Energy storage system in combination with supercritical carbon dioxide transport pipeline and control method thereof

Abstract

The application discloses a kind of energy storage systems in combination with supercritical carbon dioxide conveying pipeline and control method thereof.The energy storage system includes sequentially closed-loop connection along the transmission direction of carbon dioxide working medium in sequence gas storage unit, energy storage unit, supercritical carbon dioxide conveying pipeline and release unit, the energy storage unit and the supercritical carbon dioxide conveying pipeline are connected with condensing unit, the supercritical carbon dioxide conveying pipeline and the release unit are connected with throttling unit, the condensing unit and the throttling unit are connected with cold energy cycle unit;The cold energy cycle unit is configured to absorb and store cold energy from the throttling unit in the release stage, and also used to input stored cold energy to the condensing unit in the energy storage stage.The scheme of the application not only can reduce the investment construction cost and operating cost of energy storage system, but also can provide safe and long energy storage for oil and gas exploitation, thereby reducing the electricity cost of oil and gas exploitation.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide energy storage, and in particular to an energy storage system combined with a supercritical carbon dioxide transmission pipeline and a control method thereof. Background Art

[0002] With the continuous exploitation of traditional energy sources such as oil and natural gas, some old oil and gas fields have entered the middle and late stages of development, especially some low-permeability reservoirs, where traditional extraction methods have low recovery rates. Supercritical carbon dioxide has the advantages of being easily soluble in crude oil and causing it to expand, reducing crude oil viscosity, and reducing the interfacial tension between the displacing and displaced phases. The use of supercritical carbon dioxide flooding technology to enhance crude oil recovery has been widely used both domestically and internationally. Supercritical carbon dioxide flooding technology is often combined with carbon capture, storage, and utilization (CCUS) technology to capture and store carbon dioxide from industrial flue gases (such as those from thermal power plants). The stored carbon dioxide gas is then converted into supercritical carbon dioxide, which is then transported long distances to oil fields for oil recovery via supercritical carbon dioxide transmission pipelines. Supercritical carbon dioxide transmission pipelines are pipelines capable of storing and transporting supercritical carbon dioxide.

[0003] The power supply systems for oil and gas production often incorporate renewable energy generation equipment to meet the high demand for electricity and reduce electricity costs. However, renewable energy sources such as wind and solar power suffer from intermittency, volatility, and uncertainty, leading to temporal and spatial mismatches in power supply and demand. This problem will only worsen as the proportion of renewable energy power supply increases. Therefore, as the installed capacity of renewable energy power in the oil and gas industry continues to grow, the need for secure, long-term energy storage becomes even more pressing.

[0004] Supercritical carbon dioxide energy storage is a technology that uses supercritical carbon dioxide as a working medium for energy storage and conversion. When renewable energy sources such as wind and solar energy are at their peak power generation period, excess electricity is used to drive a compressor to compress carbon dioxide at room temperature and pressure to a supercritical state and store it in a high-pressure storage tank, completing the energy storage phase. When the power grid is at its peak power consumption period and wind and solar energy output is insufficient, the supercritical carbon dioxide is released into the expansion turbine, driving the generator to generate electricity, completing the energy release phase. Since a large amount of heat energy is generated during the compression process, this heat energy is usually stored through a heat exchanger and used to replenish the heat of the carbon dioxide during the energy release process. Due to the high pressure of supercritical carbon dioxide, a specially designed corresponding pressure vessel is required as a high-pressure storage tank to store supercritical carbon dioxide, resulting in high construction costs and a large footprint for supercritical carbon dioxide energy storage.

[0005] At present, there are no reports on the scheme of combining supercritical carbon dioxide transmission pipelines used for oil field recovery with supercritical carbon dioxide energy storage. Summary of the Invention

[0006] In view of this, the present invention provides an energy storage system combined with a supercritical carbon dioxide transmission pipeline and a control method thereof to solve the problem of how to reduce the construction cost of the supercritical carbon dioxide energy storage system.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An energy storage system combined with a supercritical carbon dioxide delivery pipeline comprises a gas storage unit, an energy storage unit, a supercritical carbon dioxide delivery pipeline, and an energy release unit, which are sequentially connected in a closed loop along the transmission direction of the carbon dioxide working medium. A condensing unit is connected between the energy storage unit and the supercritical carbon dioxide delivery pipeline, a throttling unit is connected between the supercritical carbon dioxide delivery pipeline and the energy release unit, and a cold energy circulation unit is connected between the condensing unit and the throttling unit.

[0009] The cold energy circulation unit is configured to absorb and store cold energy from the throttling unit during the energy release phase, and to input the stored cold energy into the condensing unit during the energy storage phase.

[0010] In a specific embodiment, the condensing unit includes a condenser and a carbon dioxide delivery pump connected to each other, the condenser is connected to the energy storage unit, and the carbon dioxide delivery pump is connected to the supercritical carbon dioxide delivery pipeline; the throttling unit includes a throttle valve and a heat recovery heat exchanger connected to each other, the throttle valve is connected to the supercritical carbon dioxide delivery pipeline, and the heat recovery heat exchanger is connected to the energy release unit; the cold energy circulation unit is connected between the condenser and the heat recovery heat exchanger.

[0011] In a specific embodiment, the cold energy circulation unit includes a low-temperature cold storage container and a normal-temperature cold storage container, and the low-temperature cold storage container and the normal-temperature cold storage container are cyclically connected to the condenser and the regenerative heat exchanger through a circulation pipeline; in the energy release stage, the normal-temperature cold storage container transports the stored normal-temperature heat exchange medium to the regenerative heat exchanger for heat exchange and absorption of cold energy, and obtains low-temperature heat exchange medium, which is transported to the low-temperature cold storage container for storage; in the energy storage stage, the low-temperature cold storage container transports the stored low-temperature heat exchange medium to the condenser for heat exchange and provides cold energy, and obtains normal-temperature heat exchange medium, which is transported to the normal-temperature cold storage container for storage;

[0012] The normal temperature heat exchange medium is a heat exchange medium with a temperature of 25°C to 30°C, and the low temperature heat exchange medium is a heat exchange medium with a temperature below 20°C.

[0013] In a specific embodiment, the throttle valve is configured to reduce the pressure and temperature of the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline to obtain carbon dioxide gas at normal pressure and a temperature of 5°C~10°C, which is then delivered to the heat exchanger, and then delivered to the energy release unit after heat exchange and output of cold energy through the heat exchanger.

[0014] In a specific embodiment, the condenser is configured to perform heat exchange cooling on the high-temperature and high-pressure carbon dioxide gas received from the energy storage unit to obtain supercritical carbon dioxide that matches the delivery parameters of the supercritical carbon dioxide delivery pipeline, and deliver it to the supercritical carbon dioxide delivery pipeline via the carbon dioxide delivery pump.

[0015] In a specific embodiment, the energy storage unit includes a compressor and an energy storage heat exchanger connected in sequence between the gas storage unit and the condensing unit, and the energy release unit includes an energy release heat exchanger and a turbine connected in sequence between the throttling unit and the gas storage unit; a thermal energy circulation unit is connected between the energy storage heat exchanger and the energy release heat exchanger.

[0016] In a specific embodiment, the gas storage unit includes a gas storage device and a carbon dioxide adsorption storage device connected in parallel between the output end of the energy release unit and the input end of the energy storage unit; the carbon dioxide adsorption storage device is configured to absorb and store the carbon dioxide gas output from the energy release unit by adsorption during the energy release stage, and to release the carbon dioxide gas by desorption during the energy storage stage and input it into the energy storage unit.

[0017] In a specific embodiment, the carbon dioxide adsorption storage device is a carbon dioxide adsorption storage device based on an amine absorption method, and the carbon dioxide adsorption storage device includes an absorption tower and a desorption tower that are cyclically connected through a lean liquid transmission pipeline and a rich liquid transmission pipeline. The absorption tower is connected to the output end of the energy release unit through a gas input pipeline, and the desorption tower is connected to the input end of the energy storage unit through a gas output pipeline.

[0018] Another aspect of the present invention is to provide a control method for the energy storage system combined with the supercritical carbon dioxide transmission pipeline as described above, the control method comprising:

[0019] In the energy release stage, the throttling unit decompresses and cools the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline and outputs cold energy, obtaining carbon dioxide gas that is delivered to the energy release unit; the energy release unit heats and expands the carbon dioxide gas and then performs work externally, obtaining normal-pressure carbon dioxide gas that is delivered to the gas storage unit for storage; wherein, the cold energy circulation unit absorbs and stores the cold energy output from the throttling unit;

[0020] During the energy storage stage, the energy storage unit compresses the normal-pressure carbon dioxide gas in the gas storage unit to obtain high-temperature and high-pressure carbon dioxide gas, which is then transported to the condensing unit; the condensing unit cools the high-temperature and high-pressure carbon dioxide gas to obtain supercritical carbon dioxide that matches the transport parameters of the supercritical carbon dioxide transport pipeline, which is then transported to the supercritical carbon dioxide transport pipeline; wherein the cold energy circulation unit provides cold energy to the condensing unit for cooling the high-temperature and high-pressure carbon dioxide gas.

[0021] In a specific embodiment, the gas storage unit includes a gas storage device and a carbon dioxide adsorption storage device connected in parallel between the output end of the energy release unit and the input end of the energy storage unit; the control method includes:

[0022] During the energy release phase, the carbon dioxide adsorption storage device is controlled to operate in a carbon dioxide adsorption and storage mode and to operate synchronously with the energy release unit, so that the atmospheric pressure carbon dioxide gas output from the energy release unit is simultaneously delivered to the gas storage device and the carbon dioxide adsorption storage device for storage respectively;

[0023] During the energy storage stage, the carbon dioxide adsorption storage device is controlled to desorb and release carbon dioxide and operate synchronously with the energy storage unit, and the gas storage device and the carbon dioxide adsorption storage device simultaneously provide carbon dioxide gas to the energy storage unit.

[0024] The energy storage system and control method thereof provided in the embodiments of the present invention in combination with a supercritical carbon dioxide transmission pipeline have the following beneficial effects compared to the prior art:

[0025] (1) The supercritical carbon dioxide transmission pipeline used for oil field recovery is combined with the supercritical carbon dioxide energy storage system, and the supercritical carbon dioxide transmission pipeline is used as the high-pressure energy storage space in the energy storage system. There is no need to set up an additional high-pressure storage tank like in the traditional energy storage system, thereby greatly reducing the investment and construction cost of the supercritical carbon dioxide energy storage system and reducing the area occupied by the energy storage system.

[0026] (2) Based on the characteristics of supercritical carbon dioxide transmission pipelines that can store and transport supercritical carbon dioxide working medium, the energy storage system can carry out long-term energy storage work, especially meeting the safety and long-term energy storage needs of the oil and gas extraction industry. In addition, the energy storage system can store energy when electricity is sufficient and release energy when electricity is insufficient, participating in the peak and frequency regulation of electricity used in oil and gas extraction, ensuring the stability of power supply for oil and gas extraction and reducing the electricity cost of oil and gas extraction.

[0027] (3) The energy storage system is provided with a cold energy circulation unit: in the energy release stage, the cold energy circulation unit absorbs and stores the cold energy released when the carbon dioxide working fluid changes from a supercritical state to a normal pressure state; in the energy storage stage, the cold energy circulation unit can input the stored cold energy into the condensation unit to cool the high-temperature and high-pressure carbon dioxide gas, and obtain supercritical carbon dioxide that matches the transmission parameters of the supercritical carbon dioxide transmission pipeline for storage. In this way, the energy storage system can realize the internal circulation of cold energy, which not only reduces energy waste, but also reduces the energy storage system's dependence on external energy (cold source), greatly improving the overall energy efficiency of the system and reducing the operating cost of the energy storage system.

[0028] Taking the above aspects into consideration, the solution proposed by the present invention organically combines the supercritical carbon dioxide transmission pipeline used for oil field recovery with the supercritical carbon dioxide energy storage system, which not only reduces the investment, construction and operating costs of the energy storage system, but also provides safe and long-term energy storage for oil and gas production, thereby ensuring the stability of power supply for oil and gas production and reducing the electricity cost of oil and gas production, thereby achieving dual benefits and greatly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the energy storage system in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in and described with reference to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0031] It should be noted that the same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted.

[0033] The embodiment of the present invention first provides an energy storage system combined with a supercritical carbon dioxide transmission pipeline, such as Figure 1 As shown, the energy storage system mainly includes a gas storage unit 1, an energy storage unit 2, a supercritical carbon dioxide delivery pipeline 3, and an energy release unit 4. The gas storage unit 1, the energy storage unit 2, the supercritical carbon dioxide delivery pipeline 3, and the energy release unit 4 are sequentially connected in a closed loop along the transmission direction of the carbon dioxide working medium. A condensing unit 5 is connected between the energy storage unit 2 and the supercritical carbon dioxide delivery pipeline 3, and a throttling unit 6 is connected between the supercritical carbon dioxide delivery pipeline 3 and the energy release unit 4.

[0034] Among them, the gas storage unit 1 is used to store gaseous carbon dioxide at normal pressure, and the supercritical carbon dioxide transmission pipeline 3 is a pipeline that can store and transport supercritical carbon dioxide, specifically to transport the supercritical carbon dioxide at the carbon capture end to the oil field over a long distance to utilize carbon dioxide for oil recovery. The gaseous carbon dioxide flowing out of the gas storage unit 1 is converted into high-temperature and high-pressure carbon dioxide gas with a preset energy storage pressure by the energy storage unit 2, and is processed by the condensation unit 5 to form supercritical carbon dioxide, which flows into the supercritical carbon dioxide transmission pipeline 3, completing energy storage in the process. The supercritical carbon dioxide output from the supercritical carbon dioxide transmission pipeline 3 is decompressed and cooled by the throttling unit 6 and then input into the energy release unit 4, where it absorbs heat energy and releases energy to be converted into gaseous carbon dioxide at normal pressure, and flows into the gas storage unit 1, completing energy release and application in the process. Typically, the energy storage unit 2 compresses the gaseous carbon dioxide during off-peak periods or when utilizing wind and solar power curtailment, converts it into supercritical carbon dioxide through the condensing unit 5, and inputs it into the supercritical carbon dioxide transmission pipeline 3, converting the energy into compression energy and thermal energy for storage; during peak periods of electricity consumption, the throttling unit 6 first processes the supercritical carbon dioxide into subcritical carbon dioxide, and then the energy release unit 4 heats and expands the subcritical carbon dioxide to perform work, releasing the stored energy and converting it into electrical energy for use.

[0035] The specific components of the gas storage unit 1, the energy storage unit 2, and the energy release unit 4 can be implemented with reference to existing technologies. The gas storage unit 1 is also known in the prior art as a gas storage silo, gas storage reservoir, or gas storage assembly, for example, as disclosed in existing patent applications CN119289275A, CN116221616A, CN117628836A, and CN116857027A. As previously mentioned, the supercritical carbon dioxide delivery pipeline 3 is a pipeline for transporting supercritical carbon dioxide over long distances to oil fields and can be understood as a storage container for supercritical carbon dioxide.

[0036] Based on the energy storage system described above, the supercritical carbon dioxide transmission pipeline 3 used to transport carbon dioxide to the oil field is combined with the supercritical carbon dioxide energy storage system. The supercritical carbon dioxide transmission pipeline 3 serves as the high-pressure energy storage space in the energy storage system, eliminating the need for additional high-pressure storage tanks (such as liquid carbon dioxide storage tanks or supercritical carbon dioxide storage tanks) as in traditional energy storage systems. This greatly reduces the investment and construction costs of the supercritical carbon dioxide energy storage system and also reduces the area occupied by the energy storage system. Furthermore, based on the ability of the supercritical carbon dioxide transmission pipeline 3 to store and transport the supercritical carbon dioxide working medium, the energy storage system is capable of long-term energy storage, particularly meeting the safe and long-term energy storage needs of the oil and gas production industry. Furthermore, the energy storage system can store energy when electricity is sufficient and release energy when electricity is insufficient, participating in the peak and frequency regulation of electricity used in oil and gas production, ensuring the stability of the power supply for oil and gas production and reducing the electricity costs of oil and gas production.

[0037] As a specific example, in this embodiment, Figure 1 As shown, the energy storage unit 2 mainly includes a compressor 21 and an energy storage heat exchanger 22 connected between the gas storage unit 1 and the condensing unit 5. The gaseous carbon dioxide in the gas storage unit 1 is compressed by the compressor 21, then cooled by heat exchange in the energy storage heat exchanger 22, and then input into the condensing unit 5. The condensing unit 5 processes the gas into supercritical carbon dioxide that matches the delivery parameters of the supercritical carbon dioxide delivery pipeline 3 and delivers it to the supercritical carbon dioxide delivery pipeline 3.

[0038] As a specific example, in this embodiment, Figure 1 As shown, the energy release unit 4 mainly includes an energy release heat exchanger 41 and a turbine 42 connected between the throttling unit 6 and the gas storage unit 1. The carbon dioxide gas output from the throttling unit 6 is heated by the energy release heat exchanger 41 and then input into the turbine 42 to perform external work (such as electricity generation) to release energy, which is converted into gaseous carbon dioxide at normal pressure and stored in the gas storage unit 1.

[0039] Furthermore, a thermal energy circulation unit 7 is connected between the energy storage heat exchanger 22 and the energy release heat exchanger 41 .

[0040] The thermal energy circulation unit 7 is primarily used to absorb and store the heat energy generated by the compression of carbon dioxide gas by the energy storage unit 2 during the energy storage phase. During the energy release phase, the stored heat energy is used to heat the carbon dioxide gas in the energy release unit 4, thereby achieving thermal energy recycling. The specific composition and structure of the thermal energy circulation unit 7 can be implemented with reference to existing technologies.

[0041] As a preferred solution, in this embodiment, Figure 1As shown, a cold energy cycle unit 8 is connected between the condensing unit 5 and the throttling unit 6, and is configured to absorb and store cold energy from the throttling unit 6 in the energy releasing stage, and to input the stored cold energy to the condensing unit 5 in the energy storing stage.

[0042] In the energy releasing stage, the cold energy cycle unit 8 absorbs and stores the cold energy released when the carbon dioxide working medium changes from a supercritical state to a normal pressure state. In the energy storing stage, the cold energy cycle unit 8 can input the stored cold energy to the condensing unit 5, so as to cool the high-temperature and high-pressure carbon dioxide gas and store the supercritical carbon dioxide with parameters matching the supercritical carbon dioxide delivery pipeline 3. Thus, the energy storage system can realize internal circulation of cold energy, which not only reduces energy waste, but also reduces the dependence of the energy storage system on external energy (cold source), greatly improves the overall energy efficiency of the system, and reduces the operating cost of the energy storage system.

[0043] In specific solutions, as shown in the accompanying drawings, Figure 1 The condensing unit 5 includes a condenser 51 and a carbon dioxide delivery pump 52 connected to each other, the condenser 51 is connected to the energy storage unit 2, and the carbon dioxide delivery pump 52 is connected to the supercritical carbon dioxide delivery pipeline 3. The throttling unit 6 includes a throttling valve 61 and a regenerative heat exchanger 62 connected to each other, the throttling valve 61 is connected to the supercritical carbon dioxide delivery pipeline 3, and the regenerative heat exchanger 62 is connected to the energy releasing unit 4. The cold energy cycle unit 8 is connected between the condenser 51 and the regenerative heat exchanger 62.

[0044] In the energy releasing stage, the supercritical carbon dioxide output from the supercritical carbon dioxide delivery pipeline 3 is throttled and depressurized by the throttling valve 61 to form a normal pressure and low temperature carbon dioxide gas input to the regenerative heat exchanger 62. After heat exchange in the regenerative heat exchanger 62, on the one hand, cold energy is output to the cold energy cycle unit 8, and on the other hand, the temperature of the carbon dioxide gas is increased and input to the energy releasing unit 4. As a preferred solution, the throttling valve 61 is configured to depressurize and cool the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline 3 to obtain a carbon dioxide gas with a normal pressure and a temperature of 5-10℃, which is delivered to the regenerative heat exchanger 62, and after heat exchange in the regenerative heat exchanger 62 and output of cold energy, is delivered to the energy releasing unit 4.

[0045] During the energy storage phase, the high-temperature, high-pressure carbon dioxide gas output by the energy storage unit 2 is input into the condenser 51, and heat exchange is performed using the cold energy provided by the cold energy circulation unit 8 as a cold source, so that the carbon dioxide gas is converted into supercritical carbon dioxide, which is then driven by the carbon dioxide delivery pump 52 and input into the supercritical carbon dioxide delivery pipeline 3. As a preferred solution, the condenser 51 is configured to perform heat exchange cooling on the high-temperature, high-pressure carbon dioxide gas received from the energy storage unit 2 to obtain supercritical carbon dioxide that matches the delivery parameters of the supercritical carbon dioxide delivery pipeline 3, and is delivered to the supercritical carbon dioxide delivery pipeline 3 via the carbon dioxide delivery pump 52.

[0046] In specific plans, such as Figure 1 As shown, the cold energy circulation unit 8 includes a low-temperature cold storage container 81 and a normal-temperature cold storage container 82. The low-temperature cold storage container 81 and the normal-temperature cold storage container 82 are circulated in communication with the condenser 51 and the regenerative heat exchanger 62 via a circulation pipeline 83. During the energy release phase, the normal-temperature cold storage container 81 transports the stored normal-temperature heat exchange medium to the regenerative heat exchanger 62 for heat exchange and absorption of cold energy, obtaining low-temperature heat exchange medium that is transported to the low-temperature cold storage container 82 for storage; during the energy storage phase, the low-temperature cold storage container 82 transports the stored low-temperature heat exchange medium to the condenser 51 for heat exchange and provides cold energy, obtaining normal-temperature heat exchange medium that is transported to the normal-temperature cold storage container 81 for storage. As a preferred solution, the normal-temperature heat exchange medium is a heat exchange medium with a temperature of 25°C to 30°C, and the low-temperature heat exchange medium is a heat exchange medium with a temperature below 20°C.

[0047] As a preferred solution, in this embodiment, Figure 1 As shown, the gas storage unit 1 includes a gas storage device 11 and a carbon dioxide adsorption storage device 12 connected in parallel between the output end of the energy release unit 4 and the input end of the energy storage unit 2. The carbon dioxide adsorption storage device 12 is configured to absorb and store carbon dioxide gas output from the energy release unit 4 by adsorption during the energy release phase, and to release carbon dioxide gas by desorption during the energy storage phase for input to the energy storage unit 2. In other words, the gas storage device 11 and the carbon dioxide adsorption storage device 12 work together to store carbon dioxide gas.

[0048] In a traditional carbon dioxide energy storage system, a large building gas storage device (such as a flexible gas bag) is needed to store carbon dioxide gas, which occupies a large area and is not conducive to the construction of a carbon dioxide energy storage system combined with an oil field environment and a supercritical carbon dioxide pipeline. Although the separate adsorption storage device has high storage density, it is limited by the adsorption and desorption rate, and it is difficult to match the flow requirements of carbon dioxide gas output and input in the energy storage stage and the energy release stage. Therefore, in the present application, the traditional gas storage device 11 and the carbon dioxide adsorption storage device 12 are combined, the carbon dioxide adsorption storage device 12 has higher storage density and smaller area, and the carbon dioxide gas is stored together with the gas storage device 11, which can meet the gas flow requirements in the energy storage stage and the energy release stage. Therefore, the gas storage unit 1 can greatly reduce the area occupied under the condition of storing the same amount of carbon dioxide gas.

[0049] The carbon dioxide adsorption storage device 12 can select existing various types of adsorption storage devices. As a specific case, in the present embodiment, the carbon dioxide adsorption storage device 12 is a carbon dioxide adsorption storage device based on the amine absorption method. Specifically, as shown in Figure 1 The carbon dioxide adsorption storage device 12 includes an absorption tower 123 and a desorption tower 124 connected in circulation through a lean liquid conveying pipeline 121 and a rich liquid conveying pipeline 122, the absorption tower 123 is connected to the output end of the energy release unit 4 through a gas input pipeline 126, and the desorption tower 124 is connected to the input end of the energy storage unit 2 through a gas output pipeline 125. The lean liquid conveying pipeline 121 and the rich liquid conveying pipeline 122 are coupled to each other through a lean-rich heat exchanger 127, so that the lean liquid conveyed by the lean liquid conveying pipeline 121 and the rich liquid conveyed by the rich liquid conveying pipeline 122 can be heat exchanged.

[0050] During the energy release phase, a portion of the carbon dioxide gas output from the energy release unit 4 is input into the gas storage device 11, and the remaining portion is input into the absorption tower 123 via the gas input pipeline 126. In the absorption tower 123, the lean liquid input from the lean liquid transmission pipeline 121 absorbs the carbon dioxide gas to form a rich liquid, which is then stored in the absorption tower 123. During the energy release phase, on the one hand, the gas storage device 11 inputs carbon dioxide gas into the energy storage unit 2; on the other hand, the rich liquid stored in the absorption tower 123 is transported via the rich liquid transmission pipeline 122 to the desorption tower 124. The desorption tower 124 desorbs the rich liquid to generate lean liquid and carbon dioxide gas. The carbon dioxide gas is input into the energy storage unit 2 via the gas output pipeline 125, and the lean liquid is transported via the lean liquid transmission pipeline 121 to the lean-rich heat exchanger 127, where it exchanges heat with the rich liquid transported from the rich liquid transmission pipeline 122 before being stored. After heat exchange, the lean liquid can be directly stored in the lean-rich heat exchanger 127, or a storage container can be added to transport it to the absorption tower 123 during the energy release stage.

[0051] It should be noted that the lean liquid refers to the amine adsorption liquid regenerated after desorption in the desorption tower 124 , and the rich liquid refers to the amine adsorption liquid after adsorbing carbon dioxide gas in the absorption tower 123 .

[0052] Based on the energy storage system combined with the supercritical carbon dioxide delivery pipeline provided in the above embodiment, the embodiment of the present invention also provides a control method for the energy storage system. Specifically, the control method:

[0053] (1) During the energy release phase: The throttling unit 6 decompresses and cools the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline 3 and outputs cold energy, obtaining carbon dioxide gas that is delivered to the energy release unit 4. The energy release unit 4 then heats and expands the carbon dioxide gas and performs work externally, obtaining atmospheric-pressure carbon dioxide gas that is delivered to the gas storage unit 1 for storage. During the energy release phase, the cold energy circulation unit 8 absorbs and stores the cold energy output from the throttling unit 6.

[0054] (2) During the energy storage phase: The energy storage unit 2 compresses the atmospheric-pressure carbon dioxide gas in the gas storage unit 1 to obtain high-temperature, high-pressure carbon dioxide gas, which is then delivered to the condensing unit 5. The condensing unit 5 then cools the high-temperature, high-pressure carbon dioxide gas to obtain supercritical carbon dioxide that matches the delivery parameters of the supercritical carbon dioxide delivery pipeline 3 and delivers it to the supercritical carbon dioxide delivery pipeline 3. During the energy storage phase, the cold energy circulation unit 8 provides cold energy to the condensing unit 5 for cooling the high-temperature, high-pressure carbon dioxide gas.

[0055] As described above, in the preferred solution, the gas storage unit 1 comprises the gas storage device 11 and the carbon dioxide adsorption storage device 12 connected in parallel between the output end of the energy release unit 4 and the input end of the energy storage unit 2. Based on this, the control method further comprises:

[0056] In the energy release phase, the carbon dioxide adsorption storage device 12 is controlled to be in the adsorption storage carbon dioxide working condition and operates synchronously with the energy release unit 4, so that the normal pressure carbon dioxide gas output from the energy release unit 4 is simultaneously transported to the gas storage device 11 and the carbon dioxide adsorption storage device 12 for storage respectively.

[0057] In the energy storage phase, the carbon dioxide adsorption storage device 12 is controlled to be in the desorption release carbon dioxide working condition and operates synchronously with the energy storage unit 2, so that the carbon dioxide gas is simultaneously provided to the energy storage unit 2 from the gas storage device 11 and the carbon dioxide adsorption storage device 12.

[0058] In summary, the energy storage system and the control method thereof provided by the above embodiments of the present application can not only reduce the investment construction cost and the operation cost of the energy storage system, but also provide safe and long-time energy storage for oil and gas exploitation, thereby ensuring the stability of power supply for oil and gas exploitation and reducing the electricity cost of oil and gas exploitation, and can also reduce the floor area of the energy storage system, thereby achieving multiple benefits and greatly reducing the production cost.

[0059] The above is only a specific embodiment of the present application, and it should be noted that for ordinary skilled persons in the technical field, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. An energy storage system combined with a supercritical carbon dioxide delivery pipeline, characterized in that: It includes a gas storage unit, an energy storage unit, a supercritical carbon dioxide delivery pipeline and an energy release unit which are sequentially connected in a closed loop along the transmission direction of the carbon dioxide working medium, a condensing unit is connected between the energy storage unit and the supercritical carbon dioxide delivery pipeline, and a throttling unit is connected between the supercritical carbon dioxide delivery pipeline and the energy release unit; The energy storage unit includes a compressor and an energy storage heat exchanger sequentially connected between the gas storage unit and the condensing unit; the energy release unit includes an energy release heat exchanger and a turbine sequentially connected between the throttling unit and the gas storage unit; a heat energy circulation unit is connected between the energy storage heat exchanger and the energy release heat exchanger; A cold energy circulation unit is connected between the condensing unit and the throttling unit, and the cold energy circulation unit is configured to absorb and store cold energy from the throttling unit in the energy release stage, and to input the stored cold energy into the condensing unit in the energy storage stage; the condensing unit includes a condenser and a carbon dioxide delivery pump that are interconnected, the condenser is connected to the energy storage unit, the carbon dioxide delivery pump is connected to the supercritical carbon dioxide delivery pipeline, the throttling unit includes a throttle valve and a regenerative heat exchanger that are interconnected, the throttle valve is connected to the supercritical carbon dioxide delivery pipeline, the regenerative heat exchanger is connected to the energy release unit, and the cold energy circulation unit is connected between the condenser and the regenerative heat exchanger; The gas storage unit includes a gas storage device and a carbon dioxide adsorption storage device connected in parallel between the output end of the energy release unit and the input end of the energy storage unit; the carbon dioxide adsorption storage device is configured to absorb and store carbon dioxide gas output from the energy release unit by adsorption during the energy release phase, and to release carbon dioxide gas by desorption during the energy storage phase and input it into the energy storage unit; In which, during the energy release stage, the normal-pressure carbon dioxide gas output from the energy release unit is simultaneously transported to the gas storage device and the carbon dioxide adsorption storage device for storage respectively; in the energy storage stage, the gas storage device and the carbon dioxide adsorption storage device simultaneously provide carbon dioxide gas to the energy storage unit.

2. The energy storage system according to claim 1, characterized in that The cold energy circulation unit includes a low-temperature cold storage container and a normal-temperature cold storage container, and the low-temperature cold storage container and the normal-temperature cold storage container are cyclically connected to the condenser and the regenerative heat exchanger through a circulation pipeline; in the energy release stage, the normal-temperature cold storage container transports the stored normal-temperature heat exchange medium to the regenerative heat exchanger for heat exchange and absorption of cold energy, and obtains low-temperature heat exchange medium which is transported to the low-temperature cold storage container for storage; in the energy storage stage, the low-temperature cold storage container transports the stored low-temperature heat exchange medium to the condenser for heat exchange and provides cold energy, and obtains normal-temperature heat exchange medium which is transported to the normal-temperature cold storage container for storage; The normal temperature heat exchange medium is a heat exchange medium with a temperature of 25°C to 30°C, and the low temperature heat exchange medium is a heat exchange medium with a temperature below 20°C.

3. The energy storage system according to claim 2, characterized in that: The throttle valve is configured to reduce the pressure and temperature of the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline to obtain carbon dioxide gas at normal pressure and a temperature of 5°C~10°C, which is delivered to the heat exchanger, and then delivered to the energy release unit after heat exchange and output of cold energy through the heat exchanger.

4. The energy storage system according to claim 2, characterized in that: The condenser is configured to perform heat exchange cooling on the high-temperature and high-pressure carbon dioxide gas received from the energy storage unit to obtain supercritical carbon dioxide that matches the delivery parameters of the supercritical carbon dioxide delivery pipeline, and deliver it to the supercritical carbon dioxide delivery pipeline via the carbon dioxide delivery pump.

5. The energy storage system according to claim 1, characterized in that: The carbon dioxide adsorption storage device is a carbon dioxide adsorption storage device based on the amine absorption method, and includes an absorption tower and a desorption tower that are cyclically connected through a lean liquid transmission pipeline and a rich liquid transmission pipeline. The absorption tower is connected to the output end of the energy release unit through a gas input pipeline, and the desorption tower is connected to the input end of the energy storage unit through a gas output pipeline.

6. A control method for an energy storage system combined with a supercritical carbon dioxide transmission pipeline according to any one of claims 1 to 5, characterized in that: The control method includes: In the energy release stage, the throttling unit decompresses and cools the supercritical carbon dioxide received from the supercritical carbon dioxide delivery pipeline and outputs cold energy, obtaining carbon dioxide gas that is delivered to the energy release unit; the energy release unit heats and expands the carbon dioxide gas and then performs work externally, obtaining normal-pressure carbon dioxide gas that is delivered to the gas storage unit for storage; wherein, the cold energy circulation unit absorbs and stores the cold energy output from the throttling unit; During the energy storage phase, the energy storage unit compresses the atmospheric-pressure carbon dioxide gas in the gas storage unit to obtain high-temperature and high-pressure carbon dioxide gas, which is then transported to the condensing unit. The condensing unit cools the high-temperature and high-pressure carbon dioxide gas to obtain supercritical carbon dioxide that matches the transport parameters of the supercritical carbon dioxide transport pipeline, which is then transported to the supercritical carbon dioxide transport pipeline. The cold energy circulation unit provides cold energy to the condensing unit for cooling the high-temperature and high-pressure carbon dioxide gas. In the energy release phase, the carbon dioxide adsorption storage device is controlled to operate in a carbon dioxide adsorption and storage mode and to operate synchronously with the energy release unit, so that the atmospheric pressure carbon dioxide gas output from the energy release unit is simultaneously delivered to the gas storage device and the carbon dioxide adsorption storage device for storage respectively; In the energy storage stage, the carbon dioxide adsorption storage device is controlled to desorb and release carbon dioxide and operate synchronously with the energy storage unit, and the gas storage device and the carbon dioxide adsorption storage device simultaneously provide carbon dioxide gas to the energy storage unit.

Images