Ocean thermal power generation and carbon capture coupling system

Abstract

The present application relates to the technical field of ocean energy exploitation, and provides a marine temperature difference power generation and carbon capture coupling system, which adopts a water-based carbon capture method, utilizes the low-temperature and high-pressure environment characteristics at a preset depth in the ocean, carries out two-stage carbon capture on industrial flue gas by using the water on the ground, improves the CO2 absorption effect, can obtain high-concentration CO2 gas, and is easy to obtain, low in cost, simple in technology, and friendly to the environment. In addition, the system fully utilizes the cold energy at the preset depth in the ocean, introduces ORC, outputs power under low energy consumption, couples the marine temperature difference power generation and carbon capture processes, achieves the purpose of single system double benefits of outputting power and reducing the influence of the greenhouse effect at the same time, and makes the system more applicable. Compared with the prior art, the energy consumption and operation and maintenance cost of the system are greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of marine energy extraction technology, and in particular to a coupled system for ocean thermal energy conversion and carbon capture. Background Technology

[0002] Currently, carbon capture technologies mainly include chemical absorption technology and physical adsorption technology. Chemical absorption technology usually uses chemical absorbents with amine solvents as the main component. It generally suffers from problems such as high regeneration heat load, high treatment costs due to solvent volatilization and degradation, and complex equipment corrosion and environmental emission control, resulting in high operating costs.

[0003] Physical adsorption technology is mainly a water-based carbon capture method. It has advantages such as being environmentally friendly, having low solvent costs, and being highly resistant to degradation. However, it has a relatively weak capacity to absorb carbon dioxide and its capture energy consumption is relatively high.

[0004] It is evident that existing chemical absorption and physical adsorption technologies are generally constrained by bottlenecks such as high regeneration energy consumption, complex corrosion and solvent management, and strong dependence on onshore cooling resources. As a result, when achieving large-scale emission reduction in the context of continuous industrial flue gas emissions, it is difficult to reduce energy consumption and operation and maintenance costs. Summary of the Invention

[0005] This invention provides a coupled system for ocean thermal energy conversion and carbon capture to address the shortcomings of existing technologies.

[0006] The present invention provides a coupled system for ocean thermal energy conversion and carbon capture, comprising: a first pretreatment device, a second pretreatment device, a power generation device and a second capture device located on land, and a first capture device and a third capture device located at a predetermined depth in the ocean.

[0007] The first collection device is connected to the first pretreatment device, the power generation device, and the second collection device respectively; the second pretreatment device is connected to the second collection device, the power generation device, and the third collection device respectively, and the third collection device is connected to the second collection device.

[0008] The first pretreatment device is used to pressurize the incoming industrial flue gas to the target pressure; the first collection device is used to absorb CO2 gas in the industrial flue gas using surface water to obtain a first CO2 aqueous solution and a first residual gas, and the first CO2 aqueous solution is connected to the second collection device, and the first residual gas is connected to the power generation device.

[0009] The second collection device is used to exchange heat between the incoming CO2 aqueous solution and the organic Rankine cycle working fluid, and to separate CO2 gas containing impurities.

[0010] The second pretreatment device is used to pressurize the CO2 gas containing impurities to the target pressure to obtain compressed high-temperature CO2 gas; the third collection device is used to absorb the CO2 gas to obtain a second CO2 aqueous solution and a second residual gas, and to connect the second CO2 aqueous solution to the second collection device to purify the compressed high-temperature CO2 gas to obtain high-purity CO2 gas. The second residual gas is mixed with the first residual gas and then connected to the power generation device; the power generation device is used to generate electricity based on the connected residual gas.

[0011] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the second capture device is connected to the first capture device and the third capture device respectively;

[0012] The second collection device is also used to separate the remaining aqueous solution and connect the remaining aqueous solution to the first collection device and the third collection device respectively;

[0013] The surface water accessed by the first collection device includes the accessed residual aqueous solution and the surface water injected, and the surface water accessed by the third collection device includes the accessed residual aqueous solution and the surface water injected.

[0014] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the second capture device includes a first water pump, a multi-stream heat exchanger, a first gas-liquid separator, a second gas-liquid separator, a first heat exchanger, and a CO2 storage tank, wherein the multi-stream heat exchanger serves as a condenser within an organic Rankine cycle assembly; and the first heat exchanger is connected between the second water pump and the turbine within the organic Rankine cycle assembly.

[0015] The first pretreatment device is connected to the first heat exchanger via the first water pump; the first pretreatment device is connected to the first collection device via the first heat exchanger.

[0016] The multi-stream heat exchanger is connected to the second pretreatment device and the first collection device through the first gas-liquid separator, and is connected to the CO2 storage tank and the third collection device through the second gas-liquid separator.

[0017] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the first capture device includes a first underwater absorption tower and a first buffer airbag;

[0018] The side of the first underwater absorption tower is connected to the bottom of the first gas-liquid separator and the first heat exchanger, respectively;

[0019] The top of the first underwater absorption tower is connected to the power generation device through the first buffer airbag;

[0020] The bottom of the first underwater absorption tower is connected to the multi-stream heat exchanger.

[0021] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the third capture device includes a second underwater absorption tower and a second buffer airbag;

[0022] The side of the second underwater absorption tower is connected to the bottom of the second gas-liquid separator and the second pretreatment device, respectively;

[0023] The top of the second underwater absorption tower is connected to the second pretreatment device through the second buffer airbag;

[0024] The bottom of the second underwater absorption tower is connected to the multi-stream heat exchanger.

[0025] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the second pretreatment device includes a first compressor assembly;

[0026] The first compressor assembly includes a first compressor, a second heat exchanger, a second compressor, and a third heat exchanger connected in sequence;

[0027] The first compressor is connected to the second collection device; the first compressor and the second compressor are used to pressurize the CO2 gas containing impurities to the target pressure to obtain the compressed high-temperature CO2 gas;

[0028] The second heat exchanger is used to cool the compressed high-temperature CO2 gas;

[0029] The third heat exchanger is connected to the power generation device and the third collection device respectively, and is used to exchange heat between the compressed high-temperature CO2 gas and the second residual gas.

[0030] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the first pretreatment device includes a cooling and drying component and a second compressor component, and the cooling and drying component and the second compressor component are connected in communication;

[0031] The cooling and drying assembly is used to cool and dry the industrial flue gas.

[0032] The second compressor assembly includes a third compressor, a fourth heat exchanger, a fourth compressor, a fifth heat exchanger, a fifth compressor, a sixth heat exchanger, a sixth compressor, and a seventh heat exchanger connected in sequence, and the fourth heat exchanger, the fifth heat exchanger, the sixth heat exchanger, and the seventh heat exchanger are all connected to the power generation device through a cold storage tank and a hot storage tank, respectively.

[0033] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the power generation device comprises an eighth heat exchanger, a first expander, a ninth heat exchanger, a second expander, a tenth heat exchanger, a third expander, an eleventh heat exchanger and a fourth expander connected in sequence.

[0034] The eighth heat exchanger, the ninth heat exchanger, the tenth heat exchanger, and the eleventh heat exchanger are all connected to the cold storage tank and the hot storage tank, respectively.

[0035] The eighth heat exchanger is connected to both the first collection device and the second pretreatment device.

[0036] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the first capture device further includes a third buffer airbag, a fourth buffer airbag and a fifth buffer airbag.

[0037] The third, fourth, and fifth buffer airbags are all connected to the bottom of the first underwater absorption tower to stabilize the system pressure.

[0038] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture is provided, wherein the third capture device further includes a sixth buffer airbag, a seventh buffer airbag and an eighth buffer airbag.

[0039] The sixth, seventh, and eighth buffer airbags are all connected to the bottom of the second underwater absorption tower to stabilize the system pressure.

[0040] According to the present invention, a coupled system for ocean thermal energy conversion and carbon capture further includes a first mixer, a second mixer, and a third mixer;

[0041] Both the first collection device and the second pretreatment device are connected to the power generation device through the first mixer;

[0042] The second collection device is connected to the first collection device through the second mixer, and is also connected to the third collection device through the third mixer;

[0043] The second and third mixers are also used to access surface water.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The ocean thermal energy conversion and carbon capture (OTEC) coupling system provided by this invention employs a water-based carbon capture method. Utilizing the low-temperature, high-pressure environment at a predetermined depth in the ocean, it uses surface water to perform two-stage carbon capture of industrial flue gas, improving CO2 absorption efficiency and yielding high-concentration CO2 gas. Furthermore, the absorbent is readily available, low-cost, technically simple, and environmentally friendly. In addition, the system fully utilizes the cold energy at the predetermined depth in the ocean, introducing ORC (Ocean Thermal Energy Conversion) to output electricity with low energy consumption. This couples OTEC with the carbon capture process, achieving a dual benefit of power output while reducing the greenhouse effect, making the system more valuable. Compared to existing technologies, this system significantly reduces energy consumption and operation and maintenance costs. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on the drawings described below without creative effort.

[0047] Figure 1 This is one of the structural schematic diagrams of the ocean thermal energy conversion and carbon capture coupling system provided by the present invention;

[0048] Figure 2 This is the second schematic diagram of the coupled ocean thermal energy conversion and carbon capture system provided by the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 100-First pretreatment device; 200-Second pretreatment device; 300-Power generation device; 400-Second collection device; 500-First collection device; 600-Third collection device; 1-Heat exchanger; 2-Third gas-liquid separator; 3-Second engine; 4-Third compressor; 5-Fourth heat exchanger; 6-Fourth compressor; 7-Fifth heat exchanger; 8-Fifth compressor; 9-Sixth heat exchanger; 10-Sixth compressor; 11-Seventh heat exchanger; 12-Cold storage tank; 13-Eighth heat exchanger; 14-First expander; 15-Ninth heat exchanger; 16-Second expander; 17-Tenth heat exchanger; 18-Third expander; 19-Eleventh heat exchanger; 20-Fourth expander; 21-Heat storage tank; 22-Generator; 23-First water... 24-Lower absorption tower; 25-First buffer airbag; 26-First mixer; 27-Third buffer airbag; 28-Five buffer airbag; 29-Third water pump; 30-Multi-stream heat exchanger; 31-First gas-liquid separator; 32-Second mixer; 33-First engine; 34-First compressor; 35-Second heat exchanger; 36-Second compressor; 37-Third heat exchanger; 38-Second underwater absorption tower; 39-Second buffer airbag; 40-Fourth water pump; 41-Sixth buffer airbag; 42-Seventh buffer airbag; 43-Eighth buffer airbag; 44-First heat exchanger; 45-Turbine; 46-Second water pump; 47-Second gas-liquid separator; 48-CO2 storage tank; 49-Third mixer; 50-First water pump. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] Figure 1 This is a schematic diagram of a coupled ocean thermal energy conversion and carbon capture system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the ocean thermal energy conversion and carbon capture coupling system includes: a first pretreatment device 100, a second pretreatment device 200, a power generation device 300 and a second capture device 400 located on land, and a first capture device 500 and a third capture device 600 located at a predetermined depth in the ocean.

[0053] The first collection device 500 is connected to the first pretreatment device 100, the power generation device 300 and the second collection device 400 respectively; the second pretreatment device 200 is connected to the second collection device 400, the power generation device 300 and the third collection device 600 respectively, and the third collection device 600 is connected to the second collection device 400.

[0054] The first pretreatment device 100 is used to pressurize the incoming industrial flue gas to the target pressure; the first collection device 500 is used to absorb CO2 gas in the industrial flue gas using groundwater to obtain a first CO2 aqueous solution and a first residual gas, and the first CO2 aqueous solution is connected to the second collection device 400, and the first residual gas is connected to the power generation device 300.

[0055] The second collection device 400 is used to exchange heat between the incoming CO2 aqueous solution and the working fluid of the Organic Rankine Cycle (ORC) and separate CO2 gas containing impurities.

[0056] The second pretreatment device 200 is used to pressurize the CO2 gas containing impurities to the target pressure to obtain compressed high-temperature CO2 gas; the third collection device 600 is used to absorb the CO2 gas in the compressed high-temperature CO2 gas to obtain a second CO2 aqueous solution and a second residual gas, and to connect the second CO2 aqueous solution to the second collection device 400 to purify the CO2 gas to obtain high-purity CO2 gas, and to connect the second residual gas and the first residual gas to the power generation device 300;

[0057] The power generation device 300 is used to generate electricity based on the incoming residual gas.

[0058] Specifically, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention may include a primary absorption system, a secondary absorption system, and a power generation device; the primary absorption system includes a first pretreatment device, a first capture device, and a second capture device, and the secondary absorption system includes a second pretreatment device and a third capture device. Both the primary and secondary absorption systems can connect the obtained residual gas to the power generation device for power generation.

[0059] The preset depth can be around 1 km. At the preset depth, the typical seawater temperature and hydrostatic pressure are 4℃ and 10 MPa, respectively.

[0060] The industrial flue gas fed into the first pretreatment unit mainly includes H2O, CO2, N2, O2, etc., with a temperature and pressure of approximately 303.15K and 2.5bar, respectively.

[0061] The first pretreatment device is used to pressurize the industrial flue gas to a target pressure. The target pressure is used to ensure that the industrial flue gas has pressure conditions that match the external ocean pressure when it reaches the first capture device. That is, the industrial flue gas at the target pressure is transmitted through the pipeline between the first pretreatment device and the first capture device. After overcoming the resistance along the way, when it reaches the first capture device, its pressure is equivalent to the ocean static pressure at a preset depth.

[0062] The first pretreatment unit is connected to the first collection unit. Industrial flue gas at the target pressure is transmitted to the first collection unit via a pipeline between the two units. The first collection unit mixes the industrial flue gas with incoming surface water and uses the surface water to absorb the CO2 gas in the industrial flue gas, obtaining a first CO2 aqueous solution and a first residual gas. The first CO2 aqueous solution is connected to a second collection unit for CO2 gas separation, and the first residual gas is connected to a power generation unit for power generation.

[0063] Understandably, at a predetermined depth, the surface water accessed by the first capture device has the same pressure and temperature as the seawater at that location. According to Henry's Law, low temperature and high pressure conditions facilitate the capture of water-based carbon. Therefore, the first capture device can achieve efficient physical absorption of CO2 from industrial flue gas, yielding a CO2-rich first aqueous solution and a first residual gas. The first residual gas may include unabsorbed O2, N2, and a small amount of undissolved CO2 from the industrial flue gas, as well as other high-pressure gases.

[0064] The second capture device is connected to the first capture device. The second capture device exchanges heat between the incoming CO2 aqueous solution and the ORC working fluid. By absorbing the heat released from the condensation of the ORC working fluid and fully exchanging heat with the surface warm seawater, it separates the CO2 gas containing impurities from the CO2 aqueous solution and uses the ORC to generate electricity. The CO2 aqueous solution entering the second capture device may include the first CO2 aqueous solution obtained from the first capture device and the second CO2 aqueous solution obtained from the third capture device.

[0065] The second pretreatment device pressurizes the CO2 gas containing impurities to a target pressure, obtaining compressed high-temperature CO2 gas. This compressed high-temperature CO2 gas is then connected to a third collection device. The third collection device mixes the compressed high-temperature CO2 gas with surface water to absorb the CO2 in the compressed high-temperature CO2 gas, resulting in a second CO2 aqueous solution and a second residual gas. This second CO2 aqueous solution is then connected to the second collection device to purify the impurity CO2 gas, obtaining high-purity CO2 gas. The second residual gas can be mixed with the first residual gas and then connected to a power generation device for power generation.

[0066] The power generation device is connected to the first collection device and the second pretreatment device respectively. The power generation device can be connected to the remaining gas and use the remaining gas to generate electricity by expanding it with an expander.

[0067] The ocean thermal energy conversion and carbon capture (OTEC) coupling system provided in this embodiment of the invention employs a water-based carbon capture method. Utilizing the low-temperature, high-pressure environment at a predetermined depth in the ocean, it uses surface water to perform two-stage carbon capture of industrial flue gas, improving CO2 absorption efficiency and yielding high-concentration CO2 gas. Furthermore, the absorbent is readily available, low-cost, technically simple, and environmentally friendly. In addition, the system fully utilizes the cold energy at the predetermined depth in the ocean, introducing ORC (Ocean Thermal Energy Conversion) to output electricity with low energy consumption. This couples OTEC with the carbon capture process, achieving a dual benefit of power output while reducing the greenhouse effect, making the system more valuable. Compared to existing technologies, this system significantly reduces energy consumption and operation and maintenance costs.

[0068] Based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention has the second capture device 400 connected to the first capture device 500 and the third capture device 600 respectively.

[0069] The second collection device 400 is also used to separate the remaining aqueous solution and connect the remaining aqueous solution to the first collection device 500 and the third collection device 600 respectively;

[0070] The surface water accessed by the first collection device 500 includes the accessed residual aqueous solution and the surface water injected, and the surface water accessed by the third collection device 600 includes the accessed residual aqueous solution and the surface water injected, which can realize the full utilization of the residual aqueous solution.

[0071] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes a second capture device 400 comprising a first water pump 50, a multi-stream heat exchanger 30, a first gas-liquid separator 31, a second gas-liquid separator 47, a first heat exchanger 44, and a CO2 storage tank 48. The multi-stream heat exchanger 30 serves as a condenser within an organic Rankine cycle assembly. The first heat exchanger 44 is connected between the second water pump 46 and the turbine 45 within the organic Rankine cycle assembly.

[0072] The first pretreatment device 100 is connected to the first heat exchanger 44 via the first water pump 50; the first pretreatment device 100 is connected to the first collection device 500 via the first heat exchanger 44.

[0073] The multi-stream heat exchanger 30 is connected to the second pretreatment device 200 and the first collection device 500 through the first gas-liquid separator 31, and is connected to the CO2 storage tank 48 and the third collection device 600 through the second gas-liquid separator 47.

[0074] Specifically, the first water pump can draw industrial flue gas at the target pressure obtained from the first pretreatment device to the first heat exchanger, which acts as a regenerator within the organic Rankine cycle assembly, providing heat for the Rankine cycle.

[0075] By using a multi-stream heat exchanger, CO2 gas can be effectively separated from the CO2 aqueous solution in the first and third collection devices and used for power generation.

[0076] It should be noted that, in order to ensure that the cold energy is effectively delivered to the shore, insulation measures are required for the cold water entering the multi-stream heat exchanger.

[0077] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes a first underwater absorption tower 23 and a first buffer airbag 24 in the first capture device 500.

[0078] The side of the first underwater absorption tower 23 is connected to the bottom of the first gas-liquid separator 31 and the first heat exchanger 44, respectively.

[0079] The top of the first underwater absorption tower 23 is connected to the power generation device 300 through the first buffer airbag 24;

[0080] The bottom of the first underwater absorption tower 23 is connected to the multi-stream heat exchanger 30 via a third water pump 29.

[0081] Specifically, the first underwater absorption tower can be connected to the first pretreatment device through the first heat exchanger, and the industrial flue gas at the target pressure after undergoing reverse heat exchange through the first heat exchanger can be connected to it.

[0082] The first underwater absorption tower can also be connected to the remaining aqueous solution obtained from the first gas-liquid separator and the surface water, i.e., surface water.

[0083] The first underwater absorption tower uses the incoming surface water to capture carbon and separates it into a first CO2 aqueous solution and a first residual gas.

[0084] The first CO2 aqueous solution is fed into the second collection device to obtain CO2 gas.

[0085] The first residual gas is sequentially pressure-stabilized by the first underwater absorption tower and the first buffer gasbag before being output and then enters the power generation device to expand and generate electricity.

[0086] In this embodiment of the invention, the physical properties are fully utilized, and the low temperature and high pressure characteristics of the deep sea are cleverly utilized, so that the surface water at a predetermined depth in the ocean can fully absorb CO2 gas.

[0087] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes a third capture device 600 comprising a second underwater absorption tower 38 and a second buffer airbag 39.

[0088] The side of the second underwater absorption tower 38 is connected to the bottom of the second gas-liquid separator 47 and the second pretreatment device 200, respectively.

[0089] The top of the second underwater absorption tower 38 is connected to the second pretreatment device 200 through the second buffer airbag 39;

[0090] The bottom of the second underwater absorption tower 38 is connected to the multi-stream heat exchanger 30 via the fourth water pump 40.

[0091] Specifically, the second underwater absorption tower can be connected to the CO2 gas obtained from the second pretreatment device, as well as the residual aqueous solution obtained from the second gas-liquid separator and the surface water, i.e., surface water.

[0092] The second underwater absorption tower captures carbon from the incoming surface water and separates it into a second CO2 aqueous solution and a second residual gas.

[0093] The second CO2 aqueous solution is fed into the second collection device to obtain high-purity CO2 gas.

[0094] The second residual gas is successively pressure-stabilized by the second underwater absorption tower and the second buffer gasbag before being output and entering the power generation device to expand and generate electricity.

[0095] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes a second pretreatment device 200 comprising a first compressor assembly; the first compressor assembly comprises a first compressor 34, a second heat exchanger 35, a second compressor 36 and a third heat exchanger 37 connected in sequence.

[0096] The first compressor 34 is connected to the second collection device 400, specifically to the first gas-liquid separator 31 in the second collection device 400; the first compressor 34 and the second compressor 36 are used to pressurize the CO2 gas containing impurities to the target pressure to obtain the compressed high-temperature CO2 gas;

[0097] The second heat exchanger 35 is used to cool the compressed high-temperature CO2 gas;

[0098] The third heat exchanger 37 is connected to the power generation device 300 and the third collection device 600 respectively. Specifically, it is connected to the eighth heat exchanger 13 in the power generation device 300 and the side of the second underwater absorption tower 38 in the third collection device 600, and is used to exchange heat between the compressed high-temperature CO2 gas and the second residual gas.

[0099] Specifically, the first compressor 34 can be connected to the first engine 33, and both the first compressor 34 and the second compressor 36 are driven by the first engine 33.

[0100] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes a first pretreatment device comprising a cooling and drying component and a second compressor component, wherein the cooling and drying component and the second compressor component are connected.

[0101] The cooling and drying assembly is used to cool and dry the industrial flue gas.

[0102] The second compressor assembly includes a third compressor 4, a fourth heat exchanger 5, a fourth compressor 6, a fifth heat exchanger 7, a fifth compressor 8, a sixth heat exchanger 9, a sixth compressor 10, and a seventh heat exchanger 11 connected in sequence. The fourth heat exchanger 5, the fifth heat exchanger 7, the sixth heat exchanger 9, and the seventh heat exchanger 11 are all connected to the power generation device 300 through a cold storage tank 12 and a heat storage tank 21, respectively.

[0103] Specifically, the cooling and drying assembly includes a heat exchanger 1 and a third gas-liquid separator 2. The top of the third gas-liquid separator 2 is connected to the second compressor assembly, specifically to the third compressor 4 in the second compressor assembly.

[0104] The third compressor 4 can be connected to the second engine 3. The third compressor 4, the fourth compressor 6, the fifth compressor 8 and the sixth compressor 10 are all driven by the second engine 3.

[0105] The third compressor 4, the fourth compressor 6, the fifth compressor 8, and the sixth compressor 10 can achieve multi-stage compression of industrial flue gas.

[0106] The fourth heat exchanger 5, the fifth heat exchanger 7, the sixth heat exchanger 9, and the seventh heat exchanger 11 can cool the industrial flue gas by exchanging heat with the heat transfer oil in a counter-current manner.

[0107] Cold storage tank 12 is used to store the cold energy of the heat transfer oil, and heat storage tank 21 is used to store the heat energy of the heat transfer oil.

[0108] like Figure 2As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention includes an eighth heat exchanger 13, a first expander 14, a ninth heat exchanger 15, a second expander 16, a tenth heat exchanger 17, a third expander 18, an eleventh heat exchanger 19 and a fourth expander 20 connected in sequence.

[0109] The eighth heat exchanger 13, the ninth heat exchanger 15, the tenth heat exchanger 17 and the eleventh heat exchanger 19 are all connected to the cold storage tank 12 and the heat storage tank 21, respectively.

[0110] The eighth heat exchanger 13 is connected to the first collection device 500 and the second pretreatment device 200, respectively, and specifically connected to the first buffer airbag 24 in the first collection device 500 and the third heat exchanger 37 in the second pretreatment device 200.

[0111] The first expander 14 is connected to the generator 22, and the generator 22 is driven by the first expander 14, the second expander 16, the third expander 18 and the fourth expander 20.

[0112] In this embodiment of the invention, an energy cascade path with multi-stage compression-interstage heat exchange-waste heat reuse and high-pressure residual gas expansion recovery as the core maximizes the usable work contained in the pressure and temperature difference, and reduces the energy consumption of capture.

[0113] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention further includes a third buffer airbag 26, a fourth buffer airbag 27 and a fifth buffer airbag 28 in the first capture device 500.

[0114] The third buffer airbag 26, the fourth buffer airbag 27 and the fifth buffer airbag 28 are all connected to the bottom of the first underwater absorption tower 23 to stabilize the system pressure.

[0115] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention further includes a sixth buffer airbag 41, a seventh buffer airbag 42 and an eighth buffer airbag 43 in the third capture device 600.

[0116] The sixth buffer airbag 41, the seventh buffer airbag 42 and the eighth buffer airbag 43 are all connected to the bottom of the second underwater absorption tower 38 to stabilize the system pressure.

[0117] In this embodiment of the invention, each buffer airbag is made of flexible material and expands / contracts with changes in flow rate to keep the internal pressure consistent with the external deep-sea pressure.

[0118] like Figure 2 As shown, based on the above embodiments, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention further includes a first mixer 25, a second mixer 32 and a third mixer 49;

[0119] Both the first collection device 500 and the second pretreatment device 200 are connected to the power generation device 300 through the first mixer 25;

[0120] The second collection device 400 is connected to the first collection device 500 through the second mixer 32, and is connected to the third collection device 600 through the third mixer 49;

[0121] The second mixer 32 and the third mixer 49 are also used to access surface water.

[0122] Specifically, the first buffer airbag 24 in the first collection device 500 and the third heat exchanger 37 in the second pretreatment device 200 are both connected to the eighth heat exchanger 13 in the power generation device 300 through the first mixer 25.

[0123] The bottom of the first gas-liquid separator 31 in the second collection device 400 is connected to the side of the first underwater absorption tower 23 in the first collection device 500 through the second mixer 32.

[0124] The bottom of the second gas-liquid separator 47 in the second collection device 400 is connected to the side of the second underwater absorption tower 38 in the third collection device 600 via the third mixer 49.

[0125] In summary, the ocean thermal energy conversion and carbon capture coupling system provided in this embodiment of the invention utilizes the natural environment of high pressure and low temperature in the deep sea, along with the surface-deep sea temperature difference, to absorb CO2 gas from industrial flue gas using water as a physical absorption medium. The CO2 is efficiently dissolved underwater, and the unabsorbed gas is used to recover pressure potential energy through expansion for power generation. Simultaneously, the cold energy carried ashore by the CO2 aqueous solution is directionally coupled to the condenser of the organic Rankine cycle component, forming an integrated energy and material closed loop of "capture-power generation-condensation," synergistically reducing unit capture energy consumption and overall operating costs at the system level. This system can achieve integrated capture and power generation configuration, reducing unit capture energy consumption and increasing CO2 capture rate. It achieves synergistic benefits in both resource utilization and system energy consumption reduction, overcoming the shortcomings of current systems that only focus on power generation efficiency and fail to couple with CO2 capture and desorption. Ultimately, it improves system-level energy efficiency and carbon emission reduction synergy, providing a replicable technical path for industrial carbon reduction and sustainable economic operation. Moreover, the system employs a two-stage carbon capture process, which can significantly improve the absorption of CO2, thereby yielding a high concentration of CO2 gas.

[0126] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0127] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coupled system for ocean thermal energy conversion and carbon capture, characterized in that, The application relates to a CO2 capture and power generation system. The system comprises a first pre-treatment device, a second pre-treatment device, a power generation device and a second capture device located on the ground, and a first capture device and a third capture device located at a preset depth in the sea; The first capture device is in communication with the first pre-treatment device, the power generation device and the second capture device respectively; the second pre-treatment device is in communication with the second capture device, the power generation device and the third capture device respectively, and the third capture device is in communication with the second capture device; The first pre-treatment device is used for boosting the industrial flue gas to a target pressure; the first capture device is used for absorbing CO2 gas in the industrial flue gas by using ground water to obtain a first CO2 aqueous solution and a first residual gas, and the first CO2 aqueous solution is connected to the second capture device, and the first residual gas is connected to the power generation device; the target pressure is used for making the industrial flue gas reach the first capture device and have a pressure condition matched with the external sea pressure; The second capture device is used for exchanging heat between the connected CO2 aqueous solution and an organic Rankine cycle working medium, and separating out CO2 gas containing impurity gas; The second pre-treatment device is used for boosting the CO2 gas containing impurity gas to the target pressure to obtain compressed high-temperature CO2 gas; the third capture device is used for absorbing the CO2 gas to obtain a second CO2 aqueous solution and a second residual gas, and the second CO2 aqueous solution is connected to the second capture device, the compressed high-temperature CO2 gas is purified to obtain high-purity CO2 gas, and the second residual gas is mixed with the first residual gas and then connected to the power generation device; the power generation device is used for generating power according to the connected residual gas; The second capture device is in communication with the first capture device and the third capture device respectively; The second capture device is also used for separating out residual aqueous solution and connecting the residual aqueous solution to the first capture device and the third capture device respectively; The ground water connected to the first capture device comprises the connected residual aqueous solution and ground injection water, and the ground water connected to the third capture device comprises the connected residual aqueous solution and ground injection water.

2. The ocean thermal power generation and carbon capture coupling system according to claim 1, characterized in that, The second capture device comprises a first water pump, a multi-stream heat exchanger, a first gas-liquid separator, a second gas-liquid separator, a first heat exchanger and a CO2 storage tank, the multi-stream heat exchanger is used as a condenser in an organic Rankine cycle assembly; the first heat exchanger is in communication between a second water pump and a turbine in the organic Rankine cycle assembly; The first pre-treatment device is in communication with the first heat exchanger through the first water pump; the first pre-treatment device is in communication with the first capture device through the first heat exchanger; The multi-stream heat exchanger is in communication with the second pre-treatment device and the first capture device through the first gas-liquid separator respectively, and in communication with the CO2 storage tank and the third capture device through the second gas-liquid separator respectively.

3. The ocean thermal power generation and carbon capture coupling system according to claim 2, wherein, The first capture device comprises a first underwater absorption tower and a first buffer air bag; The side of the first underwater absorption tower is communicated with the bottom of the first gas-liquid separator and the first heat exchanger respectively; The top of the first underwater absorption tower is communicated with the power generation device through the first buffer air bag; The bottom of the first underwater absorption tower is communicated with the multi-stream heat exchanger.

4. The ocean thermal power generation and carbon capture coupling system according to claim 2, wherein, The third trapping device comprises a second underwater absorption tower and a second buffer air bag; The side of the second underwater absorption tower is communicated with the bottom of the second gas-liquid separator and the second pretreatment device respectively; The top of the second underwater absorption tower is communicated with the second pretreatment device through the second buffer air bag; The bottom of the second underwater absorption tower is communicated with the multi-stream heat exchanger.

5. The ocean thermal power generation and carbon capture coupling system according to claim 4, wherein, The second pretreatment device comprises a first compressor assembly; The first compressor assembly comprises a first compressor, a second heat exchanger, a second compressor and a third heat exchanger which are communicated in sequence; The first compressor is communicated with the second trapping device; the first compressor and the second compressor are used for boosting the CO2 gas containing impurities to the target pressure to obtain the compressed high-temperature CO2 gas; The second heat exchanger is used for cooling the compressed high-temperature CO2 gas; The third heat exchanger is communicated with the power generation device and the third trapping device respectively and is used for heat exchange of the compressed high-temperature CO2 gas and the second residual gas.

6. The ocean thermal power generation and carbon capture coupling system according to claim 1, wherein, The first pretreatment device comprises a cooling and drying assembly and a second compressor assembly, and the cooling and drying assembly and the second compressor assembly are communicated; The cooling and drying assembly is used for cooling and drying the industrial flue gas; The second compressor assembly comprises a third compressor, a fourth heat exchanger, a fourth compressor, a fifth heat exchanger, a fifth compressor, a sixth heat exchanger, a sixth compressor and a seventh heat exchanger which are communicated in sequence, and the fourth heat exchanger, the fifth heat exchanger, the sixth heat exchanger and the seventh heat exchanger are all communicated with the power generation device through a cold storage tank and a heat storage tank respectively.

7. The ocean thermal power generation and carbon capture coupling system according to claim 6, wherein, The power generation device comprises an eighth heat exchanger, a first expander, a ninth heat exchanger, a second expander, a tenth heat exchanger, a third expander, an eleventh heat exchanger and a fourth expander which are communicated in sequence; The eighth heat exchanger, the ninth heat exchanger, the tenth heat exchanger and the eleventh heat exchanger are all communicated with the cold storage tank and the heat storage tank respectively; The eighth heat exchanger is communicated with the first trapping device and the second pretreatment device respectively.

8. The ocean thermal power generation and carbon capture coupling system according to claim 3, characterized in that, The first trapping device further comprises a third buffer air bag, a fourth buffer air bag and a fifth buffer air bag; The third buffer air bag, the fourth buffer air bag and the fifth buffer air bag are all communicated with the bottom of the first underwater absorption tower and are used for stabilizing system pressure.

9. The ocean thermal power generation and carbon capture coupling system according to claim 4, characterized in that, The third trapping device further comprises a sixth buffer air bag, a seventh buffer air bag and an eighth buffer air bag; The sixth buffer air bag, the seventh buffer air bag and the eighth buffer air bag are all communicated with the bottom of the second underwater absorption tower and are used for stabilizing system pressure.

10. The ocean thermal power generation and carbon capture coupling system according to any one of claims 1-9, characterized in that, Further comprising a first mixer, a second mixer and a third mixer; The first trapping device and the second pretreatment device are both communicated with the power generation device through the first mixer; The second trapping device is in communication with the first trapping device through the second mixer and with the third trapping device through the third mixer. The second mixer and the third mixer are also used for accessing surface water.

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