Concentrating solar energy coupling terrestrial heat long-time energy storage and control system and method

Abstract

The invention relates to a concentrated solar energy and terrestrial heat coupling long-time energy storage and control system and method. The system comprises a concentrated solar energy collection system, a heat energy conversion and transmission system, a terrestrial heat long-time energy storage system, a heater module and an energy utilization system. The concentrating solar energy collecting system is used for focusing sunlight and converting the focused solar energy into heat energy; the heat energy conversion and transmission system is used for receiving heat energy from the concentrating solar energy collection system and transmitting the heat energy to the geothermal long-time energy storage system or directly used for power generation; according to the geothermal long-time energy storage system, the natural heat storage characteristic of underground deep rocks is utilized, and heat energy is stored by injecting high-temperature hot fluid; the heater module is used for heating an organic working medium by using heat energy stored by high-temperature hot fluid from a hot well through heat exchanger equipment; the energy utilization system is used for achieving the gradient utilization process of energy. The utilization efficiency of concentrated solar energy and the sustainable utilization rate of geothermal energy are improved. And maximum storage and efficient output of energy are realized.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology in energy technology, and specifically to a concentrated solar energy coupled geothermal long-term energy storage and control system and method, which is particularly suitable for large-scale renewable energy storage and conversion. Background Art

[0002] With the growth of global energy demand and the increasing pressure of environmental protection, the development and utilization of renewable energy has become a key way to solve the energy crisis and environmental problems. As a clean and renewable energy, solar energy has broad development potential and application prospects. However, one of the main limiting factors of solar energy is the intermittent nature of its production capacity - that is, energy can only be collected and converted during sunny daytime, which leads to discontinuous energy supply.

[0003] At present, concentrated solar power (CSP) technology has become an important means to improve the efficiency of solar energy utilization. The CSP system concentrates sunlight into a small area through concentrating mirrors, generating high temperatures to drive traditional steam cycle generators or other energy conversion equipment. Although CSP technology improves the conversion efficiency of solar energy, its storage solutions still rely on battery storage or thermal energy storage systems, which are usually costly and unstable in efficiency.

[0004] In this context, geothermal energy storage technology provides a new solution. By converting and storing the thermal energy generated by concentrated solar energy in a high-temperature and high-pressure environment underground, long-term energy storage can be achieved, and when needed, it can be converted into electricity or heat energy through geothermal batteries for supply. However, current geothermal energy storage technology still faces many challenges in practical applications, including energy storage efficiency, cost control, environmental impact, and technical complexity.

[0005] In summary, the existing energy storage and conversion technologies fail to fully meet the requirements of high efficiency, low cost and environmental protection. Therefore, it is particularly important to develop a new type of long-term energy storage system of concentrated solar energy coupled with geothermal batteries. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a concentrated solar energy coupled geothermal long-term energy storage and control system;

[0007] The invention of the concentrated solar energy coupled with geothermal long-term energy storage and control system can not only solve the storage and stable power supply problems of solar energy and geothermal energy, but also bring significant advantages in terms of economy and environmental protection. The invention can effectively integrate concentrated solar energy and geothermal energy, and use geothermal energy to achieve long-term, cross-season, efficient energy storage and stable energy output.

[0008] The present invention also provides a concentrated solar energy coupled geothermal long-term energy storage and control method.

[0009] The technical solution of the present invention is:

[0010] A concentrated solar energy coupled geothermal long-term energy storage and control system, comprising a concentrated solar energy collection system, a heat energy conversion and transmission system, a geothermal long-term energy storage system, a heater module, and an energy utilization system;

[0011] The concentrated solar energy collection system is used to focus sunlight and convert the focused solar energy into thermal energy;

[0012] The thermal energy conversion and transmission system is used to receive thermal energy from the concentrated solar energy collection system and transmit the thermal energy to the geothermal long-term energy storage system or directly use it for power generation;

[0013] The geothermal long-term energy storage system utilizes the natural heat storage characteristics of deep underground rocks and stores thermal energy by injecting high-temperature thermal fluid;

[0014] The heater module uses the stored heat energy from the high-temperature hot fluid in the hot well through the heat exchanger device to heat the organic working fluid;

[0015] The energy utilization system is used to realize a cascade utilization process of energy.

[0016] Preferably, according to the present invention, the concentrated solar energy collection system comprises a concentrating unit and a thermal energy collection unit;

[0017] The light concentrating unit focuses sunlight onto the heat energy collecting unit;

[0018] The thermal energy collection unit converts concentrated solar energy into thermal energy.

[0019] Further preferably, the focusing unit uses a reflector or lens with a focusing ratio of more than 300;

[0020] The sunlight is focused onto a thermal energy collection unit; the thermal energy collection unit uses a high-temperature and high-pressure heat exchanger to convert the focused solar energy into thermal energy.

[0021] Preferably according to the present invention, the heat energy conversion and transmission system includes a high-temperature and high-pressure heat exchanger; the high-temperature and high-pressure heat exchanger adopts a spiral tube heat transfer structure, and the high-temperature and high-pressure heat exchanger is also equipped with a sealing system.

[0022] Preferably, according to the present invention, the geothermal long-term energy storage system includes a high-temperature seepage heat transfer unit, a fracturing unit, an injection-storage-heat extraction unit, and a reservoir dynamic monitoring and intelligent management and control unit;

[0023] Among them, the high-temperature seepage heat transfer unit is used to monitor the underground high-temperature fluid seepage pressure change curve, and monitor the underground seepage flow rate, and reversely infer the process pressure and flow of the seepage through the surface pressure change; at the same time, the fracturing unit is integrated in the geothermal exploitation process, and fracturing is carried out through the fracturing unit. During the fracturing process, the stress changes underground and on the surface are monitored in real time through the stress monitoring system, and the collected data are transmitted to the ground monitoring station in real time. By analyzing the monitoring data, the fracturing parameters are adjusted in real time to optimize the generation and expansion of cracks. Next, the degree of formation fracturing is recorded in detail, so that the fracturing process is coupled with the unit process of underground heat injection-deep flow.

[0024] Further preferably, in the high-temperature seepage heat transfer unit, a cooling fluid is injected into the rock under high temperature and high pressure conditions underground, and underground sensors are used to observe and record how the thermal stress caused by the temperature difference affects the crack expansion and permeability of the rock, and ultimately the influence of the crack morphology, expansion path, and rock stress distribution on the fluid flow rate; at the same time, geological principles and thermodynamic analysis are used to analyze the interaction between heat flow and solid structure in the formation; and the underground heat flow solidification coupling process is used to improve the heat storage stability and durability of the formation.

[0025] Further preferably, the injection-storage-extraction unit realizes effective injection and extraction of thermal energy through an underground thermal fluid dynamic management system; the underground thermal fluid dynamic management system includes pumping equipment and control valves.

[0026] Further preferably, the reservoir dynamic monitoring and intelligent management and control unit includes a data acquisition and sensing system, a data processing and analysis system, an intelligent control system, and a human-machine interface and visualization system;

[0027] The data acquisition and sensing system collects the temperature, pressure and flow of the underground reservoir in real time and transmits it to the data processing and analysis system; the data processing and analysis system integrates and preprocesses the data, eliminates data noise, ensures the accuracy of the data, and then analyzes the real-time data and predicts the dynamic response of the reservoir in combination with the numerical simulation module; based on the analysis results, the intelligent control system adjusts the pressure and flow operating parameters of the injected fluid; the human-machine interface and visualization system provides a human-machine interface and displays complex data and simulation results in a graphical way, helping operators to view real-time monitoring data, dynamic response curves and control instructions through the human-machine interface, and understand the reservoir status and system behavior.

[0028] Preferably, according to the present invention, the energy utilization system is used to realize a cascade utilization process of energy, including utilizing the thermal fluid from the production well for power generation and direct heating, and the thermal power generation process is divided into two flash evaporation stages, which are used to drive high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator, and the high-pressure steam and low-pressure steam generate electricity in the high-pressure turbine and the low-pressure turbine, respectively.

[0029] A concentrated solar energy coupled geothermal long-term energy storage and control method is implemented by the above-mentioned concentrated solar energy coupled geothermal long-term energy storage and control system, comprising:

[0030] When the concentrated solar energy system is in the heat absorption condition, the heat injection unit transmits the high-temperature heat energy collected from the concentrated solar energy system to the geothermal long-term energy storage system;

[0031] According to the requirements of the specific injection mode, the high-temperature fluid collected in the concentrating tower of the concentrated solar energy system is heated to a specific temperature range through the combined heater module, and enters the high-pressure heat exchanger, and exchanges heat with the underground cold fluid (steam / sco2 and other working fluids), and the underground cold fluid is injected into the underground high-temperature heat storage rock layer;

[0032] Underground heat storage: This includes injecting hot fluid into rocks, observing and recording the temperature difference and pressure curve in the underground heat storage rock layer, and then inferring the crack expansion and permeability of the rock, evaluating the heat storage characteristics and capacity of the underground rock layer, and thus controlling the injected heat;

[0033] According to the injection-storage-heat extraction mode, heat is extracted from the hot well, and the outlet flow is controlled and the outflow fluid temperature is monitored based on the flow and heat transfer characteristics of the hot fluid in the reservoir;

[0034] The produced thermal fluid enters the flash-ORC combined power generation unit. The thermal power generation process is divided into two flash stages to drive the high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator. Electricity is generated in the high-pressure turbine and the low-pressure turbine respectively, and the overall thermal efficiency of the system is improved; after the power generation cycle is completed, the tail water is recharged into the reservoir from the cold well.

[0035] The present invention has the following beneficial effects:

[0036] The concentrated solar energy coupled geothermal long-term energy storage and control system provided by the present invention improves the utilization efficiency of concentrated solar energy and the sustainable utilization rate of geothermal energy. It realizes the maximum storage and efficient output of energy, especially for long-term energy storage across seasons, and can meet the peak period of energy demand, enhances the environmental adaptability and economy of the long-term energy storage system, and provides strong technical support for the practical application and commercialization of large-scale renewable energy. This long-term energy storage system adopts a modular and scalable architecture in system design, which is convenient for expansion or adjustment according to actual needs and adapting to different geographical and climatic conditions. It can effectively improve the heating efficiency of the heat network, and improve the utilization rate of low-grade heat in the entire system, realizing the cascade utilization of heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 It is a schematic diagram of the structure of the concentrated solar energy coupled geothermal long-term energy storage and control system of the present invention;

[0039] Figure 2 A schematic diagram of the injection-storage-production process provided by an embodiment of the present invention;

[0040] 1. Concentrated solar energy collection system, 2. High temperature and high pressure heat exchanger, 3. Cold fluid well, 4. Hot fluid well, 5. Geothermal long-term energy storage layer, 6. Cover layer, 7. High pressure separator, 8. Low pressure separator, 9. High pressure / low pressure turbine, 10. Condenser. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1

[0043] A concentrated solar energy coupled geothermal long-term energy storage and control system, comprising a concentrated solar energy collection system 1, a heat energy conversion and transmission system, a geothermal long-term energy storage system, a heater module, and an energy utilization system (heating and power generation subsystem); Figure 1As shown, it specifically includes a concentrated solar energy collection system 1, a high-parameter heat exchanger 2, a cold fluid well 3, a hot fluid well 4, a geothermal long-term energy storage layer 5, a cover layer 6, a high-pressure separator 7, a low-pressure separator 8, a high-pressure / low-pressure turbine 9, and a condenser 10.

[0044] The concentrated solar energy collection system 1 is used to focus sunlight and convert the focused solar energy into thermal energy;

[0045] The heat energy conversion and transmission system is used to effectively receive heat energy from the concentrated solar energy collection system 1 and transmit the heat energy to the geothermal long-term energy storage system or directly use it for power generation;

[0046] Geothermal long-term energy storage systems utilize the natural heat storage properties of deep underground rocks to store thermal energy by injecting high-temperature thermal fluids (such as hot steam or molten salt);

[0047] The heater module uses the high-temperature hot fluid from the hot well through the heat exchanger device to store the heat energy for heating the organic working fluid; the heater module includes the heat exchanger device.

[0048] The energy utilization system is used to realize the cascade utilization process of energy. The energy utilization system is mainly composed of a flash organic circulation system, which mainly includes: a high-pressure separator 7, a low-pressure separator 8, a high-pressure / low-pressure turbine 9, a condenser 10, etc.

[0049] Example 2

[0050] The difference between the concentrated solar energy coupled geothermal long-term energy storage and control system described in Example 1 is that:

[0051] The concentrated solar energy collection system 1 comprises a concentrating unit and a thermal energy collection unit; the concentrating unit focuses sunlight to the thermal energy collection unit; the thermal energy collection unit converts the focused solar energy into thermal energy for further storage or direct energy conversion.

[0052] The focusing unit uses a reflector or lens with a focusing ratio of more than 300;

[0053] Focus sunlight to the thermal energy collection unit; the thermal energy collection unit uses a high temperature and high pressure heat exchanger 2 to convert the focused solar energy into thermal energy. For further storage or direct energy conversion, the thermal energy collection unit is equipped with a high temperature absorber, usually using molten salt or other high-efficiency heat transfer materials (heat exchange materials are water, superheated steam or thermal oil) as a medium. These materials can remain stable when reaching a temperature (1200oC), effectively converting and storing the concentrated solar thermal energy.

[0054] The key to the heat conversion and transmission system is to be able to work stably under high temperature (500-1200℃) range and pressure conditions to ensure efficient conversion and transmission of heat energy. The high temperature and high pressure heat exchanger 2 under high pressure conditions is the core component of the heat conversion and transmission system, which is used to withstand temperatures up to hundreds of degrees Celsius and the corresponding high pressure environment. These high temperature and high pressure heat exchangers 2 are usually made of special high temperature and high pressure materials, such as special steel or high performance alloys, to ensure long-term reliability and durability. The heat conversion and transmission system includes a high temperature and high pressure heat exchanger 2; the high temperature and high pressure heat exchanger 2 adopts a spiral tube efficient heat transfer structure to maximize the heat exchange area and improve the heat exchange efficiency. In addition, the high temperature and high pressure heat exchanger 2 is also equipped with a high performance sealing system to prevent leakage under high pressure operating conditions. The heat conversion and transmission system also integrates an automatic cleaning function, which reduces fouling and maintains efficient heat exchange performance through periodic backwashing or chemical cleaning. The heat conversion and transmission system is tightly integrated, real-time monitoring of key parameters such as temperature, pressure and flow, and automatically adjusts the operating conditions to ensure that the system operates under monitoring.

[0055] The geothermal long-term energy storage system includes a high-temperature seepage heat transfer unit, a fracturing unit, an injection-storage-heat extraction unit, and a reservoir dynamic monitoring and intelligent management and control unit;

[0056] These units work together to achieve efficient long-term storage and management of solar energy. These media have good thermal stability and low heat loss characteristics under the high temperature and pressure environment in the formation.

[0057] Among them, the high-temperature seepage heat transfer unit is used to monitor the pressure change curve of underground high-temperature fluid seepage and the flow rate of underground seepage, and reversely infer the process pressure and flow rate of seepage through the pressure change on the surface; at the same time, the fracturing unit is integrated in the geothermal exploitation process, and fracturing is carried out through the fracturing unit. During the fracturing process, the stress changes of the underground and the surface are monitored in real time through the stress monitoring system, and the collected data are transmitted to the ground monitoring station in real time to help operators to instantly understand the situation of crack generation and expansion. By analyzing the monitoring data, the operator can adjust the fracturing parameters in real time, such as injection pressure and flow, to optimize the generation and expansion of cracks, and then record the degree of formation fracturing in detail, so that the fracturing process is coupled with the unit process of underground heat injection-deep flow. Among them, the unit process of underground heat injection-deep flow refers to the process of hot fluid flowing in the underground rock formation after being injected underground, including processes such as heat conduction, convection and fluid seepage, which is interdependent with the fracturing process. The cracks generated by the fracturing unit change the permeability of the formation, making the high-temperature seepage heat transfer process more efficient. At the same time, in turn, by monitoring the output data (such as pressure, temperature, and flow) of the underground high-temperature seepage heat transfer unit, the fracturing process can be further optimized, thereby forming a feedback closed-loop system. Because the actual amount of bottom monitoring data is small, the present invention develops a reservoir dynamic monitoring and intelligent management and control unit based on multi-source data. The early data sources include the early geological information collection for the development address and the numerical simulation of the fluid-heat-solid multi-physical field coupling developed. Utilizing the above-mentioned high-temperature deep flow and high-temperature seepage heat transfer unit monitoring historical data, the dynamic response curve of the overall system is numerically simulated for the injection-heat storage-heat extraction process in the heat storage process, thereby realizing the role of long-term energy storage.

[0058] In the high-temperature seepage heat transfer unit, cooling fluid is injected into the rock under high temperature and high pressure conditions underground. Through underground sensors, the thermal stress caused by the temperature difference is observed and recorded to determine how it affects the crack expansion and permeability of the rock, and finally the crack morphology, expansion path, and rock stress distribution affect the fluid flow rate. In this way, the dynamic changes of cracks under different operating conditions and the efficiency of heat energy transfer can be studied, providing a scientific basis for the effective exploitation and management of geothermal energy. At the same time, the interaction between heat flow and solid structure in the formation is analyzed by using geological principles and thermodynamic analysis; including: combining geological principles and thermodynamic analysis to establish a multi-physics coupling model, which simultaneously considers fluid flow, heat conduction, convection, and the mechanical response of rocks. Next, based on the analysis of actual measurement data or historical data, the boundary conditions of the model are set according to geological and thermodynamic parameters, such as temperature, pressure, flow rate, etc. Finally, numerical simulation is used to analyze the flow path, temperature change, and impact of thermal fluids in the formation on rock structure under different operating conditions. The simulation results can help understand how heat flow affects the stability of solid structures and the formation and expansion process of cracks. Through the underground heat flow solidification coupling process, the thermal storage stability and durability of the formation are improved.

[0059] The injection-storage-extraction unit achieves effective injection and extraction of thermal energy through the underground thermal fluid dynamic management system; the underground thermal fluid dynamic management system includes efficient pumping equipment and precise control valves. Ensure the precise flow and distribution of thermal fluid in the formation. The system dynamically adjusts the flow rate and path of the thermal fluid by real-time monitoring of the temperature and pressure changes of the formation to optimize the storage and recovery process of thermal energy.

[0060] The reservoir dynamic monitoring and intelligent management and control unit includes data acquisition and sensing system, data processing and analysis system, intelligent control system and human-machine interface and visualization system;

[0061] The data acquisition and sensing system collects the temperature, pressure and flow of the underground reservoir in real time and transmits it to the data processing and analysis system; the data processing and analysis system integrates and preprocesses the data, eliminates data noise, ensures the accuracy of the data, and then analyzes the real-time data and predicts the dynamic response of the reservoir in combination with the numerical simulation module; based on the analysis results, the intelligent control system adjusts the pressure and flow operating parameters of the injected fluid to optimize the thermal management of the reservoir; the human-machine interface and visualization system provides a human-machine interface and displays complex data and simulation results in a graphical way, helping operators to view real-time monitoring data, dynamic response curves and control instructions through the human-machine interface, and understand the reservoir status and system behavior.

[0062] The energy utilization system is used to realize the cascade utilization process of energy, including the use of thermal fluid from the production well for power generation and direct heating. The thermal power generation process is divided into two flash stages to drive high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator. The high-pressure steam and low-pressure steam generate electricity in the high-pressure turbine and the low-pressure turbine respectively. And improve the overall thermal efficiency of the energy utilization system.

[0063] Figure 2 A schematic diagram of the injection-storage-production process provided in an embodiment of the present invention; the injection-storage-production process is set through a periodic function, the horizontal axis is time and is expressed in hours, the vertical axis is the injection-storage-production system value, 0-6h value is 1, 7-12h is -1, 13-24h is 0, thereby representing the injection-production plan, that is, injection is 6 hours, production is 6 hours, and then the well is shut down for 12 hours.

[0064] Example 3

[0065] The difference between the concentrated solar energy coupled geothermal long-term energy storage and control system described in Example 2 is that:

[0066] In order to meet the rapid peak-shaving needs of the power grid, high-temperature and high-pressure heating devices become particularly important. Efficient heating elements and optimized structures are required to ensure that 3L / s of the fluid circulating medium (sCO2) is heated to 550°C within 5 hours and the circulating medium pressure is 22MPa. Iron-chromium-aluminum resistance strips and ceramic fiber modules are used as internal heating and insulation materials. Multi-zone temperature control in the height direction can ensure heating uniformity, and the upper limit of the design temperature that can be achieved is 900°C. Secondly, during the heating process, temperature, pressure, flow control and stability are essential. Precise control and stability need to be achieved, and advanced temperature monitoring and control technology is used. The thermal energy collection unit is equipped with a high-temperature absorber, which usually uses molten salt or other high-efficiency heat conduction materials (heat exchange materials are water, superheated steam or thermal oil) as the medium. These materials can remain stable when the temperature (1200°C) is reached, effectively converting and storing the concentrated solar thermal energy;

[0067] Next, the collected high-temperature thermal fluid is passed through the high-temperature and high-pressure heat exchanger 2 to effectively receive thermal energy from the concentrated solar energy collection system 1 and transmit it to the underground heat storage unit or directly for power generation. The key to this system is that it can work stably under high temperature (500-1200oC) and pressure conditions to ensure efficient conversion and transmission of thermal energy. In order to ensure long-term reliability and durability, the heat exchange system needs to be closely integrated with the intelligent control system to monitor key parameters such as temperature, pressure and flow in real time, and ensure that the system operates under monitoring by automatically adjusting the operating conditions.

[0068] Based on the concentrated solar energy collection system 1 and the high-temperature and high-pressure heat exchanger 2, the thermal fluid well 4 passes through the cap layer 6 and is injected into the geothermal long-term energy storage layer 5. This subsystem uses the natural heat storage characteristics of deep underground rocks to store thermal energy by injecting high-temperature thermal fluids (such as hot steam or molten salt). Its subsystem includes multiple key components, including a high-temperature seepage heat transfer unit, a fracturing unit, an injection-storage-heat extraction control unit, and a reservoir dynamic monitoring and intelligent management unit. These units work together to achieve effective long-term storage and management of solar energy. The injection-storage-heat extraction unit is responsible for the effective injection and extraction of thermal energy through the underground thermal fluid dynamic management system. The system includes efficient pumping equipment and precise control valves to ensure the precise flow and distribution of thermal fluids in the formation. The system dynamically adjusts the flow rate and path of the thermal fluid by real-time monitoring of the temperature and pressure changes of the formation to optimize the storage and recovery process of thermal energy. The above steps are the injection step-charging process.

[0069] After a period of time, according to demand, the system will carry out the process of extracting heat energy-discharging, that is, the process of using the stored heat energy in a cascade of effective energy, including using the thermal fluid of the extraction well for power generation and direct heating purposes. The thermal power generation process is divided into two flash stages, which are used to drive high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator, which generates electricity in the high-pressure turbine and the low-pressure turbine respectively and improves the overall thermal efficiency of the system. At the same time, the cold fluid obtained returns to the power generation cycle through the condenser 10.

[0070] Example 4

[0071] A concentrated solar energy coupled geothermal long-term energy storage and control method is implemented by the concentrated solar energy coupled geothermal long-term energy storage and control system described in Example 1 or 2, comprising:

[0072] When the CSP system is in the heat absorption condition, the heat injection unit transfers the high-temperature heat energy collected from the CSP system to the geothermal long-term energy storage system; the CSP system concentrates sunlight into a small area through concentrators to generate high temperature, driving traditional steam cycle generators or other energy conversion equipment. The heat injection unit refers to the high-temperature heat energy collected from the CSP system to the underground heat storage layer, including high-temperature and pressure-resistant transmission pipelines and precision-controlled pumping systems.

[0073] According to the requirements of the specific injection mode, mainly using abandoned wind and photovoltaic power, heating to a specific temperature range through a combined heater module, the high-temperature fluid collected by the concentrating tower in the concentrated solar energy system enters the high-pressure heat exchanger and exchanges heat with the underground cold fluid (steam / sco2 and other working fluids), and the underground cold fluid is injected into the underground high-temperature heat storage rock layer; the concentrating tower refers to a tower collector that usually uses the captured heat energy to heat the fluid circulation working fluid (such as supercritical CO2). High-temperature heat storage rock layers are generally referred to as strata, rock bodies or structural belts buried underground with effective voids and permeability. It can store geothermal energy through convection and enrichment of heat-carrying fluids.

[0074] Underground heat storage: This includes injecting hot fluid into rocks, observing and recording the temperature difference and pressure curve in the underground heat storage rock layer, and then inferring the crack expansion and permeability of the rock, evaluating the heat storage characteristics and capacity of the underground rock layer, and thus controlling the injected heat;

[0075] Conducting hydraulic fracturing experiments under reservoir conditions can monitor the actual physical process of crack initiation, expansion and extension, directly observe the formed fractures, and conduct detailed analysis with the help of numerical simulation. Permeability is controlled by the computer through the permeation pressure system, and the electricity, gas and liquid are mutually regulated to complete the control of pressure and permeability. The confining pressure, axial pressure and permeation pressure can be servo-controlled separately to complete the test research under various conditions.

[0076] According to the injection-storage-heat extraction mode, based on the heat flow solidification coupling mechanism between fluid and rock, the seepage and migration law of high-temperature fluid in rock, and the change law of different rock reservoirs before and after injection and extraction, the automatic identification and optimal allocation of fluid state, the system integration optimization of high-temperature and high-pressure fluid heat source power generation device and the maximization of the utilization efficiency of thermal energy cascade are realized at the same time. Heat is extracted from the hot well, according to the flow and heat transfer characteristics of the hot fluid in the reservoir, the flow rate of the outlet is controlled and the temperature of the outflowing fluid is monitored;

[0077] Flash-ORC combined power generation technology combines the advantages of flash and ORC power generation systems, which can effectively improve the conversion efficiency and power generation capacity of geothermal resources. The high-temperature geothermal fluid from the production well is introduced into the flash evaporator, where part of the water will quickly flash into steam. The generated steam enters the high-pressure / low-pressure turbine 9 of the steam turbine to drive the generator to generate electricity. The exhaust steam of the steam turbine then enters the condenser, where it is condensed into liquid, and then re-injected into the ground through a circulating pump or used for other scenarios such as heating, completing the flash system cycle. The produced thermal fluid enters the flash-ORC combined power generation unit. The thermal power generation process is divided into two-stage flash evaporation stages to drive high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator, which generate electricity in the high-pressure turbine and the low-pressure turbine respectively and improve the overall thermal efficiency of the system; after the two-stage flash evaporation process, the thermal fluid still retains a certain amount of heat, which is then transferred to low-boiling point organic working fluids (such as R245fa, isopentane, etc.) in the ORC system to evaporate it and drive the ORC turbine to generate electricity, further converting the remaining thermal energy into electrical energy; after the power generation cycle is completed, the tail water is recharged to the reservoir from the cold well.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A concentrated solar energy coupled geothermal long-term energy storage and control system, characterized in that: Including concentrated solar energy collection system, thermal energy conversion and transmission system, geothermal long-term energy storage system, heater module, energy utilization system; The concentrated solar energy collection system is used to focus sunlight and convert the focused solar energy into thermal energy; The thermal energy conversion and transmission system is used to receive thermal energy from the concentrated solar energy collection system and transmit the thermal energy to the geothermal long-term energy storage system or directly use it for power generation; The geothermal long-term energy storage system utilizes the natural heat storage characteristics of deep underground rocks and stores thermal energy by injecting high-temperature thermal fluid; The heater module uses the stored heat energy from the high-temperature hot fluid in the hot well through the heat exchanger device to heat the organic working fluid; The energy utilization system is used to realize a cascade utilization process of energy.

2. A concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 1, characterized in that: The concentrated solar energy collection system includes a light collecting unit and a heat energy collection unit; The light concentrating unit focuses sunlight onto the heat energy collecting unit; The thermal energy collection unit converts concentrated solar energy into thermal energy.

3. A concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 2, characterized in that: The focusing unit uses a reflector or lens with a focusing ratio of more than 300; The sunlight is focused onto a thermal energy collection unit; the thermal energy collection unit uses a high-temperature and high-pressure heat exchanger to convert the focused solar energy into thermal energy.

4. A concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 1, characterized in that: The heat energy conversion and transmission system includes a high-temperature and high-pressure heat exchanger; the high-temperature and high-pressure heat exchanger adopts a spiral tube heat transfer structure, and the high-temperature and high-pressure heat exchanger is also equipped with a sealing system.

5. The concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 1 is characterized in that: The geothermal long-term energy storage system includes a high-temperature seepage heat transfer unit, a fracturing unit, an injection-storage-heat extraction unit, and a reservoir dynamic monitoring and intelligent management and control unit; Among them, the high-temperature seepage heat transfer unit is used to monitor the underground high-temperature fluid seepage pressure change curve, and monitor the underground seepage flow rate, and reversely infer the process pressure and flow of the seepage through the surface pressure change; at the same time, the fracturing unit is integrated in the geothermal exploitation process, and fracturing is carried out through the fracturing unit. During the fracturing process, the stress changes underground and on the surface are monitored in real time through the stress monitoring system, and the collected data are transmitted to the ground monitoring station in real time. By analyzing the monitoring data, the fracturing parameters are adjusted in real time to optimize the generation and expansion of cracks. Next, the degree of formation fracturing is recorded in detail, so that the fracturing process is coupled with the unit process of underground heat injection-deep flow.

6. A concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 5, characterized in that: In the high-temperature seepage heat transfer unit, cooling fluid is injected into the rock under high temperature and high pressure conditions underground. Through underground sensors, it is observed and recorded how the thermal stress caused by the temperature difference affects the crack expansion and permeability of the rock, and finally the influence of the crack morphology, expansion path, and rock stress distribution on the fluid flow rate. At the same time, geological principles and thermodynamic analysis are used to analyze the interaction between heat flow and solid structure in the formation. Through the underground heat flow solidification coupling process, the heat storage stability and durability of the formation are improved.

7. A concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 5, characterized in that: The injection-storage-extraction unit realizes effective injection and extraction of thermal energy through an underground thermal fluid dynamic management system; the underground thermal fluid dynamic management system includes pumping equipment and control valves.

8. The concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 5 is characterized in that: The reservoir dynamic monitoring and intelligent management and control unit includes a data acquisition and sensing system, a data processing and analysis system, an intelligent control system, and a human-machine interface and visualization system; The data acquisition and sensing system collects the temperature, pressure and flow of underground reservoirs in real time and transmits them to the data processing and analysis system; The data processing and analysis system integrates and preprocesses the data, eliminates data noise, ensures data accuracy, and then analyzes the real-time data and combines it with the numerical simulation module to predict the dynamic response of the reservoir; According to the analysis results, the intelligent control system adjusts the pressure and flow operating parameters of the injected fluid; the human-machine interface and visualization system provides a human-machine interface and displays complex data and simulation results in a graphical way, helping operators to view real-time monitoring data, dynamic response curves and control instructions through the human-machine interface, and understand reservoir status and system behavior.

9. The concentrated solar energy coupled geothermal long-term energy storage and control system according to claim 5, characterized in that: The energy utilization system is used to realize the cascade utilization process of energy, including utilizing the thermal fluid of the production well for power generation and direct heating. The thermal power generation process is divided into two flash evaporation stages, which are used to drive high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator. The high-pressure steam and low-pressure steam generate electricity in the high-pressure turbine and the low-pressure turbine respectively.

10. A concentrated solar energy coupled geothermal long-term energy storage and control method, which is implemented by the concentrated solar energy coupled geothermal long-term energy storage and control system according to any one of claims 1 to 9, comprising: When the concentrated solar energy system is in the heat absorption condition, the heat injection unit transmits the high-temperature heat energy collected from the concentrated solar energy system to the geothermal long-term energy storage system; According to the requirements of the specific injection mode, the high-temperature fluid collected in the concentrating tower of the concentrated solar energy system is heated to a specific temperature range through the combined heater module, and enters the high-pressure heat exchanger to exchange heat with the underground cold fluid, and the underground cold fluid is injected into the underground high-temperature heat storage rock layer; Underground heat storage: This includes injecting hot fluid into rocks, observing and recording the temperature difference and pressure curve in the underground heat storage rock layer, and then inferring the crack expansion and permeability of the rock, evaluating the heat storage characteristics and capacity of the underground rock layer, and thus controlling the injected heat; According to the injection-storage-heat extraction mode, heat is extracted from the hot well, and the outlet flow is controlled and the outflow fluid temperature is monitored based on the flow and heat transfer characteristics of the hot fluid in the reservoir; The produced thermal fluid enters the flash-ORC combined power generation unit. The thermal power generation process is divided into two flash stages to drive the high-pressure and low-pressure turbines: high-pressure steam is obtained in the high-pressure flash evaporator, and low-pressure steam is obtained in the low-pressure flash evaporator. Electricity is generated in the high-pressure turbine and the low-pressure turbine respectively, and the overall thermal efficiency of the system is improved; after the power generation cycle is completed, the tail water is recharged into the reservoir from the cold well.

Images