Comprehensive energy system cooperatively constructed by pumped storage power station and enhanced geothermal energy system and construction and operation method of comprehensive energy system

Abstract

The invention relates to the field of energy engineering, in particular to a comprehensive energy system cooperatively constructed by a pumped storage power station and an enhanced geothermal energy system, which comprises the pumped storage power station, the enhanced geothermal energy system, an intelligent dispatching management system, a connecting facility and a power grid system, the pumped storage power station and the enhanced geothermal energy system are connected through a connecting facility and achieve cooperative operation under the control of the intelligent dispatching management system.

Description

Technical Field

[0001] The present invention relates to the field of energy engineering, and specifically to an integrated energy system jointly constructed by a pumped-storage power station and an enhanced geothermal system (EGS), as well as its construction and operation methods, aiming to achieve efficient utilization and complementarity of energy through technological innovation. Background Art

[0002] As one of the most mature large-scale energy storage methods at present, the pumped-storage power station has various functions such as peak shaving and valley filling, frequency modulation and phase modulation, and emergency standby, which is of great significance for maintaining the safe and stable operation of the power grid. It pumps and stores water through the height difference between high and low water levels in the reservoir, converts the surplus electric energy of the power grid into the potential energy of water for storage, and then releases it for power supply during the peak load of the power grid, thus realizing the temporal and spatial transfer and efficient utilization of electric energy. The enhanced geothermal system (EGS) is a new type of geothermal power generation technology that uses deep underground high-temperature rock masses (hot dry rocks) as heat sources. It creates a fracture network in the rock by drilling geothermal wells in the hot dry rock and injecting high-pressure fluids (such as water or carbon dioxide), and makes the fluid circulate in the fractures, thereby extracting the heat energy in the rock and converting it into electric energy. The EGS technology has the advantages of large resource reserves, wide distribution, and high utilization efficiency, and is considered one of the most potential clean energies in the future.

[0003] Although the pumped-storage power station and the EGS system each have significant advantages in the energy field, they both have certain limitations when operating alone. Although the pumped-storage power station has high energy storage efficiency, it depends on the supply of surplus power of the power grid, and its construction cost is high, and it is greatly restricted by geographical conditions. While the EGS system can stably provide geothermal energy, the hydraulic fracturing process in its initial construction consumes a large amount of energy and water resources, and the technical complexity is high, and the investment payback period is long. Therefore, it is necessary to design an integrated energy system jointly constructed by a pumped-storage power station and an enhanced geothermal system (EGS), as well as its construction and operation methods, to explore the synergistic effect between the pumped-storage power station and the EGS system, construct an integrated energy system, and achieve efficient complementarity and conversion of energy. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies existing in the prior art, and to provide an integrated energy system jointly constructed by a pumped-storage power station and an enhanced geothermal system (EGS), as well as its construction and operation methods, which utilize the water resource and power advantages of the pumped-storage power station to support the construction and operation of the EGS system, and at the same time the EGS system provides stable power supply for the power grid, realizing the efficient utilization and complementarity of energy.

[0005] The purpose of the present invention is completed by the following technical solutions: An integrated energy system jointly constructed by a pumped-storage power station and an enhanced geothermal energy system, comprising a pumped-storage power station, an enhanced geothermal energy system, an intelligent scheduling and management system, connection facilities and a power grid system. The pumped-storage power station and the enhanced geothermal energy system are connected through the connection facilities and operate synergistically under the control of the intelligent scheduling and management system.

[0006] In a further technical solution, the pumped-storage power station includes an upper reservoir, a lower reservoir and a water conveyance pipeline connecting the two. A pump unit and a generator unit are connected to the water conveyance pipeline; the upper and lower reservoirs are respectively located at different elevations and are used for storing and releasing water resources to realize the storage and release of electric energy; the water conveyance pipeline connects the upper and lower reservoirs and is used for conveying water flow to realize the pumping and discharging processes; the pump unit pumps water from the lower place to the upper reservoir during the pumping process to store electric energy; the generator unit drives a turbine to generate electricity by using the gravitational potential energy of the water flow during the discharging process to release the stored electric energy. When the power grid load is at a low ebb, the pumped-storage power station is started to store water. The pump unit pumps water from the lower reservoir to the upper reservoir, and the upper reservoir releases part of the high-pressure water directly for the hydraulic fracturing operation of the enhanced geothermal energy system. When the power grid is at a peak or the surplus power is insufficient, water flows from the upper reservoir to the lower reservoir, and the generator unit generates electricity by using the gravitational potential energy of the water flow; the enhanced geothermal energy system is started to generate electricity to supplement the power required for pumping of the pumped-storage power station or directly supply power to the power grid system for grid connection.

[0007] In a further technical solution, the enhanced geothermal energy system includes a geothermal well, a hydraulic fracturing device and a geothermal power generation device; the geothermal well is used for the extraction and utilization of geothermal energy and includes an injection well, a fractured reservoir (hot dry rock formation), and a production well. The geothermal well is directly drilled into the hot dry rock formation. The hydraulic fracturing device uses high-pressure water flow to perform hydraulic fracturing on the hot dry rock to form a fracture network, enabling the geothermal fluid to circulate. The geothermal power generation device uses the heat energy in the geothermal fluid pumped out from the fracture network to drive a turbine to generate electricity and convert geothermal energy into electric energy.

[0008] In a further technical solution, the enhanced geothermal energy system further includes an energy storage unit for storing the heat energy generated by the system.

[0009] In a further technical solution, the intelligent scheduling and management system includes: A data acquisition module that real-time collects the operation data of the pumped-storage power station, the enhanced geothermal energy system, the connection facilities and the power grid system, including data information such as power grid load, energy storage status, and environmental parameters. A prediction and analysis module that, based on historical data and the operation data real-time collected by the data acquisition module, combines preset algorithms and models to perform prediction and analysis on the power grid load and energy storage demand within a certain period of time. The decision-making optimization module formulates an optimal operation plan according to the prediction analysis results and in combination with the preset scheduling strategy; The execution control module automatically adjusts the system operation state according to the operation plan to ensure the efficient and stable operation of the system.

[0010] In a further technical solution, the intelligent scheduling management system further includes a communication module for data exchange with an external control center.

[0011] In a further technical solution, the water pump units and generator sets of the pumped storage power station are both located in the underground power house to reduce the impact on the ground environment.

[0012] In a further technical solution, the geothermal wells of the enhanced geothermal energy system are located below the pumped storage power station, and the efficient utilization of resources is realized by sharing water resources.

[0013] Another technical solution of the present invention is: a construction method of the comprehensive energy system described above, including: Site selection and exploration to determine the specific locations of the pumped storage power station and the geothermal wells; System construction, including the construction of upper and lower reservoirs, water conveyance pipelines, water pump units and generator sets; Hydraulic fracturing, using the water pressure of the pumped storage power station to perform hydraulic fracturing on the hot dry rock to form a fracture network.

[0014] Another technical solution of the present invention is: an operation method of the comprehensive energy system described above, including: System commissioning, performing joint commissioning of the pumped storage power station and the enhanced geothermal energy system; Real-time monitoring, monitoring the operation data of the comprehensive energy system; Prediction analysis, according to the real-time operation data and historical data, in combination with the preset algorithms and models, predicting and analyzing the grid load and energy storage demand within a certain period of time; Formulating an operation plan, formulating an optimal operation plan according to the prediction analysis results and in combination with the preset scheduling strategy; Executing the operation plan, automatically adjusting the system operation state according to the operation plan.

[0015] The beneficial effects of the present invention are: 1. The present invention innovatively proposes to directly drill geothermal wells below the pumped storage power station and use the high-pressure water stored during the pumped storage process as the water source for hydraulic fracturing of the EGS system. This design not only reduces the dependence of the EGS system on external water resources, but also realizes the sharing and recycling of water resources, improving the utilization efficiency of water resources; 2. During the low load period of the power grid, while the pumped - storage power station stores water, its high - pressure water is directly used for the hydraulic fracturing operation of the EGS system, promoting the development and utilization of geothermal energy. When the power grid is at peak load or there is insufficient surplus power, the EGS system generates electricity to supplement the power required for the pumped - storage power station to pump water, or directly feeds power into the grid, realizing the efficient complementarity and utilization of energy. 3. The intelligent dispatching and management system can adjust the operation strategies of the pumped - storage power station and the EGS system in real - time according to factors such as power grid load prediction, energy storage requirements, and environmental conditions. By optimizing resource allocation and energy dispatching, it can maximize energy utilization efficiency, reduce operation costs, and enhance the flexibility and reliability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the integrated energy system according to the embodiment of the present invention.

[0017] Figure 2 It is a schematic structural diagram of the pumped - storage power station in the embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of the fracture network of the enhanced geothermal system in the embodiment of the present invention.

[0019] DESCRIPTION OF THE REFERENCE NUMERALS: Pumped - storage power station 1, Enhanced geothermal system 2, Intelligent dispatching and management system 3, Connection facilities 4, Power grid system 5, Pumped - storage power station mountain body 11, Upper reservoir 12, Upper water conveyance pipeline 13, Underground power plant 14, Pumping unit 15, Generator unit 16, Lower water conveyance pipeline 17, Lower reservoir 18, Injection well 21, Production well 22, Dry - hot rock thermal reservoir caprock 23, Dry - hot rock thermal reservoir layer 24, Fracture network 25, Fluid direction 26. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following will introduce the present invention in detail with reference to the drawings: As shown in FIGS. Figure 1 、 2 、3, an integrated energy system jointly constructed by a pumped - storage power station and an enhanced geothermal system (EGS) includes a pumped - storage power station 1, an enhanced geothermal system 2, an intelligent dispatching and management system 3, connection facilities 4, a power grid system 5, a pumped - storage power station mountain body 11, an upper reservoir 12, an upper water conveyance pipeline 13, an underground power plant 14, a pumping unit 15, a generator unit 16, a lower water conveyance pipeline 17, a lower reservoir 18, an injection well 21, a production well 22, a dry - hot rock thermal reservoir caprock 23, a dry - hot rock thermal reservoir layer 24, and a fracture network 25. Figure 3 Also shown in the figure is: Fluid direction 26.

[0021] The pumped - storage power station 1 and the enhanced geothermal system 2 are connected through a connection facility 4 and operate in coordination under the control of the intelligent scheduling management system 3.

[0022] The connection facility 4 includes: pipelines (such as the upper water conveyance pipeline 13 and the lower water conveyance pipeline 17), valves, water pumps, turbines, etc., to ensure the efficient flow of water and steam in the system.

[0023] The intelligent scheduling system 3 includes: Data acquisition module: Real - time monitors the operation data of the pumped - storage power station, enhanced geothermal system, connection facility, and power grid system, including data information such as grid load, energy storage status, and environmental parameters; Prediction and analysis module: Based on historical data and real - time operation data, combined with preset algorithms and models, predicts and analyzes the grid load and energy storage demand; Decision - making and optimization module: According to the prediction and analysis results and preset scheduling strategies, formulates the optimal operation plan to achieve the coordinated operation of the pumped - storage power station and the EGS system; Execution and control module: According to the instructions of the decision - making and optimization module, automatically adjusts the operation status of the pumped - storage power station and the EGS system to ensure the efficient and stable operation of the system.

[0024] Reference appendix Figure 2, the pumped-storage power station system 1 consists of a pumped-storage power station mountain body 11, an upper reservoir 12, an upper water conveyance pipeline 13, an underground powerhouse 14, a pump unit 15, a generator unit 16, a lower water conveyance pipeline 17, and a lower reservoir 18. Among them, the pumped-storage power station mountain body 11 has sufficient water source guarantee, appropriate head difference, and suitable geological conditions. The upper reservoir 12 is located at a higher elevation, forming a certain water level difference with the lower reservoir 18. During the low-load period of the power grid system 5, the surplus power of the power grid is used to drive the pump unit 15 to pump the water from the lower reservoir 18 to the upper reservoir 12 for storage, converting electrical energy into the potential energy of water. When the power grid system 5 is at the peak-load period or needs to supplement power, the water discharge gate of the upper reservoir 12 is opened, and the water flows through the upper water conveyance pipeline 17 into the underground powerhouse 14, driving the turbine to rotate, and then driving the generator unit 16 to generate electricity, converting the stored potential energy of water into electrical energy. The lower reservoir 18 is located at a lower elevation and is connected to the upper reservoir 12 through a water conveyance system. During the pumping process of the pumped-storage power station, the lower reservoir 18 serves as a water source to provide sufficient water volume for the pump. During the power generation process, the lower reservoir 18 receives the water flowing down from the upper reservoir 12 and stores it for reuse in pumping. The underground powerhouse 14 is usually located near the upper reservoir 12 or the lower reservoir 18, connected to the upper water conveyance pipeline 13 and the lower water conveyance pipeline 17, and includes chambers such as the main and auxiliary powerhouse, main transformer cavern, and busbar cavern, and includes the pump unit 15 and the generator unit 16, etc. The underground powerhouse is used to place electromechanical equipment such as energy storage units, pumps, turbines, generators, and transformers. The basic functions of the pumped-storage power station, such as pumping and power generation, as well as important functions such as frequency modulation, phase modulation, load ramping, and emergency standby, are all completed by the electromechanical equipment in the powerhouse.

[0025] Reference appendix Figure 3 , the enhanced geothermal system 2 includes an injection well 21, a production well 22, a hot dry rock reservoir caprock 23, a hot dry rock reservoir 24, and a fracture network 25. It also includes an energy storage unit for storing the thermal energy generated by the system, such as reservoir-type heat storage, underground storage tanks, and material heat storage, etc.

[0026] Geothermal wells (including injection well 21 and production well 22) are the core facilities in the EGS system, directly drilled into the deep underground hot dry rock layer. The geothermal wells are located in areas with suitable geological conditions and rich geothermal resources, and the location relationship with the pumped-storage power station or other energy facilities needs to be considered to achieve resource sharing and complementarity. During the circulation process of the geothermal fluid in the injection well 21, the fracture network 24, and the production well 22, the thermal energy of the hot dry rock reservoir 24 is transferred to the ground, providing a heat source for power generation or other thermal energy utilization.

[0027] The hot dry rock reservoir 24 refers to a high-temperature dense rock mass that is stored at a certain depth underground (usually 3 - 10 km), with no or only a small amount of fluid inside, and has a reasonable burial depth and can extract internal heat using heat exchange technology. Cold fluid is pressed into the hot dry rock reservoir 24 in the injection well 21, and the hot fluid generated through heat exchange is discharged from the production well 22 for heating, power generation, etc. The lithology is generally granite, granodiorite, diorite - granite, etc., with characteristics such as high density, high thermal conductivity, low porosity, low permeability, and the presence of fracture pores.

[0028] The hot dry rock thermal reservoir caprock 23 refers to an impermeable or weakly permeable rock layer overlying the hot dry rock reservoir 24, which plays an insulating and sealing role. It prevents the upward dissipation of geothermal energy, enabling geothermal energy to accumulate in the hot dry rock reservoir 24.

[0029] The hydraulic fracturing device is installed near the wellhead of the geothermal well. By accessing the high-pressure water when the pumped-storage power station discharges water or equipment such as a high-pressure pump, fluid is injected into the geothermal well. The high-pressure water flow is used to hydraulically fracture the hot dry rock, creating a fracture network, increasing the permeability of the geothermal fluid, transforming the originally low-permeability hot dry rock into a permeable geothermal reservoir, enabling more geothermal fluid to participate in the cycle, and thus increasing the extraction amount of geothermal energy.

[0030] The geothermal power generation device is located on the ground and is connected to the geothermal well, including equipment such as a heat exchanger, a turbine, and a generator, which together constitute a geothermal power generation system. The geothermal fluid releases heat energy in the heat exchanger, transferring the heat energy to the working medium (such as water or steam). The working medium expands when heated, driving the turbine to rotate. The turbine drives the generator to rotate, converting mechanical energy into electrical energy, and the electrical energy is then transmitted to the user end through the power grid system 5 to meet the power demand.

[0031] This embodiment also provides a construction and operation method for an integrated energy system jointly constructed by the above-mentioned pumped-storage power station and enhanced geothermal system (EGS): 1. Site selection and exploration: Select an area with suitable geological conditions and rich hot dry rock resources as the construction site, conduct detailed geological exploration, and determine the specific locations of the pumped-storage power station and the geothermal well. 2. System construction: Construct a pumped-storage power station, including upper and lower reservoirs, water conveyance pipelines, pump units, and generator sets, etc. Drill a geothermal well below the pumped-storage power station to reach the hot dry rock layer, and install a hydraulic fracturing device and a geothermal power generation device. Lay a water conveyance pipeline connecting the pumped-storage power station and the geothermal well, and introduce water into the geothermal well of the EGS system through the pump system of the pumped-storage power station to achieve the sharing and recycling of water resources. 3. Hydraulic fracturing: In the initial stage of EGS system construction, the hydraulic pressure of the pumped-storage power station is used to hydraulically fracture the hot dry rock to form a fracture network, and the water pressure is adjusted to optimize the distribution of the fracture network and improve the heat exchange efficiency; 4. System commissioning: Conduct joint commissioning of the system to ensure the normal collaborative operation between the pumped-storage power station and the EGS system; 5. Operation and management: According to the power grid load forecast and energy storage demand, formulate the system operation plan; start the water storage of the pumped-storage power station and assist in the hydraulic fracturing of EGS during the low load period of the power grid; start the power generation of the EGS system and supplement the water pumping required by the pumped-storage power station during the peak load or insufficient surplus power of the power grid. At the same time, monitor the operation status of the system in real time and adjust the operation strategy in a timely manner to optimize the energy utilization efficiency. In the event of an emergency in the power grid, the pumped-storage power station and the EGS system can respond quickly and provide the necessary power support.

[0032] The above algorithms and models in this embodiment can all refer to the prior art.

[0033] The above are only the preferred embodiments of the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A comprehensive energy system constructed by a pumped storage power station and an enhanced geothermal energy system, characterized in that: It includes a pumped storage power station, an enhanced geothermal energy system, an intelligent dispatching and management system, connection facilities and a power grid system. The pumped storage power station and the enhanced geothermal energy system are connected via the connection facilities and achieve coordinated operation under the control of the intelligent dispatching and management system.

2. The integrated energy system constructed by the pumped storage power station and the enhanced geothermal energy system according to claim 1 is characterized by: The pumped storage power station comprises an upper reservoir, a lower reservoir and a water pipeline connecting the upper reservoir and the lower reservoir, and the water pipeline is connected to a water pump unit and a generator unit; When the grid load is low, the pumped storage power station is started to store water, and the pump unit pumps the water from the lower reservoir to the upper reservoir. The upper reservoir releases part of the high-pressure water and is directly used for hydraulic fracturing operations in the enhanced geothermal energy system. When the power grid is at peak or there is insufficient surplus electricity, water flows from the upper reservoir to the lower reservoir, and the generator set uses the gravitational potential energy of the water flow to generate electricity; the enhanced geothermal energy system is started to generate electricity to supplement the electricity needed to pump water from the pumped storage power station, or directly connect to the power grid system to supply electricity.

3. The integrated energy system constructed by the pumped storage power station and the enhanced geothermal energy system according to claim 2 is characterized by: The enhanced geothermal energy system includes a geothermal well, a hydraulic fracturing device and a geothermal power generation device. The geothermal well is drilled directly into a hot dry rock layer. The hydraulic fracturing device uses high-pressure water flow to hydraulically fracture the hot dry rock to form a fracture network. The geothermal power generation device uses thermal energy in the geothermal fluid extracted from the fracture network to generate electricity.

4. The integrated energy system constructed by the pumped storage power station and the enhanced geothermal energy system according to claim 3 is characterized by: The enhanced geothermal energy system further comprises an energy storage unit for storing thermal energy generated by the system.

5. The integrated energy system constructed by synergistically combining a pumped storage power station and an enhanced geothermal energy system according to claim 1 is characterized in that: The intelligent dispatching management system comprises: Data acquisition module, which collects real-time operating data of pumped storage power plants, enhanced geothermal energy systems, connecting facilities and power grid systems; The prediction and analysis module predicts and analyzes the grid load and energy storage demand within a certain period of time based on historical data and the operating data collected in real time by the data acquisition module, combined with preset algorithms and models; The decision-making optimization module formulates the optimal operation plan based on the prediction analysis results and the preset scheduling strategy; The execution control module automatically adjusts the system operation status according to the operation plan.

6. The integrated energy system constructed by synergistically combining a pumped storage power station and an enhanced geothermal energy system according to claim 5 is characterized in that: The intelligent dispatching management system further includes a communication module for exchanging data with an external control center.

7. The integrated energy system constructed by the pumped storage power station and the enhanced geothermal energy system according to claim 1 is characterized by: The pump units and generator sets of the pumped storage power station are both located in underground powerhouses to reduce the impact on the ground environment.

8. The integrated energy system constructed by synergistically combining a pumped storage power station and an enhanced geothermal energy system according to claim 1 is characterized by: The geothermal wells of the enhanced geothermal energy system are located below the pumped storage power station, and efficient use of resources is achieved by sharing water resources.

9. A method for constructing an integrated energy system according to any one of claims 1 to 8, characterized in that: include: Site selection and exploration to determine the specific locations of pumped storage power stations and geothermal wells; System construction, including the construction of upper and lower reservoirs, water pipelines, pumping units and generator sets; Hydraulic fracturing uses the water pressure from a pumped-storage power station to hydraulically fracture hot dry rock to form a network of fractures.

10. An operating method of the integrated energy system according to any one of claims 1 to 8, characterized in that: include: System commissioning, joint commissioning of pumped storage power station and enhanced geothermal energy system; Real-time monitoring, monitoring the operation data of the integrated energy system; Predictive analysis: Based on real-time operation data and historical data, combined with preset algorithms and models, predictive analysis of grid load and energy storage demand within a certain period of time; Formulate an operation plan, and formulate the optimal operation plan based on the forecast analysis results and the preset scheduling strategy; Execute the operation plan and automatically adjust the system operation status according to the operation plan.

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