Gas storage device for underwater gas storage

Abstract

The utility model discloses a gas storage device for underwater gas storage, which comprises an air bag and a limiting frame, wherein the air bag is arranged in natural water sources such as ocean, an anchoring system is arranged in water and connected with the air bag, the air bag is fixed in the water through the anchoring system, the air bag is arranged in the limiting frame, and an adjusting floating ball is arranged at the top of the limiting frame. The pressure difference between the inside and the outside of the gas storage device is small, the requirement for the pressure bearing capacity of the pressure container is remarkably reduced, the investment cost of the gas storage device is reduced, seawater or lake water is directly used for providing external water pressure so as to adapt to different geographical conditions and energy requirements, an environment chamber does not need to be arranged, and the complexity and the cost of the gas storage device are reduced.

Description

Technical Field

[0001] This utility model relates to a gas storage device for underwater gas storage, belonging to the field of energy storage system technology. Background Technology

[0002] my country's offshore wind and solar power installations are developing rapidly, requiring corresponding energy storage systems. Pumped storage has a long construction cycle and is subject to site selection restrictions; traditional compressed air energy storage systems, such as those using underground salt caverns, are also constrained by geological conditions.

[0003] Existing technologies include compressed air energy storage using water pressure, such as the patent titled "A Constant Pressure Power Generation Method for Underwater Flexible Compressed Air Energy Storage Airbag" (Patent No.: CN202310200070.0), which discloses the use of a water-fillable environmental chamber and an underwater flexible airbag for air energy storage. However, this system requires the construction of environmental chambers and other equipment, resulting in high equipment costs, ineffective utilization of natural resources, and high system complexity.

[0004] my country's offshore wind and solar power installations are developing rapidly, necessitating the deployment of corresponding energy storage systems. Based on this, we propose a gas storage device for underwater gas storage, making full use of the marine environment and underwater pressure. Utility Model Content

[0005] The purpose of this invention is to provide a gas storage device for underwater gas storage. This invention does not require an environmental chamber, reducing system complexity and cost. It can be flexibly deployed in the ocean to adapt to different geographical conditions and energy demands.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a gas storage device for underwater gas storage, comprising:

[0007] An airbag, which is placed in water, is used to store gas. The airbag is placed in natural water sources such as the ocean, and the high water pressure allows the airbag to store gas at higher pressure.

[0008] An anchoring system, wherein the anchoring system is placed in water and connected to an airbag, and the airbag is fixed in the water by the anchoring system;

[0009] The limiting frame contains the airbag, and an adjustable float is provided at the top of the limiting frame. The adjustable float ensures that the airbag and the limiting frame will not fall significantly under the minimum pressure of the airbag, and that the airbag will not oscillate with the seawater during the initial inflation process.

[0010] The aforementioned gas storage device for underwater gas storage includes a capsule-shaped air bladder made of polyvinyl chloride coated fabric. A reinforcing band is provided on the upper part of the side wall of the air bladder, and the reinforcing band is made of multi-layer polyvinyl chloride coated fabric.

[0011] In the aforementioned gas storage device for underwater gas storage, the reinforcing belt is connected to the limiting frame via a fixing rope.

[0012] The aforementioned gas storage device for underwater gas storage has a limiting frame made of fiberglass, coated with anti-corrosion paint, and cylindrical in shape to reduce the impact of water flow.

[0013] The aforementioned gas storage device for underwater gas storage includes an anchoring system comprising a concrete caisson and a rope. One end of the rope is connected to the concrete caisson, and the other end of the rope is connected to the bottom of a limiting frame. The length of the rope is adjustable to facilitate adjustment of the burial depth of the airbag, thereby adjusting the initial external pressure.

[0014] The aforementioned gas storage device for underwater gas storage has a cylindrical concrete caisson that is impregnated with silane for corrosion protection to avoid uneven seawater erosion.

[0015] The aforementioned gas storage device for underwater gas storage includes an air bladder connected to an air pipe, on which a valve switch is installed.

[0016] The aforementioned gas storage device for underwater gas storage includes a gas bladder connected to a pressure gauge.

[0017] Compared with existing technologies, this invention has at least the following advantages: The gas storage device of this invention has a small internal and external pressure difference, significantly reducing the pressure-bearing capacity requirements of the pressure vessel and lowering the investment cost of the gas storage device; the gas storage device of this invention uses flexible materials, is retractable, and is easy to replace, relocate, and recycle; furthermore, the gas bladder itself is made of coated fabric, which has the advantages of good sealing performance and corrosion resistance. This invention can be flexibly deployed in the ocean, directly utilizing seawater or lake water to provide external water pressure, adapting to different geographical conditions and energy demands, and eliminating the need for an environmental chamber, thus reducing system complexity and cost. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the airbag and limiting frame structure of this utility model.

[0020] Reference numerals: 1-Airbag, 2-Anchoring system, 3-Air tube, 4-Valve switch, 5-Limiting frame, 6-Reinforcing belt, 7-Adjusting float, 8-Concrete caisson, 9-Rope, 10-Pressure gauge.

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0022] Embodiment 1 of this utility model: A gas storage device for underwater gas storage, comprising: an airbag 1, which is placed in water and used to store gas; the airbag 1 is placed in a natural water source such as the ocean, where the high water pressure allows the airbag 1 to store higher pressure gas; an anchoring system 2, which is placed in water and connected to the airbag 1, and the airbag 1 is fixed in the water by the anchoring system 2; the airbag 1 is placed inside a limiting frame 5, and an adjusting float 7 is provided on the top of the limiting frame 5; the buoyancy of the adjusting float 7 is preferably the total weight of the limiting frame 5 and the airbag 1 minus the buoyancy caused by the preset pressure of the airbag 1; the adjusting float 7 ensures that the position of the airbag 1 and the limiting frame 5 will not fall significantly under the minimum pressure of the airbag 1, and that the airbag 1 will not fully expand and oscillate with the seawater during the initial inflation process.

[0023] Embodiment 2 of this utility model: A gas storage device for underwater gas storage, comprising: an airbag 1, which is placed in water and used to store gas; the airbag 1 is placed in a natural water source such as the ocean, where the high water pressure allows the airbag 1 to store higher pressure gas; an anchoring system 2, which is placed in water and connected to the airbag 1, and the airbag 1 is fixed in the water by the anchoring system 2; the airbag 1 is placed inside a limiting frame 5, and an adjusting float 7 is provided on the top of the limiting frame 5. The buoyancy of the adjusting float 7 is preferably the total weight of the limiting frame 5 and the airbag 1 minus the buoyancy caused by the preset pressure of the airbag 1. The adjusting float 7 ensures that the position of the airbag 1 and the limiting frame 5 will not fall significantly under the minimum pressure of the airbag 1, and that the airbag 1 will not fully expand and oscillate with the seawater during the initial inflation process.

[0024] Airbag 1 is capsule-shaped and made of polyvinyl chloride coated fabric. The tensile strength of the polyvinyl chloride coated fabric is 35-56 MPa, the elongation is 2%-40%, it has a certain degree of flexibility, and its thermal conductivity is low, approximately 4187 × 10⁻⁶. -5 With a specific heat capacity of 4.2 × 10⁻⁶ W / (m·K), the PVC-coated fabric exhibits good thermal insulation properties. 3 J / (kg·K), coefficient of thermal expansion is 10 -5 / ℃, the PVC coated fabric has good dimensional stability under temperature changes and high heat resistance temperature. The continuous use temperature can reach 5~18.5℃, which is suitable for use in a wide temperature range. The upper part of the side wall of the airbag 1 is provided with a reinforcing band 6. The reinforcing band 6 is connected to the limiting frame 5 by a fixing rope. The limiting frame 5 is made of fiberglass and is cylindrical to reduce the impact of water flow.

[0025] Embodiment 3 of this utility model: A gas storage device for underwater gas storage, comprising: an airbag 1, which is placed in water and used to store gas; the airbag 1 is placed in a natural water source such as the ocean, where the high water pressure allows the airbag 1 to store higher pressure gas; an anchoring system 2, which is placed in water and connected to the airbag 1, and the airbag 1 is fixed in the water by the anchoring system 2; the airbag 1 is placed inside a limiting frame 5, and an adjusting float 7 is provided on the top of the limiting frame 5; the buoyancy of the adjusting float 7 is preferably the total weight of the limiting frame 5 and the airbag 1 minus the buoyancy caused by the preset pressure of the airbag 1; the adjusting float 7 ensures that the position of the airbag 1 and the limiting frame 5 will not fall significantly under the minimum pressure of the airbag 1, and that the airbag 1 will not fully expand and oscillate with the seawater during the initial inflation process.

[0026] Airbag 1 is capsule-shaped and made of polyvinyl chloride coated fabric. The tensile strength of the polyvinyl chloride coated fabric is 35-56 MPa, the elongation is 2%-40%, it has a certain degree of flexibility, and its thermal conductivity is low, approximately 4187 × 10⁻⁶. -5 With a specific heat capacity of 4.2 × 10⁻⁶ W / (m·K), the PVC-coated fabric exhibits good thermal insulation properties. 3 J / (kg·K), coefficient of thermal expansion is 10 -5 / ℃, the PVC coated fabric has good dimensional stability under temperature changes and high heat resistance temperature. The continuous use temperature can reach 5~18.5℃, which is suitable for use in a wide temperature range. The upper part of the side wall of the airbag 1 is provided with a reinforcing band 6. The reinforcing band 6 is connected to the limiting frame 5 by a fixing rope. The limiting frame 5 is made of fiberglass and is cylindrical to reduce the impact of water flow.

[0027] The anchoring system 2 includes a concrete caisson 8 and a rope 9. One end of the rope 9 is connected to the concrete caisson 8. The rope 9 is connected to the bottom of the limiting frame 5. The length of the rope 9 is adjustable to facilitate the adjustment of the burial depth of the airbag 1, thereby adjusting the initial external pressure. The concrete caisson 8 is cylindrical to avoid uneven seawater erosion and is protected against corrosion by silane impregnation.

[0028] Embodiment 4 of this utility model: A gas storage device for underwater gas storage, comprising: an airbag 1, which is placed in water and used to store gas; the airbag 1 is placed in a natural water source such as the ocean, where high water pressure allows the airbag 1 to store higher pressure gas; an anchoring system 2, which is placed in water and connected to the airbag 1, and the airbag 1 is fixed in the water by the anchoring system 2; the airbag 1 is placed inside a limiting frame 5, and an adjusting float 7 is provided on the top of the limiting frame 5; the buoyancy of the adjusting float 7 is preferably the total weight of the limiting frame 5 and the airbag 1 minus the buoyancy caused by the preset pressure of the airbag 1; the adjusting float 7 ensures that the position of the airbag 1 and the limiting frame 5 will not fall significantly under the minimum pressure of the airbag 1, and that the airbag 1 will not fully expand and oscillate with the seawater during the initial inflation process.

[0029] Airbag 1 is capsule-shaped and made of polyvinyl chloride coated fabric. The tensile strength of the polyvinyl chloride coated fabric is 35-56 MPa, the elongation is 2%-40%, it has a certain degree of flexibility, and its thermal conductivity is low, approximately 4187 × 10⁻⁶. -5 With a specific heat capacity of 4.2 × 10⁻⁶ W / (m·K), the PVC-coated fabric exhibits good thermal insulation properties. 3 J / (kg·K), coefficient of thermal expansion is 10 -5 / ℃, the PVC coated fabric has good dimensional stability under temperature changes and high heat resistance temperature. The continuous use temperature can reach 5~18.5℃, which is suitable for use in a wide temperature range. The upper part of the side wall of the airbag 1 is provided with a reinforcing band 6. The reinforcing band 6 is connected to the limiting frame 5 by a fixing rope. The limiting frame 5 is made of fiberglass and is cylindrical to reduce the impact of water flow.

[0030] The anchoring system 2 includes a concrete caisson 8 and a rope 9. One end of the rope 9 is connected to the concrete caisson 8. The rope 9 is connected to the bottom of the limiting frame 5. The length of the rope 9 is adjustable to facilitate the adjustment of the burial depth of the airbag 1, thereby adjusting the initial external pressure. The concrete caisson 8 is cylindrical to avoid uneven seawater erosion and is protected against corrosion by silane impregnation.

[0031] The airbag 1 is connected to a pressure gauge 10 for monitoring the air pressure inside the airbag and facilitating connection to an automatic control system. The airbag 1 is also connected to an air tube 3, which is equipped with a valve switch 4 for inflating and deflating the airbag 1.

[0032] The working principle of one embodiment of this utility model is as follows: When in use, the airbag 1 is submerged 1000m underwater. The cylindrical height of the airbag 1 is 10m, and the diameter of the hemispherical tank is 6m (the airbag volume is approximately 395m³). 3Since the size of airbag 1 is relatively small compared to the water depth, the water pressure change at the top and bottom of the airbag is ignored. The external pressure on the airbag caused by the external water pressure is P = ρgh = 1000 x 9.8 x 1000 Pa = 9.8 MPa. Initially, airbag 1 is pre-filled with a certain amount of gas, with an initial preset pressure assumed to be 0.5 MPa. The final storage pressure of airbag 1 is set to 12 MPa, meaning the pressure difference between the inside and outside of airbag 1 is only 12 - 9.8 MPa = 2.2 MPa. Under the same conditions, traditional gas storage tanks need to withstand a pressure of 12 MPa, reducing the requirements for the pressure-bearing strength and deformation of the gas tank. The tensile strength of PVC fabric is 35-56 MPa, providing sufficient margin. The elastic modulus of polyvinyl chloride (PVC) is approximately between 2900-3400 MPa, therefore the deformation of the airbag is very small, only 0.39% (11.5 / 2900).

[0033] During off-peak electricity demand: The surplus electricity from offshore wind power, floating photovoltaic power generation systems, etc., drives the compressor to deliver air into airbag 1. Airbag 1 inflates until it reaches the final storage pressure. Data from pressure gauge 10 is used to stop air storage. During peak electricity demand: Airbag 1 deflates. Under the external pressure of seawater, airbag 1 collapses. The compressed air in airbag 1 drives a turbine expander to generate electricity until airbag 1 drops to a preset pressure. Data from pressure gauge 10 is used to stop power generation. Seabed temperatures are low. For example, at a depth of 1000m in the South China Sea, the seawater temperature is only 4.4°C, nearly 10°C lower than the sea surface temperature of 15°C. When airbag 1 has a large volume and a slow inflation / deflation rate, combined with the heat exchange properties of the low-temperature seawater surrounding airbag 1, the direct contact between the air delivery pipe 14 and the seawater allows for sufficient heat transfer. The thermodynamic process of the air inside airbag 1 can be approximated as an isothermal process.

Claims

1. A gas storage device for underwater gas storage, characterized in that, include: An airbag (1) is placed in water; An anchoring system (2), which is placed in the water and connected to the airbag (1), and the airbag (1) is fixed in the water by the anchoring system (2); The limiting frame (5) is provided with the airbag (1) inside the limiting frame (5) and the top of the limiting frame (5) is provided with an adjusting float (7).

2. A gas storage device for underwater gas storage according to claim 1, characterized in that, The airbag (1) is capsule-shaped and made of polyvinyl chloride coated fabric. The upper part of the side wall of the airbag (1) is provided with a reinforcing band (6), which is made of multi-layer polyvinyl chloride coated fabric.

3. A gas storage device for underwater gas storage according to claim 2, characterized in that, The reinforcing band (6) is connected to the limiting frame (5) by a fixing rope.

4. A gas storage device for underwater gas storage according to claim 3, characterized in that, The limiting frame (5) is made of fiberglass and the surface of the limiting frame (5) is coated with anti-corrosion paint.

5. A gas storage device for underwater gas storage according to claim 3, characterized in that, The anchoring system (2) includes a concrete caisson (8) and a rope (9). One end of the rope (9) is connected to the concrete caisson (8). One end of the rope (9) is connected to the bottom of the limiting frame (5), and the length of the rope (9) is adjustable.

6. A gas storage device for underwater gas storage according to claim 5, characterized in that, The concrete caisson (8) is cylindrical and is protected against corrosion by silane impregnation.

7. A gas storage device for underwater gas storage according to claim 6, characterized in that, The airbag (1) is connected to an air tube (3), and a valve switch (4) is provided on the air tube (3).

8. A gas storage device for underwater gas storage according to claim 7, characterized in that, The airbag (1) is connected to a pressure gauge (10).

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