechanism (3) is provided with a flow detection unit for monitoring the real-time exhaust gas flow; A capture mechanism (5), the air inlet of which is connected to the air outlet of the pre-storage mechanism (4) via a second pipe, and the capture mechanism (5) is provided with a solvent distributor (51) and a reaction chamber for providing a reaction space for carbon dioxide and the capture solvent; The pre-storage mechanism (4) has a straight-through state and a buffer state. In the straight-through state, the industrial exhaust gas directly enters the second pipeline through the pre-storage mechanism (4); in the buffer state, the industrial exhaust gas is temporarily stored in the pre-storage mechanism (4). A control module is electrically connected to the flow detection unit and is configured to: When the real-time exhaust gas flow rate is greater than or equal to a first preset flow rate, controlling the pre-storage mechanism (4) to enter the straight-through state; When the real-time exhaust gas flow rate is less than a first preset flow rate, the pre-storage mechanism (4) is controlled to enter the cache state, and after the cache gas volume in the pre-storage mechanism (4) reaches the first preset capacity, the pre-storage mechanism (4) is switched to the through state; The pre-storage mechanism (4) comprises a storage shell having a storage space therein, a storage tank body (41) being provided in the storage space, an air inlet end of the pre-storage mechanism (4) being an air inlet of the storage tank body (41), an air outlet end being an air outlet of the storage tank body (41), a first switch being provided at the air outlet of the storage tank body (41), the first switch being used to control the connection and disconnection between the storage tank body (41) and the second pipe, so as to realize a straight-through state and a cache state of the pre-storage mechanism (4); In the storage space, a first heat exchange component (43) is provided on the outer jacket of the storage tank (41), the first heat exchange component (43) having a heat exchange cavity, a spiral guide baffle being provided in the heat exchange cavity, and the heat exchange cavity being connected to a waste heat recovery unit; The waste heat recovery unit comprises: A heat storage box (8) is provided with a temperature stratification partition inside to form a high temperature zone (81) and a medium temperature zone (82); A heat medium circulation main line connected in series to the outlet of the heat storage tank (8) and the diversion controller; Heat medium input assembly, including: A first input pipe connecting the secondary side outlet of the third heat exchange component (2) and the high temperature zone (81) inlet of the heat storage tank (8); A second input pipe connecting the secondary side outlet of the second heat exchange component (7) and the inlet of the medium temperature zone (82) of the heat storage tank (8); Heat medium output assembly, including: A first output pipe is led out from the flow diversion controller and connected to the heat exchange chamber inlet of the first heat exchange component (43) to input the heat medium of the medium temperature zone (82) into the heat exchange chamber; A second output pipe is led out from the split flow controller and connected to the heat medium inlet of the reboiler to input the heat medium of the high temperature zone (81) into the reboiler; Heat transfer return assembly, including: A first return pipe connecting the heat exchange chamber outlet of the first heat exchange component (43) and the medium temperature zone (82) inlet of the heat storage tank (8); The second reflux pipe is connected to the heat medium outlet of the reboiler and the secondary side inlet of the third heat exchange component (2).

2. The carbon dioxide capture device according to claim 1, characterized in that: The capture mechanism (5) has a rich liquid outlet; the rich liquid outlet is connected to a solvent regeneration mechanism (6) via a rich liquid delivery pipeline, and the solvent regeneration mechanism (6) comprises: a regeneration tower including a reboiler for heating the rich liquid to release carbon dioxide; a lean liquid circulation component (61), wherein the inlet of the lean liquid circulation component (61) is connected to the lean liquid outlet of the regeneration tower, and the outlet of the lean liquid circulation component (61) is connected to the solvent distributor (51) via a second heat exchange component (7); The primary side channel of the second heat exchange component (7) is connected to the outlet of the lean liquid circulation component (61), and the secondary side channel is connected to the waste heat recovery unit.

3. The carbon dioxide capture device according to claim 1, characterized in that: The dust removal mechanism (3) is connected to the cooling mechanism (1) via a third pipe. The cooling mechanism (1) comprises a third heat exchange component (2). The primary side inlet of the third heat exchange component (2) is connected to the original exhaust gas inlet pipe, and the primary side outlet of the third heat exchange component (2) is connected to the dust removal mechanism (3).

4. The carbon dioxide capture device according to claim 1, characterized in that: The waste heat recovery unit further comprises an emergency branch circuit in the high temperature zone (81) of the heat storage tank (8) that is independent of the heat medium output component, and the emergency branch circuit comprises: A heat pipe having an inlet connected to an auxiliary outlet of a high temperature zone (81) of a heat storage tank (8), the auxiliary outlet being isolated from a main outlet space supplying heat to a reboiler; A heat exchange enhancement unit (42), wherein the primary side inlet is connected to the outlet of the heat extraction pipe, and the primary side outlet is connected to the auxiliary inlet of the high temperature zone (81) of the heat storage tank (8) through a high temperature return pipe; The secondary side channel of the heat exchange enhancement unit (42) is sleeved outside the storage tank body (41), forming a high-temperature heat exchange flow channel independent of the medium-temperature heat medium flow channel.

5. A carbon dioxide capture process, implemented based on the carbon dioxide capture device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Real-time monitoring of industrial exhaust gas flow; If the industrial tail gas flow rate is less than or equal to a first preset flow rate, the first switch is closed, and the amount of buffered gas in the storage tank (41) is monitored in real time; If the amount of cached gas is greater than or equal to a first preset value, the first heat exchange component (43) is turned on to call the heat medium in the medium temperature zone (82) of the heat storage tank (8) to preheat the cached gas; If the amount of buffered gas is greater than or equal to a first preset capacity, the first switch is turned on to input the preheated buffered gas into the capture mechanism (5); the first preset capacity is greater than the first preset value; Controlling the solvent distributor (51) to spray the solvent into the reaction chamber at a target spraying amount that matches the real-time air intake amount, and the generated rich liquid is input into the solvent regeneration mechanism (6) through the rich liquid outlet; monitoring the rich liquid level in the regeneration tower of the solvent regeneration mechanism (6) in real time, and starting the reboiler when the rich liquid level reaches a second preset value to call the heat medium in the high temperature zone (81) of the heat storage tank (8) to heat the rich liquid; The second heat exchange component (7) is turned on to cool the lean liquid returned to the solvent distributor (51), so that the lean liquid after cooling can re-participate in the capture reaction in the reaction chamber; The opening of the first heat exchange component (43) to call the heat medium in the medium temperature zone (82) of the heat storage tank (8) to preheat the cache gas comprises the following steps: Real-time monitoring of a first real-time temperature and a first real-time flow rate of the heat medium in the heat exchange cavity to obtain available heat; Obtaining a target heat requirement based on the amount of buffered gas and the buffered gas temperature in the storage tank (41); If the target heat requirement is less than or equal to the available heat, the heat medium in the medium temperature zone (82) of the heat storage tank (8) is continuously called at the first real-time flow rate.

6. The carbon dioxide capture process according to claim 5, characterized in that: After obtaining the target heat requirement, the following steps are also included: If the target heat requirement is greater than the available heat, the heat to be compensated is obtained, where the heat to be compensated is the difference between the target heat requirement and the available heat; Determine whether the heat to be compensated is reliable and increase the strategic compensation of calling the heat medium in the medium temperature zone (82); If so, the heat medium in the medium temperature zone (82) of the heat storage tank (8) is called at a second real-time flow rate, wherein the second real-time flow rate is obtained by adding the first real-time flow rate to the flow rate increment corresponding to the heat to be compensated; If not, an emergency branch circuit independent of the heat medium output component in the high temperature zone (81) of the heat storage tank (8) is opened to call the heat medium in the high temperature zone (81) of the heat storage tank (8) to preheat the buffer gas.

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