A cross-season heat storage medium-deep geothermal and solar energy coupling energy supply regulation system

Abstract

The present application relates to the technical field of multi-energy complementary, in particular to a cross-season heat storage medium-deep geothermal and solar energy coupling energy supply regulation system, comprising a power supply mechanism for supplying power for the operation of the system; a heat source mechanism comprising a geothermal component and a solar heat supply component, which can supply heat alone or in combination; a heat exchange mechanism comprising a heat conduction component and a heat pump component connected in communication, allowing heat exchange between heat and user terminals with heat demand; a heat storage mechanism comprising a first heat storage component in communication with the heat pump component for storing the heat of the heat pump component; and a water replenishment mechanism in communication with the heat conduction component and the user terminal for water replenishment. Through innovative system integration and intelligent control strategy, the present application establishes a whole-year tail water heat replenishment mechanism, realizes efficient, stable and environmentally friendly use of energy, and is particularly suitable for regional heating, refrigeration and energy complementary application scenarios, and has significant popularization and application value.

Description

Technical Field

[0001] This invention relates to the field of multi-energy complementarity technology, and in particular to a cross-seasonal thermal storage system that couples medium-deep geothermal and solar energy for energy supply and regulation. Background Technology

[0002] Given the current scarcity of fossil fuels, building a clean, low-carbon, safe, and efficient modern energy system is even more urgent. From the perspective of current technological development, solar and geothermal energy are inexhaustible clean energy sources and can be regarded as the main direction of development.

[0003] As the most abundant permanent energy source in nature, solar energy has a huge total energy volume, providing a nearly unlimited clean power foundation for human sustainable development. However, the energy output of solar energy has the defects of strong intermittency, instability and seasonality. Its peak supply period often does not coincide with the peak energy load. In particular, the characteristics of surplus heat in summer and insufficient heat in winter create a sharp contradiction with the actual energy demand in many regions, limiting its ability to serve as a reliable main energy source. Geothermal energy, as a widely distributed, stable, and weather-independent baseload energy source, is an indispensable and important component of the renewable energy system. The efficient development and utilization of medium-deep geothermal energy has irreplaceable value in optimizing the energy structure and ensuring energy security. However, in the development of geothermal energy, especially medium-deep hydrothermal geothermal systems, the continuous extraction of underground hot water and reinjection of low-temperature tailwater into the geothermal reservoir is the core bottleneck leading to the decline in system efficiency. This process forms and advances a "cold front" underground. When it reaches the extraction well, it will trigger a thermal breakthrough, that is, a sharp drop in the temperature of the produced fluid. This not only directly leads to the failure of the system's heating or power generation capacity, but may also cause irreversible damage to the geothermal reservoir, seriously threatening the long-term economic viability and sustainability of geothermal projects.

[0004] Therefore, developing a cross-seasonal thermal storage system that couples medium-deep geothermal and solar energy for power supply and regulation, breaking through the limitations of single technologies, and building an efficient and stable multi-energy complementary system is an urgent research topic. Summary of the Invention

[0005] The purpose of this invention is to provide a mid-deep geothermal and solar energy coupling and regulation system for cross-seasonal thermal storage, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a cross-seasonal thermal storage system for coupled medium-deep geothermal and solar energy supply and regulation, comprising:

[0007] The power supply mechanism includes multiple power supply modules used in combination to supply power for the operation of the system;

[0008] The heat source mechanism includes a geothermal component and a solar heating component, wherein the geothermal component and the solar heating component are arranged in parallel, and the geothermal component and the solar heating component can provide heat independently or in combination.

[0009] The heat exchange mechanism includes a heat-conducting component and a heat pump component that are connected to each other. The heat-conducting component and the heat pump component are respectively connected to the geothermal component and the solar heating component, so that heat can be exchanged with the user end that has a heat demand.

[0010] A heat storage mechanism includes a first heat storage component, which is connected to the heat pump component and is used to store the heat of the heat pump component.

[0011] A water replenishment mechanism is connected to the heat-conducting component and the user terminal for water replenishment.

[0012] Preferably, the geothermal component includes a collection well and a reinjection well. The heat source collected in the collection well flows along the heat-conducting component and exchanges heat with the user end to provide heat. After the heat source water is heated, its temperature decreases and it is reinjected into the reinjection well.

[0013] Preferably, the solar heating component includes a photovoltaic thermal panel for collecting solar heat and generating electricity. The electricity supplied by the photovoltaic thermal panel is incorporated into the power supply mechanism to power the system. The heat supplied by the photovoltaic thermal panel is stored in a hot water storage tank, which is connected to the heat-conducting component for heat exchange.

[0014] Preferably, the first heat storage component includes a shallow underground pipe buried in the underground rock strata, the shallow underground pipe being connected to a heat pump component; the heat from the heat pump component is introduced into the underground rock strata through the shallow underground pipe for storage.

[0015] Preferably, the heat-conducting component includes an intermediate water plate heat exchanger and a direct-supply plate heat exchanger. The hot water in the direct-supply plate heat exchanger exchanges heat with the user end and then enters the intermediate water plate heat exchanger. The heat pump component exchanges heat with the intermediate water plate heat exchanger to collect the remaining heat for the user end to use for heating.

[0016] Preferably, the water replenishment mechanism includes a constant pressure water replenishment device connected to the water source, and the outlet of the constant pressure water replenishment device is independently connected to the intermediate water plate heat exchanger and the user end respectively; a fully automatic softening device and a softened water tank are connected in sequence between the water source and the constant pressure water replenishment device, and the softened water in the softened water tank is replenished into the constant pressure water replenishment device.

[0017] Preferably, when the groundwater temperature is lower than the temperature of the hot water storage tank, the groundwater in the collection well is pumped into the hot water storage tank to absorb heat. The groundwater after absorbing heat enters the direct-supply plate heat exchanger to exchange heat with the user end in the primary stage. After the primary heat exchange, the groundwater enters the intermediate water plate heat exchanger to exchange heat with the heat pump assembly in the secondary stage. The heat pump assembly uses the extracted heat to heat the user end again. The tailwater that has cooled down again is mixed with the external water source that has been heated by heat exchange through the shallow buried pipe and then reinjected into the reinjection well.

[0018] Preferably, when the groundwater temperature is higher than the temperature of the hot water storage tank, the groundwater in the collection well is pumped into the direct-supply plate heat exchanger for primary heat exchange with the user end; the groundwater after primary heat exchange flows into the intermediate water plate heat exchanger and exchanges heat with the secondary heat pump component, the heat pump component extracts the heat to supply heat to the user end again, the low-temperature tailwater after secondary heat exchange flows back to the hot water storage tank for heat exchange and temperature increase, and the heated groundwater is reinjected into the reinjection well.

[0019] Preferably, when the user terminal has a cooling demand, the heat pump component exchanges heat with the user terminal to cool the user terminal; the heat pump component transfers the extracted heat to the shallow buried pipe and stores it in the soil and rock structure.

[0020] Preferably, when the system is in solar-heated mode, the groundwater in the collection well is pumped into a hot water storage tank, where it absorbs heat and heats up; the heated groundwater is then reinjected into the reinjection well.

[0021] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a mid-deep geothermal and solar coupled energy supply and control system for cross-seasonal thermal storage. Through the coordinated design of the power supply mechanism, heat source mechanism, heat exchange mechanism, thermal storage mechanism, and water replenishment mechanism, it integrates multiple power supply modules, geothermal and solar heating components. Heat exchange is achieved through heat conduction and heat pump components, cross-seasonal heat storage is completed using thermal storage components, and the water replenishment mechanism ensures system water supply, ultimately achieving multi-energy coordinated power supply and cross-seasonal energy dispatch. The power supply mechanism includes multiple jointly used power supply modules. The combined power supply of these modules, along with subsequent energy storage and grid supplementation strategies, ensures stable power supply, improves system operational reliability, and provides stable power support for the entire system operation. The heat source system includes geothermal components and solar heating components, supporting both standalone and coupled heating modes. The selection can be based on season and temperature parameters to improve heating effect and efficiency, compensate for the shortcomings of single energy sources, and achieve multi-energy complementarity. The heat exchange system consists of interconnected heat-conducting components and heat pump components. The heat-conducting components transfer heat from the heat source system to the user end for the initial heating. The cooled water after heating re-enters the heat pump components for heat recovery, and the recovered heat is used again to heat the user end. Through cascaded heat exchange, energy utilization efficiency is improved, especially in the extraction and enhancement of low-grade geothermal energy. The groundwater after the second heat exchange flows back underground. Simultaneously, the heat pump components can also serve as a cooling device for the user end, storing excess heat underground through heat storage components for use during low-temperature periods. This enables cross-seasonal heat storage and scheduling, solving the problem of misaligned energy supply and demand and avoiding waste heat. The water replenishment mechanism is connected to the heat-conducting components and the user end respectively, providing water replenishment for the key components of the system and the user end, ensuring the stability of the system circulation, preventing equipment failure due to water shortage, and extending the service life of the system. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0023] Figure 1 This is a schematic diagram of the cross-seasonal thermal storage medium-deep geothermal and solar energy coupling power supply and regulation system of the present invention;

[0024] Figure 2 This is a schematic diagram of the geothermal energy-photovoltaic-thermal synergistic heating and shallow buried pipe heat supplementation of the present invention;

[0025] Figure 3 This is a schematic diagram of the geothermal heating and photovoltaic tailwater heat replenishment mode of the present invention;

[0026] Figure 4 This is a schematic diagram of the shallow buried pipe cooling mode of the present invention;

[0027] Figure 5 This is a schematic diagram of the solar heating mode of the present invention;

[0028] Figure 6 This is a schematic diagram of the power distribution system of the present invention;

[0029] In the diagram: 1. Water source; 2. Fully automatic water softening device; 3. Softened water tank; 4. Constant pressure water supply device; 5. First solenoid valve; 6. Second solenoid valve; 7. Third solenoid valve; 8. First circulating pump; 9. User end; 10. Evaporator; 11. Compressor; 12. Condenser; 13. Throttling valve; 14. Second circulating pump; 15. Shallow buried pipe; 16. Fourth solenoid valve; 17. Recharge booster; 18. Intermediate water plate heat exchanger; 19. Direct supply plate heat exchanger; 20. Recharge well; 21. Water intake pump; 22. Collection well; 23. Swirl 24. Sand separator; 25. Fifth solenoid valve; 26. Sixth solenoid valve; 27. Tenth solenoid valve; 28. Third circulation pump; 29. ​​Hot water storage tank; 30. First battery; 31. Inverter; 32. Photovoltaic controller; 33. Second battery; 34. Power distribution network; 35. Photovoltaic thermal panel; 36. Power grid; 37. Fourth circulation pump; 38. Seventh solenoid valve; 39. Eighth solenoid valve; 40. Fifth circulation pump; 41. Sixth circulation pump; 42. Seventh circulation pump; 43. Eighth circulation pump; 44. Ninth solenoid valve; 45. Ninth circulation pump. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figures 1 to 6 As shown, this embodiment provides a cross-seasonal thermal storage system that couples medium-deep geothermal and solar energy for power supply and regulation, including:

[0033] The power supply mechanism includes multiple power supply modules used in combination to supply power for the operation of the system;

[0034] The heat source mechanism includes geothermal components and solar heating components, which are arranged side by side. The geothermal components and solar heating components can provide heat independently or in combination.

[0035] The heat exchange mechanism includes a heat-conducting component and a heat pump component connected to each other. The heat-conducting component and the heat pump component are respectively connected to the geothermal component and the solar heating component, so that heat can be exchanged with the user end 9 that has heat demand.

[0036] A heat storage mechanism includes a first heat storage component, which is connected to a heat pump component and is used to store the heat from the heat pump component.

[0037] The water replenishment mechanism is connected to the heat conduction component and the user terminal 9 for water replenishment.

[0038] This invention discloses a cross-seasonal geothermal and solar coupled energy supply and control system. Through the coordinated design of a power supply mechanism, a heat source mechanism, a heat exchange mechanism, a thermal storage mechanism, and a water replenishment mechanism, it integrates multiple power supply modules, geothermal and solar heating components. Heat exchange is achieved through heat conduction and heat pump components, cross-seasonal heat storage is accomplished using thermal storage components, and the water replenishment mechanism ensures system water supply, ultimately achieving multi-energy coordinated power supply and cross-seasonal energy dispatch. The power supply mechanism includes multiple jointly used power supply modules. The combined power supply of these modules, along with subsequent energy storage and grid supplementation strategies, ensures stable power supply, improves system operational reliability, and provides stable power support for the entire system operation. The heat source system includes geothermal components and solar heating components, supporting both standalone and coupled heating modes. The selection can be based on season and temperature parameters to improve heating effect and efficiency, compensate for the shortcomings of single energy sources, and achieve multi-energy complementarity. The heat exchange system consists of interconnected heat-conducting components and heat pump components. The heat-conducting components transfer heat from the heat source system to user terminal 9 for the first heating. The cooled water after heating re-enters the heat pump components for heat recovery, and the recovered heat is used again to heat user terminal 9. Through cascaded heat exchange, energy utilization efficiency is improved, especially in the extraction and enhancement of low-grade geothermal energy. The groundwater after the second heat exchange flows back underground. Simultaneously, the heat pump components can also serve as a cooling device for user terminal 9, storing excess heat underground through heat storage components for use during low-temperature periods. This enables cross-seasonal heat storage and scheduling, solving the problem of misaligned energy supply and demand and avoiding waste heat. The water replenishment mechanism is connected to the heat conduction components and the user terminal 9 respectively, providing water replenishment for the key components of the system and the user terminal 9, ensuring the stability of the system circulation, preventing equipment failure due to water shortage, and extending the service life of the system.

[0039] In one embodiment of the invention, the invention uses seasonality as the first decision level, dividing the year into a heating season (centered on heating) and a non-heating season (centered on heat storage, heat replenishment, or cooling). Based on this, key temperature parameters and the actual load at the user end are used as the second decision level. An automatic control system dynamically switches operating modes and finely adjusts the equipment. Specifically, during the heating season, based on a temperature comparison between the geothermal and solar heating components, the central control system automatically selects either a "geothermal-photovoltaic thermal synergistic heating with shallow underground pipe heat replenishment" or "geothermal heating with photovoltaic tailwater heat replenishment" mode, and adjusts the system accordingly to achieve cascaded utilization of heat energy and reinjection water heat replenishment. During the non-heating season, the system activates a heat storage mode during the cooling period, storing waste heat underground through a heat storage mechanism, and operates a "solar heat replenishment" mode during the non-cooling period, actively replenishing heat to the ground, thereby achieving cross-seasonal energy scheduling of "summer storage for winter use."

[0040] In one embodiment of the present invention, the intelligent control strategy of the present invention is based on a "season-parameter" two-level decision architecture. Through the central control system, the system dynamically switches the system operation mode and finely adjusts the equipment status by real-time monitoring and processing of multi-source information, thereby realizing the cascade utilization of energy, cross-seasonal scheduling and optimization of the overall system energy efficiency.

[0041] In one embodiment of the invention, see Appendix Figure 6 As shown, the power supply system consists of a photovoltaic thermal panel 34, a first battery 29 and a second battery 32, a photovoltaic controller 31, an inverter 30, and a distribution network 33. The direct current (DC) generated by the photovoltaic thermal panel 34 is managed by the photovoltaic controller 31. On one hand, it charges the first battery 29 to store electrical energy; on the other hand, it is converted into alternating current (AC) by the inverter 30. The converted AC power works in conjunction with the power grid 35, which is also equipped with a second battery 32 to purchase electricity during off-peak periods. Finally, the distribution network 33 provides a stable and reliable power supply to all electrical components within the system. Different power sources are flexibly allocated through the distribution network 33, thereby achieving energy complementarity and optimized utilization.

[0042] In one embodiment of the present invention, the power management mode of this system follows the principle of prioritizing self-generation and self-consumption, followed by energy storage buffering, and finally grid supplementation, as specifically described below.

[0043] The first priority is direct photovoltaic power generation: During periods of sufficient sunlight, the system prioritizes the use of electricity generated by the photovoltaic thermal panels 34 to directly power all electrical equipment within the system. The photovoltaic controller 31 monitors the photovoltaic power generation and the total power consumption of the system equipment in real time. When the photovoltaic power generation is greater than or equal to the real-time power of the system, the system is fully powered by photovoltaics, and any excess power is automatically stored in the first storage battery 29.

[0044] The second priority is battery discharge: when there is no sunlight or insufficient photovoltaic power, the first battery 29 and the second battery 32 release electrical energy through the inverter 30 to make up for the power shortage in the system; the first battery 29 is discharged first, followed by the second battery 32. The charging and discharging strategies of the first battery 29 and the second battery 32 are intelligently managed by the photovoltaic controller 31.

[0045] The third priority is grid 35 supplementation: when the photovoltaic thermal panels 34 and the battery cannot meet the system's power demand, the system automatically switches to the public grid 35 for power supply, ensuring stable operation of the system under any circumstances. In extreme cases, grid 35 can directly supply power to the system load, ensuring the normal operation of the system load.

[0046] In one embodiment of the present invention, the power supply mechanism of the present invention can achieve seamless switching between photovoltaic, storage battery and power grid 35, forming multiple power protections and greatly improving the reliability of system power supply.

[0047] In one embodiment of the present invention, the system will adopt a time-of-use pricing strategy. During periods of low electricity prices, the control system can instruct the purchase of electricity from the grid 35 to charge the second battery 32, thereby achieving peak shaving and valley filling and reducing the overall operating cost of the system.

[0048] The scheme is further optimized. The geothermal components include a collection well 22 and a reinjection well 20. The heat source collected in the collection well 22 flows along the heat-conducting components and exchanges heat with the user terminal 9 to provide heat. After the heat source water is heated, its temperature decreases and it is reinjected into the reinjection well 20. The collection well 22 serves as the geothermal energy collection area. Groundwater is extracted from the collection well 22 by a water pump 21. Before use, the groundwater is treated by a cyclone desander 23 to remove solid particles carried in the geothermal fluid, preventing wear and blockage of subsequent equipment and pipelines. When geothermal energy is used to provide heat to the user terminal 9, the groundwater is heated to the user terminal 9. After cooling, the groundwater is pressurized by the reinjection pressurizer 17 and reinjected into the reinjection well 20 to ensure the sustainable development of geothermal resources.

[0049] The scheme is further optimized, and the solar heating components include photovoltaic thermal panels 34 for collecting solar heat and generating electricity. The electricity supplied by the photovoltaic thermal panels 34 is fed into the power supply mechanism to power the system, and the heat supplied by the photovoltaic thermal panels 34 is stored in a hot water storage tank 28, which is connected to the heat-conducting components for heat exchange. The photovoltaic thermal panels 34 are one of the core energy input sources of the system, capable of generating both electrical and thermal energy, realizing the comprehensive utilization of solar energy through photovoltaic and solar thermal processes, and significantly improving the solar energy conversion efficiency. The electricity generated by the photovoltaic thermal panels 34 can be used by the system, while the generated heat is collected in the hot water storage tank 28. The hot water storage tank 28 serves as the core container for cross-seasonal heat storage, storing surplus solar heat from the non-heating season and releasing it for use during the heating season, thus resolving the temporal and spatial contradiction between energy supply and demand.

[0050] Further optimizing the scheme, the first thermal storage component includes a shallow underground pipe 15 buried in the underground rock strata, which is connected to a heat pump component. The heat from the heat pump component is transferred into the underground rock strata and stored through the shallow underground pipe 15. The shallow underground pipe 15 is buried underground and uses brine as a medium. The second circulation pump 14 stores the heat carried by the medium in the shallow rock and soil, thereby realizing cross-seasonal energy dispatching of "summer storage and winter use".

[0051] The scheme is further optimized. The heat-conducting components include an intermediate water plate heat exchanger 18 and a direct-supply plate heat exchanger 19. The hot water in the direct-supply plate heat exchanger 19 exchanges heat with the user terminal 9 and then enters the intermediate water plate heat exchanger 18. The heat pump component exchanges heat with the intermediate water plate heat exchanger 18 to collect the remaining heat for heating the user terminal 9. The intermediate water plate heat exchanger 18 and the direct-supply plate heat exchanger 19 are the core components of the heat-conducting components. The intermediate water plate heat exchanger 18 serves as a key energy exchange hub, realizing heat transfer between the geothermal loop and the heat pump loop, while physically isolating the different loops. When the heating demand is not high, the direct-supply plate heat exchanger 19 realizes direct heat exchange between the geothermal fluid and the circulating water of the user terminal 9, meeting the basic load and achieving high efficiency and energy saving.

[0052] The scheme is further optimized. The water replenishment mechanism includes a constant pressure water replenishment device 4 connected to the water source 1. The outlet of the constant pressure water replenishment device 4 is independently connected to the intermediate water plate heat exchanger 18 and the user end 9, respectively. A fully automatic softening device 2 and a softened water tank 3 are connected in sequence between the water source 1 and the constant pressure water replenishment device 4. The softened water in the softened water tank 3 is replenished into the constant pressure water replenishment device 4. The outlet of water source 1 is connected to the inlet of fully automatic softening device 2 via a pipeline to remove calcium and magnesium ions from the water, prevent scaling in the system, and ensure the efficient and long-term operation of equipment such as heat exchangers and heat pumps. The outlet of fully automatic softening device 2 is connected to the inlet of softened water tank 3 via a pipeline to store softened water and provide a water source for system replenishment. The outlet of softened water tank 3 is connected to the inlet of constant pressure water replenishment device 4 via a pipeline. The outlet of constant pressure water replenishment device 4 is connected to the inlet of solenoid valve via a pipeline to maintain the stability of the system network pressure and automatically replenish water when the system water volume fluctuates. During water replenishment, softened water starts from the outlet of the third solenoid valve 7, and the water replenishment loop is divided into two independent branches. The first branch is directly connected to the inlet of the first circulating water pump via a pipeline to deliver softened water to the circulation system of user end 9. The second branch is connected to the heat exchange pipeline between the intermediate water plate heat exchanger 18 and the heat pump assembly via a pipeline through the second solenoid valve 6 in the form of a three-way fitting to provide a water source for this heat exchange loop.

[0053] In one embodiment of the present invention, the system is also equipped with several temperature sensors distributed at key nodes such as the hot water storage tank 28, the photovoltaic thermal panel 34, the cyclone separator 23, and the reinjection pressurizer 17, for real-time monitoring of the system's energy flow status. The data is used to optimize system efficiency, protect equipment safety, and precisely control the temperature of the reinjection tailwater to protect the geothermal reservoir, forming the basis for the system's intelligent operation.

[0054] In one embodiment of the present invention, the central control system acts as the "intelligent brain" of the entire system, monitoring the cooling and heating loads of the user terminal 9, as well as the system's electrical load and photovoltaic power generation in real time. Based on multi-source information, the power of all circulating pumps, the opening and closing of each solenoid valve, and the operating status of the heat pump unit are uniformly controlled through intelligent algorithms, realizing the coordinated management and multi-objective optimization of "source, grid, load, and storage", ensuring the efficient, stable, and economical operation of the system.

[0055] Working Mode 1

[0056] When the groundwater temperature is lower than that of the hot water storage tank 28, the groundwater in the collection well 22 is pumped into the hot water storage tank 28 to absorb heat. The heated groundwater then enters the direct-supply plate heat exchanger 19 for primary heat exchange with the user end 9. After primary heat exchange, the groundwater enters the intermediate water plate heat exchanger 18 for secondary heat exchange with the heat pump assembly. The heat pump assembly uses the extracted heat to heat the user end 9 again. The cooled tailwater mixes with the external water source that has been heated through the shallow buried pipe 15 and is then reinjected into the reinjection well 20. (See appendix) Figure 2As shown, during the heating season, when the groundwater outlet temperature is lower than the temperature of the hot water storage tank 28, the system automatically enters the geothermal-photovoltaic-thermal synergistic heating and shallow buried pipe 15 supplementary heating mode. Its core operating logic is to prioritize the use of solar energy for preheating and upgrading low-grade geothermal energy, followed by cascade heat exchange, to achieve efficient utilization of low-grade heat energy. The third circulation pump 27, fifth circulation pump 39, sixth circulation pump 40, seventh circulation pump 41, and the fifth solenoid valve 24, first solenoid valve 5, ninth solenoid valve 43, second solenoid valve 6, third solenoid valve 7, and eighth solenoid valve 38 are opened, while the sixth solenoid valve 25, tenth solenoid valve 26, and seventh solenoid valve 37 are closed. At this time, the water intake pump 21 extracts medium-deep groundwater to the cyclone separator 23 for purification. Subsequently, the purified groundwater is sent to the hot water storage tank 28 to further absorb heat, thus raising its temperature. The heated groundwater first enters the direct-supply plate heat exchanger 19, where it undergoes its first heat exchange with the user terminal 9, which requires heat, and assumes the basic heating load. The cooled groundwater continues to flow into the intermediate-water plate heat exchanger 18, where it undergoes a second heat exchange with the heat pump assembly, which consists of an evaporator 10, a compressor 11, a condenser 12, and a throttling valve 13. The heat pump assembly extracts this low-grade heat energy and improves its grade before supplying heat to the user terminal 9 again, thus achieving the cascade utilization of groundwater. Finally, the tailwater, whose temperature has dropped to its lowest point, mixes with the heated makeup water flowing through the shallow buried pipe 15, thereby increasing the overall temperature of the reinjection water. The heated tailwater is then pressurized by the reinjection pressurizer 17 and reinjected into the reinjection well 20.

[0057] In one embodiment of the present invention, the third circulation pump 27 is responsible for the active heat exchange circulation inside the hot water storage tank 28, and the ninth circulation pump 44 is responsible for the active heating circulation inside the hot water storage tank 28. The control system adjusts the pump by monitoring the real-time light intensity: increasing the speed of the ninth circulation pump 44 to increase the circulation flow rate and quickly bring the heat generated by the photovoltaic thermal panel 34 into the hot water storage tank 28 to maximize the solar energy collection efficiency; while on cloudy days or at night, the pump speed is reduced or the pump operates intermittently to maintain the temperature balance inside the hot water storage tank 28 and save energy. At the same time, when the sunlight is strong, the speed of the third circulation pump 27 is increased to increase the circulation flow rate into the hot water storage tank 28 and quickly exchange the heat stored in the hot water storage tank 28 with the external water source to maximize the solar energy collection efficiency; while on cloudy days or at night, the pump speed is reduced or the pump operates intermittently to maintain the temperature balance inside the hot water storage tank 28 and save energy.

[0058] In one embodiment of the present invention, the sixth circulation pump 40 is responsible for delivering the high-temperature groundwater heated by the hot water storage tank 28 and the photovoltaic thermal plate 34 to the user end 9. The control system adjusts the flow rate by monitoring the heat load demand of the user end 9: at the beginning of heating or when the load is low, the speed of the sixth circulation pump 40 is appropriately reduced, the flow rate is reduced, the heat exchange time of the groundwater in the direct supply plate heat exchanger 19 and the intermediate water plate heat exchanger 18 is extended, and the tailwater temperature is further reduced; when the user load increases, the speed is increased to meet the heating demand.

[0059] In one embodiment of the present invention, the seventh circulating pump 41 is responsible for driving the circulation between the intermediate water plate heat exchanger 18 and the heat pump assembly, and operates in coordination with the sixth circulating pump 40. The speed of the seventh circulating pump 41 is adjusted according to the operating status of the heat pump assembly and the load demand of the user end 9 to ensure the heat exchange efficiency between the intermediate water plate heat exchanger 18 and the heat pump assembly, and realize the cascade utilization of energy.

[0060] In one embodiment of the present invention, the fifth circulation pump 39 is responsible for driving the makeup water flowing through the shallow buried pipe 15. The control system adjusts the flow rate by monitoring the difference between the temperature of the underground tailwater and the target reinjection temperature: if the difference is large, the speed of the fifth circulation pump 39 is increased to increase the flow rate, so that more makeup water absorbs shallow geothermal energy to heat the underground tailwater and increase the reinjection temperature; if the difference is small, the speed is reduced to save energy.

[0061] In one embodiment of the present invention, the outlet of the constant pressure water supply device 4 is connected to the inlet of the shallow buried pipe 15 via a pipeline through the first solenoid valve 5, the third solenoid valve 7 and the fifth circulating pump 39, which are in the open state. The outlet of the shallow buried pipe 15 is connected to the mixing point via a pipeline. At the mixing point, the low temperature groundwater at the outlet of the intermediate water plate heat exchanger 18 is mixed with the replenishment water heated by the shallow buried pipe 15 and the mixed pipeline is connected to the inlet of the reinjection pressurizer 17. The outlet of the reinjection pressurizer 17 is finally connected to the inlet of the reinjection well 20 via a pipeline.

[0062] Working Mode Two

[0063] When the groundwater temperature is higher than that of the hot water storage tank 28, the groundwater in the collection well 22 is pumped into the direct-supply plate heat exchanger 19 for primary heat exchange with the user end 9. After primary heat exchange, the groundwater flows into the intermediate water plate heat exchanger 18 and exchanges heat with the secondary heat pump assembly. The heat pump assembly uses the extracted heat to heat the user end 9 again. The low-temperature tailwater after secondary heat exchange flows back to the hot water storage tank 28 for heat exchange and temperature increase. The heated groundwater is then reinjected into the reinjection well 20. See Appendix Figure 3As shown, when the groundwater outlet temperature is higher than the temperature of the hot water storage tank 28, the system automatically enters the geothermal heating and photovoltaic tailwater supplementary heating mode, directly utilizing high-quality geothermal energy to provide heating for users. Simultaneously, the "coldness" contained in the low-temperature tailwater after heat exchange is stored in the hot water storage tank 28, achieving energy transfer and storage. The third circulation pump 27, fourth circulation pump 36, sixth circulation pump 40, seventh circulation pump 41, and the ninth solenoid valve 43, tenth solenoid valve 26, second solenoid valve 6, and third solenoid valve 7 are opened, while the fifth solenoid valve 24, sixth solenoid valve 25, eighth solenoid valve 38, fourth solenoid valve 16, and first solenoid valve 5 are closed. At this time, the water intake pump 21 extracts medium-deep groundwater and purifies it through the cyclone separator 23. The purified high-temperature groundwater is directly transported to the direct-supply plate heat exchanger 19 for efficient primary heat exchange with the heat user end 9 to meet basic heating needs. The groundwater, cooled after the first heat exchange, continues to flow into the intermediate plate heat exchanger 18, where it undergoes a second heat exchange with the heat pump assembly, which consists of an evaporator 10, a compressor 11, a condenser 12, and a throttling valve 13. The heat pump assembly further enhances the quality of this heat energy before supplying additional heat to the user end 9, thus achieving deep cascade utilization of energy. In this mode, the low-temperature tailwater flowing out of the heat pump assembly is guided to the hot water storage tank 28, where it exchanges heat with the high-temperature water, raising its own temperature. Finally, the heated groundwater is pressurized by the reinjection pressurizer 17 and transported to the reinjection well 20 for reinjection.

[0064] In one embodiment of the present invention, the sixth circulation pump 40 is responsible for delivering high-temperature groundwater to the user end 9. The control system adjusts the flow rate by monitoring the heat load demand of the user end 9. In the early stage of heating or when the load is low, the speed of the sixth circulation pump 40 is appropriately reduced, the flow rate is reduced, and the heat exchange time of the groundwater in the direct supply plate heat exchanger 19 and the intermediate water plate heat exchanger 18 is extended to further reduce the tailwater temperature. When the user load increases, the speed is increased to meet the heating demand.

[0065] In one embodiment of the present invention, the seventh circulating pump 41 is responsible for driving the circulation between the intermediate water plate heat exchanger 18 and the heat pump assembly, and operates in coordination with the sixth circulating pump 40. The speed of the seventh circulating pump 41 is adjusted according to the operating status of the heat pump assembly and the load demand of the user end 9 to ensure the heat exchange efficiency between the intermediate water plate heat exchanger 18 and the heat pump assembly, and realize the cascade utilization of energy.

[0066] In one embodiment of the present invention, the core function of the fourth circulation pump 36 is to transport the low-temperature tailwater to the hot water storage tank 28. The control system regulates the flow by monitoring the temperature difference between the tailwater and the lower part of the hot water storage tank 28. When the temperature difference is large, the speed of the fourth circulation pump 36 and the third circulation pump 27 is increased to increase the tailwater flow rate, thereby enhancing its heat exchange intensity in the hot water storage tank 28 and rapidly increasing the temperature of the reinjection water. When the temperature difference decreases, the speed is reduced to achieve energy saving and stable operation.

[0067] In one embodiment of the present invention, the pipe connections in both Embodiment 1 and this embodiment only describe the flow at the geothermal water end, without briefly describing the flow of brine supplied to the user end 9. The working path of the brine supply to the user end 9 is now described: In the heat exchange loop of the user end 9 of the system, the brine outlet of the heat exchange medium at the user end 9 is split into two parallel branches: the first branch is connected to the brine side inlet of the direct-supply plate heat exchanger 19, where it undergoes primary heat exchange with the high-temperature groundwater; the second branch is connected to the brine side inlet of the heat pump component evaporator 10, further absorbing low-temperature heat energy from the groundwater; the brine side outlet of the direct-supply plate heat exchanger 19 and the brine side outlet of the evaporator 10 are joined by a T-fitting pipe and flow back to the brine inlet of the heat exchange medium at the user end 9, forming a complete open loop.

[0068] Comprehensive analysis shows that regardless of whether the system operates in Implementation Example 1 or Implementation Example 2, targeted tailwater reheating measures are set up. This is a significant advantage of the system in maintaining underground thermal balance. Combined with the basic strategy of "storing heat in summer and using it in winter" to replenish the strata with waste heat from the non-heating season, the problem of "thermal breakthrough" of the groundwater layer caused by continuous heat extraction without reinjection or low-temperature reinjection can be effectively avoided.

[0069] Work Mode 3

[0070] When user terminal 9 has a cooling demand, the heat pump component exchanges heat with user terminal 9 to cool it; the heat pump component transfers the extracted heat to the shallow buried pipe 15 and stores it in the soil structure. See Appendix Figure 4As shown, when user terminal 9 has a cooling demand, the system activates this mode to supplement heat to the shallow underground thermal field and meet the user's cooling needs. Its core operating logic is to transfer waste heat from the building through the heat pump assembly and store it in the shallow soil and rock mass, reserving heat for winter heating. The second circulation pump 14 and the eighth circulation pump 42 start, and the fourth solenoid valve 16 and the seventh solenoid valve 37 open. The heat that user terminal 9 needs to discharge is first transported to the heat pump assembly, which consists of an evaporator 10, a compressor 11, a condenser 12, and a throttling valve 13. Subsequently, the heat pump assembly drives brine as the circulating working fluid through the refrigeration loop, carrying the heat to the shallow buried pipe 15 and storing it in the surrounding shallow soil and rock layer, thereby meeting the cooling needs of user terminal 9. Simultaneously, it achieves summer storage for winter use; that is, the heat stored in the soil and rock layer during the non-heating season will be used to increase the tailwater reinjection temperature during the heating season.

[0071] In one embodiment of the present invention, the second circulation pump 14 is responsible for transferring the heat from the heat pump condenser 12 to the shallow buried pipe 15. The control system monitors the cooling load demand of the user terminal 9. When the cooling load is large and the ambient temperature is high, the speed of the second circulation pump 14 is increased, the flow rate on the buried pipe side is increased, the heat dissipation capacity is enhanced, and the cooling efficiency of the heat pump component is improved. When under partial load, its speed is reduced, so that the soil and rock have more time for heat conduction and diffusion, and avoid the formation of "heat accumulation" around it.

[0072] In one embodiment of the present invention, the eighth circulation pump 42 is responsible for driving the circulation between the user terminal 9 and the heat pump component evaporator 10, and operates in coordination with the second circulation pump 14. The speed of the eighth circulation pump 42 is adjusted according to the actual cooling demand of the user terminal 9 and the system operating status to ensure the heat exchange efficiency between the user terminal 9 and the heat pump component, thereby achieving precise matching of the cooling load and efficient operation of the system.

[0073] In one embodiment of the present invention, the shallow buried pipe 15 is thermally coupled to the condenser 12 within the heat pump assembly via a brine circulation loop. Specifically, the outlet of the shallow buried pipe 15 is connected to the brine inlet of the condenser 12 via a pipe through a second circulation pump 14 and a fourth solenoid valve 16, while the brine outlet of the condenser 12 is connected back to the inlet of the shallow buried pipe 15 via a pipe, forming a closed brine circulation loop for heat transfer. The condenser 12 serves as a heat exchange interface, with its internal refrigerant channels isolated from the brine channels and heat conducted through its walls. During system operation, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 flows within the condenser 12, while the low-temperature brine from the shallow buried pipe 15 flows on the other side. The high-temperature refrigerant releases heat to the low-temperature brine through the condensation process, thereby achieving indirect heat exchange between the refrigerant and the brine. The heated brine is then transported to the shallow buried pipe 15, storing the heat it carries in the shallow soil and rock mass.

[0074] In one embodiment of the present invention, the user terminal 9 is thermally coupled to the evaporator 10 within the heat pump assembly via a user-side brine circulation loop. Specifically, the temperature-regulating outlet of the user terminal 9 is connected to the brine inlet of the evaporator 10 via a pipe through a seventh solenoid valve 37; the brine outlet of the evaporator 10 is then connected back to the temperature-regulating inlet of the user terminal 9 via a pipe. This constitutes a closed-loop brine circulation loop serving the heat exchange of the user terminal 9. The evaporator 10 serves as a heat exchange interface, with its internal refrigerant flow channel isolated from the user-side brine flow channel and heat conducted through its walls. During system operation, in cooling mode, the warm water returning from the user terminal 9, carrying residual heat, exchanges heat with the low-temperature, low-pressure liquid refrigerant within the evaporator 10. The refrigerant absorbs heat and evaporates into a gaseous state, while the brine is cooled, thereby achieving the effect of cooling the user terminal 9.

[0075] Working Mode 4

[0076] When the system is in solar-heated mode, groundwater in collection well 22 is pumped into hot water storage tank 28, where it absorbs heat and heats up. The heated groundwater is then reinjected into reinjection well 20. See appendix. Figure 5 As shown, the solar-powered heating mode directly utilizes surplus solar energy to actively and efficiently replenish the underground thermal field, ensuring that the reinjection water temperature reaches the set requirements and avoiding cold pollution. Solar-powered heating mode: Directly utilizes surplus solar energy to actively and efficiently replenish the underground thermal field, ensuring that the reinjection water temperature reaches the set requirements and avoiding cold pollution. In this mode, the fifth solenoid valve 24, the first solenoid valve 5, the eighth solenoid valve 38, the fourth solenoid valve 16, the second solenoid valve 6, the third solenoid valve 7, and the seventh solenoid valve 37 are closed, while the sixth solenoid valve 25 and the tenth solenoid valve 26 are open; simultaneously, the fourth circulation pump 36 and the third circulation pump 27 are open, while the sixth circulation pump 40, the seventh circulation pump 41, the eighth circulation pump 42, the second circulation pump 14, the fifth circulation pump 39, and the first circulation pump 8 are closed. The water intake pump 21 extracts groundwater from the collection well 22 and transports it to the hydrocyclone desander 23 for purification. The purified groundwater is sent into the hot water storage tank 28, where it absorbs heat energy generated by the photovoltaic thermal panel 34, thus raising its temperature. Finally, the heated high-temperature water is pressurized by the reinjection pressurizer 17 and transported to the reinjection well 20 to complete the reinjection.

[0077] In one embodiment of the present invention, the system achieves dual optimization control of the efficiency of the photovoltaic thermal panel 34 and the final reinjection water temperature through the coordinated regulation of the third circulation pump 27 and the fourth circulation pump 36. The control system continuously monitors the actual reinjection water temperature and compares it with the target reinjection temperature set by the system. If the actual temperature is lower than the target value, an instruction to increase the total heating load of the system is generated. By reducing the speed of the third circulation pump 27 and the fourth circulation pump 36, the flow rate is reduced, allowing the fluid to obtain a longer heating time in the hot water storage tank 28, thereby increasing the outlet and reinjection water temperatures. If the actual temperature reaches or exceeds the target value, the heating load is maintained or reduced. By increasing the speed of the third circulation pump 27 and the fourth circulation pump 36, the flow rate is increased, preventing the photovoltaic thermal panel 34 from overheating due to insufficient heat exchange, ensuring that it always operates in the most efficient heat collection range, and simultaneously reinjecting the stored heat to the ground more quickly.

[0078] In one embodiment of the present invention, the cooling mode and the solar heating mode of the system can be activated simultaneously.

[0079] In one embodiment of the present invention, a ninth circulation pump 44 is installed on the pipeline between the photovoltaic thermal plate 34 and the hot water storage tank 28 to regulate the water circulation between the photovoltaic thermal plate 34 and the hot water storage tank 28 and maintain the stable operation of the system.

[0080] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0081] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A cross-seasonal geothermal and solar coupled energy supply and regulation system, characterized in that, include: The power supply mechanism includes multiple power supply modules used in combination to supply power for the operation of the system; The heat source mechanism includes a geothermal component and a solar heating component, wherein the geothermal component and the solar heating component are arranged in parallel, and the geothermal component and the solar heating component can provide heat independently or in combination. The heat exchange mechanism includes a heat-conducting component and a heat pump component connected together. The heat-conducting component and the heat pump component are respectively connected to the geothermal component and the solar heating component, so that heat can be exchanged with the user end (9) with heat demand. A heat storage mechanism includes a first heat storage component, which is connected to the heat pump component and is used to store the heat of the heat pump component. A water replenishment mechanism is connected to the heat-conducting component and the user terminal (9) respectively for water replenishment; The geothermal component includes a collection well (22) and a reinjection well (20). The first heat storage component includes a shallow underground pipe (15) buried in the underground rock strata. The solar heating component includes a photovoltaic thermal plate (34) for collecting solar heat and generating electricity. The heat supplied by the photovoltaic thermal plate (34) is stored in a hot water storage tank (28). The heat conduction component includes an intermediate water plate heat exchanger (18) and a direct supply plate heat exchanger (19). When the groundwater temperature is lower than that of the hot water storage tank (28), the groundwater in the collection well (22) is pumped into the hot water storage tank (28) to absorb heat. After absorbing heat, the groundwater enters the direct-supply plate heat exchanger (19) and exchanges heat with the user end (9) in the primary stage. After the primary heat exchange, the groundwater enters the intermediate water plate heat exchanger (18) and exchanges heat with the heat pump assembly in the secondary stage. The heat pump assembly uses the extracted heat to heat the user end (9) again. The tailwater that is cooled down again mixes with the external water source that flows through the shallow buried pipe (15) and heats up, and is then reinjected into the reinjection well (20). When the groundwater temperature is higher than that of the hot water storage tank (28), the groundwater in the collection well (22) is pumped into the direct-supply plate heat exchanger (19) for primary heat exchange with the user end (9); the groundwater after primary heat exchange flows into the intermediate water plate heat exchanger (18) and exchanges heat with the heat pump assembly for secondary heat exchange. The heat pump assembly uses the extracted heat to heat the user end (9) again. The low-temperature tailwater after secondary heat exchange flows back to the hot water storage tank (28) for heat exchange and temperature rise. The heated groundwater is then reinjected into the reinjection well (20). When the user terminal (9) has a cooling demand, the heat pump assembly exchanges heat with the user terminal (9) to cool the user terminal (9); the heat pump assembly transfers the extracted heat to the shallow buried pipe (15) and stores it in the soil and rock structure.

2. The cross-seasonal thermal storage system for medium-deep geothermal and solar coupled energy supply and regulation as described in claim 1, characterized in that: The heat source collected in the collection well (22) flows along the heat-conducting component and exchanges heat with the user end (9) to provide heat; after the heat source water is heated, the temperature decreases and it is reinjected into the reinjection well (20).

3. The cross-seasonal thermal storage system for medium-deep geothermal and solar coupled energy supply and regulation as described in claim 2, characterized in that: The electricity supplied by the photovoltaic thermal plate (34) is incorporated into the power supply mechanism to power the system, and the hot water storage tank (28) is connected to the heat-conducting component for heat exchange.

4. The cross-seasonal thermal storage system for medium-deep geothermal and solar coupled energy supply and regulation as described in claim 3, characterized in that: The shallow underground pipe (15) is connected to the heat pump assembly; the heat from the heat pump assembly is introduced into the underground rock strata and stored in the shallow underground pipe (15).

5. The cross-seasonal thermal storage system for medium-deep geothermal and solar energy coupling power supply and regulation as described in claim 4, characterized in that: The hot water in the direct-supply plate heat exchanger (19) exchanges heat with the user end (9) and then enters the intermediate water plate heat exchanger (18). The heat pump assembly exchanges heat with the intermediate water plate heat exchanger (18) to collect the remaining heat for the user end (9) to keep warm.

6. The cross-seasonal thermal storage system for medium-deep geothermal and solar coupled energy supply and regulation as described in claim 5, characterized in that: The water replenishment mechanism includes a constant pressure water replenishment device (4) connected to the water source (1). The outlet of the constant pressure water replenishment device (4) is independently connected to the intermediate water plate heat exchanger (18) and the user terminal (9). The water source (1) and the constant pressure water replenishment device (4) are connected in sequence to a fully automatic softening device (2) and a softened water tank (3). The softened water in the softened water tank (3) is replenished into the constant pressure water replenishment device (4).

7. The cross-seasonal thermal storage system for medium-deep geothermal and solar coupled energy supply and regulation as described in claim 3, characterized in that: When the system is in solar heating mode, the groundwater in the collection well (22) is pumped into the hot water storage tank (28), where it absorbs heat and heats up; the heated groundwater is then reinjected into the reinjection well (20).

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