Flexible carbon dioxide trapping system and control method thereof

Abstract

The invention relates to the field of environmental protection, and discloses a flexible carbon dioxide trapping system and a control method thereof.Based on the scheme, a first nozzle tubular liquid distributor can be operated when the flexible trapping system is in a low-load first type operation condition, and a second nozzle tubular liquid distributor can be operated when the flexible trapping system is in a high-load second type operation condition; operating the first groove type liquid distributor; when the flexible trapping system is in a low-load third-type operation condition, the second nozzle pipe type liquid distributor and the third nozzle pipe type liquid distributor are operated, and when the flexible trapping system is in a high-load fourth-type operation condition, the second groove type liquid distributor and the third groove type liquid distributor are operated, and the second nozzle pipe type liquid distributor and the third nozzle pipe type liquid distributor are operated. The system can adapt to various change conditions, such as changes of flue gas flow, CO2 concentration in flue gas, CO2 capture rate and downstream CO2 demand quantity, and can be adjusted to an operation state adaptive to the change conditions, so that flexible control is realized, and long-term stable operation of the system is ensured.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, specifically to a flexible carbon dioxide capture system and a control method for the flexible carbon dioxide capture system. Background Technology

[0002] Capturing, utilizing, and storing carbon dioxide (CO2) is a key means of achieving carbon neutrality. For the combustion process of fossil fuels, CO2 capture technologies can be divided into pre-combustion capture, oxygen-enriched combustion, and post-combustion capture. In the field of post-combustion capture technology, chemical absorption CO2 capture technology is widely used due to its good capture effect and mature technology.

[0003] Currently, when using chemical absorption CO2 capture technology for post-combustion CO2 capture, factors such as flue gas flow rate, CO2 concentration in the flue gas, CO2 capture rate, and downstream CO2 demand are constantly changing. For example, different operating loads of coal-fired boiler units lead to variations in the flue gas flow rate; different boiler operating conditions or different raw coal used result in variations in the CO2 concentration in the flue gas; and changes in oil reserves and injection well conditions lead to changes in downstream CO2 demand for CO2 production.

[0004] However, existing chemical absorption CO2 capture systems often struggle to adapt well to these changes and cannot adjust to a suitable operating state, thus affecting the long-term stable operation of the CO2 capture system. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that existing CO2 capture systems are unable to adapt well to changing operating conditions, thus affecting the long-term stable operation of the CO2 capture system, and to provide a flexible carbon dioxide capture system and its control method.

[0006] To achieve the above objectives, a first aspect of the present invention provides a flexible carbon dioxide capture system, comprising a scrubbing tower, a first trough-type liquid distributor, a first nozzle-tube type liquid distributor, a first pumping unit, an absorption tower, a second trough-type liquid distributor, a second nozzle-tube type liquid distributor, a second pumping unit, a heat exchanger, a regeneration tower, a third trough-type liquid distributor, a third nozzle-tube type liquid distributor, and a third pumping unit; the first trough-type liquid distributor and the first nozzle-tube type liquid distributor are disposed at the top of the scrubbing tower, with the first trough-type liquid distributor located above the first nozzle-tube type liquid distributor; the scrubbing water outlet of the scrubbing tower is connected to the inlet of the first pumping unit, the outlet of the first pumping unit is connected to the liquid inlets of the first trough-type liquid distributor and the first nozzle-tube type liquid distributor respectively, and the flue gas outlet of the scrubbing tower is connected to the flue gas inlet of the absorption tower; the second trough-type liquid distributor... The distributor and the second nozzle-tube liquid distributor are disposed at the top of the absorption tower, and the second trough liquid distributor is located above the second nozzle-tube liquid distributor; the third trough liquid distributor and the third nozzle-tube liquid distributor are disposed at the top of the regeneration tower, and the third trough liquid distributor is located above the third nozzle-tube liquid distributor; the rich liquid outlet of the absorption tower is connected to the inlet of the second pumping unit, the outlet of the second pumping unit is connected to the rich liquid inlet of the heat exchanger, and the rich liquid outlet of the heat exchanger is connected to the liquid inlet to be distributed of the third trough liquid distributor and the third nozzle-tube liquid distributor, respectively; the first lean liquid outlet of the regeneration tower is connected to the inlet of the third pumping unit, the outlet of the third pumping unit is connected to the lean liquid inlet of the heat exchanger, and the lean liquid outlet of the heat exchanger is connected to the liquid inlet to be distributed of the second trough liquid distributor and the second nozzle-tube liquid distributor, respectively.

[0007] In this embodiment, the maximum value of the liquid distribution flow range of the first trough-type liquid distributor is greater than the maximum value of the liquid distribution flow range of the first nozzle-type liquid distributor, and the minimum value of the liquid distribution flow range of the first trough-type liquid distributor is greater than the minimum value of the liquid distribution flow range of the first nozzle-type liquid distributor; the maximum value of the liquid distribution flow range of the second trough-type liquid distributor is greater than the maximum value of the liquid distribution flow range of the second nozzle-type liquid distributor, and the minimum value of the liquid distribution flow range of the second trough-type liquid distributor is greater than the minimum value of the liquid distribution flow range of the second nozzle-type liquid distributor; the maximum value of the liquid distribution flow range of the third trough-type liquid distributor is greater than the maximum value of the liquid distribution flow range of the third nozzle-type liquid distributor, and the minimum value of the liquid distribution flow range of the third trough-type liquid distributor is greater than the minimum value of the liquid distribution flow range of the third nozzle-type liquid distributor.

[0008] In this embodiment of the application, when the carbon dioxide flexible capture system is running, only one of the first trough liquid distributor and the first nozzle tube liquid distributor is running, only one of the second trough liquid distributor and the second nozzle tube liquid distributor is running, and only one of the third trough liquid distributor and the third nozzle tube liquid distributor is running.

[0009] In this embodiment, the first pumping unit includes a first delivery pump and a second delivery pump, which are connected in parallel; the second pumping unit includes a third delivery pump and a fourth delivery pump, which are connected in parallel; the third pumping unit includes a fifth delivery pump and a sixth delivery pump, which are connected in parallel.

[0010] In this embodiment of the application, one of the first delivery pump and the second delivery pump is equipped with a frequency converter; one of the third delivery pump and the fourth delivery pump is equipped with a frequency converter; and one of the fifth delivery pump and the sixth delivery pump is equipped with a frequency converter.

[0011] In this embodiment of the application, the flexible carbon dioxide capture system further includes a first cooler: the outlets of the first delivery pump and the second delivery pump are both connected to the wash water inlet of the first cooler, and the wash water outlet of the first cooler is connected to the liquid distribution inlet of the first tank-type liquid distributor and the first nozzle-type liquid distributor, respectively.

[0012] In this embodiment of the application, the flexible carbon dioxide capture system further includes a second cooler; the lean liquid outlet of the heat exchanger is connected to the lean liquid inlet of the second cooler, and the lean liquid outlet of the second cooler is connected to the liquid inlet to be distributed of the second trough-type liquid distributor and the second nozzle-type liquid distributor, respectively.

[0013] In this embodiment of the application, the flexible carbon dioxide capture system further includes a third cooler and a separator; the carbon dioxide outlet of the regeneration tower is connected to the carbon dioxide inlet of the third cooler, the carbon dioxide outlet of the third cooler is connected to the carbon dioxide inlet of the separator, and the condensate outlet of the separator is connected to the condensate inlet of the regeneration tower.

[0014] In this embodiment of the application, the flexible carbon dioxide capture system further includes a reboiler; the second lean liquid outlet of the regeneration tower is connected to the lean liquid inlet of the reboiler, and the lean liquid outlet of the reboiler is connected to the lean liquid inlet of the regeneration tower.

[0015] A second aspect of the present invention provides a control method for the above-mentioned flexible carbon dioxide capture system, the control method comprising: calculating a target flue gas flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand; Based on the target flue gas flow rate, the reference flue gas flow rate, and the reference washing water flow rate, the target washing water flow rate is calculated; the real-time flue gas flow rate is adjusted to the target flue gas flow rate, and the washing water flow rate of the first pumping unit is controlled to the target washing water flow rate. When the target flue gas flow rate is greater than half of the reference flue gas flow rate, the washing water output by the first pumping unit is delivered to the first tank-type liquid distributor. When the target flue gas flow rate is less than or equal to half of the reference flue gas flow rate, the washing water output by the first pumping unit is delivered to the first nozzle-type liquid distributor.

[0016] In this embodiment of the application, the first pumping unit includes a first delivery pump and a second delivery pump; the step of delivering the washing water output from the first pumping unit to the first tank-type liquid distributor includes: controlling both the first delivery pump and the second delivery pump to operate, so as to deliver the washing water to the first tank-type liquid distributor; the step of delivering the washing water output from the first pumping unit to the first nozzle-type liquid distributor includes: controlling one of the first delivery pump and the second delivery pump to operate, so as to deliver the washing water to the first nozzle-type liquid distributor.

[0017] In this embodiment of the application, one of the first delivery pump and the second delivery pump is equipped with a frequency converter; the control of both the first delivery pump and the second delivery pump to operate includes: controlling both the first delivery pump and the second delivery pump to operate, and controlling the frequency converter not to start; the control of one of the first delivery pump and the second delivery pump to operate includes: controlling the one of the first delivery pump and the second delivery pump equipped with a frequency converter to operate, and controlling the frequency converter to start.

[0018] In this embodiment, the flexible carbon dioxide capture system further includes a first cooler. The outlets of the first delivery pump and the second delivery pump are both connected to the wash water inlet of the first cooler. The wash water outlet of the first cooler is connected to the liquid distribution inlet of the first tank-type liquid distributor and the first nozzle-type liquid distributor, respectively. After calculating the target flue gas flow rate based on the real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand, the control method further includes: calculating a first target cooling water flow rate based on the target flue gas flow rate, the reference flue gas flow rate, and the reference cooling water flow rate of the first cooler; and controlling the cooling water flow rate of the first cooler to the first target cooling water flow rate.

[0019] A third aspect of the present invention provides a control method for the above-mentioned flexible carbon dioxide capture system, the control method comprising: calculating a target rich liquid flow rate and a target lean liquid flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate and real-time carbon dioxide demand; The rich liquid flow rate of the second pumping unit is adjusted to the target rich liquid flow rate, and the lean liquid flow rate of the third pumping unit is adjusted to the target lean liquid flow rate. When the target rich liquid flow rate is greater than half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third tank-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second tank-type liquid distributor. When the target rich liquid flow rate is less than or equal to half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third nozzle-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second nozzle-type liquid distributor. The carbon dioxide content in the rich liquid is higher than the carbon dioxide content in the lean liquid.

[0020] In this embodiment, the second pumping unit includes a third transfer pump and a fourth transfer pump, and the third pumping unit includes a fifth transfer pump and a sixth transfer pump; the step of transporting the rich liquid output from the second pumping unit to the third tank-type liquid distributor and the step of transporting the lean liquid output from the third pumping unit to the second tank-type liquid distributor includes: controlling both the third and fourth transfer pumps to operate to transport the rich liquid to the third tank-type liquid distributor, and controlling both the fifth and sixth transfer pumps to operate to transport the lean liquid to the second tank-type liquid distributor; The process of delivering the rich liquid output from the second pumping unit to the third nozzle-tube liquid distributor and delivering the lean liquid output from the third pumping unit to the second nozzle-tube liquid distributor includes: controlling one of the third and fourth delivery pumps to operate to deliver the rich liquid to the third nozzle-tube liquid distributor, and controlling one of the fifth and sixth delivery pumps to operate to deliver the lean liquid to the second nozzle-tube liquid distributor.

[0021] In this embodiment, one of the third and fourth delivery pumps is equipped with a frequency converter, and one of the fifth and sixth delivery pumps is equipped with a frequency converter. Controlling the operation of both the third and fourth delivery pumps includes: controlling both the third and fourth delivery pumps to operate while preventing the frequency converter from starting; controlling the operation of both the fifth and sixth delivery pumps includes: controlling both the fifth and sixth delivery pumps to operate while preventing the frequency converter from starting; controlling the operation of one of the third and fourth delivery pumps includes: controlling the operation of the one equipped with a frequency converter and starting the frequency converter; controlling the operation of one of the fifth and sixth delivery pumps includes: controlling the operation of the one equipped with a frequency converter and starting the frequency converter.

[0022] In this embodiment, the flexible carbon dioxide capture system further includes a second cooler, wherein the lean liquid outlet of the heat exchanger is connected to the lean liquid inlet of the second cooler, and the lean liquid outlet of the second cooler is connected to the liquid inlet to be distributed of the second trough-type liquid distributor and the second nozzle-type liquid distributor, respectively; the control method further includes: calculating a second target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand; and controlling the cooling water flow rate of the second cooler to the second target cooling water flow rate.

[0023] In this embodiment, the flexible carbon dioxide capture system further includes a third cooler and a separator. The carbon dioxide outlet of the regeneration tower is connected to the carbon dioxide inlet of the third cooler, the carbon dioxide outlet of the third cooler is connected to the carbon dioxide inlet of the separator, and the condensate outlet of the separator is connected to the condensate inlet of the regeneration tower. The control method further includes: calculating a third target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand; and controlling the cooling water flow rate of the third cooler to the third target cooling water flow rate.

[0024] The carbon dioxide flexible capture system, based on the above technical solution, includes a scrubbing tower, a first trough-type liquid distributor, a first nozzle-tube type liquid distributor, a first pumping unit, an absorption tower, a second trough-type liquid distributor, a second nozzle-tube type liquid distributor, a second pumping unit, a heat exchanger, a regeneration tower, a third trough-type liquid distributor, a third nozzle-tube type liquid distributor, and a third pumping unit. The first trough-type liquid distributor and the first nozzle-tube type liquid distributor are located at the top of the scrubbing tower, with the first trough-type liquid distributor positioned above the first nozzle-tube type liquid distributor. The scrubbing water outlet of the scrubbing tower is connected to the inlet of the first pumping unit, and the outlet of the first pumping unit is connected to the liquid inlets of both the first trough-type liquid distributor and the first nozzle-tube type liquid distributor. The flue gas outlet of the scrubbing tower is connected to the flue gas inlet of the absorption tower. The second trough-type liquid distributor and the second nozzle-tube type liquid distributor... A liquid distributor is located at the top of the absorption tower, and the second trough-type liquid distributor is located above the second nozzle-type liquid distributor. The third trough-type liquid distributor and the third nozzle-type liquid distributor are located at the top of the regeneration tower, with the third trough-type liquid distributor located above the third nozzle-type liquid distributor. The rich liquid outlet of the absorption tower is connected to the inlet of the second pumping unit, the outlet of the second pumping unit is connected to the rich liquid inlet of the heat exchanger, and the rich liquid outlet of the heat exchanger is connected to the liquid inlets of the third trough-type liquid distributor and the third nozzle-type liquid distributor, respectively. The first lean liquid outlet of the regeneration tower is connected to the inlet of the third pumping unit, the outlet of the third pumping unit is connected to the lean liquid inlet of the heat exchanger, and the lean liquid outlet of the heat exchanger is connected to the liquid inlets of the second trough-type liquid distributor and the second nozzle-type liquid distributor, respectively. Based on the flexible carbon dioxide capture system provided in this application embodiment, the first nozzle-tube liquid distributor can be operated when the flexible carbon dioxide capture system is in a first type of low-load operating condition; the first tank-type liquid distributor can be operated when the flexible carbon dioxide capture system is in a second type of high-load operating condition; the second nozzle-tube liquid distributor and the third nozzle-tube liquid distributor can be operated when the flexible carbon dioxide capture system is in a third type of low-load operating condition; and the second tank-type liquid distributor and the third tank-type liquid distributor can be operated when the flexible carbon dioxide capture system is in a fourth type of high-load operating condition. This allows it to adapt to various changing conditions, such as changes in flue gas flow rate, CO2 concentration in flue gas, CO2 capture rate, and downstream CO2 demand, and adjust to an operating state that is compatible with these changing conditions, achieving flexible control and ensuring the long-term stable operation of the flexible carbon dioxide capture system.

[0025] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings: Figure 1 The schematic diagram illustrates a structural schematic of a flexible carbon dioxide capture system according to an embodiment of this application; Figure 2 The schematic diagram illustrates the structure of a first nozzle tube liquid distributor and a first trough liquid distributor according to embodiments of this application; Figure 3 This illustration schematically shows a flow chart of a control method for a flexible carbon dioxide capture system according to an embodiment of this application. Figure 4 This illustration schematically shows a flow chart of another flexible carbon dioxide capture system control method according to an embodiment of this application; Figure 5 This illustration schematically shows a flow chart of another control method for a flexible carbon dioxide capture system according to an embodiment of this application; Figure 6 This illustration schematically shows a flow chart of another control method for a flexible carbon dioxide capture system according to an embodiment of this application; Figure 7 This illustration schematically shows a flow chart of another control method for a flexible carbon dioxide capture system according to an embodiment of this application; Figure 8 The schematic diagram illustrates a control method flow chart for another flexible carbon dioxide capture system according to an embodiment of this application.

[0027] Explanation of reference numerals in the attached figures 100—Flexible carbon dioxide capture system; 101—Scrubbing tower; 102—First trough-type liquid distributor; 103—First nozzle-type liquid distributor; 104—First pumping unit; 1041—First transfer pump; 1042—Second transfer pump; 1043—First control valve; 1044—First flow controller; 1045—Second control valve; 1046—Second flow controller; 105—Absorption tower; 106—Second trough-type liquid distributor; 107—Second nozzle-type liquid distributor; 108—Second pumping unit; 1081—Third transfer pump; 1082—Fourth transfer pump; 1083—Third control valve; 1084—Third flow controller; 1085—Fourth control valve; 1086—Fourth flow controller; 109—Heat exchanger; 110—Regeneration tower; 111—Third trough-type liquid distributor; 112—Third nozzle-type liquid distributor; 113—Third pumping unit; 1131—Fifth transfer pump; 1132—Sixth transfer pump; 1133—Fifth control valve; 1134—Fifth flow controller; 1135—Sixth control valve; 1136—Sixth flow controller; 114—Flue gas flow detection device; 115—Carbon dioxide concentration detection device; 116—First cooler; 117—First cooling water control valve; 118—First cooling water flow controller; 119—First three-way valve; 120—Exhaust fan; 121—Regulating baffle; 122—Second three-way valve; 123—Second cooler; 124—Second cooling water control valve; 125—Second cooling water flow controller; 126—Third three-way valve; 127—Third cooler; 128—Separator; 129—Third cooling water control valve; 130—Third cooling water flow controller; 131—Seventh transfer pump; 132—Reboiler; 133—Heating medium control valve; 134—Heating medium flow controller. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] If the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0030] As described in the background section, the capture, utilization, and storage of carbon dioxide (CO2) is a key means to achieve carbon neutrality. For the combustion process of fossil fuels, CO2 capture technologies can be divided into pre-combustion capture, oxygen-enriched combustion, and post-combustion capture. In the field of post-combustion capture technology, chemical absorption CO2 capture technology is widely used due to its good capture effect and mature technology. Currently, when using chemical absorption CO2 capture technology for post-combustion capture, flue gas flow rate, CO2 concentration in flue gas, CO2 capture rate, and downstream CO2 demand often change continuously. For example, different operating loads of coal-fired boiler units lead to changes in the flue gas flow rate; different operating conditions of the boiler or different raw coal used lead to changes in the CO2 concentration in the flue gas; and changes in oil reserves and injection well conditions lead to changes in downstream CO2 demand for CO2 products. However, existing chemical absorption CO2 capture systems often struggle to adapt well to these changes and cannot adjust to a suitable operating state, thus affecting the long-term stable operation of the CO2 capture system.

[0031] To address this, one embodiment of this application provides a flexible carbon dioxide capture system, such as... Figure 1As shown, the flexible carbon dioxide capture system 100 may include a scrubbing tower 101, a first trough-type liquid distributor 102, a first nozzle-type liquid distributor 103, a first pumping unit 104, an absorption tower 105, a second trough-type liquid distributor 106, a second nozzle-type liquid distributor 107, a second pumping unit 108, a heat exchanger 109, a regeneration tower 110, a third trough-type liquid distributor 111, a third nozzle-type liquid distributor 112, and a third pumping unit 113; the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor... The first tank-type liquid distributor 102 is located above the first nozzle-type liquid distributor 103; the washing water outlet of the washing tower 101 is connected to the inlet of the first pumping unit 103, the outlet of the first pumping unit 103 is connected to the liquid inlet of the first tank-type liquid distributor 102 and the first nozzle-type liquid distributor 103 respectively, and the flue gas outlet of the washing tower 101 is connected to the flue gas inlet of the absorption tower 105; the second tank-type liquid distributor 106 and the first nozzle-type liquid distributor 103 are connected to the first nozzle-type liquid distributor 102 and the first nozzle-type liquid distributor 103 respectively. A two-nozzle tubular liquid distributor 107 is disposed at the top of the absorption tower 105, and a second trough-type liquid distributor 106 is located above the second nozzle tubular liquid distributor 107; a third trough-type liquid distributor 111 and a third nozzle tubular liquid distributor 112 are disposed at the top of the regeneration tower 110, with the third trough-type liquid distributor 111 located above the third nozzle tubular liquid distributor 112; the rich liquid outlet of the absorption tower 105 is connected to the inlet of the second pumping unit 108, and the outlet of the second pumping unit 108 is connected to the... The rich liquid inlet of the heat exchanger 109 is connected, and the rich liquid outlet of the heat exchanger 109 is connected to the liquid inlet to be distributed of the third trough liquid distributor 111 and the third nozzle tube liquid distributor 112, respectively; the first lean liquid outlet of the regeneration tower 110 is connected to the inlet of the third pumping unit 113, the outlet of the third pumping unit 113 is connected to the lean liquid inlet of the heat exchanger 109, and the lean liquid outlet of the heat exchanger 109 is connected to the liquid inlet to be distributed of the second trough liquid distributor 106 and the second nozzle tube liquid distributor 107, respectively.

[0032] The scrubbing tower 101 can be used to scrub and cool the flue gas X introduced into it, and dust removal can be achieved from the flue gas X through scrubbing. In practical applications, a flue gas flow detection device 114 and a carbon dioxide concentration detection device 115 can be installed on the pipeline used to introduce the flue gas X into the scrubbing tower 101. The flue gas flow detection device 114 can be used to detect the flue gas flow rate in real time, and the carbon dioxide concentration detection device 115 can be used to detect the carbon dioxide concentration in the flue gas in real time.

[0033] In scrubbing tower 101, scrubbing water flows from top to bottom, while flue gas X flows from bottom to top. The scrubbing water and flue gas X come into countercurrent contact, thereby achieving scrubbing and cooling of flue gas X. The scrubbed and cooled flue gas X is discharged through the flue gas outlet at the top of scrubbing tower 101, and the scrubbing water obtained after scrubbing and cooling flue gas X is discharged through the scrubbing water outlet at the bottom of scrubbing tower 101.

[0034] In this embodiment, the first trough-type liquid distributor 102 and the first nozzle-tube type liquid distributor 103 are disposed at the top of the scrubbing tower 101. The first trough-type liquid distributor 102 is located above the first nozzle-tube type liquid distributor 103. This can be understood as follows: along the X-direction of flue gas flow within the scrubbing tower 101, the first trough-type liquid distributor 102 is located downstream of the first nozzle-tube type liquid distributor 103, and both the first trough-type liquid distributor 102 and the first nozzle-tube type liquid distributor 103 are located downstream of the packing layer of the scrubbing tower 101. The structures of the first trough-type liquid distributor 102 and the first nozzle-tube type liquid distributor 103 can be as follows: Figure 2 As shown.

[0035] The maximum value of the liquid distribution flow range of the first tank-type liquid distributor 102 is greater than that of the first nozzle-type liquid distributor 103. Simultaneously, the minimum value of the liquid distribution flow range of the first tank-type liquid distributor 102 is greater than that of the first nozzle-type liquid distributor 103. In other words, the first tank-type liquid distributor 102 is suitable for distributing larger flow rates of washing water, while the first nozzle-type liquid distributor 103 is suitable for distributing smaller flow rates of washing water.

[0036] The washing water discharged from the washing water outlet at the bottom of the washing tower 101 is further pumped back to the top of the washing tower 101 via the first pumping unit 104, and then evenly distributed within the washing tower 101 through the first trough-type liquid distributor 102 or the first nozzle-type liquid distributor 103, flowing downwards to continue washing and cooling the flue gas X, thus achieving cyclic washing of the flue gas. In other words, when the carbon dioxide flexible capture system 100 is running, only one of the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor 103 is operational; that is, only one of the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor 103 is used to distribute the washing water. Specifically, when the carbon dioxide flexible capture system 100 is in the first type of operating condition, the first nozzle tube liquid distributor 103 is operated; when the carbon dioxide flexible capture system 100 is in the second type of operating condition, the first tank liquid distributor 102 is operated; wherein, the flue gas flow rate corresponding to the first type of operating condition is less than the flue gas flow rate corresponding to the second type of operating condition, the first type of operating condition can correspond to a low load condition, and the second type of operating condition can correspond to a high load condition.

[0037] In specific implementation, the first pumping unit 104 may include a first transfer pump 1041 and a second transfer pump 1042, which are connected in parallel. That is, the inlets of both the first transfer pump 1041 and the second transfer pump 1042 are connected to the washing water outlet of the scrubbing tower 101; the outlet of the first transfer pump 1041 is connected to the liquid inlet of both the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor 103; and the outlet of the second transfer pump 1042 is connected to both the liquid inlet of both the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor 103. Furthermore, when the flexible carbon dioxide capture system 100 is in the first type of operating condition, only one of the first transfer pump 1041 and the second transfer pump 1042 operates; when the flexible carbon dioxide capture system 100 is in the second type of operating condition, both the first transfer pump 1041 and the second transfer pump 1042 operate.

[0038] Furthermore, one of the first transfer pump 1041 and the second transfer pump 1042 can be equipped with a frequency converter; for example, the first transfer pump 1041 can be equipped with a frequency converter. When the carbon dioxide flexible capture system 100 is in the first type of operating condition, requiring the operation of one of the first transfer pump 1041 and the second transfer pump 1042, the one equipped with the frequency converter can be operated. This reduces the investment and operating costs of the carbon dioxide flexible capture system 100.

[0039] To facilitate flow control, a first control valve 1043 can be installed on the outlet pipe of the first delivery pump 1041. The first control valve 1043 can be connected to a first flow controller 1044. The first flow controller 1044 can acquire the output flow of the first delivery pump 1041 and adjust the first control valve 1043 according to the flow, thereby adjusting the output flow of the first delivery pump 1041. Similarly, a second control valve 1045 can be installed on the outlet pipe of the second delivery pump 1042. The second control valve 1045 can be connected to a second flow controller 1046. The second flow controller 1046 can acquire the output flow of the second delivery pump 1042 and adjust the second control valve 1045 according to the flow, thereby adjusting the output flow of the second delivery pump 1042.

[0040] In practical applications, to ensure that the washing water recycled back to the top of the scrubbing tower 101 can continue to cool the flue gas X, the carbon dioxide flexible capture system 100 may further include a first cooler 116. The outlets of the first transfer pump 1041 and the second transfer pump 1042 are both connected to the washing water inlet of the first cooler 116. The washing water outlet of the first cooler 116 is connected to the liquid distribution inlets of the first trough-type liquid distributor 102 and the first nozzle-type liquid distributor 103, respectively. The first cooler 116 also has a cooling water inlet and a cooling water outlet. It is understood that the washing water introduced through the washing water inlet of the first cooler 116 and the cooling water introduced through the cooling water inlet of the first cooler 116 undergo heat exchange in the first cooler 116. After being cooled, the washing water is discharged from the washing water outlet of the first cooler 116 and transported to the top of the scrubbing tower 101, while the cooling water, having absorbed heat due to the heat exchange, is discharged from the cooling water outlet of the first cooler 116. The first cooler 116 can be a shell-and-tube heat exchanger or a plate heat exchanger, and one or more units can be connected in parallel according to actual needs.

[0041] A first cooling water control valve 117 may also be provided on the pipeline for introducing cooling water into the first cooler 116. The first cooling water control valve 117 can be connected to a first cooling water flow controller 118. The first cooling water flow controller 118 can obtain the cooling water flow rate entering the first cooler 116 and adjust the first cooling water control valve 117 according to the flow rate, thereby realizing the adjustment of the cooling water flow rate entering the first cooler 116.

[0042] To further control the flow direction of the washing water, i.e., to control whether the washing water flows into the first tank-type liquid distributor 102 or the first nozzle-type liquid distributor 103, in this embodiment of the application, a first three-way valve 119 may be further provided. The inlet of the first three-way valve 119 is connected to the washing water outlet of the first cooler 116, the first outlet of the first three-way valve 119 is connected to the liquid inlet of the first tank-type liquid distributor 102, and the second outlet of the first three-way valve 119 is connected to the liquid inlet of the first nozzle-type liquid distributor 103.

[0043] To ensure that the washing water circulating from the bottom outlet of the scrubbing tower 101 back to the top of the scrubbing tower 101 can continue to scrub and remove dust from the flue gas X, maintaining good dust collection and holding capabilities, a portion of the washing water can be discharged after cooling by the first cooler 116, and fresh washing water can be added. In specific implementation, a washing water discharge pipe and a washing water replenishment pipe can be added to the pipeline corresponding to the washing water outlet of the first cooler 116. A portion of the washing water is discharged through the washing water discharge pipe, and fresh washing water is added through the washing water replenishment pipe.

[0044] The flue gas outlet of scrubbing tower 101 is connected to the flue gas inlet of absorption tower 105. That is, the scrubbed and cooled flue gas Y is discharged through the flue gas outlet at the top of scrubbing tower 101 and then further conveyed into absorption tower 105. In practical applications, an induced draft fan 120 equipped with a frequency converter can be installed on the pipeline used to introduce flue gas Y into absorption tower 105. At the same time, a regulating baffle 121 can be installed on the pipeline used to introduce flue gas X into scrubbing tower 101. The frequency converter of induced draft fan 120 and the regulating baffle 121 jointly regulate the flow rate of flue gas.

[0045] Absorber tower 105 can further absorb carbon dioxide from flue gas Y using lean absorbent solution (also simply called lean solution, i.e., an absorbent solution with a low carbon dioxide content). In absorber tower 105, the lean absorbent solution flows downwards, while flue gas Y flows upwards, resulting in counter-current contact between the lean absorbent solution and flue gas Y, thus achieving carbon dioxide absorption. Flue gas Z, after further removing most of the carbon dioxide, is discharged through the top of absorber tower 105, while the rich absorbent solution (also simply called rich solution, i.e., an absorbent solution with a higher carbon dioxide content) that has absorbed carbon dioxide is discharged through the rich solution outlet at the bottom of absorber tower 101.

[0046] The rich liquid discharged from the rich liquid outlet at the bottom of the absorption tower 105 is further transported to the heat exchanger 109 via the second pumping unit 108. In the heat exchanger 109, the rich liquid introduced through the rich liquid inlet and the lean liquid introduced through the lean liquid inlet exchanger undergo heat exchange. The rich liquid, after its temperature rises, is discharged through the rich liquid outlet of the heat exchanger 109, and the lean liquid, after its temperature decreases, is discharged through the lean liquid outlet of the heat exchanger 109. The heat exchanger 109 can be a shell-and-tube heat exchanger or a plate heat exchanger, and one or more units can be installed in parallel depending on actual needs.

[0047] In specific implementation, the second pumping unit 108 may include a third transfer pump 1081 and a fourth transfer pump 1082, which are connected in parallel. That is, the inlet of the third transfer pump 1081 and the inlet of the fourth transfer pump 1082 are both connected to the rich liquid outlet of the absorption tower 105, and the outlet of the third transfer pump 1081 and the outlet of the fourth transfer pump 1082 are both connected to the rich liquid inlet of the heat exchanger 109. Furthermore, when the carbon dioxide flexible capture system is in the third type of operating condition, only one of the third transfer pump 1081 and the fourth transfer pump 1082 is operating; when the carbon dioxide flexible capture system is in the fourth type of operating condition, both the third transfer pump 1081 and the fourth transfer pump 1082 are operating. The rich liquid flow rate of the absorbent corresponding to the third type of operating condition is less than that corresponding to the fourth type of operating condition. The third type of operating condition can correspond to a low-load condition, and the fourth type of operating condition can correspond to a high-load condition.

[0048] Furthermore, one of the third transfer pump 1081 and the fourth transfer pump 1082 can be equipped with a frequency converter; for example, the third transfer pump 1081 can be equipped with a frequency converter. When the carbon dioxide flexible capture system is in the third type of operating condition, requiring the operation of one of the third transfer pump 1081 and the fourth transfer pump 1082, the one equipped with the frequency converter can be operated. This reduces the investment and operating costs of the carbon dioxide flexible capture system 100.

[0049] In a specific implementation, a third control valve 1083 can also be installed on the outlet pipe of the third delivery pump 1081. The third control valve 1083 can be connected to a third flow controller 1084. The third flow controller 1084 can obtain the output flow of the third delivery pump 1081 and adjust the third control valve 1083 according to the flow, thereby adjusting the output flow of the third delivery pump 1081. Similarly, a fourth control valve 1085 can also be installed on the outlet pipe of the fourth delivery pump 1082. The fourth control valve 1085 can be connected to a fourth flow controller 1086. The fourth flow controller 1086 can obtain the output flow of the fourth delivery pump 1082 and adjust the fourth control valve 1085 according to the flow, thereby adjusting the output flow of the fourth delivery pump 1082.

[0050] The reduced-temperature lean liquid discharged from the lean liquid outlet of heat exchanger 109 is sent to the top of absorption tower 105 and evenly distributed within absorption tower 105 via the second trough-type liquid distributor 106 or the second nozzle-type liquid distributor 107. In other words, when the flexible carbon dioxide capture system 100 is operating, only one of the second trough-type liquid distributor 106 and the second nozzle-type liquid distributor 107 is operational; that is, only one of the second trough-type liquid distributor 106 and the second nozzle-type liquid distributor 107 is used to distribute the lean liquid.

[0051] In this embodiment, the second trough-type liquid distributor 106 and the second nozzle-tube type liquid distributor 107 are disposed at the top of the absorption tower 105. The second trough-type liquid distributor 106 is located above the second nozzle-tube type liquid distributor 107. This can be understood as follows: along the Y-direction of flue gas flow within the absorption tower 105, the second trough-type liquid distributor 106 is located downstream of the second nozzle-tube type liquid distributor 107, and both the second trough-type liquid distributor 106 and the second nozzle-tube type liquid distributor 107 are located downstream of the packing layer of the absorption tower 105. The structure of the second trough-type liquid distributor 106 can be referred to... Figure 2 The structures of the first tank-type liquid distributor 102 and the second nozzle-type liquid distributor 107 can be referenced. Figure 2 The structure of the first nozzle tubular liquid distributor 103.

[0052] Specifically, the maximum value of the liquid distribution flow range of the second tank-type liquid distributor 106 is greater than that of the second nozzle-type liquid distributor 107, and the minimum value of the liquid distribution flow range of the second tank-type liquid distributor 106 is greater than that of the second nozzle-type liquid distributor 107. In other words, the second tank-type liquid distributor 106 is suitable for distributing larger flow rates of lean liquid, while the second nozzle-type liquid distributor 107 is suitable for distributing smaller flow rates of lean liquid. Specifically, when the carbon dioxide flexible capture system 100 is in the third type of operating condition, the second nozzle-type liquid distributor 107 operates; when the carbon dioxide flexible capture system 100 is in the fourth type of operating condition, the second tank-type liquid distributor 106 operates.

[0053] To facilitate control over the flow direction of the lean liquid, i.e., to control whether the lean liquid flows into the second trough-type liquid distributor 106 or the second nozzle-type liquid distributor 107, in this embodiment, a second three-way valve 122 may be further provided. The inlet of the second three-way valve 122 is connected to the lean liquid outlet of the second cooler 123, the first outlet of the second three-way valve 122 is connected to the liquid inlet to be distributed in the second trough-type liquid distributor 106, and the second outlet of the second three-way valve 122 is connected to the liquid inlet to be distributed in the second nozzle-type liquid distributor 107.

[0054] In practical applications, to further improve the carbon dioxide absorption capacity of the lean liquid, the flexible carbon dioxide capture system 100 may further include a second cooler 123. The lean liquid outlet of the heat exchanger 109 is connected to the lean liquid inlet of the second cooler 123. The lean liquid outlet of the second cooler 123 is connected to the liquid distribution inlets of the second trough-type liquid distributor 106 and the second nozzle-type liquid distributor 107, respectively. The second cooler 123 also has a cooling water inlet and a cooling water outlet. It is understood that the lean liquid introduced through the lean liquid inlet of the second cooler 123 and the cooling water introduced through the cooling water inlet of the second cooler 123 undergo heat exchange in the second cooler 123. After the lean liquid is further cooled by the cooling water, it is discharged from the lean liquid outlet of the second cooler 123 and transported to the top of the absorption tower 105, while the cooling water, after absorbing heat due to the heat exchange, is discharged from the cooling water outlet of the second cooler 123. The second cooler 123 can be a shell-and-tube heat exchanger or a plate heat exchanger, and one or more units can be connected in parallel according to actual needs.

[0055] A second cooling water control valve 124 may also be installed on the pipeline used to introduce cooling water into the second cooler 123. The second cooling water control valve 124 can be connected to a second cooling water flow controller 125. The second cooling water flow controller 125 can obtain the cooling water flow rate entering the second cooler 123 and adjust the second cooling water control valve 124 according to the flow rate, thereby realizing the adjustment of the cooling water flow rate entering the second cooler 123.

[0056] The rich liquid outlet of heat exchanger 109 is connected to the liquid inlet of the third trough-type liquid distributor 111 and the third nozzle-type liquid distributor 112, respectively. This means that the warmed rich liquid discharged from the rich liquid outlet of heat exchanger 109 is further fed into the top of regeneration tower 110 and evenly distributed within regeneration tower 110 via either the third trough-type liquid distributor 111 or the third nozzle-type liquid distributor 112. In other words, when the carbon dioxide flexible capture system 100 is operating, only one of the third trough-type liquid distributor 111 or the third nozzle-type liquid distributor 112 is operational; that is, only one of the third trough-type liquid distributor 111 or the third nozzle-type liquid distributor 112 is used to distribute the rich liquid.

[0057] In this embodiment, the third trough-type liquid distributor 111 and the third nozzle-tube type liquid distributor 112 are disposed at the top of the regeneration tower 110. The third trough-type liquid distributor 111 is located above the third nozzle-tube type liquid distributor 112. This can be understood as follows: along the steam flow direction within the regeneration tower 110, the third trough-type liquid distributor 111 is located downstream of the third nozzle-tube type liquid distributor 112, and both the third trough-type liquid distributor 111 and the third nozzle-tube type liquid distributor 112 are located downstream of the packing layer of the regeneration tower 110. The structure of the third trough-type liquid distributor 111 can be referred to... Figure 2 The structures of the first tank-type liquid distributor 102 and the third nozzle-type liquid distributor 112 can be referenced. Figure 2 The structure of the first nozzle tubular liquid distributor 103.

[0058] The maximum value of the liquid distribution flow range of the third tank-type liquid distributor 111 is greater than that of the third nozzle-type liquid distributor 112. Simultaneously, the minimum value of the liquid distribution flow range of the third tank-type liquid distributor 111 is greater than that of the third nozzle-type liquid distributor 112. In other words, the third tank-type liquid distributor 111 is suitable for distributing larger flow rates of rich liquid, while the third nozzle-type liquid distributor 112 is suitable for distributing smaller flow rates of rich liquid. Specifically, when the carbon dioxide flexible capture system 100 is in the third type of operating condition, the third nozzle-type liquid distributor 112 operates; when the carbon dioxide flexible capture system 100 is in the fourth type of operating condition, the third tank-type liquid distributor 111 operates.

[0059] To facilitate control of the flow direction of the rich liquid, i.e., to control whether the rich liquid flows into the third tank-type liquid distributor 111 or the third nozzle-type liquid distributor 112, a third three-way valve 126 may be further provided in this embodiment. The inlet of the third three-way valve 126 is connected to the rich liquid outlet of the heat exchanger 109, the first outlet of the third three-way valve 126 is connected to the liquid inlet to be distributed in the third tank-type liquid distributor 111, and the second outlet of the third three-way valve 126 is connected to the liquid inlet to be distributed in the third nozzle-type liquid distributor 112.

[0060] The regeneration tower 110 utilizes steam to heat the rich liquor, causing it to desorb and release carbon dioxide. In the regeneration tower 110, the rich liquor flows downwards, while steam flows upwards, with the steam contacting the rich liquor in a counter-current manner to heat it. The carbon dioxide released by the desorption of the rich liquor is discharged through the carbon dioxide outlet at the top of the regeneration tower 110. After releasing carbon dioxide, the rich liquor becomes lean liquor, which is discharged through the first lean liquor outlet at the bottom of the regeneration tower 110.

[0061] The lean liquid discharged from the first lean liquid outlet at the bottom of the regeneration tower 110 is further transported to the lean liquid inlet of the heat exchanger 109 via the third pumping unit 113, where it exchanges heat with the rich liquid introduced through the rich liquid inlet of the heat exchanger 109.

[0062] In specific implementation, the third pumping unit 113 may include a fifth transfer pump 1131 and a sixth transfer pump 1132, which are connected in parallel. That is, the inlet of the fifth transfer pump 1131 and the inlet of the sixth transfer pump 1132 are both connected to the first lean liquid outlet of the regeneration tower 110, and the outlet of the fifth transfer pump 1131 and the outlet of the sixth transfer pump 1132 are both connected to the lean liquid inlet of the heat exchanger 109. Furthermore, when the carbon dioxide flexible capture system is in the third type of operating condition, only one of the fifth transfer pump 1131 and the sixth transfer pump 1132 is operating; when the carbon dioxide flexible capture system is in the fourth type of operating condition, both the fifth transfer pump 1131 and the sixth transfer pump 1132 are operating.

[0063] Furthermore, one of the fifth transfer pump 1131 and the sixth transfer pump 1132 can be equipped with a frequency converter; for example, the fifth transfer pump 1131 can be equipped with a frequency converter. When the carbon dioxide flexible capture system is in the third type of operating condition, requiring the operation of one of the fifth transfer pump 1131 and the sixth transfer pump 1132, the one equipped with the frequency converter can be operated. This reduces the investment and operating costs of the carbon dioxide flexible capture system 100.

[0064] In specific implementation, a fifth control valve 1133 can also be installed on the outlet pipe of the fifth delivery pump 1131. The fifth control valve 1133 can be connected to a fifth flow controller 1134. The fifth flow controller 1134 can obtain the output flow of the fifth delivery pump 1131 and adjust the fifth control valve 1133 according to the flow, thereby adjusting the output flow of the fifth delivery pump 1131. Similarly, a sixth control valve 1135 can also be installed on the outlet pipe of the sixth delivery pump 1132. The sixth control valve 1135 can be connected to a sixth flow controller 1136. The sixth flow controller 1136 can obtain the output flow of the sixth delivery pump 1132 and adjust the sixth control valve 1135 according to the flow, thereby adjusting the output flow of the sixth delivery pump 1132.

[0065] Considering that the carbon dioxide released from the rich liquid desorption will carry some water vapor when discharged from the top of the regeneration tower 110, the flexible carbon dioxide capture system 100 may also include a third cooler 127 and a separator 128 to maintain gas-liquid balance. The carbon dioxide outlet at the top of the regeneration tower 110 is connected to the carbon dioxide inlet of the third cooler 127, the carbon dioxide outlet of the third cooler 127 is connected to the carbon dioxide inlet of the separator 128, and the condensate outlet of the separator 128 is connected to the condensate inlet of the regeneration tower 110. The third cooler 127 also has a cooling water inlet and a cooling water outlet.

[0066] Specifically, the carbon dioxide carrying water vapor discharged from the top carbon dioxide outlet of the regeneration tower 110 is further fed into the third cooler 127. In the third cooler 127, the carbon dioxide carrying water vapor exchanges heat with cooling water introduced through the cooling water inlet of the third cooler 127. The water vapor is condensed and precipitated. The carbon dioxide and the precipitated condensate are discharged from the carbon dioxide outlet of the third cooler 127 and transported to the separator 128, while the cooling water, having absorbed heat during the heat exchange, is discharged from the cooling water outlet of the third cooler 127. The third cooler 127 can be a shell-and-tube heat exchanger or a plate heat exchanger, and one or more units can be installed in parallel depending on actual needs.

[0067] A third cooling water control valve 129 may also be installed on the cooling water inlet pipe of the third cooler 127. The third cooling water control valve 129 can be connected to the third cooling water flow controller 130. The third cooling water flow controller 130 can obtain the cooling water flow rate entering the third cooler 127 and adjust the third cooling water control valve 129 according to the flow rate, thereby realizing the adjustment of the cooling water flow rate entering the third cooler 127.

[0068] In separator 128, carbon dioxide and condensate are separated. Carbon dioxide is discharged from the carbon dioxide outlet at the top of separator 128, and condensate is discharged from the condensate outlet at the bottom of separator 128 and conveyed to the condensate inlet of regeneration tower 110. In a specific implementation, a seventh transfer pump 131 may be installed on the pipeline used to introduce the condensate discharged from the condensate outlet of separator 128 into regeneration tower 110. The condensate inlet of regeneration tower 110 may be located at the top of regeneration tower 110, between the packing layer and the third trough-type liquid distributor 111.

[0069] Furthermore, the flexible carbon dioxide capture system 100 may also include a reboiler 132. The second lean liquid outlet at the bottom of the regeneration tower 110 is connected to the lean liquid inlet of the reboiler 132, and the lean liquid outlet of the reboiler 132 is connected to the lean liquid inlet at the bottom of the regeneration tower 110. The reboiler 132 also has a heating medium inlet and a heating medium outlet. It is understood that the lean liquid introduced through the lean liquid inlet of the reboiler 132 and the heating medium (such as low-pressure steam) introduced through the heating medium inlet of the reboiler 132 undergo heat exchange in the reboiler 132. After the lean liquid generates steam, it is discharged from the lean liquid outlet of the reboiler 132 and transported to the lean liquid inlet at the bottom of the regeneration tower 110. The heating medium, after releasing heat due to heat exchange, is discharged from the heating medium outlet of the reboiler 132. The reboiler 132 can be a shell-and-tube heat exchanger or a plate heat exchanger, and one or more units can be installed in parallel according to actual needs.

[0070] A heating medium control valve 133 can also be installed on the heating medium inlet pipe of the reboiler 132. The heating medium control valve 133 can be connected to the heating medium flow controller 134. The heating medium flow controller 134 can obtain the flow rate of the heating medium entering the reboiler 132 and adjust the heating medium control valve 133 according to the flow rate, thereby realizing the adjustment of the flow rate of the heating medium entering the reboiler 132.

[0071] It is understood that, based on the carbon dioxide flexible capture system 100 provided in the embodiments of this application, when the carbon dioxide flexible capture system 100 is in a first type of operating condition, it operates the first nozzle-tube liquid distributor 103 and one of the first transfer pump 1041 and the second transfer pump 1042; when the carbon dioxide flexible capture system 100 is in a second type of operating condition, it operates the first tank-type liquid distributor 102 and the first transfer pump 1041 and the second transfer pump 1042; and when the carbon dioxide flexible capture system 100 is in a third type of operating condition, it operates the second nozzle-tube liquid distributor 107, the third nozzle-tube liquid distributor 112, and the third transfer pump 1081 and... When the flexible carbon dioxide capture system is in the fourth type of operating condition, one of the fourth transfer pumps 1082, and one of the fifth transfer pumps 1131 and the sixth transfer pump 1132 operate the second tank liquid distributor 106, the third tank liquid distributor 111, the third transfer pump 1081 and the fourth transfer pump 1082, and the fifth transfer pump 1131 and the sixth transfer pump 1132, respectively. This allows the system to adapt to various changes, such as changes in flue gas flow rate, CO2 concentration in flue gas, CO2 capture rate, and downstream CO2 demand. It can adjust to the operating state that is compatible with these changes, achieve flexible control, and thus ensure the long-term stable operation of the flexible carbon dioxide capture system.

[0072] Statistics show that the aforementioned changes often lead to a load range expanding to 20%–110% of the baseline operating condition (100% operating load), rather than the traditionally common operating load range of 60–110%. Existing CO2 capture systems struggle to adjust to an operating state compatible with this 20%–110% range. However, the flexible CO2 capture system provided in the above embodiments of this application can be adjusted to an operating state compatible with this 20%–110% range. In other words, the flexible CO2 capture system provided in the above embodiments of this application can cope with significant changes and fluctuations in flue gas flow rate, CO2 concentration in the flue gas, CO2 capture rate, and downstream CO2 demand, exhibiting high operational load flexibility.

[0073] Furthermore, by installing trough-type liquid distributors and nozzle-type liquid distributors in the washing tower, absorption tower, and regeneration tower, uniform distribution of the liquid to be distributed can be achieved in all three towers, regardless of whether the liquid distribution flow rate is small or large. This avoids the need for parallel operation of multiple towers (such as multiple parallel washing towers, multiple parallel absorption towers, and multiple parallel regeneration towers) in existing technologies to cover a wider liquid distribution flow range, thereby reducing investment costs.

[0074] Based on the flexible carbon dioxide capture system provided in the above embodiments of this application, one embodiment of this application also provides a control method for the flexible carbon dioxide capture system, such as... Figure 3As shown, the control method may include the following steps: Step 201: Calculate the target flue gas flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand.

[0075] The real-time flue gas flow rate can be detected by a flue gas flow rate detection device installed on the pipeline used to introduce flue gas into the scrubbing tower. The real-time carbon dioxide concentration, i.e., the real-time carbon dioxide concentration in the flue gas, can be detected by a carbon dioxide concentration detection device installed on the pipeline used to introduce flue gas into the scrubbing tower. The real-time carbon dioxide demand, i.e., the downstream real-time carbon dioxide demand, corresponds to the planned carbon dioxide flow rate at the separator's carbon dioxide outlet. The planned carbon dioxide capture rate can be calculated based on the real-time flue gas flow rate, real-time carbon dioxide concentration, and real-time carbon dioxide demand.

[0076] In this embodiment of the application, the target flue gas flow rate can be calculated based on the following formula (1): F 目标烟气 =F CO2需求 / (CR 计划 ×x CO2实时 (1); In the above formula (1), F 目标烟气 Target flue gas flow rate; F CO2需求 Real-time carbon dioxide demand; CR 计划 The planned capture rate of carbon dioxide; x CO2实时 This represents the real-time carbon dioxide concentration.

[0077] Wherein, the planned carbon dioxide capture rate = CR 计划 It can be calculated based on the following formula (2): CR 计划 =F CO2需求 / (F 烟气实时 ×x CO2实时 (2); In the above formula (2), F 烟气实时 This represents the real-time flue gas flow rate.

[0078] Based on the above formulas (1) and (2), it can be seen that the target flue gas flow rate is a function of the real-time flue gas flow rate, the real-time carbon dioxide concentration, the planned carbon dioxide capture rate, and the real-time carbon dioxide demand. Therefore, when any parameter among the real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand changes, resulting in a change in operating conditions, the calculated target flue gas flow rate is the flue gas flow rate corresponding to that changed operating condition. By controlling the parts related to scrubbing flue gas in the flexible carbon dioxide capture system according to the target flue gas flow rate, the parts related to scrubbing flue gas can be adjusted to a suitable operating state to adapt to the changing operating conditions.

[0079] Step 202: Calculate the target washing water flow rate based on the target flue gas flow rate, the reference flue gas flow rate, and the reference washing water flow rate.

[0080] Among them, the reference flue gas flow rate is the flue gas flow rate of the carbon dioxide flexible capture system under the reference operating conditions (also known as the normal design operating conditions, corresponding to 100% operating load), and the reference scrubbing water flow rate is the scrubbing water flow rate of the first pumping unit of the carbon dioxide flexible capture system under the reference operating conditions.

[0081] In this embodiment of the application, the target washing water flow rate can be calculated based on the following formula (3): F 目标洗涤水 =(F 目标烟气 ×F 基准洗涤水 ) / F 基准烟气 (3); In the above formula (3), F 目标洗涤水 Target washing water flow rate; F 基准洗涤水 The reference washing water flow rate; F 基准烟气 The reference flue gas flow rate is used.

[0082] Step 203: Adjust the real-time flue gas flow rate to the target flue gas flow rate and control the washing water flow rate of the first pumping unit to the target washing water flow rate. When the target flue gas flow rate is greater than half of the reference flue gas flow rate, deliver the washing water output by the first pumping unit to the first tank-type liquid distributor. When the target flue gas flow rate is less than or equal to half of the reference flue gas flow rate, deliver the washing water output by the first pumping unit to the first nozzle-type liquid distributor.

[0083] Among them, if the target flue gas flow rate is less than or equal to half of the reference flue gas flow rate, it can correspond to the first type of operating condition; if the target flue gas flow rate is greater than half of the reference flue gas flow rate, it can correspond to the second type of operating condition.

[0084] When adjusting the real-time flue gas flow rate to the target flue gas flow rate, the real-time flue gas flow rate can be adjusted by regulating the speed of the induced draft fan frequency converter.

[0085] It is understood that, through the solution provided by the above embodiments of this application, when the flue gas flow rate, CO2 concentration in the flue gas, CO2 capture rate and downstream CO2 demand change, the part of the carbon dioxide flexible capture system related to the scrubbing flue gas can be adjusted to an operating state that adapts to the changing operating conditions, thereby achieving flexible control.

[0086] Furthermore, when the first pumping unit includes a first transfer pump and a second transfer pump, the step 203 above, in which the washing water output from the first pumping unit is delivered to the first tank-type liquid distributor, can specifically include: controlling both the first and second transfer pumps to operate, so as to deliver the washing water to the first tank-type liquid distributor. In specific implementation, the washing water flow rates of the first and second transfer pumps can be controlled to be equal, both being half of the target washing water flow rate.

[0087] Meanwhile, if the first pumping unit includes a first delivery pump and a second delivery pump, the washing water output from the first pumping unit in step 203 can be delivered to the first nozzle tubular liquid distributor. Specifically, this can include controlling one of the first delivery pump and the second delivery pump to operate so as to deliver the washing water to the first nozzle tubular liquid distributor.

[0088] Furthermore, when the first pumping unit includes a first delivery pump and a second delivery pump, and one of the first and second delivery pumps is equipped with a frequency converter, controlling both the first and second delivery pumps to operate can specifically include: controlling both the first and second delivery pumps to operate, while controlling the frequency converter not to start. The first and second delivery pumps operate at industrial frequency.

[0089] Meanwhile, when the first pumping unit includes a first delivery pump and a second delivery pump, and one of the first delivery pump and the second delivery pump is equipped with a frequency converter, controlling the operation of the first delivery pump and the second delivery pump includes: controlling the operation of the first delivery pump and the second delivery pump equipped with a frequency converter, and controlling the frequency converter to start.

[0090] It is understandable that by adopting the above solution, the combination of frequency conversion and power frequency can effectively reduce investment and improve system stability while ensuring flexible operation.

[0091] In the case of a flexible carbon dioxide capture system including a first cooler, such as Figure 4 As shown, after step 201, the control method provided in this application embodiment may further include steps 204 and 205, as detailed below: Step 204: Calculate the first target cooling water flow rate based on the target flue gas flow rate, the reference flue gas flow rate, and the reference cooling water flow rate of the first cooler.

[0092] The reference cooling water flow rate is the cooling water flow rate of the first cooler when the carbon dioxide flexible capture system is in reference operating conditions.

[0093] In this embodiment of the application, the first target cooling water flow rate can be calculated based on the following formula (4): F 第一目标冷却水 =(F 目标烟气 ×F 基准冷却水1) / F 基准烟气 (4); In the above formula (4), F 第一目标冷却水 The primary target cooling water flow rate; F 基准冷却水1 This is the reference cooling water flow rate for the first cooler.

[0094] Step 205: Control the cooling water flow rate of the first cooler to the first target cooling water flow rate.

[0095] It is understandable that by adopting the above scheme, the cooling water consumption of the first cooler can be reduced proportionally, which can reduce costs while ensuring flexible and stable operation and control.

[0096] Based on the flexible carbon dioxide capture system provided in the above embodiments of this application, one embodiment of this application also provides another control method for a flexible carbon dioxide capture system, such as... Figure 5 As shown, the control method may include the following steps: Step 301: Calculate the target rich liquid flow rate and the target lean liquid flow rate based on the real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand.

[0097] In this embodiment of the application, the target rich liquid flow rate can be calculated based on the following formula (5): F 目标富液 =f1(CR 计划 , x CO2实时 ,F CO2需求 (5); In the above formula (5), F 目标富液 The target enrichment flow rate is given. In specific implementation, the specific form of the above formula (5) can be determined according to the different absorbents used. It can be a higher-order polynomial, power function, exponential function, fractional function, logarithmic function, or a combination of the above functions.

[0098] In this embodiment of the application, the target lean liquid flow rate can be calculated based on the following formula (6): F 目标贫液 =f2(CR 计划 , x CO2实时 ,F CO2需求 (6); In the above formula (6), F 目标贫液 The target lean liquid flow rate. In specific implementation, the specific form of the above formula (6) can be determined according to the different absorbents used. It can be a higher-order polynomial, power function, exponential function, fractional function, logarithmic function or a combination of the above functions.

[0099] Due to the planned capture rate of carbon dioxide (CR) 计划The target rich liquid flow rate and target lean liquid flow rate can be calculated based on real-time flue gas flow rate, real-time carbon dioxide concentration, and real-time carbon dioxide demand. Therefore, both are functions of these parameters. Consequently, when any of these parameters changes, leading to a change in operating conditions, the calculated target rich liquid flow rate and target lean liquid flow rate correspond to the changed operating conditions. Controlling the components related to carbon dioxide absorption and desorption in the flexible carbon dioxide capture system based on the target rich liquid flow rate and target lean liquid flow rate allows these components to be adjusted to an appropriate operating state, adapting to changing conditions.

[0100] Step 302: Adjust the rich liquid flow rate of the second pumping unit to the target rich liquid flow rate and adjust the lean liquid flow rate of the third pumping unit to the target lean liquid flow rate. When the target rich liquid flow rate is greater than half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third tank-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second tank-type liquid distributor. When the target rich liquid flow rate is less than or equal to half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third nozzle-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second nozzle-type liquid distributor.

[0101] The reference rich liquid flow rate is the rich liquid flow rate of the second pumping unit of the carbon dioxide flexible capture system under reference operating conditions.

[0102] If the target rich liquid flow rate is less than or equal to half of the reference rich liquid flow rate, it corresponds to the third type of operating condition. If the target rich liquid flow rate is greater than half of the reference rich liquid flow rate, it corresponds to the fourth type of operating condition.

[0103] It is understood that, through the solution provided by the above embodiments of this application, when the flue gas flow rate, CO2 concentration in the flue gas, CO2 capture rate and downstream CO2 demand change, the parts related to carbon dioxide absorption and desorption in the flexible carbon dioxide capture system can be adjusted to an operating state that adapts to the changing operating conditions, thereby achieving flexible control.

[0104] Furthermore, when the second pumping unit includes a third and a fourth transfer pump, and the third pumping unit includes a fifth and a sixth transfer pump, the above-mentioned step 302, which involves transporting the rich solution output from the second pumping unit to the third tank-type liquid distributor and the lean solution output from the third pumping unit to the second tank-type liquid distributor, can specifically include: controlling both the third and fourth transfer pumps to operate to transport the rich solution to the third tank-type liquid distributor, and controlling both the fifth and sixth transfer pumps to operate to transport the lean solution to the second tank-type liquid distributor. In specific implementations, the rich solution flow rates of the third and fourth transfer pumps can be controlled to be equal, each being half of the target rich solution flow rate; alternatively, the lean solution flow rates of the fifth and sixth transfer pumps can be controlled to be equal, each being half of the target lean solution flow rate.

[0105] Meanwhile, when the second pumping unit includes a third and a fourth transfer pump, and the third pumping unit includes a fifth and a sixth transfer pump, the above-mentioned step 302, which involves transporting the rich liquid output from the second pumping unit to the third nozzle-tube liquid distributor and the lean liquid output from the third pumping unit to the second nozzle-tube liquid distributor, may specifically include: controlling one of the third and fourth transfer pumps to operate in order to transport the rich liquid to the third nozzle-tube liquid distributor, and controlling one of the fifth and sixth transfer pumps to operate in order to transport the lean liquid to the second nozzle-tube liquid distributor.

[0106] Furthermore, when one of the third and fourth transfer pumps and one of the fifth and sixth transfer pumps are equipped with a frequency converter, the control of both the third and fourth transfer pumps to operate can specifically include: controlling both the third and fourth transfer pumps to operate while controlling the frequency converter not to start; the control of both the fifth and sixth transfer pumps to operate can specifically include: controlling both the fifth and sixth transfer pumps to operate while controlling the frequency converter not to start.

[0107] Meanwhile, when one of the third and fourth transfer pumps and one of the fifth and sixth transfer pumps are equipped with a frequency converter, controlling the operation of one of the third and fourth transfer pumps may specifically include: controlling the operation of the one of the third and fourth transfer pumps equipped with a frequency converter and controlling the frequency converter to start; controlling the operation of one of the fifth and sixth transfer pumps may specifically include: controlling the operation of the one of the fifth and sixth transfer pumps equipped with a frequency converter and controlling the frequency converter to start.

[0108] In the case of a flexible carbon dioxide capture system including a second cooler, such as Figure 6 As shown, the control method provided in this application embodiment may further include steps 401 and 402, as detailed below: Step 401: Calculate the second target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand.

[0109] In this embodiment of the application, the second target cooling water flow rate can be calculated based on the following formula (7): F 第二目标冷却水 = f3(CR 计划 , x CO2实时 ,F CO2需求 (7); In the above formula (7), F 第二目标冷却水 The second target is the cooling water flow rate. In specific implementation, the specific form of the above formula (7) can be determined according to the different absorbents used. It can be a higher-order polynomial, power function, exponential function, fractional function, logarithmic function, or a combination of the above functions.

[0110] Step 402: Control the cooling water flow rate of the second cooler to the second target cooling water flow rate.

[0111] It is understandable that by adopting the above solution, the cooling water consumption of the second cooler can be reduced proportionally, which can reduce costs while ensuring flexible and stable operation and control.

[0112] In the case of a flexible carbon dioxide capture system including a third cooler, such as Figure 7 As shown, the control method provided in this application embodiment may further include steps 501 and 502, as detailed below: Step 501: Calculate the third target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand.

[0113] In this embodiment of the application, the third target cooling water flow rate can be calculated based on the following formula (8): F 第三目标冷却水 =f4(CR 计划 , x CO2实时 ,F CO2需求 (8); In the above formula (8), F 第三目标冷却水 The third target is the cooling water flow rate. In specific implementation, the specific form of the above formula (8) can be determined according to the different absorbents used. It can be a higher-order polynomial, power function, exponential function, fractional function, logarithmic function or a combination of the above functions.

[0114] Step 502: Control the cooling water flow rate of the third cooler to the third target cooling water flow rate.

[0115] It is understandable that by adopting the above solution, the cooling water consumption of the third cooler can be reduced proportionally, thereby reducing costs while ensuring flexible and stable operation and control.

[0116] In the case of a flexible carbon dioxide capture system including a reboiler, such as Figure 8 As shown, the control method provided in this application embodiment may further include steps 601 and 602, as detailed below: Step 601: Calculate the target heating medium flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand.

[0117] In this embodiment of the application, the target heating medium flow rate can be calculated based on the following formula (9): F 目标加热介质 = f5(CR 计划 , x CO2实时 ,F CO2需求 (9); In the above formula (9), F 目标加热介质 The target heating medium flow rate. In specific implementation, the specific form of the above formula (7) can be determined according to the different absorbents used. It can be a higher-order polynomial, power function, exponential function, fractional function, logarithmic function or a combination of the above functions.

[0118] Step 602: Control the flow rate of the heating medium in the reboiler to the target flow rate.

[0119] It is understandable that by adopting the above scheme, the amount of heating medium (such as low-pressure steam) used in the reboiler can be reduced proportionally, which can reduce costs while ensuring flexible and stable operation and control.

[0120] The solutions provided in this application will be described below with reference to specific embodiments. It should be understood that the following embodiments are merely specific implementation methods and do not imply any improper limitation on the solutions of this application.

[0121] The flexible carbon dioxide capture systems corresponding to Examples 1-4 below are: Figure 1 The carbon dioxide flexible capture system shown uses a 30wt% MEA (ethanolamine) solution as the absorbent. The baseline operating conditions and the flexible control range of the operating conditions are shown in Table 1.

[0122] Table 1. Baseline operating condition and flexible control range under operating condition

[0123] Furthermore, the baseline operating conditions are as follows: F 基准烟气=58000 Nm 3 / h, F 基准洗涤水 =150t / h, F 基准冷却水1 =112t / h, baseline carbon dioxide concentration x CO2基准 =12.2%, benchmark carbon dioxide demand F CO2基准 =12.5t / h, CO2 baseline capture rate CR 基准 =F CO2基准 / (F 基准烟气 ×x CO2基准 =0.9, reference rich liquid F 基准富液 = 213.7t / h.

[0124] Example 1 F CO2需求 =20,000 tons / year (2.5t / h), x CO2实时 =8%, CR 计划 =70%.

[0125] 1) For the parts of the carbon dioxide flexible capture system related to scrubbing flue gas: According to calculations, F 目标烟气 =F CO2需求 / (CR 计划 ×x CO2实时 = 22727.2 Nm 3 / h; F 目标洗涤水 =(F 目标烟气 ×F 基准洗涤水 ) / F 基准烟气 =58.77t / h; F 第一目标冷却水 =(F 目标烟气 ×F 基准冷却水1 ) / F 基准烟气 =43.89t / h; Due to F 目标烟气 < F 基准烟气 This corresponds to the first type of operating condition, therefore the following controls are implemented: The flue gas flow rate was adjusted to 22727.2 Nm by regulating the speed of the induced draft fan's frequency converter. 3 / h; control the operation of one of the first and second transfer pumps equipped with a frequency converter, and start the frequency converter; control the flow rate of the started transfer pump in the first and second transfer pumps to be 58.77t / h; control the delivery of washing water to the first nozzle tubular liquid distributor; and control the cooling water flow rate of the first cooler to be 43.89t / h.

[0126] 2) For the parts of the flexible carbon dioxide capture system related to carbon dioxide absorption and desorption: According to calculations, F目标富液 =f1(CR 计划 , x CO2实时 ,F CO2需求 = 46.85 t / h; F 目标贫液 =f2(CR 计划 , x CO2实时 ,F CO2需求 = 44.74 t / h; F 第二目标冷却水 = f3(CR 计划 , x CO2实时 ,F CO2需求 = 29.83 t / h; F 第三目标冷却水 =f4(CR 计划 , x CO2实时 ,F CO2需求 = 60.56 t / h; F 目标加热介质 = f5(CR 计划 , x CO2实时 ,F CO2需求 = 3.61 t / h; Due to F 目标富液 < F 基准富液 This corresponds to the third type of operating condition, therefore the following controls are implemented: The system controls the operation of one of the third and fourth transfer pumps equipped with a frequency converter and starts the frequency converter; controls the flow rate of the started transfer pump among the third and fourth transfer pumps to be 46.85 t / h; controls the delivery of rich liquor to the third nozzle-tube liquid distributor; controls the cooling water flow rate of the second cooler to be 29.83 t / h; controls the operation of one of the fifth and sixth transfer pumps equipped with a frequency converter and starts the frequency converter; controls the flow rate of the started transfer pump among the fifth and sixth transfer pumps to be 44.74 t / h; controls the delivery of lean liquor to the second nozzle-tube liquid distributor; controls the cooling water flow rate of the third cooler to be 60.56 t / h; and controls the flow rate of the low-pressure steam heating medium in the reboiler to be 3.61 t / h.

[0127] Example 2 F CO2需求 =110,000 tons / year (13.75 t / h), x CO2实时 =14%, CR 计划 =95%.

[0128] 1) For the parts of the carbon dioxide flexible capture system related to scrubbing flue gas: According to calculations, F 目标烟气 =F CO2需求 / (CR计划 ×x CO2实时 = 52631.6 Nm 3 / h; F 目标洗涤水 =(F 目标烟气 ×F 基准洗涤水 ) / F 基准烟气 =136t / h; F 第一目标冷却水 =(F 目标烟气 ×F 基准冷却水1 ) / F 基准烟气 =101.63t / h; Due to F 目标烟气 > F 基准烟气 This corresponds to the second type of operating condition, therefore the following controls are implemented: The flue gas flow rate was adjusted to 52631.6 Nm by regulating the speed of the induced draft fan's frequency converter. 3 / h; Control both the first and second delivery pumps to run, without starting the frequency converter; Control the flow rates of both the first and second delivery pumps to be [value missing]. F 目标洗涤水 =68t / h; control the washing water to be delivered to the first tank-type liquid distributor; and control the cooling water flow rate of the first cooler to be 101.63t / h.

[0129] 2) For the parts of the flexible carbon dioxide capture system related to carbon dioxide absorption and desorption: According to calculations, F 目标富液 =f1(CR 计划 , x CO2实时 ,F CO2需求 = 229.5 t / h; F 目标贫液 =f2(CR 计划 , x CO2实时 ,F CO2需求 = 217.44 t / h; F 第二目标冷却水 = f3(CR 计划 , x CO2实时 ,F CO2需求 =154.69t / h; F 第三目标冷却水 =f4(CR 计划 , x CO2实时 ,F CO2需求 = 288.16 t / h; F 目标加热介质 = f5(CR 计划 , x CO2实时 ,F CO2需求=17.7t / h; Due to F 目标富液 > F 基准富液 This corresponds to the fourth type of operating condition, therefore the following controls are implemented: Control both the third and fourth transfer pumps to run without starting the frequency converter; control the flow rates of both the third and fourth transfer pumps to be [missing information]. F 目标富液 =114.75t / h; control the rich liquid delivery to the third tank liquid distributor; control the cooling water flow rate of the second cooler to 154.69t / h; control both the fifth and sixth delivery pumps to run, without starting the frequency converter; control the flow rates of the fifth and sixth delivery pumps to be 114.75t / h. F 目标贫液 =108.72t / h; control the lean liquor delivery to the second tank liquid distributor; control the cooling water flow rate of the third cooler to 288.16t / h; and control the flow rate of the low-pressure steam heating medium of the reboiler to 17.7t / h.

[0130] Example 3 F CO2需求 =19,600 tons / year (2.45 t / h), x CO2实时 =8.84%, CR 计划 =95%.

[0131] 1) For the parts of the carbon dioxide flexible capture system related to scrubbing flue gas: According to calculations, F 目标烟气 =F CO2需求 / (CR 计划 ×x CO2实时 =11600Nm 3 / h; F 目标洗涤水 =(F 目标烟气 ×F 基准洗涤水 ) / F 基准烟气 =30t / h; F 第一目标冷却水 =(F 目标烟气 ×F 基准冷却水1 ) / F 基准烟气 =22.4t / h; Due to F 目标烟气 < F 基准烟气 This corresponds to the first type of operating condition, therefore the following controls are implemented: The flue gas flow rate was adjusted to 11600 Nm by regulating the speed of the induced draft fan inverter. 3 / h; control the operation of one of the first and second transfer pumps equipped with a frequency converter, and start the frequency converter; control the flow rate of the started transfer pump in the first and second transfer pumps to be 30t / h; control the delivery of washing water to the first nozzle tubular liquid distributor; and control the cooling water flow rate of the first cooler to be 22.4t / h.

[0132] 2) For the parts of the flexible carbon dioxide capture system related to carbon dioxide absorption and desorption: According to calculations, F 目标富液 =f1(CR 计划 , x CO2实时 ,F CO2需求 = 44.83 t / h; F 目标贫液 =f2(CR 计划 , x CO2实时 ,F CO2需求 = 42.73 t / h; F 第二目标冷却水 = f3(CR 计划 , x CO2实时 ,F CO2需求 = 28.86 t / h; F 第三目标冷却水 =f4(CR 计划 , x CO2实时 ,F CO2需求 = 57.58 t / h; F 目标加热介质 = f5(CR 计划 , x CO2实时 ,F CO2需求 = 3.64 t / h; Due to F 目标富液 < F 基准富液 This corresponds to the third type of operating condition, therefore the following controls are implemented: The system controls the operation of one of the third and fourth transfer pumps equipped with a frequency converter, and starts the frequency converter; controls the flow rate of the started transfer pump among the third and fourth transfer pumps to be 44.83 t / h; controls the delivery of rich liquor to the third nozzle-tube liquid distributor; controls the cooling water flow rate of the second cooler to be 28.86 t / h; controls the operation of one of the fifth and sixth transfer pumps equipped with a frequency converter, and starts the frequency converter; controls the flow rate of the started transfer pump among the fifth and sixth transfer pumps to be 42.73 t / h; controls the delivery of lean liquor to the second nozzle-tube liquid distributor; controls the cooling water flow rate of the third cooler to be 57.58 t / h; and controls the flow rate of the low-pressure steam heating medium in the reboiler to be 3.64 t / h.

[0133] Example 4 F CO2需求 =106,000 tons / year (13.25 t / h), x CO2实时 =8%, CR 计划 =75%.

[0134] 1) For the parts of the carbon dioxide flexible capture system related to scrubbing flue gas: According to calculations, F 目标烟气 =F CO2需求 / (CR 计划 ×x CO2实时 =64242Nm 3 / h; F 目标洗涤水 =(F 目标烟气 ×F 基准洗涤水 ) / F 基准烟气 =166t / h; F 第一目标冷却水 =(F 目标烟气 ×F 基准冷却水1 ) / F 基准烟气 =124t / h; Due to F 目标烟气 > F 基准烟气 This corresponds to the second type of operating condition, therefore the following controls are implemented: The flue gas flow rate was adjusted to 64242 Nm by adjusting the speed of the induced draft fan inverter. 3 / h; Control both the first and second delivery pumps to run, without starting the frequency converter; Control the flow rates of both the first and second delivery pumps to be [value missing]. F 目标洗涤水 =83t / h; control the washing water to be delivered to the first tank-type liquid distributor; and control the cooling water flow rate of the first cooler to be 124t / h.

[0135] 2) For the parts of the flexible carbon dioxide capture system related to carbon dioxide absorption and desorption: According to calculations, F 目标富液 =f1(CR 计划 , x CO2实时 ,F CO2需求 = 248.5 t / h; F 目标贫液 =f2(CR 计划 , x CO2实时 ,F CO2需求 = 237.2 t / h; F 第二目标冷却水 = f3(CR 计划 , x CO2实时 ,F CO2需求 =158t / h; F 第三目标冷却水 =f4(CR 计划 , x CO2实时 ,F CO2需求 = 320.98 t / h; F 目标加热介质 = f5(CR 计划 , x CO2实时 ,F CO2需求 =19.3t / h; Due to F 目标富液 > F 基准富液 This corresponds to the fourth type of operating condition, therefore the following controls are implemented: Control both the third and fourth transfer pumps to run without starting the frequency converter; control the flow rates of both the third and fourth transfer pumps to be [unspecified]. F 目标富液 =124.25t / h; control the rich liquid delivery to the third tank liquid distributor; control the cooling water flow rate of the second cooler to 158t / h; control both the fifth and sixth delivery pumps to run, without starting the frequency converter; control the flow rates of the fifth and sixth delivery pumps to be... F 目标贫液 =118.6t / h; control the lean liquor delivery to the second tank liquid distributor; control the cooling water flow rate of the third cooler to 320.98t / h; and control the low-pressure steam heating medium flow rate of the reboiler to 19.3t / h.

[0136] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0137] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A flexible carbon dioxide capture system, characterized in that, The flexible carbon dioxide capture system includes a scrubbing tower, a first trough-type liquid distributor, a first nozzle-tube type liquid distributor, a first pumping unit, an absorption tower, a second trough-type liquid distributor, a second nozzle-tube type liquid distributor, a second pumping unit, a heat exchanger, a regeneration tower, a third trough-type liquid distributor, a third nozzle-tube type liquid distributor, and a third pumping unit. The first trough-type liquid distributor and the first nozzle-tube type liquid distributor are located at the top of the scrubbing tower, with the first trough-type liquid distributor positioned above the first nozzle-tube type liquid distributor. The scrubbing water outlet of the scrubbing tower is connected to the inlet of the first pumping unit, and the outlet of the first pumping unit is connected to the liquid inlets of the first trough-type liquid distributor and the first nozzle-tube type liquid distributor, respectively. The flue gas outlet of the scrubbing tower is connected to the flue gas inlet of the absorption tower. The second trough-type liquid distributor and the second nozzle-tube type liquid distributor... A liquid distributor is installed at the top of the absorption tower, with the second trough-type liquid distributor located above the second nozzle-type liquid distributor. The third trough-type liquid distributor and the third nozzle-type liquid distributor are installed at the top of the regeneration tower, with the third trough-type liquid distributor located above the third nozzle-type liquid distributor. The rich liquid outlet of the absorption tower is connected to the inlet of the second pumping unit, the outlet of the second pumping unit is connected to the rich liquid inlet of the heat exchanger, and the rich liquid outlet of the heat exchanger is connected to the liquid inlets of the third trough-type liquid distributor and the third nozzle-type liquid distributor, respectively. The first lean liquid outlet of the regeneration tower is connected to the inlet of the third pumping unit, the outlet of the third pumping unit is connected to the lean liquid inlet of the heat exchanger, and the lean liquid outlet of the heat exchanger is connected to the liquid inlets of the second trough-type liquid distributor and the second nozzle-type liquid distributor, respectively.

2. The flexible carbon dioxide capture system according to claim 1, characterized in that, The maximum value of the liquid distribution flow range of the first trough liquid distributor is greater than the maximum value of the liquid distribution flow range of the first nozzle tube liquid distributor, and the minimum value of the liquid distribution flow range of the first trough liquid distributor is greater than the minimum value of the liquid distribution flow range of the first nozzle tube liquid distributor. The maximum value of the liquid distribution flow range of the second trough liquid distributor is greater than the maximum value of the liquid distribution flow range of the second nozzle pipe liquid distributor, and the minimum value of the liquid distribution flow range of the second trough liquid distributor is greater than the minimum value of the liquid distribution flow range of the second nozzle pipe liquid distributor. The maximum value of the liquid distribution flow range of the third trough liquid distributor is greater than the maximum value of the liquid distribution flow range of the third nozzle tube liquid distributor, and the minimum value of the liquid distribution flow range of the third trough liquid distributor is greater than the minimum value of the liquid distribution flow range of the third nozzle tube liquid distributor.

3. The flexible carbon dioxide capture system according to claim 1, characterized in that, When the carbon dioxide flexible capture system is running, only one of the first trough liquid distributor and the first nozzle pipe liquid distributor is operating, only one of the second trough liquid distributor and the second nozzle pipe liquid distributor is operating, and only one of the third trough liquid distributor and the third nozzle pipe liquid distributor is operating.

4. The flexible carbon dioxide capture system according to claim 1, characterized in that, The first pumping unit includes a first delivery pump and a second delivery pump, which are connected in parallel; the second pumping unit includes a third delivery pump and a fourth delivery pump, which are connected in parallel; the third pumping unit includes a fifth delivery pump and a sixth delivery pump, which are connected in parallel.

5. The flexible carbon dioxide capture system according to claim 4, characterized in that, One of the first and second delivery pumps is equipped with a frequency converter; one of the third and fourth delivery pumps is equipped with a frequency converter; and one of the fifth and sixth delivery pumps is equipped with a frequency converter.

6. The flexible carbon dioxide capture system according to claim 4, characterized in that, The flexible carbon dioxide capture system also includes a first cooler: the outlets of the first delivery pump and the second delivery pump are both connected to the wash water inlet of the first cooler, and the wash water outlet of the first cooler is connected to the liquid distribution inlet of the first tank-type liquid distributor and the first nozzle-type liquid distributor, respectively.

7. The flexible carbon dioxide capture system according to claim 1, characterized in that, The flexible carbon dioxide capture system also includes a second cooler; the lean liquid outlet of the heat exchanger is connected to the lean liquid inlet of the second cooler, and the lean liquid outlet of the second cooler is connected to the liquid inlet of the second trough liquid distributor and the liquid distribution inlet of the second nozzle tube liquid distributor, respectively.

8. The flexible carbon dioxide capture system according to claim 1, characterized in that, The flexible carbon dioxide capture system also includes a third cooler and a separator; the carbon dioxide outlet of the regeneration tower is connected to the carbon dioxide inlet of the third cooler, the carbon dioxide outlet of the third cooler is connected to the carbon dioxide inlet of the separator, and the condensate outlet of the separator is connected to the condensate inlet of the regeneration tower.

9. The flexible carbon dioxide capture system according to claim 1, characterized in that, The flexible carbon dioxide capture system also includes a reboiler; the second lean liquid outlet of the regeneration tower is connected to the lean liquid inlet of the reboiler, and the lean liquid outlet of the reboiler is connected to the lean liquid inlet of the regeneration tower.

10. A control method for a flexible carbon dioxide capture system according to any one of claims 1-9, characterized in that, The control method includes: calculating the target flue gas flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand. Based on the target flue gas flow rate, the reference flue gas flow rate, and the reference washing water flow rate, the target washing water flow rate is calculated; the real-time flue gas flow rate is adjusted to the target flue gas flow rate, and the washing water flow rate of the first pumping unit is controlled to the target washing water flow rate. When the target flue gas flow rate is greater than half of the reference flue gas flow rate, the washing water output by the first pumping unit is delivered to the first tank-type liquid distributor. When the target flue gas flow rate is less than or equal to half of the reference flue gas flow rate, the washing water output by the first pumping unit is delivered to the first nozzle-type liquid distributor.

11. The control method according to claim 10, characterized in that, The first pumping unit includes a first delivery pump and a second delivery pump; the step of delivering the washing water output from the first pumping unit to the first tank-type liquid distributor includes: controlling both the first delivery pump and the second delivery pump to operate, so as to deliver the washing water to the first tank-type liquid distributor; the step of delivering the washing water output from the first pumping unit to the first nozzle-type liquid distributor includes: controlling one of the first delivery pump and the second delivery pump to operate, so as to deliver the washing water to the first nozzle-type liquid distributor.

12. The control method according to claim 11, characterized in that, One of the first and second delivery pumps is equipped with a frequency converter; controlling both the first and second delivery pumps to operate includes: controlling both the first and second delivery pumps to operate, and controlling the frequency converter not to start; controlling one of the first and second delivery pumps to operate includes: controlling the one of the first and second delivery pumps equipped with a frequency converter to operate, and controlling the frequency converter to start.

13. The control method according to claim 11, characterized in that, The flexible carbon dioxide capture system further includes a first cooler. The outlets of the first delivery pump and the second delivery pump are both connected to the wash water inlet of the first cooler. The wash water outlet of the first cooler is connected to the liquid distribution inlet of the first tank-type liquid distributor and the first nozzle-type liquid distributor, respectively. After calculating the target flue gas flow rate based on the real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand, the control method further includes: calculating a first target cooling water flow rate based on the target flue gas flow rate, the reference flue gas flow rate, and the reference cooling water flow rate of the first cooler; and controlling the cooling water flow rate of the first cooler to the first target cooling water flow rate.

14. A control method for a flexible carbon dioxide capture system according to any one of claims 1-9, characterized in that, The control method includes: calculating the target rich liquid flow rate and the target lean liquid flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate and real-time carbon dioxide demand. The rich liquid flow rate of the second pumping unit is adjusted to the target rich liquid flow rate, and the lean liquid flow rate of the third pumping unit is adjusted to the target lean liquid flow rate. When the target rich liquid flow rate is greater than half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third tank-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second tank-type liquid distributor. When the target rich liquid flow rate is less than or equal to half of the reference rich liquid flow rate, the rich liquid output from the second pumping unit is delivered to the third nozzle-type liquid distributor, and the lean liquid output from the third pumping unit is delivered to the second nozzle-type liquid distributor. The carbon dioxide content in the rich liquid is higher than the carbon dioxide content in the lean liquid.

15. The control method according to claim 14, characterized in that, The second pumping unit includes a third transfer pump and a fourth transfer pump, and the third pumping unit includes a fifth transfer pump and a sixth transfer pump; the step of transporting the rich liquid output from the second pumping unit to the third tank-type liquid distributor and the lean liquid output from the third pumping unit to the second tank-type liquid distributor includes: controlling both the third and fourth transfer pumps to operate to transport the rich liquid to the third tank-type liquid distributor, and controlling both the fifth and sixth transfer pumps to operate to transport the lean liquid to the second tank-type liquid distributor; The process of delivering the rich liquid output from the second pumping unit to the third nozzle-tube liquid distributor and delivering the lean liquid output from the third pumping unit to the second nozzle-tube liquid distributor includes: controlling one of the third and fourth delivery pumps to operate to deliver the rich liquid to the third nozzle-tube liquid distributor, and controlling one of the fifth and sixth delivery pumps to operate to deliver the lean liquid to the second nozzle-tube liquid distributor.

16. The control method according to claim 15, characterized in that, One of the third and fourth delivery pumps is equipped with a frequency converter, and one of the fifth and sixth delivery pumps is equipped with a frequency converter; controlling the operation of both the third and fourth delivery pumps includes: controlling both the third and fourth delivery pumps to operate while preventing the frequency converter from starting; controlling the operation of both the fifth and sixth delivery pumps includes: controlling both the fifth and sixth delivery pumps to operate while preventing the frequency converter from starting; controlling the operation of one of the third and fourth delivery pumps includes: controlling the operation of the one equipped with a frequency converter and starting the frequency converter; controlling the operation of one of the fifth and sixth delivery pumps includes: controlling the operation of the one equipped with a frequency converter and starting the frequency converter.

17. The control method according to claim 14, characterized in that, The flexible carbon dioxide capture system further includes a second cooler, wherein the lean liquid outlet of the heat exchanger is connected to the lean liquid inlet of the second cooler, and the lean liquid outlet of the second cooler is connected to the liquid inlet to be distributed of the second trough-type liquid distributor and the second nozzle-type liquid distributor, respectively; the control method further includes: calculating a second target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand; and controlling the cooling water flow rate of the second cooler to the second target cooling water flow rate.

18. The control method according to claim 14, characterized in that, The flexible carbon dioxide capture system further includes a third cooler and a separator. The carbon dioxide outlet of the regeneration tower is connected to the carbon dioxide inlet of the third cooler, the carbon dioxide outlet of the third cooler is connected to the carbon dioxide inlet of the separator, and the condensate outlet of the separator is connected to the condensate inlet of the regeneration tower. The control method further includes: calculating a third target cooling water flow rate based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand; and controlling the cooling water flow rate of the third cooler to the third target cooling water flow rate.

19. The control method according to claim 14, characterized in that, The flexible carbon dioxide capture system further includes a reboiler, wherein the second lean liquor outlet of the regeneration tower is connected to the lean liquor inlet of the reboiler, and the lean liquor outlet of the reboiler is connected to the lean liquor inlet of the regeneration tower; the control method further includes: Based on real-time flue gas flow rate, real-time carbon dioxide concentration, planned carbon dioxide capture rate, and real-time carbon dioxide demand, the target heating medium flow rate is calculated; and the heating medium flow rate of the reboiler is controlled to the target heating medium flow rate.

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