Energy storage system

Abstract

The utility model provides an energy storage system which comprises a gas storage, an energy storage system and a control system. The air energy storage module can store and release energy through compression and expansion of air and is connected with the air storage; the carbon dioxide energy storage module can store and release energy by utilizing the phase change of carbon dioxide, and is connected with the gas storage; the pumped storage module comprises a reservoir arranged on the ground, and the reservoir is connected with the gas storage; wherein the air, the carbon dioxide and the water in the reservoir alternately enter the gas storage, and the sequence that the water enters the gas storage is located between the carbon dioxide and the air, so that the carbon dioxide and the air are isolated. Therefore, the pumped storage module and the gas storage are arranged in the underground space, the overground space is saved, and the utilization rate of the space is increased; the three energy storage modules are coupled to store energy, so that the energy storage capacity is doubled, the energy storage density is greatly improved, and the unit cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage system. Background Art

[0002] Pumped storage is an excellent large-scale electricity storage method, with an installed capacity accounting for more than 80% of the world's total energy storage capacity. However, pumped storage has a low energy density and specific requirements for geographical conditions. Further large-scale construction in the future will encounter development bottlenecks. Therefore, both at home and abroad, methods to improve pumped storage are being actively studied, including underground pumped storage. Introducing compressed air storage technology, such as compressed air storage and compressed carbon dioxide storage, into pumped storage systems to build hybrid forms of energy storage can complement each other's advantages, solve the difficulties in developing pumped storage, and improve technical and economic efficiency. Utility Model Content

[0003] In view of this, the present application provides an energy storage system, which couples a pumped storage module, an air storage module and a carbon dioxide storage module, and the pumped storage module and the gas storage reservoir are arranged underground, which not only improves the utilization rate of space but also doubles the energy storage capacity, greatly improves the energy storage density, and reduces the unit cost. In order to achieve the above purpose, the present application provides the following technical solutions:

[0004] An energy storage system, comprising:

[0005] Gas storage, located underground;

[0006] An air energy storage module, which can store and release energy by compression and expansion of air and is connected to the gas storage reservoir;

[0007] A carbon dioxide energy storage module, which can utilize the phase change of the carbon dioxide to store and release energy and is connected to the gas storage reservoir;

[0008] A pumped storage module comprises a reservoir arranged on the ground, wherein the reservoir is connected to the gas storage reservoir;

[0009] The air, the carbon dioxide and the water in the reservoir enter the gas storage reservoir alternately, and the water enters the gas storage reservoir in an order between the carbon dioxide and the air, so as to isolate the carbon dioxide from the air.

[0010] Optionally, in the above energy storage system, the gas storage reservoir is located in an underground chamber.

[0011] Optionally, in the above energy storage system, the gas storage pressure of the gas storage reservoir is equal to the water head pressure of the water reservoir.

[0012] Optionally, in the above-mentioned energy storage system, the air energy storage module is connected to the gas storage reservoir through a first pipeline, and the carbon dioxide energy storage module is connected to the gas storage reservoir through a second pipeline, and water seal traps are provided in the first pipeline and the second pipeline to intercept water entering the first pipeline and the second pipeline.

[0013] Optionally, in the above energy storage system, the water reservoir is connected to the gas storage reservoir via a third pipeline, and a gas barrier device is provided at the connection between the third pipeline and the gas storage reservoir.

[0014] Optionally, in the above energy storage system, both the first pipeline and the second pipeline are connected to the top of the gas storage reservoir.

[0015] Optionally, in the above energy storage system, the third pipeline is connected to the bottom of the gas storage reservoir.

[0016] Optionally, in the above energy storage system, the air energy storage module and the carbon dioxide energy storage module are both arranged on the ground.

[0017] The present application provides an energy storage device, which couples an air energy storage module, a carbon dioxide energy storage module and a pumped storage module at the same site. Air and carbon dioxide can share the same gas storage reservoir, and the water in the reservoir is used to isolate air or carbon dioxide to avoid mixing of the two working fluids, thereby improving both energy storage and space utilization. The pumped storage module and the gas storage reservoir are arranged in an underground space, saving ground space and improving space utilization. The above three energy storage modules are coupled for energy storage, which doubles the energy storage capacity, greatly improves the energy storage density, and reduces the unit cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in 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 only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0019] Figure 1 Schematic diagram of the composition of the energy storage system in the embodiment of the present application.

[0020] exist Figure 1 middle:

[0021] 1. Gas storage reservoir; 2. Air energy storage module; 3. Carbon dioxide energy storage module; 31. Liquid carbon dioxide storage tank; 4. Pumped storage module; 5. First pipeline; 6. Second pipeline; 7. Third pipeline. DETAILED DESCRIPTION

[0022] The present application provides an energy storage system, which couples a pumped storage module, an air energy storage module and a carbon dioxide energy storage module, and the pumped storage module and the gas storage reservoir are arranged underground, which not only improves the utilization rate of the space but also doubles the energy storage capacity, greatly improves the energy storage density, and reduces the unit cost.

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] like Figure 1 As shown, an embodiment of the present application provides an energy storage system, wherein a gas storage reservoir 1 is arranged underground; an air energy storage module 2 can store and release energy by compression and expansion of air, and is connected to the gas storage reservoir 1; a carbon dioxide energy storage module 3 can store and release energy by phase change of carbon dioxide, and is connected to the gas storage reservoir 1; a pumped storage module 4 includes a reservoir arranged on the ground, and the reservoir is connected to the gas storage reservoir 1.

[0025] It should be noted that the carbon dioxide energy storage module 3 includes a liquid carbon dioxide storage tank 31, which is used to contain compressed and liquefied carbon dioxide, that is, carbon dioxide liquid.

[0026] It should also be noted that the air energy storage module 2 , the carbon dioxide energy storage module 3 and the pumped storage module 4 can be constructed simultaneously, or can be expanded on the basis of the pumped storage module 4 .

[0027] In the specific working process, when the pumped storage module 4 is in the initial state before energy storage begins, the reservoir has a large amount of water stored or is full, and the water content in the reservoir can fill the gas storage reservoir 1. The gas storage reservoir 1 is filled with carbon dioxide gas, and the liquid carbon dioxide storage tank 31 is in an empty state.

[0028] During energy storage, the water in the reservoir is pressed into the gas storage reservoir 1 under the action of gravity, and at the same time, the carbon dioxide gas in the gas storage reservoir 1 is pushed and compressed and liquefied by the carbon dioxide energy storage module 3 and then filled into the liquid carbon dioxide storage tank 31; after the gas storage reservoir 1 is completely filled with water and the carbon dioxide is completely discharged, the air is compressed by the air energy storage module 2 and then filled into the gas storage reservoir 1, and at the same time, the water in the gas storage reservoir 1 is pressed back to the reservoir by the compressed air.

[0029] When energy storage is finished, the gas storage reservoir 1 is filled with compressed air, and the liquid carbon dioxide storage tank 31 is filled with liquid carbon dioxide.

[0030] When releasing energy, the water in the reservoir is pressed into the gas storage reservoir 1 under the action of gravity, and at the same time, the compressed air in the gas storage reservoir 1 is expanded by the air energy storage module 2 to generate electricity and then discharged into the atmosphere; after the gas storage reservoir 1 is completely filled with water and the compressed air is completely discharged, the liquid carbon dioxide storage tank 31 releases carbon dioxide liquid and is gasified, expanded, and generated electricity by the carbon dioxide energy storage module 3, and then filled into the gas storage reservoir 1, and at the same time, the water in the gas storage reservoir 1 is pressed back into the reservoir.

[0031] When the energy release is finished, the pumped storage module 4 returns to the initial state before the energy storage starts.

[0032] It can be seen that the energy storage system couples the air energy storage module 2, the carbon dioxide energy storage module 3 and the pumped storage module 4 at the same site. Air and carbon dioxide can share the same gas storage reservoir 1, and the water in the reservoir is used to isolate air or carbon dioxide to avoid mixing of the two working fluids, which not only improves energy storage but also improves space utilization; the pumped storage module 4 and the gas storage reservoir 1 are arranged in the underground space, saving the above-ground space and improving the space utilization; the above three energy storage modules are coupled for energy storage, which doubles the energy storage capacity, greatly improves the energy storage density, and reduces the unit cost.

[0033] It should be noted that the construction of the reservoir has accelerated the construction of the energy storage system and saved construction costs.

[0034] Among them, the gas storage reservoir 1 is located in the underground chamber, which makes full use of the underground space, saves the above-ground space, and improves the utilization rate of the space.

[0035] In some other optional embodiments, the chamber can be directly used as the gas storage reservoir 1, that is, there is no need to set up a separate gas storage reservoir 1.

[0036] In some optional embodiments, the gas storage pressure of the gas storage reservoir 1 is equal to the water head pressure of the reservoir, so that the gas storage pressure of the gas storage reservoir 1 is constant, avoiding the impact on the gas storage reservoir 1 when the pressure is unstable, and improving the stability of the gas storage reservoir 1.

[0037] In some optional embodiments, the air energy storage module 2 is connected to the gas storage reservoir 1 through the first pipeline 5, and the carbon dioxide energy storage module 3 is connected to the gas storage reservoir 1 through the second pipeline 6. Water seal traps (not shown in the figure) are provided in the first pipeline 5 and the second pipeline 6 to intercept water entering the first pipeline 5 and the second pipeline 6. The water seal traps are both provided at the low point of the first pipeline and the second pipeline so that the water can be retained in the water seal trap by the dead weight of the water. To avoid water accumulation in the water seal trap or excessive water accumulation that exceeds the volume of the water seal trap, the drain valve on the water seal trap can be opened to remove the water retained in the water seal trap when the energy storage system is not working. In this way, water is prevented from entering the air energy storage module 2 and the carbon dioxide energy storage module 3. This design can effectively prevent water from damaging the equipment in the air energy storage module 2 and the carbon dioxide energy storage module 3, so as to extend the service life of the carbon dioxide energy storage module 3 and the air energy storage module 2.

[0038] In some optional embodiments, the water reservoir is connected to the gas storage reservoir 1 through the third pipeline 7, and a gas barrier device is provided at the position where the third pipeline 7 is connected to the gas storage reservoir 1. In this way, air and carbon dioxide are prevented from entering the third pipeline 7 and entering the water reservoir along the third pipeline 7 and being discharged into the atmosphere, thereby avoiding energy waste and increasing energy storage capacity.

[0039] It should be noted that the gas barrier device may include an air valve or air isolator for blocking air, and a carbon dioxide valve or gas isolator for blocking carbon dioxide gas; alternatively, the gas barrier device is an air barrier device that can effectively block air and other gases from entering the pipeline system.

[0040] In some optional embodiments, the first pipeline 5 and the second pipeline 6 are both connected to the top of the gas storage reservoir 1. The first pipeline 5 is connected to the air energy storage module 2 for conveying air; the second pipeline 6 is connected to the carbon dioxide energy storage module 3 for conveying carbon dioxide. Air and carbon dioxide alternately enter the gas storage reservoir 1 and are always separated by water, that is, a combination of air and water, or a combination of carbon dioxide or water may exist in the gas storage reservoir 1 at the same time, and the density of air and carbon dioxide is less than the density of water, that is, carbon dioxide and air are always located at the top of the gas storage reservoir 1. In this way, the first pipeline 5 and the second pipeline 6 are connected to the top of the gas storage reservoir 1, which is conducive to the flow direction of air and carbon dioxide, so that water is always at the bottom of the gas storage reservoir 1 under the action of its own gravity (that is, water is at the bottom of air or carbon dioxide gas), avoiding moisture from entering the air energy storage module 2 and the carbon dioxide energy storage module 3, which is conducive to extending the service life of the air energy storage module 2 and the carbon dioxide energy storage module 3.

[0041] In combination with the first pipeline 5 and the second pipeline 6 being connected to the top of the gas storage reservoir 1, the present application preferably configures the first pipeline 5 to be always filled with air and the second pipeline 6 to be always filled with carbon dioxide. For this purpose, a water seal trap may not be provided in the first pipeline and the second pipeline. Instead, the water's own weight may be utilized to keep the water in the gas storage reservoir 1. Liquid level sensors are provided at the connection points between the first pipeline 55 and the second pipeline 6 and the gas storage reservoir 1 to sense whether water has entered the first pipeline 5 and the second pipeline 6, so that measures can be taken to remove the water in a timely manner. The water missing from the energy storage system can be added through the reservoir.

[0042] In some optional embodiments, the third pipeline 7 and the fourth pipeline are both connected to the bottom of the gas storage reservoir 1. The density of water is greater than that of air and carbon dioxide, and it can always be located at the bottom of air and carbon dioxide under the action of its own weight, and can move downward. Therefore, the third pipeline 7 is connected to the bottom of the gas storage reservoir 1, which is conducive to the flow of water under the action of its own weight, so that the gas (i.e., carbon dioxide gas or air) can always be in a stratified state with water (i.e., water is at the bottom of the gas storage reservoir 11, and carbon dioxide gas or air is at the upper part of the gas storage reservoir 11), and better avoids the gas from entering the third pipeline 7 and being discharged to the atmosphere along the third pipeline 7, causing energy waste. It can be seen that the above connection structure improves the storage capacity.

[0043] In some optional embodiments, the air energy storage module 2 and the carbon dioxide energy storage module 3 are both arranged on the ground. Such an arrangement is conducive to the maintenance and inspection of the air energy storage module 2 and the carbon dioxide energy storage module 3.

[0044] In some other optional embodiments, one or both of the air energy storage module 2 and the carbon dioxide energy storage module 3 are located in an underground space, thereby improving space utilization.

[0045] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0046] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0047] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0048] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0049] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0050] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An energy storage system, characterized in that: include: Gas storage, located underground; An air energy storage module, which can store and release energy by compression and expansion of air and is connected to the gas storage reservoir; A carbon dioxide energy storage module, which can utilize the phase change of the carbon dioxide to store and release energy and is connected to the gas storage reservoir; A pumped storage module comprises a reservoir arranged on the ground, wherein the reservoir is connected to the gas storage reservoir; The air, the carbon dioxide and the water in the reservoir enter the gas storage reservoir alternately, and the water enters the gas storage reservoir in an order between the carbon dioxide and the air, so as to isolate the carbon dioxide from the air.

2. The energy storage system according to claim 1, characterized in that: The gas storage is located in an underground chamber.

3. The energy storage system according to claim 1, characterized in that: The gas storage pressure of the gas storage reservoir is equal to the water head pressure of the water reservoir.

4. The energy storage system according to claim 1, characterized in that: The air energy storage module is connected to the gas storage reservoir through a first pipeline, and the carbon dioxide energy storage module is connected to the gas storage reservoir through a second pipeline. Water seal traps are provided in the first pipeline and the second pipeline to intercept water entering the first pipeline and the second pipeline.

5. The energy storage system according to claim 1, characterized in that: The water reservoir is connected to the gas storage reservoir through a third pipeline, and a gas barrier device is provided at the connection point between the third pipeline and the gas storage reservoir.

6. The energy storage system according to claim 4, characterized in that: The first pipeline and the second pipeline are both connected to the top of the gas storage reservoir.

7. The energy storage system according to claim 5, characterized in that: The third pipeline is connected to the bottom of the gas storage reservoir.

8. The energy storage system according to claim 1, characterized in that: The air energy storage module and the carbon dioxide energy storage module are both arranged on the ground.

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