CN220134041U - Coupling system of compressed carbon dioxide energy storage and carbon capture - Google Patents

Abstract

The utility model discloses a coupling system for compressed carbon dioxide energy storage and carbon capture, which includes: a carbon dioxide mixed gas storage tank, a compressor, a first heat exchanger, a condensation separator, a high-pressure liquid carbon dioxide storage tank, an evaporator, a third The second heat exchanger, turbine and low-pressure liquid carbon dioxide storage tank; the outlet of the carbon dioxide mixed gas storage tank is connected to the inlet of the first heat exchanger through the compressor, and the outlet of the first heat exchanger is connected to the inlet of the high-pressure liquid carbon dioxide storage tank through the condensation separator. ; The outlet of the high-pressure liquid carbon dioxide storage tank is connected to the inlet of the second heat exchanger through the evaporator, the outlet of the second heat exchanger is connected to the inlet of the turbine, and the outlet of the turbine is connected to the low-pressure liquid carbon dioxide storage tank through the condenser. By effectively combining carbon capture and compressed carbon dioxide energy storage, carbon dioxide as an energy storage medium can be liquefied, separated and stored at lower pressures, while significantly reducing the cost of high-pressure gas storage in compressed gas energy storage systems.

Description

A coupling system for compressed carbon dioxide energy storage and carbon capture

Technical field

The utility model relates to the technical field of energy storage systems, and in particular to a coupling system of compressed carbon dioxide energy storage and carbon capture.

Background technique

The operation of traditional power grids is always in a state of dynamic balance between power generation and load, which is commonly known as the "ready-to-use state". Therefore, the planning, operation and control of the power grid are all based on the principle of supply and demand balance, that is, the generated power must be transmitted in real time, and power consumption and generation must also be balanced in real time. With the development of economy and society, this kind of planning and construction ideas are increasingly showing flaws and deficiencies, and the dispatching, control, and management of power grids are therefore becoming increasingly difficult and complex. As the peak load in the power grid continues to increase, power grid companies must continue to invest in transmission and distribution equipment to meet the demand for peak load capacity, resulting in a low overall load factor of the system, resulting in a low comprehensive utilization rate of power assets. To solve these problems, traditional power grids are in urgent need of further upgrades or even changes. Advanced and efficient large-scale energy storage technology provides new ideas and effective technical means for the upgrading and transformation of traditional power grids.

Energy storage technology separates power generation and power consumption in time and space. The generated power no longer needs to be transmitted immediately, and power consumption and power generation no longer need to be balanced in real time. At present, mature large-scale energy storage technologies mainly include pumped hydro energy storage and compressed air energy storage. The construction of pumped storage power stations is restricted by geographical conditions, and there must be a height difference between the upstream and downstream reservoirs and the two reservoirs. Compressed air energy storage technology has the advantages of high system efficiency, good environmental performance, long service life and low construction cost. It is a large-scale clean physical energy storage technology with great development prospects. Although compressed air energy storage is a relatively mature energy storage technology, its main obstacles are the low energy storage density of the system and the system's dependence on favorable geographical conditions; liquefied compressed air energy storage with greater adaptability to geographical conditions - The extremely low-temperature operating conditions of 195°C pose great challenges to equipment safety.

Compared with air, carbon dioxide has suitable critical physical properties (critical temperature 31°C), making it easy to liquefy, and has excellent thermal properties, making it a research hotspot for compressed gas energy storage systems. However, the conventional carbon dioxide energy storage system is a closed cycle. When releasing energy, the carbon dioxide emitted by the turbine must be stored in another storage tank and cannot be directly discharged into the atmosphere. If the carbon dioxide is stored in gaseous form, the existing compressed carbon dioxide energy storage system The energy density of the system is low, it occupies a large area, and it is severely restricted by geographical conditions; if it is stored in the form of liquid carbon dioxide, it relies on low-temperature cold sources such as LNG, throttling devices, or low-temperature cold storage devices that coexist sensible and latent heat to complete the liquefaction of low-pressure carbon dioxide. This causes problems such as strong dependence on system conditions, low efficiency and energy density, and complex devices.

Utility model content

The purpose of this utility model is to provide a coupling system of compressed carbon dioxide energy storage and carbon capture. By effectively combining carbon capture and compressed carbon dioxide energy storage, carbon dioxide as an energy storage medium can be liquefied, separated and stored at a lower pressure. , while significantly reducing the cost of high-pressure gas storage in compressed gas energy storage systems.

In order to achieve the above purpose, the utility model provides a coupling system for compressed carbon dioxide energy storage and carbon capture. The system includes: a carbon dioxide mixed gas storage tank, a compressor, a first heat exchanger, a condensation separator, and high-pressure liquid carbon dioxide. Storage tanks, evaporators, secondary heat exchangers, turbines and low-pressure liquid carbon dioxide storage tanks;

The outlet of the carbon dioxide mixed gas storage tank is connected to the inlet of the first heat exchanger through the compressor, and the outlet of the first heat exchanger is connected to the inlet of the high-pressure liquid carbon dioxide storage tank through the condensation separator;

The outlet of the high-pressure liquid carbon dioxide storage tank is connected to the inlet of the second heat exchanger through the evaporator, the outlet of the second heat exchanger is connected to the inlet of the turbine, and the outlet of the turbine is connected to the low-pressure liquid carbon dioxide storage tank through the condenser.

Further, the system also includes a low-temperature heat transfer medium storage tank and a high-temperature heat transfer medium storage tank,

The outlet of the low-temperature heat transfer medium storage tank is connected to the inlet of the high-temperature heat transfer medium storage tank through a first heat exchanger, and the outlet of the high-temperature heat transfer medium storage tank is connected to the low-temperature heat transfer medium storage tank through a second heat exchanger. entrance connection.

Further, the heat transfer medium flowing between the high temperature heat transfer medium storage tank and the low temperature heat transfer medium storage tank includes: heat transfer oil, high temperature molten salt or high temperature pressurized hot water.

Further, a plurality of compressors are arranged in sequence between the carbon dioxide mixed gas storage tank and the condensation separator, and the outlet of each compressor is connected to a first heat exchanger;

A plurality of turbines are arranged in sequence between the evaporator and the condenser, and a second heat exchanger is connected to the inlet of each turbine.

Further, a plurality of the compressors are electrically connected in sequence, and the compressors are connected to the electric motor through the first clutch-gearbox;

A plurality of said turbines are electrically connected in sequence, said turbines being connected to the generator through a second clutch-gearbox.

Further, a gas pretreatment device is provided between the carbon dioxide mixed gas storage tank and the compressor.

Further, a first valve is installed on the pipeline between the condensation separator and the inlet of the high-pressure liquid carbon dioxide storage tank;

A second valve is installed on the pipeline between the outlet of the high-pressure liquid carbon dioxide storage tank and the evaporator.

Further, a third valve is installed on the pipeline between the condenser and the inlet of the low-pressure liquid carbon dioxide storage tank.

The technical effects and advantages of this utility model are: 1. As an energy storage medium, carbon dioxide can be liquefied, separated and stored at a lower pressure. The power required by the compressor is smaller, and at the same time, the high-pressure gas storage cost of the compressed gas energy storage system is significantly reduced; Capture and compressed carbon dioxide energy storage are effectively combined. Both use carbon dioxide as the working fluid and have matching working parameters, which improves the overall performance, reduces the cost of replenishing carbon dioxide for the compressed carbon dioxide energy storage system, and captures relatively pure liquid carbon dioxide. ;

2. Compared with the traditional compressed carbon dioxide energy storage closed cycle system, which generally requires a low-pressure carbon dioxide gas storage bin and covers a larger area, this system adopts an open cycle. After the carbon dioxide expands and performs work, it still has a certain pressure (about 2MPa) Re-liquefaction storage and capture, on the one hand, significantly reduces the area occupied by the entire system and increases the energy storage power density; on the other hand, the relatively high pressure significantly reduces the cooling capacity consumed in the liquefaction process and reduces the energy consumption in the liquefaction process.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the present invention may be achieved and obtained by the structure pointed out in the description and the accompanying drawings.

Description of drawings

In order to explain the technical solutions in the embodiments of the present utility model more clearly, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some implementations of the utility model. For example, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a coupling system for compressed carbon dioxide energy storage and carbon capture according to an embodiment of the present invention;

In the figure, 1. Carbon dioxide mixed gas storage tank; 2. Gas pretreatment device; 3. Electric motor; 4. First clutch-gearbox; 5. Compressor; 6. First heat exchanger; 7. High-pressure liquid carbon dioxide storage Tank; 8. Condensation separator; 9-1. Low-temperature heat transfer medium storage tank; 9-2. High-temperature heat transfer medium storage tank 10. Second heat exchanger; 11. Turbine; 12. Second clutch-gearbox; 13 , generator; 14. evaporator; 15. condenser; 16. low-pressure liquid carbon dioxide storage tank.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all implementations. example. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model.

In order to solve the deficiencies of the existing technology, the utility model discloses a coupling system for compressed carbon dioxide energy storage and carbon capture, as shown in Figure 1, including a carbon dioxide mixed gas storage tank 1, a compressor 5, and a first heat exchanger. 6. Condensation separator 8, high-pressure liquid carbon dioxide storage tank 7, evaporator 14, second heat exchanger 10, turbine 11 and low-pressure liquid carbon dioxide storage tank 16, etc.;

The carbon dioxide mixed gas is stored in the carbon dioxide mixed gas storage tank 1. The carbon dioxide mixed gas can come from coal-fired thermal power plants, gas-fired thermal power plants, cement plants and other industries.

The outlet of the carbon dioxide mixed gas storage tank 1 is connected to the inlet of the first heat exchanger 6 through the compressor 5, and the outlet of the first heat exchanger 6 is connected to the inlet of the high-pressure liquid carbon dioxide storage tank 7 through the condensation separator 8; wherein, the condensation separation Device 8 is used to separate liquefied carbon dioxide;

The outlet of the high-pressure liquid carbon dioxide storage tank 7 is connected to the inlet of the second heat exchanger 10 through the evaporator 14. The outlet of the second heat exchanger 10 is connected to the inlet of the turbine 11. The outlet of the turbine 11 is connected to the low-pressure liquid carbon dioxide through the condenser 15. storage tank.

The system also includes a low-temperature heat transfer medium storage tank 9-1 and a high-temperature heat transfer medium storage tank 9-2. The outlet of the low-temperature heat transfer medium storage tank 9-1 communicates with the high-temperature heat transfer medium storage tank 9-1 through the first heat exchanger 6. 2, the outlet of the high-temperature heat transfer medium storage tank 9-2 is connected to the inlet of the low-temperature heat transfer medium storage tank 9-1 through the second heat exchanger 10; the high-temperature heat transfer medium storage tank 9-2 is connected to the low-temperature heat transfer medium storage tank 9-1. The heat transfer medium circulating between the medium storage tanks 9-1 includes: heat transfer oil, high temperature molten salt or high temperature pressurized hot water.

Among them, the outlet of the carbon dioxide mixed gas storage tank 1 is connected to the inlet end of the gas pretreatment device 2, and the outlet end of the gas pretreatment device 2 is connected to four compressors 5 in turn; the gas pretreatment device 2 can filter and dry the carbon dioxide mixed gas. Wait for preprocessing;

As shown in Figure 1, the outlet of each compressor 5 is connected to a first heat exchanger 6; the four compressors 5 are electrically connected in sequence, and one of the compressors 5 is connected to the electric motor 3 through the first clutch-gearbox 4 Connection; the four compressors 5 are driven by the electric motor 3 and the first clutch-gearbox 4 to complete compression.

Three turbines 11 are also arranged in sequence between the evaporator 14 and the condenser 15, and the inlet of each turbine 11 is connected to a second heat exchanger 10; the three turbines 11 are electrically connected in sequence, and the three turbines 11 are electrically connected in sequence. The turbine 11 is connected to the generator 13 through the second clutch-gearbox 12; one turbine 11 is connected to the generator 13 through the second clutch-gearbox 12, and the three turbines drive power generation through the second clutch-gearbox 12. Machine 13 operates to generate electricity.

A first valve is installed on the pipeline between the condensation separator 8 and the inlet of the high-pressure liquid carbon dioxide storage tank 7; the first valve is used to control the opening and closing of the inlet of the high-pressure liquid carbon dioxide storage tank 7.

A second valve is installed on the pipeline between the outlet of the high-pressure liquid carbon dioxide storage tank 7 and the evaporator 14. The second valve is used to control the opening and closing of the outlet of the high-pressure liquid carbon dioxide storage tank 7.

A third valve is installed on the pipeline between the condenser 15 and the inlet of the low-pressure liquid carbon dioxide storage tank 16. The third valve is used to control the opening and closing of the inlet of the low-pressure liquid carbon dioxide storage tank 26.

In some specific embodiments, compressed air and other compressed gases with pressure potential energy are separated and stored in the condensation separator 8 and used in subsequent energy release systems, so that the compressed air can be fully utilized.

In some specific embodiments, each gas storage tank can be set into more than two independent chambers, or pipeline steel can be used to store and release compressed carbon dioxide in groups; this can ensure that it can still operate at full capacity and have sufficient capacity after the gas storage part is consumed. Operating adjustment range.

In some specific embodiments, carbon dioxide can be expanded in the turbine 11 to a state close to normal pressure. At this time, it is difficult to liquefy carbon dioxide, and a gas storage bin can be set up to store atmospheric gaseous carbon dioxide; it can adapt to situations such as deep peak shaving, and can be larger Limit the release of compressed carbon dioxide energy;

The specific process of running the coupled system is:

The first process of system operation is the separation and energy storage process of carbon dioxide in the mixed gas containing carbon dioxide. The mixed gas containing carbon dioxide from coal-fired thermal power plants, gas-fired thermal power plants, cement plants and other industries is stored in the carbon dioxide mixed gas storage tank 1. The carbon dioxide mixed gas passes through the gas pretreatment device 2 to obtain a relatively dry and pure mixed gas. Enter compressor 5;

The compressor 5 completes the compression driven by the electric motor 3 and the first clutch-gearbox 4 to obtain a high-temperature and high-pressure mixed gas; the temperature of the high-temperature and high-pressure mixed gas decreases after passing through the first heat exchanger 6 and then enters the condensation separator 8 The temperature drops below the carbon dioxide liquefaction temperature, causing the carbon dioxide in the mixed gas to be liquefied and separated; the separated pure liquefied carbon dioxide enters the high-pressure liquid carbon dioxide storage tank 7 for storage.

At the same time, the heat transfer medium such as pressurized water, heat transfer oil or high temperature lava flows out from the low temperature heat transfer medium storage tank 9-1, passes through the first heat exchanger 6, absorbs heat to increase the temperature, and stores it in the high temperature heat transfer medium storage tank 9-2. .

The second process of system operation is the expansion and energy release of high-pressure carbon dioxide and the capture and storage process of low-pressure liquid carbon dioxide. During the peak hours of electricity consumption, high-pressure liquid carbon dioxide flows out from the high-pressure liquid carbon dioxide storage tank 7 , passes through the evaporator 14 and then vaporizes, and then is heated and superheated by the second heat exchanger 10 to obtain high-temperature and high-pressure gaseous carbon dioxide.

High-temperature and high-pressure gaseous carbon dioxide enters the turbine 11 to expand and generate work. The turbine 11 drives the generator 13 to operate and generate electricity through the second clutch-gearbox 12 . In this process, the high-temperature heat transfer medium flows out from the high-temperature heat transfer medium storage tank 9-2, exchanges heat with carbon dioxide through the second heater 10, and then enters the low-temperature heat transfer medium storage tank 9-1. The low-pressure gaseous carbon dioxide after work is condensed and liquefied through the condenser 15 and stored in the low-pressure liquid carbon dioxide storage tank 16 to complete the capture of carbon dioxide.

The coupling system proposed by the utility model makes full use of the physical and chemical properties of carbon dioxide to complete the separation of carbon dioxide from the mixed gas and the liquefaction storage after work; at the same time, it effectively combines carbon capture and compressed carbon dioxide energy storage, and uses matching working parameters to improve It improves the overall performance of the system, reduces the cost of replenishing carbon dioxide for the compressed carbon dioxide energy storage system, and captures relatively pure liquid carbon dioxide. Compared with the traditional compressed carbon dioxide energy storage system, this system uses an open cycle and does not set up a low-pressure carbon dioxide gas tank, which reduces the system footprint and reduces equipment complexity and cost.

Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art , it is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent substitutions on some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model, All should be included in the protection scope of this utility model.

Claims (8)

1. A coupling system for compressed carbon dioxide energy storage and carbon capture, characterized in that the system includes: a carbon dioxide mixed gas storage tank (1), a compressor (5), a first heat exchanger (6), a condensation Separator (8), high-pressure liquid carbon dioxide storage tank (7), evaporator (14), second heat exchanger (10), turbine (11) and low-pressure liquid carbon dioxide storage tank (16); The outlet of the carbon dioxide mixed gas storage tank (1) is connected to the inlet of the first heat exchanger (6) through the compressor (5), and the outlet of the first heat exchanger (6) is connected to the high-pressure liquid carbon dioxide storage tank through the condensation separator (8). Tank (7) entrance; The outlet of the high-pressure liquid carbon dioxide storage tank (7) is connected to the inlet of the second heat exchanger (10) through the evaporator (14). The outlet of the second heat exchanger (10) is connected to the inlet of the turbine (11). The turbine (11) The outlet of 11) is connected to the low-pressure liquid carbon dioxide storage tank (16) through the condenser (15). 2. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 1, characterized in that the system also includes a low-temperature heat-conducting medium storage tank (9-1) and a high-temperature heat-conducting medium storage tank (9 -2), The outlet of the low-temperature heat transfer medium storage tank (9-1) is connected to the inlet of the high-temperature heat transfer medium storage tank (9-2) through the first heat exchanger (6), and the high-temperature heat transfer medium storage tank (9- The outlet of 2) is connected to the inlet of the low-temperature heat transfer medium storage tank (9-1) through the second heat exchanger (10). 3. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 2, characterized in that, The heat transfer medium flowing between the high temperature heat transfer medium storage tank (9-2) and the low temperature heat transfer medium storage tank (9-1) includes: heat transfer oil, high temperature molten salt or high temperature pressurized hot water. 4. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 2 or 3, characterized in that, A plurality of compressors (5) are arranged in sequence between the carbon dioxide mixed gas storage tank (1) and the condensation separator (8), and the outlet of each compressor (5) is connected to a first heat exchanger. device(6); A plurality of turbines (11) are arranged in sequence between the evaporator (14) and the condenser (15), and a second heat exchanger (10) is connected to the inlet of each turbine (11). ). 5. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 1, characterized in that, A plurality of the compressors (5) are electrically connected in sequence, and the compressor (5) is connected to the electric motor (3) through the first clutch-gearbox (4); A plurality of turbines (11) are electrically connected in sequence, and the turbines (11) are connected to the generator (13) through a second clutch-gearbox (12). 6. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 1 or 5, characterized in that, A gas pretreatment device (2) is provided between the carbon dioxide mixed gas storage tank (1) and the compressor (5). 7. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 1, characterized in that, A first valve is installed on the pipeline between the condensation separator (8) and the inlet of the high-pressure liquid carbon dioxide storage tank (7); A second valve is installed on the pipeline between the outlet of the high-pressure liquid carbon dioxide storage tank (7) and the evaporator (14). 8. A coupling system of compressed carbon dioxide energy storage and carbon capture according to claim 7, characterized in that, A third valve is installed on the pipeline between the condenser (15) and the inlet of the low-pressure liquid carbon dioxide storage tank (16).