Energy storage system

Abstract

The utility model provides an energy storage system which comprises a gas storage which is arranged in an overground space; 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 using the phase change of carbon dioxide, and is connected with the gas storage; the pumped storage module is arranged on the ground and comprises an upper reservoir, a lower reservoir and a power device, and the pumped storage module is connected with the gas storage; wherein the air, the carbon dioxide and the water in the pumped storage module 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. The air energy storage module, the carbon dioxide energy storage module and the pumped storage module are coupled at the same site, 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 has 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. Introducing compressed air storage technology, such as compressed air energy storage and compressed carbon dioxide energy 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 energy storage module and a carbon dioxide energy storage module on the same site, so that the energy storage capacity is doubled, the energy storage density is greatly improved, and the unit cost is reduced.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] An energy storage system, comprising:

[0006] Gas storage, which is set up in the above-ground space;

[0007] 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;

[0008] 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;

[0009] A pumped storage module is arranged on the ground and comprises an upper reservoir, a lower reservoir and a power device, and the pumped storage module is connected to the gas storage reservoir;

[0010] The air, the carbon dioxide and the water in the pumped storage module enter the gas storage reservoir alternately, and the order in which the water enters the gas storage reservoir is between the carbon dioxide and the air, so as to isolate the carbon dioxide and the air.

[0011] Optionally, in the above energy storage system, the gas storage pressure of the gas storage reservoir is equal to the head pressure of the upper 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-mentioned energy storage system, the upper water reservoir is connected to the gas storage reservoir through a third pipeline, the lower water reservoir is connected to the gas storage reservoir through a fourth pipeline, an air barrier device is provided at the position where the third pipeline is connected to the gas storage reservoir, and a carbon dioxide barrier device is provided at the position where the fourth pipeline is connected to 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 and the fourth pipeline are both connected to the bottom of the gas storage reservoir.

[0016] Optionally, in the above energy storage system, the power device includes a water pump turbine.

[0017] The present application provides an energy storage system, 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 upper reservoir or the lower reservoir is used to isolate the air or carbon dioxide to avoid mixing of the two working fluids, thereby improving both energy storage and space utilization. The air energy storage module, the carbon dioxide energy storage module and the pumped storage module can be constructed simultaneously, or they can be expanded on the basis of the pumped storage module, thereby doubling the energy storage capacity, greatly improving the energy storage density, and reducing the unit construction 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; 2. Air energy storage module; 3. Carbon dioxide energy storage module; 31. Liquid carbon dioxide storage tank; 4. Pumped storage module; 41. Upper reservoir; 42. Lower reservoir; 43. Power unit; 5. First pipeline; 6. Second pipeline; 7. Third pipeline; 8. Fourth 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 on the same site, so that the energy storage capacity is doubled, the energy storage density is greatly improved, and the unit cost is reduced.

[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, the embodiment of the present application provides an energy storage system, which couples an air energy storage module 2, a carbon dioxide energy storage module 3 and a pumped storage module 4, all of which are connected to a gas storage reservoir 1, and the gas storage reservoir 1 and the pumped storage module 4 are arranged in the ground space. The air energy storage module 2 can store and release energy by compression and expansion of air; the carbon dioxide energy storage module 3 can store and release energy by phase change of carbon dioxide; the pumped storage module 4 is arranged on the ground and includes an upper reservoir 41, a lower reservoir 42 and a power device 43.

[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] In the specific working process, when the pumped storage module 4 is in the initial state before energy storage begins, only a small amount of inventory is left in the upper reservoir 41, the lower reservoir 42 is full (on the premise that water can fill the gas storage reservoir), the gas storage reservoir 1 is filled with carbon dioxide gas at a specified pressure, and the liquid carbon dioxide storage tank 31 is in an empty state.

[0027] During energy storage, the water in the lower reservoir 42 is pressed into the gas storage reservoir 1 by the power device 43, and at the same time, the water in the lower reservoir 42 pushes the carbon dioxide gas in the gas storage reservoir 1, which is 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 to the upper reservoir 41 by the compressed air. It should be pointed out that in the above energy storage process, the water in the lower reservoir 42 enters the upper reservoir 41, that is, the electrical energy is converted into potential energy for storage.

[0028] When energy storage is completed, water is pressed from the lower reservoir 42 to the upper reservoir 41, the gas storage reservoir 1 is filled with compressed air, and the liquid carbon dioxide storage tank 31 is filled with liquid carbon dioxide.

[0029] During energy release, 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. At the same time, the water in the upper reservoir 41 is pressed into the gas storage reservoir 1 under the action of gravity. 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, which is gasified and expanded by the carbon dioxide energy storage module 3 to generate electricity and then filled into the gas storage reservoir 1. At the same time, the water in the gas storage reservoir 1 is pressed into the power device 43 to generate electricity and then injected into the lower reservoir 42. It should be pointed out that in the above energy release process, the water in the upper reservoir 41 is pressed into the power device 43 to generate electricity and then enters the lower reservoir 42, that is, the potential energy is converted into electrical energy.

[0030] When the energy release is finished, the pumped storage module 4 returns to the initial state before the energy storage starts.

[0031] 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 upper reservoir 41 or the lower reservoir 42 is used to isolate the air or carbon dioxide gas to avoid mixing of the two working fluids, which not only improves energy storage but also improves space utilization; the air energy storage module 2, the carbon dioxide energy storage module 3 and the pumped storage module 4 can be constructed simultaneously, or they can be expanded on the basis of the pumped storage module 4, so that the energy storage capacity is doubled, the energy storage density is greatly improved, and the unit cost is reduced.

[0032] It should be noted that the air energy storage module 2 and the carbon dioxide energy storage module 3 are both arranged in the above-ground space, which is conducive to the maintenance and installation of the air energy storage module 2 and the carbon dioxide energy storage module 3 .

[0033] It should also be noted that the construction of the upper reservoir and the lower reservoir enables the entire energy storage system to store more energy in the energy storage stage and release more energy in the energy release stage, that is, it can increase power generation.

[0034] The gas storage pressure of the gas storage reservoir 1 is equal to the water head pressure of the upper water reservoir 41. In this way, the gas storage pressure of the gas storage reservoir 1 is constant, the impact on the gas storage reservoir 1 when the pressure is unstable is avoided, and the stability of the gas storage reservoir 1 is improved.

[0035] In an optional embodiment, 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. The first pipeline 5 and the second pipeline 6 are both provided with water seal traps (not shown in the figure) to intercept water entering the first pipeline and the second pipeline. The water seal traps are both arranged 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. In order 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.

[0036] In an optional embodiment, the upper water reservoir 41 is connected to the gas storage reservoir 1 through the third pipeline 7, and the lower water reservoir 42 is connected to the gas storage reservoir 1 through the fourth pipeline 8. An air barrier device (not shown in the figure) is provided at the position where the third pipeline 7 is connected to the gas storage reservoir 1, and a carbon dioxide barrier device (not shown in the figure) is provided at the position where the fourth pipeline 8 is connected to the gas storage reservoir 1. In this way, air is prevented from entering the third pipeline 7 and entering the upper water reservoir 41 along the third pipeline 7 to be discharged into the atmosphere. At the same time, carbon dioxide is also prevented from entering the fourth pipeline 8 and entering the lower water reservoir 42 along the fourth pipeline 8 to be discharged into the atmosphere, thereby avoiding energy waste and increasing the amount of storage capacity.

[0037] It should be noted that the air barrier device includes but is not limited to an air valve or an air isolator, etc.; the carbon dioxide barrier device includes but is not limited to a carbon dioxide valve or a gas isolator, etc.

[0038] In an optional embodiment, 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.

[0039] 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 5 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 upper reservoir or the lower reservoir.

[0040] In an optional embodiment, the third pipeline 7 and the fourth pipeline 8 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 and the fourth pipeline 8 are both 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 1, and carbon dioxide gas or air is at the upper part of the gas storage reservoir 1), and better avoid the gas from entering the third pipeline 7 and the fourth pipeline 8, and being discharged to the atmosphere along the third pipeline 7 and the fourth pipeline 8, causing energy waste. It can be seen that the above connection structure improves energy storage.

[0041] In an optional embodiment, the power device 43 includes a pump-turbine. When storing energy, the pump-turbine is used to transport water in the lower reservoir 42 to the gas storage reservoir 1. When releasing energy, the water in the gas storage reservoir 1 is pressed into the pump-turbine through the third pipeline 7 to generate electricity and then injected into the lower reservoir 42. The pump-turbine is a combination of a water pump and a water turbine. The water pump is used to pump water from a low place to a high place, and the water turbine converts the kinetic energy of the water into mechanical energy or electrical energy. Through this energy conversion process, the system can achieve efficient use of energy; using hydraulic energy for energy conversion is both efficient and environmentally friendly, which helps to reduce the impact on the environment.

[0042] It should be noted that the power device 43 includes a water pump turbine, but is not limited thereto. The specific structure of the power device 43 can be designed by those skilled in the art according to actual needs.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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 solution and cannot be used to limit the scope of protection of the present application.

[0048] 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, which is set up in the above-ground space; 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 is arranged on the ground and comprises an upper reservoir, a lower reservoir and a power device, and the pumped storage module is connected to the gas storage reservoir; The air, the carbon dioxide and the water in the pumped storage module enter the gas storage reservoir alternately, and the order in which the water enters the gas storage reservoir is between the carbon dioxide and the air, so as to isolate the carbon dioxide and the air.

2. 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 upper reservoir.

3. 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.

4. The energy storage system according to claim 1, characterized in that: The upper water reservoir is connected to the gas storage reservoir through a third pipeline, and the lower water reservoir is connected to the gas storage reservoir through a fourth pipeline. An air barrier is provided at the position where the third pipeline is connected to the gas storage reservoir, and a carbon dioxide barrier is provided at the position where the fourth pipeline is connected to the gas storage reservoir.

5. The energy storage system according to claim 3, characterized in that: The first pipeline and the second pipeline are both connected to the top of the gas storage reservoir.

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

7. The energy storage system according to claim 1, characterized in that: The power device comprises a water pump turbine.

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