Carbon dioxide energy storage coupling carbon capture system

Abstract

According to the carbon dioxide energy storage coupling carbon capture system, during energy storage, carbon dioxide discharged by the carbon capture system passes through a multi-stage compression cooling assembly in an energy storage pipeline, so that the carbon dioxide is in a high-pressure supercritical state and enters a high-pressure carbon dioxide storage tank to be stored. During energy release, the carbon dioxide is heated and expanded when passing through the multi-stage expansion heating assembly in the energy release pipeline. Expansion acting can be used for power generation. And the expanded carbon dioxide enters the LNG heat exchange system to be liquefied, and the carbon dioxide enters the liquid carbon dioxide storage tank after being cooled and liquefied. The heat conduction pipeline is used for conducting heat exchange in the energy storage and release process. According to the carbon dioxide energy storage coupling carbon capture system, redundant electric quantity can be stored in the energy storage process, energy release and power generation can be carried out in the power utilization peak period, and carbon dioxide can be liquefied through the cold capacity of LNG gas.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage equipment, and in particular to a carbon dioxide energy storage coupled carbon capture system. Background Art

[0002] As the contradiction between ecological environment destruction and resource constraints becomes increasingly prominent, vigorously developing renewable energy has become the main means to solve my country's energy security and environmental pollution problems. However, renewable energy, especially wind power and photovoltaic power generation, has obvious unfavorable factors such as volatility, periodicity and uncertainty. For example, photovoltaic power generation generates large amounts of electricity during the day when there is sunlight, but cannot generate electricity at night when there is no sunlight. The flue gas emitted by power plants needs to be carbon captured to reduce carbon dioxide emissions. The carbon dioxide after carbon capture needs to be compressed and liquefied and stored in storage tanks for external transportation. The compression and liquefaction process also consumes energy. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a carbon dioxide energy storage coupled carbon capture system, which aims to solve the problem in the related technology that the peak and valley phenomenon of renewable energy power generation such as wind power and photovoltaic power generation is obvious, and the carbon dioxide after carbon capture needs to be compressed and liquefied and stored in a storage tank for external transportation, which consumes energy and causes energy waste.

[0004] The present invention provides a carbon dioxide energy storage coupled carbon capture system, comprising: An energy storage pipeline, wherein at least one stage of compression and cooling components and a high-pressure carbon dioxide storage tank are connected in series on the energy storage pipeline, wherein each stage of the compression and cooling components comprises a compressor and a cooler, wherein the cooler is connected in series downstream of the corresponding compressor, and the inlet of the high-pressure carbon dioxide storage tank is connected in series downstream of the cooler located at the downstream end; An energy release pipeline, wherein at least one stage of expansion and heating components is connected in series on the energy release pipeline, wherein each stage of the expansion and heating components comprises a heater and an expander, wherein the expander is connected in series downstream of the corresponding heater, wherein the upstream end of the heater located upstream is connected to the outlet of the high-pressure carbon dioxide storage tank, and the downstream end of the expander located downstream is connected to the upstream end of the compressor located upstream; The heat transfer pipeline comprises a hot fluid storage tank and a cold fluid storage tank, wherein the liquid outlet of the cold fluid storage tank is respectively connected to the inlet of the cold fluid pipelines of the plurality of coolers, and the outlets of the cold fluid pipelines of the plurality of coolers are all connected to the inlet of the hot fluid storage tank, and the liquid outlet of the hot fluid storage tank is respectively connected to the inlet of the hot fluid pipelines of the plurality of heaters, and the outlets of the hot fluid pipelines of the plurality of heaters are all connected to the inlet of the cold fluid storage tank; An LNG heat exchange system, comprising an LNG heat exchanger and a liquid carbon dioxide storage tank, wherein the cold fluid pipeline of the LNG heat exchanger is used to be connected to the LNG pipeline of the LNG receiving station, the downstream end of the energy release pipeline is connected to the inlet of the liquid carbon dioxide storage tank through the hot fluid pipeline of the LNG heat exchanger, and the outlet of the liquid carbon dioxide storage tank is connected to the upstream end of the energy storage pipeline; A carbon capture system, wherein the inlet of the carbon capture system is connected to the smoke exhaust equipment of the power plant, and the outlet of the carbon capture system is connected to the upstream end of the energy storage pipeline.

[0005] According to the carbon dioxide energy storage coupled carbon capture system provided by the present invention, the carbon capture system comprises a flue gas treatment device, an absorption tower, a rich liquid pump, a lean and rich liquid heat exchanger, a lean liquid pump, a lean liquid cooler, a regeneration tower, a reboiler, a carbon dioxide buffer tank and a carbon dioxide compressor; The inlet of the flue gas treatment device is connected to the smoke exhaust equipment, and the outlet of the flue gas treatment device, the carbon dioxide inlet of the absorption tower, the rich liquid outlet of the absorption tower, the cold fluid pipeline of the lean-rich liquid heat exchanger, the rich liquid inlet of the regeneration tower, the lean liquid outlet of the regeneration tower, the reboiler, the lean liquid pump, the hot fluid pipeline of the lean-rich liquid heat exchanger, the lean liquid cooler and the lean liquid inlet of the absorption tower are connected in sequence, the carbon dioxide outlet of the regeneration tower is connected to the inlet of the carbon dioxide buffer tank, the outlet of the carbon dioxide buffer tank is connected to the carbon dioxide compressor, and the carbon dioxide compressor is connected to the upstream end of the energy storage pipeline.

[0006] The carbon dioxide energy storage coupled carbon capture system provided by the present invention also includes a power plant waste heat recovery system, which includes a boiler, a steam turbine, a condenser and an absorption heat pump. The steam outlet of the boiler, the steam turbine, the hot fluid pipeline of the condenser and the water inlet of the boiler are connected in series in sequence, the cold fluid pipeline of the condenser is connected in series with the hot fluid pipeline of the absorption heat pump, and the cold fluid pipeline of the absorption heat pump is connected in series with the hot fluid pipeline of the heater located downstream.

[0007] The carbon dioxide energy storage coupled carbon capture system provided by the present invention also includes a carbon dioxide heater, the upstream end of the cold fluid pipeline of the carbon dioxide heater is connected to the outlet of the liquid carbon dioxide storage tank, the downstream end of the cold fluid pipeline of the carbon dioxide heater is connected to the upstream end of the energy storage pipeline, and the hot fluid pipeline of the carbon dioxide heater is connected in series with the cold fluid pipeline of the condenser.

[0008] According to the carbon dioxide energy storage coupled carbon capture system provided by the present invention, the power plant waste heat recovery system also includes a heat recovery system, which is connected between the outlet of the hot fluid pipeline of the condenser and the water inlet of the boiler, and the heat recovery system is also connected to the steam turbine.

[0009] According to the carbon dioxide energy storage coupled carbon capture system provided by the present invention, two stages of the compression cooling components are connected in series on the energy storage pipeline.

[0010] According to the carbon dioxide energy storage coupled carbon capture system provided by the present invention, a three-stage expansion heating component is connected in series on the energy release pipeline.

[0011] According to the carbon dioxide energy storage coupled carbon capture system provided by the present invention, the top of the carbon dioxide buffer tank is also connected to the carbon dioxide inlet of the regeneration tower.

[0012] The present invention adopts the above technical solution, which has the following advantages: The carbon dioxide energy storage coupled carbon capture system provided by the present invention, when storing energy, the carbon dioxide discharged from the carbon capture system enters the energy storage pipeline, and when passing through each stage of compression and cooling components, it is compressed by the compressor and cooled by the cooler, and finally becomes a high-pressure supercritical state and enters the high-pressure carbon dioxide storage tank for storage. The energy consumed by the compressor comes from the nearby power grid, and the excess electrical energy can be converted into pressure energy and stored in carbon dioxide by the compressor during energy storage. When releasing energy, the supercritical carbon dioxide in the high-pressure carbon dioxide storage tank is output to the energy release pipeline by its own pressure, and when passing through each stage of expansion and heating components, it is heated by the heater and expanded in the expander. The expansion work can be used to generate electricity and re-transmit electricity to the nearby power grid. The expanded carbon dioxide enters the hot fluid pipeline of the LNG heat exchanger, and the LNG gas enters the cold fluid pipeline of the LNG heat exchanger to cool the carbon dioxide. After the carbon dioxide is cooled and liquefied, it enters the liquid carbon dioxide storage tank. At this time, the carbon dioxide can be transported out or returned to the energy storage pipeline. The fluid in the cold fluid storage tank of the heat transfer pipeline is supplied to multiple coolers respectively, so as to cool down the carbon dioxide flowing through the cooler during the energy storage process, absorb the heat in the carbon dioxide during the cooling process, and the fluid after absorbing heat becomes a hot fluid and enters the hot fluid storage tank. The hot fluid in the hot fluid storage tank is supplied to the heater to heat the carbon dioxide flowing through the heater during the energy release process. During the heating process, the heat in the hot fluid is supplied to the carbon dioxide, and the cooled fluid flows back to the cold fluid storage tank. The carbon dioxide energy storage coupled carbon capture system provided by the present invention utilizes the process of carbon dioxide compression and liquefaction to store excess electricity, thereby reducing energy waste, and can also release energy to generate electricity during peak electricity consumption. It can not only achieve the effect of large-scale access to renewable energy power generation, smooth and continuous power output, and peak and frequency regulation, but also improve the overall efficiency, safety, and economy of the power transmission and distribution side of the power grid. At the same time, the coldness of LNG gas can also be used to liquefy carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the process of the carbon dioxide energy storage coupled carbon capture system provided by the present invention.

[0015] Reference numerals: 110: primary compressor; 120: primary cooler; 130: secondary compressor; 140: secondary cooler; 150: high-pressure carbon dioxide storage tank; 210: primary heater; 220: primary expander; 230: secondary heater; 240: secondary expander; 250: tertiary heater; 260: tertiary expander; 310: cold fluid storage tank; 320: hot fluid storage tank; 410: flue gas treatment device; 420: absorption tower; 43 0; rich liquid pump; 440: lean and rich liquid heat exchanger; 450: lean liquid pump; 460: lean liquid cooler; 470: regeneration tower; 480: reboiler; 490: carbon dioxide buffer tank; 4100: carbon dioxide compressor; 510: LNG heat exchanger; 520: liquid carbon dioxide storage tank; 610: boiler; 620: steam turbine; 630: condenser; 640: absorption heat pump; 650: carbon dioxide heater; 660: heat recovery system. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0022] The carbon dioxide energy storage coupled carbon capture system provided by the present invention, when storing energy, the carbon dioxide discharged from the carbon capture system enters the energy storage pipeline, and when passing through each stage of compression and cooling components, it is compressed by the compressor and cooled by the cooler, and finally becomes a high-pressure supercritical state and enters the high-pressure carbon dioxide storage tank for storage. The energy consumed by the compressor comes from the nearby power grid, and the excess electrical energy can be converted into pressure energy and stored in carbon dioxide by the compressor during energy storage. When releasing energy, the supercritical carbon dioxide in the high-pressure carbon dioxide storage tank is output to the energy release pipeline by its own pressure, and when passing through each stage of expansion and heating components, it is heated by the heater and expanded in the expander. The expansion work can be used to generate electricity and re-transmit electricity to the nearby power grid. The expanded carbon dioxide enters the hot fluid pipeline of the LNG heat exchanger, and the LNG gas enters the cold fluid pipeline of the LNG heat exchanger to cool the carbon dioxide. After the carbon dioxide is cooled and liquefied, it enters the liquid carbon dioxide storage tank. At this time, the carbon dioxide can be transported out or returned to the energy storage pipeline. The fluid in the cold fluid storage tank of the heat transfer pipeline is supplied to multiple coolers respectively, so as to cool down the carbon dioxide flowing through the cooler during the energy storage process, absorb the heat in the carbon dioxide during the cooling process, and the fluid after absorbing heat becomes a hot fluid and enters the hot fluid storage tank. The hot fluid in the hot fluid storage tank is supplied to the heater to heat the carbon dioxide flowing through the heater during the energy release process. During the heating process, the heat in the hot fluid is supplied to the carbon dioxide, and the cooled fluid flows back to the cold fluid storage tank. The carbon dioxide energy storage coupled carbon capture system provided by the present invention utilizes the process of carbon dioxide compression and liquefaction to store excess electricity, thereby reducing energy waste, and can also release energy to generate electricity during peak electricity consumption. It can not only achieve the effect of large-scale access to renewable energy power generation, smooth and continuous power output, and peak and frequency regulation, but also improve the overall efficiency, safety, and economy of the power transmission and distribution side of the power grid. At the same time, the coldness of LNG gas can also be used to liquefy carbon dioxide.

[0023] Combine the following Figure 1 The carbon dioxide energy storage coupled carbon capture system of the present invention is described.

[0024] An embodiment of the present invention provides a carbon dioxide energy storage coupled carbon capture system, including an energy storage pipeline, an energy release pipeline, a carbon capture system, a heat transfer pipeline, an LNG heat exchange system and a power plant waste heat recovery system.

[0025] The energy storage pipeline includes at least one stage of compression and cooling assembly and a high-pressure carbon dioxide storage tank 150. Each stage of compression and cooling assembly includes a compressor and a cooler. The cooler is connected in series downstream of the corresponding compressor, and the inlet of the high-pressure carbon dioxide storage tank 150 is connected in series downstream of the cooler located at the downstream end.

[0026] Specifically, the energy storage pipeline may include a first-stage compression and cooling component, a second-stage compression and cooling component and a high-pressure carbon dioxide storage tank 150. The first-stage compression and cooling component includes a first-stage compressor 110 and a first-stage cooler 120. The second-stage compression and cooling component includes a second-stage compressor 130 and a second-stage cooler 140. The first-stage compressor 110, the first-stage cooler 120, the second-stage compressor 130, the second-stage cooler 140 and the high-pressure carbon dioxide storage tank 150 are connected in sequence.

[0027] The energy release pipeline includes at least one stage of expansion and heating assembly, each stage of expansion and heating assembly includes a heater and an expander, the expander is connected in series downstream of the corresponding heater, the upstream end of the upstream heater is connected to the outlet of the high-pressure carbon dioxide storage tank 150, and the downstream end of the downstream expander is connected to the upstream end of the upstream compressor.

[0028] Specifically, the energy release pipeline may include a primary expansion heating component, a secondary expansion heating component, and a tertiary expansion heating component. The primary expansion heating component includes a primary heater 210 and a primary expander 220, the secondary expansion heating component includes a secondary heater 230 and a secondary expander 240, and the tertiary expansion heating component includes a tertiary heater 250 and a tertiary expander 260. The primary heater 210, the primary expander 220, the secondary heater 230, the secondary expander 240, the tertiary heater 250, and the tertiary expander 260 are connected in sequence, the upstream end of the primary heater 210 is connected to the outlet of the high-pressure carbon dioxide storage tank 150, and the downstream end of the tertiary expander 260 is connected to the upstream end of the energy storage pipeline.

[0029] The heat transfer pipeline includes a hot fluid storage tank 320 and a cold fluid storage tank 310. The liquid outlet of the cold fluid storage tank 310 is respectively connected to the inlets of the cold fluid pipelines of multiple coolers, and the outlets of the cold fluid pipelines of multiple coolers are all connected to the inlet of the hot fluid storage tank 320. The liquid outlet of the hot fluid storage tank 320 is respectively connected to the inlets of the hot fluid pipelines of multiple heaters, and the outlets of the hot fluid pipelines of multiple heaters are all connected to the cold fluid storage tank 310.

[0030] Specifically, the heat transfer pipeline is filled with heat transfer media such as water or heat transfer oil. The outlet of the cold fluid storage tank 310 is connected to the inlet of the cold fluid pipeline of the primary cooler 120 and the secondary cooler 140 respectively, and the outlet of the cold fluid pipeline of the primary cooler 120 and the secondary cooler 140 is connected to the inlet of the hot fluid storage tank 320. The outlet of the hot fluid storage tank 320 is connected to the inlet of the hot fluid pipeline of the primary heater 210, the secondary heater 230 and the tertiary heater 250 respectively, and the outlet of the hot fluid pipeline of the primary heater 210, the secondary heater 230 and the tertiary heater 250 is connected to the inlet of the cold fluid storage tank 310.

[0031] The inlet of the carbon capture system is used to be connected to the smoke exhaust equipment of the power plant, and the outlet of the carbon capture system is used to be connected to the upstream end of the energy storage pipeline.

[0032] The carbon capture system includes a flue gas treatment device 410 , an absorption tower 420 , a rich liquid pump 430 , a lean and rich liquid heat exchanger 440 , a lean liquid pump 450 , a lean liquid cooler 460 , a regeneration tower 470 , a reboiler 480 , a carbon dioxide buffer tank 490 and a carbon dioxide compressor 4100 .

[0033] Among them, the inlet of the flue gas treatment device 410 is connected to the smoke exhaust equipment, and the outlet of the flue gas treatment device 410, the carbon dioxide inlet of the absorption tower 420, the rich liquid outlet of the absorption tower 420, the cold fluid pipeline of the lean-rich liquid heat exchanger 440, the rich liquid inlet of the regeneration tower 470, the lean liquid outlet of the regeneration tower 470, the reboiler 480, the lean liquid pump 450, the hot fluid pipeline of the lean-rich liquid heat exchanger 440, the lean liquid cooler 460 and the lean liquid inlet of the absorption tower 420 are connected in sequence, the carbon dioxide outlet of the regeneration tower 470 is connected to the inlet of the carbon dioxide buffer tank 490, the outlet of the carbon dioxide buffer tank 490 is connected to the carbon dioxide compressor 4100, the carbon dioxide compressor 4100 is connected to the upstream end of the energy storage pipeline, and the top of the carbon dioxide buffer tank 490 is also connected to the carbon dioxide inlet of the regeneration tower 470.

[0034] The LNG heat exchange system includes an LNG heat exchanger 510 and a liquid carbon dioxide storage tank 520. The cold fluid pipeline of the LNG heat exchanger 510 is used to connect to the LNG pipeline of the LNG receiving station. The downstream end of the energy release pipeline is also connected to the inlet of the liquid carbon dioxide storage tank 520 through the hot fluid pipeline of the LNG heat exchanger 510, and the outlet of the liquid carbon dioxide storage tank 520 is connected to the upstream end of the energy storage pipeline.

[0035] The waste heat recovery system of the power plant includes a boiler 610, a steam turbine 620, a condenser 630, an absorption heat pump 640, a carbon dioxide heater 650 and a heat recovery system 660. The steam outlet of the boiler 610, the steam turbine 620, the hot fluid pipeline of the condenser 630 and the water inlet of the boiler 610 are connected in series in sequence, the cold fluid pipeline of the condenser 630 is connected in series with the hot fluid pipeline of the absorption heat pump 640, and the cold fluid pipeline of the absorption heat pump 640 is connected in series with the hot fluid pipeline of the heater located downstream. The upstream end of the cold fluid pipeline of the carbon dioxide heater 650 is connected to the outlet of the liquid carbon dioxide storage tank 520, the downstream end of the cold fluid pipeline of the carbon dioxide heater 650 is connected to the upstream end of the energy storage pipeline, and the hot fluid pipeline of the carbon dioxide heater 650 is connected in series with the cold fluid pipeline of the condenser 630. The heat recovery system 660 is connected between the hot fluid outlet of the condenser 630 and the water inlet of the boiler 610 , and the heat recovery system 660 is also connected to the steam turbine 620 .

[0036] The specific working process of the carbon dioxide energy storage coupled carbon capture system provided by the present invention is as follows: During the energy storage stage, electricity from the power grid is input to the primary compressor 110 and the secondary compressor 130. The carbon dioxide captured by the carbon capture system is pressurized by the carbon dioxide compressor 4100 in the carbon dioxide buffer tank 490 and then enters the primary compressor 110 for further pressurization. After being cooled by the primary cooler 120, it enters the secondary compressor 130 for further pressurization. After being cooled by the secondary cooler 140, it becomes high-pressure supercritical carbon dioxide and finally enters the high-pressure carbon dioxide storage tank 150 for storage.

[0037] In the energy release stage, the supercritical carbon dioxide in the high-pressure carbon dioxide storage tank 150 is output outward by its own pressure, and enters the first-stage expander 220 for expansion after being heated by the first-stage heater 210, and enters the second-stage expander 240 for expansion after being heated by the second-stage heater 230, and then enters the third-stage expander 260 for expansion after being heated by the third-stage heater 250. After expansion and work to generate electricity, the electricity is input into the power grid. Part of the carbon dioxide after expansion and heating enters the LNG heat exchange system for storage, and part returns to the energy storage pipeline for the next cycle.

[0038] During the energy storage and energy accumulation stages, the water or heat transfer oil in the cold fluid storage tank 310 is pumped into the cold fluid pipelines in the primary cooler 120 and the secondary cooler 140. When flowing through the cold fluid pipelines, the water or heat transfer oil absorbs the heat of the carbon dioxide in the hot fluid pipelines of the primary cooler 120 and the secondary cooler 140 to cool the carbon dioxide. After absorbing heat, the water or heat transfer oil heats up and enters the hot fluid storage tank 320.

[0039] The water or heat transfer oil in the hot fluid storage tank 320 is pumped into the hot fluid pipelines of the first-stage heater 210, the second-stage heater 230 and the third-stage heater 250. When flowing through the hot fluid pipelines, the carbon dioxide in the cold fluid pipelines flowing through the first-stage heater 210, the second-stage heater 230 and the third-stage heater 250 absorbs the heat of the water or the heat transfer oil and heats up. After the water or the heat transfer oil cools down, it flows back into the cold fluid storage tank 310.

[0040] The carbon dioxide in the energy storage pipeline and the energy release pipeline comes from the carbon capture system of the power plant. The flue gas of the power plant passes through the flue gas treatment device 410 and enters the absorption tower 420. The carbon dioxide is absorbed by the lean liquid to form a rich liquid, which is then pumped out by the rich liquid pump 430, and then enters the regeneration tower 470 for regeneration after heat exchange through the lean-rich liquid heat exchanger 440, and is provided with heat by the reboiler 480. The regenerated lean liquid is pumped out by the lean liquid pump 450, heat exchanged through the lean-rich liquid heat exchanger 440, and further cooled by the lean liquid cooler 460 before entering the absorption tower 420 to form a cycle.

[0041] The power plant that provides carbon dioxide can also provide heat at the same time. The steam is heated by the boiler 610 of the waste heat recovery system of the power plant, passes through the turbine 620, the condenser 630 and the heat recovery system 660 in sequence, and then returns to the boiler 610.

[0042] The condenser 630 has two heat output paths. The first is to transfer the heat through the absorption heat pump 640 to the third-stage heater 250 to increase the power output of the energy storage system during the energy release stage. The second is to transfer the heat through the carbon dioxide heater 650 to convert liquid carbon dioxide into gas during the energy storage stage.

[0043] When the carbon dioxide finishes releasing its energy, it flows through the hot fluid pipeline of the LNG heat exchanger 510. At the same time, the LNG gas flows through the cold fluid pipeline of the LNG heat exchanger 510, thereby cooling the carbon dioxide flowing through the hot fluid pipeline of the LNG heat exchanger 510. By utilizing the cold energy of LNG, the cost of carbon dioxide liquefaction is reduced, and the external cold source is effectively utilized for the liquefaction of carbon dioxide, thereby improving the energy storage density of the carbon dioxide energy storage system.

[0044] The innovation of the system of the present invention is that the carbon dioxide energy storage coupled with the carbon capture system realizes time-sharing utilization of the heat of the power plant. In the energy storage stage, the waste heat of the power plant is used to gasify the liquid carbon dioxide, and in the energy release stage, the waste heat of the power plant is used to heat the carbon dioxide gas at the inlet of the expander.

[0045] Moreover, since the carbon captured in the power plant needs to be liquefied before being transported, a compressor is also needed for liquefaction, so the compressor and cooler in this application can be used together for carbon capture and carbon dioxide energy storage. Moreover, when carbon capture and carbon dioxide energy release, the LNG heat exchanger 510 can be shared, saving fixed investment.

[0046] The carbon dioxide from the carbon capture system and the waste heat from the power plant waste heat recovery system can come from either a coal-fired power plant or a gas-fired power plant.

[0047] The absorption heat pump 640 may adopt a lithium bromide absorption heat pump 640 unit, which can convert low-grade heat energy into high-grade heat energy to effectively increase the enthalpy difference before and after the expander, thereby increasing the work output of the expander.

[0048] The isentropic efficiency of the compressor and expander should not be less than 85%. The compressor and expander evenly distribute the inlet and outlet pressures of each machine according to the pressure ratio. The compressor and expander are composed of a multi-stage compressor and a multi-stage expander respectively, and heat can be transferred through the pipes between the stages.

[0049] The cooler and heater can adopt shell and tube heat exchanger or PCHE. The shell and tube heat exchanger has the advantage of easy disassembly and maintenance, while the PCHE has the advantages of high heat exchange effect and compact structure.

[0050] Pressure regulating valves are provided behind the liquid carbon dioxide storage tank 520 and the high-pressure carbon dioxide storage tank 150, and the pressure can be adjusted before entering the cooler and the heater.

[0051] The carbon dioxide energy storage coupled carbon capture system provided by the present invention has the following beneficial effects: There are two ways to utilize the waste heat recovery system of a power plant. One is that during the energy release stage, the waste heat in the condenser 630 is further improved in quality through the absorption heat pump 640 and then used to heat the temperature of the carbon dioxide entering the tertiary expansion machine 260, thereby increasing the work output of the tertiary expansion machine 260; the other is that during the energy storage stage, the waste heat in the condenser 630 is directly used to heat the liquid carbon dioxide in the carbon dioxide heater 650.

[0052] In a high-pressure carbon dioxide tank, carbon dioxide is stored in a high-pressure supercritical state, and in a liquid carbon dioxide tank, it is stored in a low-pressure liquid state. At the same time, since the density of the supercritical state and the liquid state is greater than that of the gaseous state, the carbon dioxide energy storage coupled with carbon capture system has the advantage of high energy storage density.

[0053] The captured carbon dioxide needs to be compressed and liquefied before being stored in the liquid carbon dioxide storage tank 520 for transportation, and the released carbon dioxide also needs to be liquefied for storage, so the LNG heat exchanger 510 and the liquid carbon dioxide storage tank 520 can be shared. At the same time, carbon dioxide liquefaction also needs to be compressed, and carbon dioxide energy storage also requires a compressor, and the two can also be shared. Therefore, the carbon dioxide energy storage coupled with the carbon capture system can reduce the cost of both at the same time.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A carbon dioxide energy storage coupled carbon capture system, characterized in that: include: An energy storage pipeline, wherein at least one stage of compression and cooling components and a high-pressure carbon dioxide storage tank (150) are connected in series on the energy storage pipeline, wherein each stage of the compression and cooling components comprises a compressor and a cooler, wherein the cooler is connected in series downstream of the corresponding compressor, and an inlet of the high-pressure carbon dioxide storage tank (150) is connected in series downstream of the cooler located at the downstream end; An energy release pipeline, wherein at least one stage of expansion and heating components is connected in series on the energy release pipeline, each stage of the expansion and heating components comprises a heater and an expander, the expander is connected in series downstream of the corresponding heater, the upstream end of the heater located upstream is connected to the outlet of the high-pressure carbon dioxide storage tank (150), and the downstream end of the expander located downstream is connected to the upstream end of the compressor located upstream; The heat transfer pipeline comprises a hot fluid storage tank (320) and a cold fluid storage tank (310), wherein the liquid outlet of the cold fluid storage tank (310) is respectively connected to the inlets of the cold fluid pipelines of the plurality of coolers, and the outlets of the cold fluid pipelines of the plurality of coolers are all connected to the inlet of the hot fluid storage tank (320), and the liquid outlet of the hot fluid storage tank (320) is respectively connected to the inlets of the hot fluid pipelines of the plurality of heaters, and the outlets of the hot fluid pipelines of the plurality of heaters are all connected to the inlet of the cold fluid storage tank (310); An LNG heat exchange system, comprising an LNG heat exchanger (510) and a liquid carbon dioxide storage tank (520), wherein a cold fluid pipeline of the LNG heat exchanger (510) is used to be connected to an LNG pipeline of an LNG receiving station, a downstream end of the energy release pipeline is connected to an inlet of the liquid carbon dioxide storage tank (520) via a hot fluid pipeline of the LNG heat exchanger (510), and an outlet of the liquid carbon dioxide storage tank (520) is connected to an upstream end of the energy storage pipeline; A carbon capture system, wherein the inlet of the carbon capture system is connected to the smoke exhaust equipment of the power plant, and the outlet of the carbon capture system is connected to the upstream end of the energy storage pipeline.

2. The carbon dioxide energy storage coupled carbon capture system according to claim 1, characterized in that: The carbon capture system comprises a flue gas treatment device (410), an absorption tower (420), a rich liquid pump (430), a lean-rich liquid heat exchanger (440), a lean liquid pump (450), a lean liquid cooler (460), a regeneration tower (470), a reboiler (480), a carbon dioxide buffer tank (490) and a carbon dioxide compressor (4100); The inlet of the flue gas treatment device (410) is connected to the smoke exhaust equipment, the outlet of the flue gas treatment device (410), the carbon dioxide inlet of the absorption tower (420), the rich liquid outlet of the absorption tower (420), the cold fluid pipeline of the lean-rich liquid heat exchanger (440), the rich liquid inlet of the regeneration tower (470), the lean liquid outlet of the regeneration tower (470), the reboiler (480), the lean liquid pump (450), the hot fluid pipeline of the lean-rich liquid heat exchanger (440), the lean liquid cooler (460) and the lean liquid inlet of the absorption tower (420) are connected in sequence, the carbon dioxide outlet of the regeneration tower (470) is connected to the inlet of the carbon dioxide buffer tank (490), the outlet of the carbon dioxide buffer tank (490) is connected to the carbon dioxide compressor (4100), and the carbon dioxide compressor (4100) is connected to the upstream end of the energy storage pipeline.

3. The carbon dioxide energy storage coupled carbon capture system according to claim 1, characterized in that: The invention also includes a power plant waste heat recovery system, which includes a boiler (610), a steam turbine (620), a condenser (630) and an absorption heat pump (640), wherein the steam outlet of the boiler (610), the steam turbine (620), the hot fluid pipeline of the condenser (630) and the water inlet of the boiler (610) are connected in series in sequence, the cold fluid pipeline of the condenser (630) is connected in series with the hot fluid pipeline of the absorption heat pump (640), and the cold fluid pipeline of the absorption heat pump (640) is connected in series with the hot fluid pipeline of the heater located downstream.

4. The carbon dioxide energy storage coupled carbon capture system according to claim 3, characterized in that: It also includes a carbon dioxide heater (650), wherein the upstream end of the cold fluid pipeline of the carbon dioxide heater (650) is connected to the outlet of the liquid carbon dioxide storage tank (520), the downstream end of the cold fluid pipeline of the carbon dioxide heater (650) is connected to the upstream end of the energy storage pipeline, and the hot fluid pipeline of the carbon dioxide heater (650) is connected in series with the cold fluid pipeline of the condenser (630).

5. The carbon dioxide energy storage coupled carbon capture system according to claim 3 or 4, characterized in that: The power plant waste heat recovery system also includes a heat recovery system (660), wherein the heat recovery system (660) is connected between the outlet of the hot fluid pipeline of the condenser (630) and the water inlet of the boiler (610), and the heat recovery system (660) is also connected to the steam turbine (620).

6. The carbon dioxide energy storage coupled carbon capture system according to claim 1, characterized in that: The energy storage pipeline is connected in series with two stages of compression cooling components.

7. The carbon dioxide energy storage coupled carbon capture system according to claim 1, characterized in that: The energy release pipeline is connected in series with a three-stage expansion heating component.

8. The carbon dioxide energy storage coupled carbon capture system according to claim 2, characterized in that: The top of the carbon dioxide buffer tank (490) is also connected to the carbon dioxide inlet of the regeneration tower (470).

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