Carbon capture system and method for staggered energy utilization based on direct steam compression

Abstract

The present invention discloses a carbon capture system for staggered energy utilization based on direct steam compression. The system comprises: a carbon capture module, provided with a carbon capture steam inlet and a return water outlet; an external heat source heat exchanger, the inlet of the external heat source heat exchanger being connected to the return water outlet and capable of generating steam; and a compressor assembly, provided with a compressor steam inlet, a water supply inlet, and a compressor steam outlet. The compressor steam inlet is connected to the outlet of the external heat source heat exchanger, the water supply inlet is connected to the return water outlet, and the compressor steam outlet is connected to the carbon capture steam inlet. The present invention has the beneficial effect of comprehensively improving the economic efficiency of the carbon capture system and effectively promoting the industrialization and promotion of carbon capture technology.

Description

Technical Field

[0001] The present invention belongs to the field of environment and energy technology, and specifically relates to a carbon capture system and method for staggered energy utilization based on direct steam compression. Background Art

[0002] Carbon capture can directly separate carbon dioxide from the fossil energy utilization process, and through carbon storage, compress the separated carbon dioxide to a supercritical high-pressure state and transport it to geological environments such as underground saline aquifers. The carbon dioxide can be stored for a long time using geological conditions such as high pressure and closure, thereby directly and effectively achieving carbon emission reduction.

[0003] Currently, carbon capture technology routes mainly include pre-combustion capture, oxygen-enriched combustion, and post-combustion capture. Among them, post-combustion capture technology is relatively mature and has better adaptability to existing energy utilization systems. It can generally be directly applied to any existing thermal power generation system. Post-combustion capture methods include chemical absorption, physical adsorption / absorption, membrane separation, cryogenic separation, etc. Among them, chemical absorption is the most mature process, but it is limited by the high regeneration energy consumption and has been insufficiently promoted and applied in practice. The energy consumption of chemical absorption is mainly concentrated in the regeneration process of the rich liquid that absorbs carbon dioxide in the regeneration tower to release carbon dioxide and re-form the lean liquid. The heating heat source is generally steam directly extracted from the power plant. The high energy consumption leads to a significant decrease in the power generation efficiency of the power plant.

[0004] The current research and development direction of chemical absorption method is mainly to develop new absorbents and optimize process flow to improve the absorption / regeneration efficiency of absorbents and reduce the energy consumption of carbon capture, but the progress is relatively slow and there is still some distance from actual promotion and application.

[0005] In view of this, from an economic perspective, the overall operating cost of the carbon capture system can be reduced by introducing low-cost heat sources such as industrial waste heat and medium- and low-temperature solar thermal collectors. Usually, the temperature of industrial waste heat or medium- and low-temperature solar thermal collectors is low, and the steam obtained cannot directly meet the temperature requirements of the carbon capture regeneration process. To solve the above problems, we can refer to the idea of recycling low-grade secondary steam in mechanical vapor recompression (MVR) technology, and directly improve the steam quality by compressing the low-pressure water vapor obtained from low-grade thermal energy through a compressor, so as to obtain high-grade steam thermal energy with less compression work, thereby providing a driving heat source for the carbon capture regeneration process. Summary of the Invention

[0006] Therefore, the present invention discloses a carbon capture system and method for staggered energy utilization based on direct steam compression, so as to achieve the purpose of comprehensively improving the economic efficiency of the carbon capture system and effectively promoting the industrialization and promotion of carbon capture technology.

[0007] The present invention provides the following technical solutions: a carbon capture system for staggered energy utilization based on direct steam compression, comprising: a carbon capture module, provided with a carbon capture steam inlet and a return water outlet; an external heat source heat exchanger, the inlet of the external heat source heat exchanger is connected to the return water outlet and can generate steam; a compressor assembly, provided with a compressor steam inlet, a water supply inlet and a compressor steam outlet, the compressor steam inlet is connected to the outlet of the external heat source heat exchanger, the water supply inlet is connected to the return water outlet, and the compressor steam outlet is connected to the carbon capture steam inlet.

[0008] Furthermore, the compressor assembly includes a plurality of compressor units arranged in series, and the structure of each compressor unit is the same.

[0009] Furthermore, the compressor unit includes a water vapor compressor, a mixer and a water spray pump, the inlet of the water vapor compressor is connected to the outlet of the external heat source heat exchanger, the outlet of the water vapor compressor is connected to the mixer, the inlet of the water spray pump is connected to the return water outlet, the outlet of the water spray pump is connected to the mixer, and the outlet of the mixer is connected to the carbon capture steam inlet.

[0010] Furthermore, the peak-shaving energy utilization carbon capture system based on direct steam compression also includes a heat storage module, which is provided with a first inlet and a first outlet. The compressor steam outlet is connected to the first inlet and the carbon capture steam inlet, and the first outlet is connected to the inlet of the external heat source heat exchanger and the water supply inlet.

[0011] Furthermore, the peak-shaving energy utilization carbon capture system based on direct steam compression also includes a buffer tank, the first outlet and the return water outlet are both connected to the inlet of the buffer tank, and the outlet of the buffer tank is connected to the inlet of the external heat source heat exchanger and the water supply inlet.

[0012] Furthermore, the heat storage module further includes a second inlet and a second outlet, the second inlet is communicated with the return water outlet; the second outlet is communicated with the carbon capture steam inlet.

[0013] Furthermore, a hot water vapor compressor is provided on the connecting pipeline between the second outlet and the carbon capture steam inlet.

[0014] The present invention also provides a method for capturing carbon from off-peak energy utilization based on direct steam compression, and uses the above-mentioned carbon capture system for off-peak energy utilization based on direct steam compression to perform carbon capture operations.

[0015] Furthermore, the carbon capture method for staggered energy utilization based on direct steam compression includes a first working mode, which includes the following steps: an external heat source heat exchanger heats liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the carbon capture module through the carbon capture steam inlet to provide heat energy for the carbon capture regeneration operation and generate liquid water; and the liquid water is transported to the external heat source heat exchanger and the water supply inlet of the compressor assembly.

[0016] Furthermore, the carbon capture method for staggered energy utilization based on direct steam compression includes a second working mode, which includes the following steps: an external heat source heat exchanger heats liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the heat storage module to supply energy for the energy storage process and generate liquid water; and the liquid water is transported to the external heat source heat exchanger and the water supply inlet of the compressor assembly.

[0017] Furthermore, the off-peak energy utilization carbon capture method based on direct steam compression includes a third working mode, which includes the following steps: the heat storage module releases heat to heat liquid water and obtain water vapor; the water vapor enters the heat-releasing water vapor compressor to increase the pressure and then is transported to the carbon capture module to provide heat energy for the carbon capture process and generate liquid water; the liquid water is transported to the heat storage module.

[0018] Furthermore, the off-peak energy utilization and carbon capture method based on direct steam compression includes a fourth working mode, which includes the following steps: the external heat source heat exchanger heats the liquid water and generates low-pressure steam, the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the heat storage module and the carbon capture module respectively to provide heat energy and generate liquid water; the liquid water is transported to the external heat source heat exchanger and the water supply inlet of the compressor assembly.

[0019] Furthermore, the off-peak energy utilization carbon capture method based on direct steam compression includes a fifth working mode, which includes the following steps: the external heat source heat exchanger heats liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the compressor steam inlet, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to mix with the low-pressure steam and compress to generate high-grade water vapor; the heat storage module releases heat to heat liquid water and obtain water vapor, and the obtained water vapor and high-grade water vapor enter the carbon capture module through the carbon capture steam inlet to provide heat energy for the carbon capture regeneration operation and generate liquid water; the liquid water is transported to the heat storage module, the external heat source heat exchanger and the water supply inlet of the compressor assembly.

[0020] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0021] Comprehensively improve the economic efficiency of carbon capture systems and effectively promote the industrialization and promotion of carbon capture technology.

[0022] It can reduce the economic cost of system operation and at the same time play the role of peak load regulation of the power grid to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 Schematic diagram of a carbon capture system for staggered energy utilization based on direct steam compression according to an embodiment of the present invention;

[0025] Figure 2 This is a flow path diagram of various media in a single energy supply mode in which steam is generated by an external heat source according to an embodiment of the present invention;

[0026] Figure 3 This is a flow path diagram of various media in a separate heat storage mode in which steam is generated by an external heat source according to an embodiment of the present invention;

[0027] Figure 4 This is a diagram of the flow paths of various media in the heat storage independent energy supply mode of an embodiment of the present invention;

[0028] Figure 5 This is a flow path diagram of various media in the embodiment of the present invention in which an external heat source generates steam for simultaneous energy supply and heat storage;

[0029] Figure 6 This is a flow path diagram of various media in a simultaneous energy supply mode in which an external heat source generates steam and stores heat in an embodiment of the present invention.

[0030] 1. External heat source heat exchanger; 21. First-stage water vapor compressor; 31. First-stage water spray pump; 41. First-stage mixer; 22. Second-stage water vapor compressor; 32. Second-stage water spray pump; 42. Second-stage mixer; 2. N-stage water vapor compressor; 3. N-stage water spray pump; 4. N-stage mixer; 5. Carbon capture module; 6. Heat storage module; 7. Buffer tank; 8. Heat release circulation pump; 9. Heat release water vapor compressor; 11. Main steam control valve; 12. Heat storage steam control valve; 221. First main return water control valve; 222. Heat storage return water control valve; 331. Second main return water control valve; 332. Heat release return water control valve; 333. Water spray control valve; 44. Heat release steam control valve. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] like Figure 1 As shown, an embodiment of the present invention provides a carbon capture system for staggered energy utilization based on direct steam compression, including: a carbon capture module 5, provided with a carbon capture steam inlet and a return water outlet; an external heat source heat exchanger 1, the inlet of the external heat source heat exchanger 1 is connected to the return water outlet and can generate steam; a compressor assembly, provided with a compressor steam inlet, a water supply inlet and a compressor steam outlet, the compressor steam inlet is connected to the outlet of the external heat source heat exchanger 1, the water supply inlet is connected to the return water outlet, and the compressor steam outlet is connected to the carbon capture steam inlet.

[0034] The embodiment of the present invention can generate water vapor through an external heat source by providing an external heat source heat exchanger 1. At the same time, by providing a compressor assembly, the water vapor can be compressed and generated into high-quality water vapor for use by the carbon capture module 5, thereby comprehensively improving the economic efficiency of the carbon capture system and effectively promoting the industrialization and promotion of carbon capture technology.

[0035] The external heat source heat carrier medium enters the external heat source heat exchanger 1 and releases heat to heat the liquid therein to obtain water vapor, and the water vapor flows out through the outlet of the external heat source heat exchanger 1.

[0036] Furthermore, the compressor assembly includes a plurality of compressor units arranged in series, and the structure of each compressor unit is the same.

[0037] Furthermore, the compressor unit includes a water vapor compressor, a mixer and a water spray pump, the inlet of the water vapor compressor is connected to the outlet of the external heat source heat exchanger 1, the outlet of the water vapor compressor is connected to the mixer, the inlet of the water spray pump is connected to the return water outlet, the outlet of the water spray pump is connected to the mixer, and the outlet of the mixer is connected to the carbon capture steam inlet.

[0038] like Figure 1 As shown in the figure, a primary water vapor compressor 21, a primary water spray pump 31, a primary mixer 41, a secondary water vapor compressor 22, a secondary water spray pump 32, and a secondary mixer 42 are shown. The primary water vapor compressor 21, the primary water spray pump 31, and the primary mixer 41 form a first compressor unit. The secondary water vapor compressor 22, the secondary water spray pump 32, and the secondary mixer 42 form a second compressor unit. The above is only the disclosure of the illustrated embodiment. The specific number of compressor units can be increased or decreased according to different needs.

[0039] The following explanation is required regarding the above content: the water vapor compressor (except for the hot water vapor compressor), the water spray pump, and the mixer all contain N stages, numbered 1, 2, ..., N. Specifically, for any stage of the water vapor compressor, taking the i-stage water vapor compressor as an example, its number is 2i; for any stage of the water spray pump, taking the i-stage water spray pump as an example, its code is 3i; for any stage of the mixer, taking the i-stage mixer as an example, its code is 4i. All the above numbers i satisfy 1≤i≤N (wherein, the numbering for the case of i=N is simplified in this article and N is omitted, i.e.: N-stage water vapor compressor 2, N-stage water spray pump 3, N-stage mixer 4). Unless otherwise specified, all subsequent numbers i in this article are arbitrary, that is, they represent any stage number within a given range.

[0040] For each level of water vapor compressor, water spray pump and mixer, taking the i (1≤i≤N) level as an example, the i-level water vapor compressor 2i and the i-level water spray pump 3i are both provided with an inlet and an outlet, and the i-level mixer 4i is both provided with a first inlet, a second inlet and an outlet; the inlet of the first-level water vapor compressor 21 is connected to the outlet of the external heat source heat exchanger 1, the outlet of the i (1≤i≤N)-level water vapor compressor 2i is connected to the first inlet of the i-level mixer 4i, the outlet of the i (1≤i≤N)-level water spray pump 3i is connected to the second inlet of the i-level mixer 4i, and the outlet of the i (1≤i≤(N-1))-level mixer 4i is connected to the inlet of the i+1-level water vapor compressor 2(i+1).

[0041] Optionally, an embodiment of the present invention further includes a main steam regulating valve 11, a heat storage steam regulating valve 12, a first main return water regulating valve 221, a heat storage return water regulating valve 222, a second main return water regulating valve 331, a heat release return water regulating valve 332, a water spray regulating valve 333, a heat release steam regulating valve 44, and pipelines connected to each other; the main steam regulating valve 11, the heat storage steam regulating valve 12, the first main return water regulating valve 221, the heat storage return water regulating valve 222, the second main return water regulating valve 331, the heat release return water regulating valve 332, the water spray regulating valve 333 and the heat release steam regulating valve 44 are all provided with inlets and outlets.

[0042] The outlet of the N-stage mixer 4, the inlet and outlet of the main steam control valve 11, and the carbon capture steam inlet are connected in sequence to form a flow channel for the steam obtained by compression of the water vapor compressors at each stage to the carbon capture module 5. The water vapor enters the carbon capture module 5 to provide a heat source for the carbon capture regeneration process and is discharged through the return water outlet; the carbon-containing exhaust gas enters the carbon capture module 5 and is separated to obtain carbon dioxide under the drive of steam thermal energy, and the formed decarbonized gas and carbon dioxide are discharged through the carbon capture module 5.

[0043] The compressor unit includes a water vapor compressor, a mixer and a water spray pump. The inlet of the water vapor compressor is connected to the outlet of the external heat source heat exchanger 1, the outlet of the water vapor compressor is connected to the mixer, the inlet of the water spray pump is connected to the return water outlet, the outlet of the water spray pump is connected to the mixer, and the outlet of the mixer is connected to the carbon capture steam inlet.

[0044] Furthermore, the peak-shaving energy utilization carbon capture system based on direct steam compression also includes a heat storage module 6, which is provided with a first inlet and a first outlet. The compressor steam outlet is connected to the first inlet and the carbon capture steam inlet, and the first outlet is connected to the inlet of the external heat source heat exchanger 1 and the water supply inlet.

[0045] Furthermore, the peak-shaving energy utilization carbon capture system based on direct steam compression also includes a buffer tank 7, the first outlet and the return water outlet are both connected to the inlet of the buffer tank 7, and the outlet of the buffer tank 7 is connected to the inlet of the external heat source heat exchanger 1 and the water supply inlet.

[0046] The thermal storage module 6 further includes a second inlet and a second outlet. The second inlet communicates with the return water outlet; the second outlet communicates with the carbon capture steam inlet. A heat release circulation pump 8 is installed in the connecting pipeline between the second inlet and the outlet of the heat release return water control valve 332. The outlet of the N-stage mixer 4, the inlet and outlet of the heat storage steam control valve 12, and the first inlet of the thermal storage module 6 are sequentially connected to form a channel for supplying steam compressed by the steam compressors at each stage to the thermal storage module 6.

[0047] Furthermore, a hot water vapor compressor 9 is provided on the connecting pipeline between the second outlet and the carbon capture steam inlet.

[0048] The first outlet, the inlet and outlet of the heat storage return water regulating valve 222, the inlet and outlet of the buffer tank 7, the inlet and outlet of the second main return water regulating valve 331, and the inlet of the external heat source heat exchanger 1 are connected in sequence to form a return water channel after the steam obtained by compression of each stage of the water vapor compressor provides heat energy for the heat storage module 6.

[0049] The second outlet, the inlet and outlet of the heat-releasing water vapor compressor 9, the inlet and outlet of the heat-releasing steam regulating valve 44, and the carbon capture steam inlet are connected in sequence to form a steam supply channel for the heat storage module 6 to supply steam to the carbon capture module 5; the return water outlet, the inlet and outlet of the first main return water regulating valve 221, the inlet and outlet of the buffer tank 7, the inlet and outlet of the heat-releasing return water regulating valve 332, the inlet and outlet of the heat-releasing circulation pump 8, and the second inlet of the heat storage module 6 are connected in sequence to form a return water channel after the steam obtained by the heat storage module 6 provides heat energy to the carbon capture module 5.

[0050] Furthermore, the first outlet and the return water outlet are both connected to the inlet of the buffer tank 7, and the outlet of the buffer tank 7 is connected to the inlet and the water supply inlet of the external heat source heat exchanger 1. The return water outlet, the inlet and outlet of the first main return water control valve 221, the inlet and outlet of the buffer tank 7, the inlet and outlet of the second main return water control valve 331, and the inlet of the external heat source heat exchanger 1 are connected in sequence, forming a return water channel for the steam obtained by compression by the various stages of the water vapor compressor to provide heat energy for the carbon capture module 5.

[0051] The outlet of the buffer tank 7, the inlet and outlet of the water spray control valve 333 are connected in sequence with the inlets of the water spray pumps at each stage (the first-stage water spray pump 31 to the N-stage water spray pump 3) to form a water spray source supply channel for the mixers at each stage (the first-stage mixer 41 to the N-stage mixer 4) to reduce the superheat of the water vapor at the outlet of the water vapor compressors at each stage (the first-stage water vapor compressor 21 to the N-stage water vapor compressor 2N) and reduce the overall water vapor compression energy consumption.

[0052] An embodiment of the present invention further provides a method for carbon capture based on direct steam compression for staggered energy utilization, which utilizes the aforementioned direct steam compression-based carbon capture system for staggered energy utilization to perform carbon capture operations. The direct steam compression-based carbon capture system for staggered energy utilization has five operating modes: a first operating mode (steam generation by an external heat source, separate energy supply mode), a second operating mode (steam generation by an external heat source, separate heat storage mode), a third operating mode (steam generation, separate energy supply mode), a fourth operating mode (steam generation by an external heat source, simultaneous energy supply and heat storage mode), and a fifth operating mode (steam generation by an external heat source, simultaneous heat storage mode).

[0053] (1) If heat storage is not required when the external heat source generates steam for energy supply, the external heat source generates steam for energy supply alone mode;

[0054] (2) If carbon capture is not required during the heat storage process, the external heat source generates steam for heat storage only, i.e., the external heat source generates steam for heat storage only mode;

[0055] (3) During peak electricity consumption, the heat released by the thermal storage module needs to be used to generate steam to provide thermal energy for carbon capture, that is, the thermal storage-only energy supply mode;

[0056] (4) During low electricity consumption, the water vapor generated by the external heat source, after being compressed by the various levels of water vapor compressors, not only provides heat energy for carbon capture, but also needs to store part of the heat energy in the heat storage module, that is, the external heat source generates steam to provide energy and store heat at the same time;

[0057] (5) When storing heat for energy supply, depending on the heat release performance of the heat storage module, an external heat source can be added to generate steam, which is then compressed by various levels of water vapor compressors to provide heat energy for the carbon capture process. This is a simultaneous energy supply mode in which an external heat source generates steam and stores heat. The above working modes are described as follows:

[0058] The carbon capture method for staggered energy utilization based on direct steam compression includes a first working mode, which includes the following steps: the external heat source heat exchanger 1 heats liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the carbon capture module 5 through the carbon capture steam inlet to provide heat energy for the carbon capture regeneration operation and generate liquid water; the liquid water is transported to the external heat source heat exchanger 1 and the water supply inlet of the compressor assembly.

[0059] In this mode, the main steam control valve 11, the first main return water control valve 221, the second main return water control valve 331 and the spray water control valve 333 are opened and play a control role.

[0060] The external heat source heats the liquid water entering the external heat source heat exchanger 1 to generate low-pressure steam. The low-pressure steam is compressed in sequence by the first-stage water vapor compressor 21, the second-stage water vapor compressor 22, ..., the N-stage water vapor compressor 2 to obtain high-quality steam. The outlet of each stage of the water vapor compressor needs to be mixed with the liquid water sprayed by the corresponding stage water pump in the corresponding stage mixer, and the water vapor superheat is eliminated before entering the next stage of the water vapor compressor. Taking the i-th stage as an example: the water vapor at the outlet of the i-stage water vapor compressor 2i and the liquid water flowing out of the i-stage water spray pump 3i are both mixed in the i-stage mixer 4i. The liquid water evaporates and the water vapor superheat is eliminated at the same time. The mixed water vapor then enters the i+1-stage water vapor compressor 2(i+1), where the outlet of the N-stage mixer 4 is the high-quality water vapor finally obtained.

[0061] High-quality steam compressed by the steam compressors at each stage enters the carbon capture module 5 through the main steam control valve 11, providing heat energy for the carbon capture regeneration process. Carbon dioxide is separated from the carbon-containing gas entering the carbon capture module 5, and the resulting decarbonized gas is discharged. The captured carbon dioxide enters subsequent processing. Condensed water, formed after the steam releases heat in the carbon capture module 5, enters the buffer tank 7 through the first main return water control valve 221 and then returns to the external heat source heat exchanger 1 through the second main return water control valve 331.

[0062] In order to ensure the water balance in the compression and water spray mixing processes of the water vapor compressors at each stage, part of the liquid water in the buffer tank 7 is drawn out through the water spray control valve 333, and then driven by the water spray pumps at each stage to enter the mixers at each stage to provide water for superheating elimination of the superheated water vapor discharged from the water vapor compressors at each stage.

[0063] After the above process, the external heat source generates steam to supply energy independently. In this mode, except for the above equipment, the rest of the equipment is closed or stopped, and the flow paths of each medium are as follows: Figure 2 shown.

[0064] The carbon capture method for staggered energy utilization based on direct steam compression includes a second working mode, which includes the following steps: the external heat source heat exchanger 1 heats liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the heat storage module 6 to provide energy for the energy storage process and generate liquid water; and the liquid water is transported to the external heat source heat exchanger 1 and the water supply inlet of the compressor assembly.

[0065] In this mode, the thermal storage steam regulating valve 12, the thermal storage return water regulating valve 222, the second main return water regulating valve 331 and the water spray regulating valve 333 are opened and play a regulating role.

[0066] The external heat source heats the liquid water entering the external heat source heat exchanger 1 to generate low-pressure steam. The low-pressure steam is compressed in sequence by the first-stage water vapor compressor 21, the second-stage water vapor compressor 22, ..., the N-stage water vapor compressor 2 to obtain high-quality steam. The outlet of each stage of the water vapor compressor needs to be mixed with the liquid water sprayed by the corresponding stage water pump in the corresponding stage mixer, and the water vapor superheat is eliminated before entering the next stage of the water vapor compressor. Taking the i-th stage as an example: the water vapor at the outlet of the i-stage water vapor compressor 2i and the liquid water flowing out of the i-stage water spray pump 3i are both mixed in the i-stage mixer 4i. The liquid water evaporates and the water vapor superheat is eliminated at the same time. The mixed water vapor then enters the i+1-stage water vapor compressor 2(i+1), where the outlet of the N-stage mixer 4 is the high-quality water vapor finally obtained.

[0067] The high-grade water vapor obtained by compression by the water vapor compressors at each stage enters the heat storage module 6 through the heat storage steam regulating valve 12, providing thermal energy for the heat storage process. The condensed water formed after the water vapor releases heat in the heat storage module 6 enters the buffer tank 7 through the heat storage return water regulating valve 222, and then returns to the external heat source heat exchanger 1 through the second main return water regulating valve 331.

[0068] In order to ensure the water balance in the compression and water spray mixing processes of the water vapor compressors at each stage, part of the liquid water in the buffer tank 7 is drawn out through the water spray control valve 333, and then driven by the water spray pumps at each stage to enter the mixers at each stage to provide water for superheating elimination of the superheated water vapor discharged from the water vapor compressors at each stage.

[0069] After the above process, the external heat source generates steam and completes the heat storage cycle. In this mode, except for the above equipment, the rest of the equipment is closed or stopped, and the flow paths of each medium are as follows: Figure 3 shown.

[0070] The off-peak energy utilization carbon capture method based on direct steam compression includes a third working mode, which includes the following steps: the heat storage module 6 releases heat to heat liquid water and obtain water vapor; the water vapor enters the hot water vapor compressor 9 to increase the pressure and then is transported to the carbon capture module 5 to provide heat energy for the carbon capture process and generate liquid water; the liquid water is transported to the heat storage module 6.

[0071] In this mode, the heat release steam regulating valve 44, the first main return water regulating valve 221 and the heat release return water regulating valve 332 are open and play a regulating role. The steam obtained by releasing heat and heating the heat storage module 6 enters the heat release water vapor compressor 9 to increase the pressure, and then enters the carbon capture module 5 through the heat release steam regulating valve 44 to provide heat energy for the carbon capture process. The condensed water formed after the steam releases heat enters the buffer tank 7 through the first main return water regulating valve 221, and enters the heat release circulation pump 8 through the heat release return water regulating valve 332 and is driven back to the heat storage module 6, completing the heat storage independent energy supply cycle. In this mode, except for the above-mentioned equipment, the rest of the equipment is in a closed or shutdown state, and the flow paths of each medium are as follows: Figure 4 The steam compression energy-consuming link is set to operate during off-peak hours, and the high-grade steam heat energy obtained from compression is stored in a heat storage device. During peak hours, the stored heat energy is used to obtain high-grade steam again, eliminating the need for electricity consumption in the compression link. This reduces the economic cost of system operation and can also play a role in peak load regulation of the power grid to a certain extent.

[0072] The off-peak energy utilization and carbon capture method based on direct steam compression includes a fourth working mode, which includes the following steps: the external heat source heat exchanger 1 heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to be mixed with the low-pressure steam and compressed to generate high-grade water vapor; the high-grade water vapor enters the heat storage module 6 and the carbon capture module 5 respectively to provide heat energy and generate liquid water; the liquid water is transported to the external heat source heat exchanger 1 and the water supply inlet of the compressor assembly.

[0073] In this mode, the main steam control valve 11, the thermal storage steam control valve 12, the first main return water control valve 221, the thermal storage return water control valve 222, the second main return water control valve 331 and the water spray control valve 333 are opened and play a control role.

[0074] The external heat source heats the liquid water entering the external heat source heat exchanger 1 to generate low-pressure steam. The low-pressure steam is compressed in sequence by the first-stage water vapor compressor 21, the second-stage water vapor compressor 22, ..., the N-stage water vapor compressor 2 to obtain high-quality steam. The outlet of each stage of the water vapor compressor needs to be mixed with the liquid water sprayed by the corresponding stage water pump in the corresponding stage mixer, and the water vapor superheat is eliminated before entering the next stage of the water vapor compressor. Taking the i-th stage as an example: the water vapor at the outlet of the i-stage water vapor compressor 2i and the liquid water flowing out of the i-stage water spray pump 3i are both mixed in the i-stage mixer 4i. The liquid water evaporates and the water vapor superheat is eliminated at the same time. The mixed water vapor then enters the i+1-stage water vapor compressor 2(i+1), where the outlet of the N-stage mixer 4 is the high-quality water vapor finally obtained.

[0075] High-grade steam compressed by the steam compressors at each stage enters the carbon capture module 5 and the thermal storage module 6 through the main steam control valve 11 and the thermal storage steam control valve 12, respectively, providing thermal energy for the carbon capture, regeneration, and thermal storage processes. The steam's thermal energy separates carbon dioxide from the carbon-containing gas entering the carbon capture module 5, and the resulting decarbonized gas is discharged, with the captured carbon dioxide entering subsequent processing. After releasing heat in the carbon capture module 5 and the thermal storage module 6, the steam forms condensed water, which then enters the buffer tank 7 through the first main return water control valve 221 and the thermal storage return water control valve 222, respectively. The condensed water then returns to the external heat source heat exchanger 1 through the second main return water control valve 331.

[0076] In order to ensure the water balance in the compression and water spray mixing processes of the water vapor compressors at each stage, part of the liquid water in the buffer tank 7 is drawn out through the water spray control valve 333, and then driven by the water spray pumps at each stage to enter the mixers at each stage to provide water for superheating elimination of the superheated water vapor discharged from the water vapor compressors at each stage.

[0077] The above process completes the external heat source to generate steam and simultaneously supply energy and store heat. In this mode, except for the above equipment, the rest of the equipment is closed or stopped, and the flow paths of each medium are as follows: Figure 5 As shown in the figure, low-pressure steam is produced by using low-grade waste heat, and then the steam quality is improved through direct steam compression. In combination with heat storage, the steam compression is set to operate during low-power consumption periods, thereby comprehensively improving the economic efficiency of the carbon capture system and effectively promoting the industrialization and promotion of carbon capture technology.

[0078] The off-peak energy utilization carbon capture method based on direct steam compression includes a fifth working mode, which includes the following steps: the external heat source heat exchanger 1 heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the compressor steam inlet, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly to mix with the low-pressure steam and compress to generate high-grade water vapor; the heat storage module 6 releases heat to heat the liquid water and obtain water vapor, and the obtained water vapor and high-grade water vapor enter the carbon capture module 5 through the carbon capture steam inlet to provide heat energy for the carbon capture regeneration operation and generate liquid water; the liquid water is transported to the heat storage module 6, the external heat source heat exchanger 1 and the water supply inlet of the compressor assembly.

[0079] In this mode, the main steam control valve 11, the first main return water control valve 221, the second main return water control valve 331, the heat release return water control valve 332, the heat release steam control valve 44 and the water spray control valve 333 are opened and play a control role.

[0080] The external heat source heats the liquid water entering the external heat source heat exchanger 1 to generate low-pressure steam. The low-pressure steam is compressed in sequence by the first-stage water vapor compressor 21, the second-stage water vapor compressor 22, ..., the N-stage water vapor compressor 2 to obtain high-quality steam. The outlet of each stage of the water vapor compressor needs to be mixed with the liquid water sprayed by the corresponding stage water pump in the corresponding stage mixer, and the water vapor superheat is eliminated before entering the next stage of the water vapor compressor. Taking the i-th stage as an example: the water vapor at the outlet of the i-stage water vapor compressor 2i and the liquid water flowing out of the i-stage water spray pump 3i are both mixed in the i-stage mixer 4i. The liquid water evaporates and the water vapor superheat is eliminated at the same time. The mixed water vapor then enters the i+1-stage water vapor compressor 2(i+1), where the outlet of the N-stage mixer 4 is the high-quality water vapor finally obtained.

[0081] High-quality steam compressed by the steam compressors at each stage enters the carbon capture module 5 through the main steam control valve 11. Simultaneously, steam heated by the heat storage module 6 is pressurized by the heat-release steam compressor 9 and then enters the carbon capture module 5 through the heat-release steam control valve 44. Together, these steam components provide thermal energy for the carbon capture regeneration process. Carbon dioxide is separated from the carbon-containing gas entering the carbon capture module 5, and the resulting decarbonized gas is exhausted. The captured carbon dioxide enters subsequent processing. Condensed water, formed after the steam releases heat in the carbon capture module 5, enters the buffer tank 7 through the first main return water control valve 221. The liquid water in the condensed water is returned to the external heat source heat exchanger 1 through the second main return water control valve 331 and then enters the heat-release circulation pump 8 through the heat-release return water control valve 332, where it is driven back to the heat storage module 6.

[0082] In order to ensure the water balance in the compression and water spray mixing processes of the water vapor compressors at each stage, part of the liquid water in the buffer tank 7 is drawn out through the water spray control valve 333, and then driven by the water spray pumps at each stage to enter the mixers at each stage to provide water for superheating elimination of the superheated water vapor discharged from the water vapor compressors at each stage.

[0083] The above process completes the external heat source to generate steam and heat storage and energy supply cycle. In this mode, except for the above equipment, the rest of the equipment is closed or stopped, and the flow paths of each medium are as follows: Figure 6 shown.

[0084] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of patent protection, should still fall within the scope of this patent. Furthermore, the technical features of the present invention may be freely combined with one another, with other technical solutions, and with other technical solutions.

Claims

1. A carbon capture system for staggered energy utilization based on direct steam compression, characterized in that: include: A carbon capture module (5) is provided with a carbon capture steam inlet and a return water outlet; an external heat source heat exchanger (1), the inlet of the external heat source heat exchanger (1) being in communication with the return water outlet and capable of generating steam; A compressor assembly is provided with a compressor steam inlet, a water supply inlet and a compressor steam outlet, wherein the compressor steam inlet is connected to the outlet of the external heat source heat exchanger (1), the water supply inlet is connected to the return water outlet, and the compressor steam outlet is connected to the carbon capture steam inlet; The compressor assembly includes a plurality of compressor units arranged in series, and the structure of each compressor unit is the same; The compressor unit includes a water vapor compressor, a mixer and a water spray pump, wherein the inlet of the water vapor compressor is connected to the outlet of the external heat source heat exchanger (1), the outlet of the water vapor compressor is connected to the mixer, the inlet of the water spray pump is communicated with the return water outlet, the outlet of the water spray pump is connected to the mixer, and the outlet of the mixer is communicated with the carbon capture steam inlet; The staggered energy utilization carbon capture system based on direct steam compression further comprises a heat storage module (6), the heat storage module (6) being provided with a first inlet and a first outlet, the compressor steam outlet being in communication with both the first inlet and the carbon capture steam inlet, and the first outlet being in communication with both the inlet of the external heat source heat exchanger (1) and the water supply inlet; The heat storage module (6) further comprises a second inlet and a second outlet, wherein the second inlet is in communication with the return water outlet; the second outlet is in communication with the carbon capture steam inlet; A heat-releasing steam compressor (9) is provided on the connecting pipeline between the second outlet and the carbon capture steam inlet.

2. The steam direct compression-based staggered energy utilization carbon capture system according to claim 1 is characterized in that: The staggered energy utilization carbon capture system based on direct steam compression further comprises a buffer tank (7), wherein the first outlet and the return water outlet are both connected to the inlet of the buffer tank (7), and the outlet of the buffer tank (7) is connected to the inlet of the external heat source heat exchanger (1) and the water supply inlet.

3. A method for carbon capture based on direct steam compression for staggered energy utilization, characterized in that: Carbon capture operations are performed using the steam direct compression-based staggered energy utilization carbon capture system described in any one of claims 1 or 2.

4. The method for carbon capture based on staggered energy utilization using direct steam compression according to claim 3 is characterized in that: The method for carbon capture of staggered energy utilization based on direct steam compression includes a first working mode, which includes the following steps: The external heat source heat exchanger (1) heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly, is mixed with the low-pressure steam, and is compressed to generate high-quality water vapor; High-grade water vapor enters the carbon capture module (5) through the carbon capture steam inlet to provide heat energy for carbon capture regeneration operation and generate liquid water; Liquid water is delivered to the water supply inlet of the external heat source heat exchanger (1) and the compressor assembly.

5. The method for carbon capture based on staggered energy utilization using direct steam compression according to claim 3 is characterized in that: The method for carbon capture of staggered energy utilization based on direct steam compression includes a second working mode, which includes the following steps: The external heat source heat exchanger (1) heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly, is mixed with the low-pressure steam, and is compressed to generate high-quality water vapor; High-quality water vapor enters the heat storage module (6) to provide energy for the energy storage process and generate liquid water; Liquid water is delivered to the water supply inlet of the external heat source heat exchanger (1) and the compressor assembly.

6. The method for carbon capture based on staggered energy utilization using direct steam compression according to claim 3, characterized in that: The method for carbon capture of staggered energy utilization based on direct steam compression includes a third working mode, which includes the following steps: The heat storage module (6) releases heat to heat liquid water and obtain water vapor; The water vapor enters the hot water vapor compressor (9) to increase the pressure and is then transported to the carbon capture module (5) to provide heat energy for the carbon capture process and generate liquid water; The liquid water is transported to the heat storage module (6).

7. The method for carbon capture based on staggered energy utilization using direct steam compression according to claim 3, characterized in that: The method for carbon capture of staggered energy utilization based on direct steam compression includes a fourth working mode, which includes the following steps: The external heat source heat exchanger (1) heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly, is mixed with the low-pressure steam, and is compressed to generate high-quality water vapor; The high-grade water vapor enters the heat storage module (6) and the carbon capture module (5) respectively to provide heat energy and generate liquid water; Liquid water is delivered to the water supply inlet of the external heat source heat exchanger (1) and the compressor assembly.

8. The method for carbon capture based on staggered energy utilization using direct steam compression according to claim 3, characterized in that: The method for carbon capture of staggered energy utilization based on direct steam compression includes a fifth working mode, which includes the following steps: The external heat source heat exchanger (1) heats the liquid water and generates low-pressure steam, and the low-pressure steam enters the compressor assembly through the steam inlet of the compressor, and at the same time, the liquid water enters the compressor assembly through the water supply inlet of the compressor assembly, is mixed with the low-pressure steam, and is compressed to generate high-quality water vapor; The heat storage module (6) releases heat to heat liquid water and obtains water vapor, and the obtained water vapor and high-grade water vapor enter the carbon capture module (5) through the carbon capture steam inlet to provide heat energy for the carbon capture regeneration operation and generate liquid water; Liquid water is transported to the heat storage module (6), the external heat source heat exchanger (1) and the water supply inlet of the compressor assembly.

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