Green large-scale long-acting energy storage system and method for electrically heating underground closed water layer

Abstract

The invention provides a system and a method for realizing green large-scale long-acting energy storage by electrically heating an underground closed water layer. According to the system, hydrocarbon closed water layers such as underground lithology or faults or oil coal serve as heat storage media, the water layers are heated through energy sources such as electric energy, new energy, heat energy or nuclear energy, the heat energy is stored underground for a long time, and the heat energy and steam kinetic energy are converted into the electric energy or energy sources in other forms to be output through a heat exchange system when needed. The method has the advantages of large-scale energy storage, high efficiency, stability, environment friendliness, low cost and the like, is suitable for various geographical conditions, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly to a system and method for realizing green large-scale long-term energy storage by electrically heating an underground closed water layer. Background Art

[0002] With the rapid development of renewable energy sources (such as wind energy, solar energy, etc.), the intermittency and instability of energy have become the main problems restricting their large-scale application. Traditional battery energy storage technologies are costly and have a short lifespan, making it difficult to meet the large-scale and long-term energy storage requirements. Underground energy storage technologies have gradually become a research hotspot due to their advantages such as large scale, low cost, and long cycle. However, existing underground energy storage technologies mostly rely on methods such as compressed air and pumped hydro storage, which have problems such as low efficiency and large geographical condition limitations. Therefore, it is of great significance to develop a green, efficient, stable, and large-scale long-term energy storage system applicable to various geographical conditions. Content

[0003] The present invention provides a system and method for realizing green large-scale long-term energy storage by electrically heating an underground closed water layer. This system uses the underground closed water layer as a heat storage medium, heats the water layer through energy sources such as electric energy, new energy, heat energy, or nuclear energy, stores the heat energy underground for a long time, and converts the heat energy into electric energy or other forms of energy output through a heat exchange system when needed. Technical Solution

[0004] Ground Energy Input: Ground electric energy, new energy (such as wind energy, solar energy), heat energy, or nuclear energy, etc. are input into the underground energy storage system through transmission lines or energy conversion devices. Electric energy is converted into heat energy through an electric heating device, and other forms of energy are converted into heat energy through corresponding energy conversion devices.

[0005] Electric Heating Device: The electric heating device is installed in the underground closed water layer and converts electric energy into heat energy and steam kinetic energy through methods such as resistance heating, induction heating, or arc heating. The design of the electric heating device needs to consider requirements such as electromagnetic scale removal, high temperature resistance, corrosion resistance, and long-term stability.

[0006] Underground Closed Water Layer: The underground closed water layer, such as a lithological closed water layer, a fault closed water layer, a hydrocarbon closed water layer such as oil / coal, etc., serves as a heat storage medium and has good heat capacity and thermal stability. The sealing property of the water layer ensures that the heat energy will not dissipate quickly, thereby realizing long-term energy storage. Therefore, the dynamic pressure of the reservoir needs to be always lower than the reservoir fracture pressure when heating the formation water. The depth, thickness, and tightness of the water layer, etc. need to be determined through geological exploration and simulation analysis to ensure energy storage efficiency and safety.

[0007] Heat Energy Storage and Extraction: Thermal energy is stored in an underground lithologic-confined aquifer through an electric heating device and exists in the form of high-temperature formation water or in a mixture with steam. When needed, the stored thermal energy and steam kinetic energy are extracted through a heat exchange system. The heat exchange system includes an underground heat exchanger and a ground heat exchanger, and transfers the thermal energy to the ground through a circulating working fluid (such as water, steam, oil, or molten salt), or generates electricity by heating high-temperature formation water steam, or directly utilizes the thermal energy of high-temperature formation water.

[0008] Energy output: The extracted thermal energy can be converted into electrical energy through a thermoelectric conversion device (such as a steam turbine, a Stirling engine, etc.). High-temperature formation water can directly generate electricity using steam power by pressure drop vaporization, or be directly used for heating, industrial processing, and other purposes. The energy output system can be adjusted according to demand to achieve efficient and stable energy supply.

[0009] Control system: The entire system is monitored and adjusted by an intelligent control system. The control system real-time monitors parameters such as underground temperature, pressure, energy input and output, and automatically adjusts the power of the electric heating device, the flow rate of the heat exchange system, etc. according to demand to ensure the efficient operation and safety of the system. Description of the drawings

[0010] Figure 1 It is a schematic diagram of the system structure of the present invention, a system for realizing large-scale long-term energy storage by electrically heating an underground confined aquifer.

[0011] Figure 2 It is a cross-sectional view of an underground lithologic-confined aquifer, a schematic cross-sectional view of the underground confined aquifer (shaded part).

[0012] Figure 3 It is a working principle diagram of the thermoelectric exchange system. 1. Site selection and exploration: Select a groundwater layer with good sealing as the energy storage site, conduct geological exploration and simulation analysis to determine the depth, thickness, and tightness of the water layer, and estimate the maximum energy storage at the fracture pressure. Detailed implementation method 1. Site selection and exploration: Select a groundwater layer with good sealing as the energy storage site, conduct geological exploration and simulation analysis to determine the depth, thickness, and tightness of the water layer, and estimate the maximum energy storage at the fracture pressure.

[0014] System installation: Install an electric heating device in the underground confined aquifer, and construct an energy input and output system and a control system on the ground.

[0015] Energy storage process: Electrical energy or other forms of energy are converted into heat energy through the ground energy input system and stored in the underground lithologically closed aquifer.

[0016] Energy extraction: When needed, the stored heat energy is extracted through the heat exchange system and converted into electrical energy or other forms of energy for output.

[0017] System operation and maintenance: The operation status of the system is monitored in real time through the intelligent control system, and regular maintenance and overhaul are carried out to ensure the long-term stable operation of the system.

[0018] Beneficial effects 1. Large-scale energy storage: Using the underground closed aquifer as the heat storage medium, large-scale and long-term energy storage can be achieved.

[0019] 2. High efficiency and stability: High-efficiency and stable energy input and output are achieved through the intelligent control system.

[0020] 3. Environmentally friendly: No pollutants are produced, and it is applicable to various geographical conditions.

[0021] 4. Low cost: The construction cost of the underground energy storage system is low, and the maintenance cost is small, with high economic efficiency.

Claims

1. A system for realizing green large-scale long-term energy storage by electrically heating an underground confined water layer, comprising a ground energy input system, an electric heating device, an underground confined water layer, a heat exchange system, an energy output system and a control system.

2. The system according to claim 1, characterized in that The underground confined water layer, including but not limited to lithological confined water layer, fault confined water layer, oil / coal / hydrocarbon confined water layer, has good thermal capacity and thermal stability and can store thermal energy for a long time.

3. The system according to claim 1, characterized in that The electric heating device converts electrical energy into thermal energy and steam kinetic energy through resistance heating, induction heating or arc heating.

4. The system according to claim 1, characterized in that The heat exchange system includes an underground heat exchanger and a ground heat exchanger, and transfers heat energy to the ground through a circulating working medium.

5. The system according to claim 4, characterized in that The circulating working medium includes but is not limited to formation water, steam, crude oil or lava.

6. The system according to claim 1, characterized in that The energy output system converts thermal energy into electrical energy through a thermoelectric conversion device, or directly uses it for heating, industrial processing, and the like.

7. The system according to claim 6, characterized in that In the energy output system, high-temperature formation water vaporizes when the pressure drops, and steam is directly used to generate electricity.

8. The system according to claim 1, characterized in that The control system monitors underground temperature, pressure, energy input and output and other parameters in real time, and automatically adjusts the system operation status according to demand.

9. A method for realizing green large-scale long-term energy storage by electrically heating an underground closed water layer, comprising the following steps: site selection and exploration, system installation, energy storage process, energy extraction and system operation and maintenance.

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