Solar light-heat / cold conversion and cross-season energy storage system suitable for abandoned mine reconstruction

Abstract

The invention discloses a solar light-heat / cold conversion and cross-season energy storage system suitable for abandoned mine transformation. The system comprises a water supply module, an energy supply module, an energy conversion module, a quality inspection and strengthening module, an energy storage module and a control module. The water supply module provides initial and supplementary water; the energy supply module collects energy for conversion and supplies energy to each module; the transduction module utilizes the energy processing multi-module to convey water and sends outlet temperature data to the control module. The quality inspection and enhancement module sends water temperature data and receives an instruction to execute operation; the energy storage module is used for storing water, collecting water temperature data at regular time and receiving post-processing instruction operation; the control module analyzes the temperature data of the transduction module and sends an instruction to the control system. The system solves the problems of mine treatment and facility idling in non-heating seasons, has cross-seasonal heat and cold storage capacity, realizes seasonal-scale energy supply and demand mismatch adjustment, energy space-time translation and all-season efficient utilization, and improves the system utilization rate and the rate of return on investment.

Description

Technical Field

[0001] This invention relates to the field of renewable and clean energy technology, and in particular to a solar photovoltaic / thermal / cold conversion and cross-seasonal energy storage system suitable for the transformation of abandoned mines. Background Technology

[0002] Solar energy is characterized by significant intermittency, instability, and spatiotemporal mismatch. Its low energy density and susceptibility to diurnal, weather, and seasonal variations lead to a severe supply-demand imbalance: peak energy collection periods (summer, daytime) often do not coincide with peak energy consumption periods (winter, nighttime). This is particularly pronounced in building energy consumption, where demand manifests in both winter heating and summer cooling, both of which are mismatched with the solar energy supply cycle: solar radiation peaks in summer, yet winter heating demands must be met; conversely, the winter's abundance of natural cold sources coincides with the low point of summer cooling demand. While current mainstream electrochemical energy storage technologies can address intraday energy storage, they are costly, have limited lifespans, and struggle to achieve large-scale, cross-seasonal energy storage. While hydrogen storage and synthetic fuel technologies theoretically offer long-term energy storage, their low system efficiency and immature industrial chains hinder large-scale application in the short term, a contradiction particularly pronounced in high-latitude regions.

[0003] In contrast, utilizing underground space to construct large-scale, cross-seasonal thermal storage systems demonstrates enormous potential in regulating the timing of energy supply and demand, and improving the system's life-cycle economic efficiency and operational reliability. International practice also shows that constructing large-scale thermal storage bodies using underground space can achieve cross-seasonal transfer of solar energy. For example, Copenhagen, Denmark, provides 80% of the year-round heating for 300,000 residents through artificial thermal storage ponds; Heilbronn, Germany, has built a high-temperature thermal storage system using abandoned salt caverns, achieving a thermal storage efficiency of over 95% and significantly reducing heating costs. Publication number CN119755693A discloses a three-stage thermal storage system and method based on cross-seasonal thermal storage in underground caverns, buried water bodies, and terminal water tanks. The system includes a heat collection system, a three-stage thermal storage system, a heat exchange system, and a user side. The heat collection system exchanges heat with the cross-seasonal stored water body through a water pump, combined with the underground cavern stored water body for thermal storage. The heat exchange pipe section absorbs heat from the cross-seasonal stored water body and transfers the heat to the user-side circulating water system through a heat exchange process using a first plate heat exchanger.

[0004] However, existing technologies are limited to utilizing summer heat energy through artificially constructed above-ground water tanks / thermal storage tanks or underground caverns, neglecting the utilization and conversion of winter cold energy. Artificially constructed above-ground thermal storage tanks are costly, require large land areas, and have stringent site requirements, limiting their application in areas with limited land resources. While underground caverns reduce the occupation of surface land, they generally face new challenges. The excavation and structural construction required for effective thermal storage are extensive, resulting in high overall project costs and economic barriers.

[0005] Meanwhile, long-term mining development has left behind a vast number of abandoned mine shafts and tunnels. These abandoned mines not only result in the idleness and waste of land resources, but also pose serious environmental and geological safety hazards such as surface subsidence, groundwater pollution, and landslides. The underground spaces of abandoned mines, especially the huge goafs and tunnels, are characterized by their large volume, stable surrounding rock, and good thermal stability. Their internal temperature fluctuations are small and stable year-round, forming a naturally isolated and excellent thermal insulation environment. This unique advantage makes them ideal as containers for large-scale thermal storage. Developing and utilizing these abandoned mine shafts as inter-seasonal thermal storage facilities can not only effectively mitigate their inherent environmental risks, but also create enormous energy storage value at extremely low cost, achieving a win-win situation for both economic and environmental benefits.

[0006] Therefore, there is an urgent need for a heat / cold conversion and cross-seasonal energy storage system that can comprehensively manage and utilize abandoned mines, turning waste into treasure, and can also achieve dual-mode operation of "summer heat storage and winter cold storage". Summary of the Invention

[0007] This invention provides a solar-thermal / cold conversion and cross-seasonal energy storage system suitable for the transformation of abandoned mines. The system aims to solve the problem of idle facilities in mine management and non-heating seasons through multi-energy coupling and intelligent control. The system also has the ability to "store heat across seasons" and "store cold across seasons", and realizes the dual mismatch of energy supply and demand on a seasonal scale, the spatiotemporal translation of energy and efficient utilization throughout the seasons, which greatly improves the system utilization rate and return on investment.

[0008] This invention provides a solar energy conversion and cross-seasonal energy storage system suitable for the transformation of abandoned mines. The system includes a water supply module, an energy supply module, an energy conversion module, a quality inspection and enhancement module, an energy storage module, and a control module.

[0009] The water supply module is used to provide initial and supplemental water for the system;

[0010] The power supply module is used to collect energy from the energy unit and convert it into energy to provide energy drive for each module;

[0011] The energy conversion module is used to convert the water supplied by the water supply module, quality inspection and enhancement module and energy storage module received at the inlet into energy using the energy provided by the energy supply module; and is used to send the temperature data collected at the outlet to the control module.

[0012] The quality inspection and enhancement module is used to collect water temperature data in the quality inspection and enhancement module and send it to the control module; it is also used to receive instructions from the control module and execute corresponding operations.

[0013] The energy storage module is used to store the water transmitted by the quality inspection and enhancement module; to collect the temperature data of the water at preset time intervals and send it to the control module; and to receive post-processing instructions sent by the control module and perform post-processing operations.

[0014] The control module analyzes the temperature data sent by the transducer module. When the temperature data meets preset conditions, it sends a pumping command to the quality inspection and enhancement module. Based on the temperature data sent by the quality inspection and enhancement module, it determines whether the corresponding preset summer and winter quality inspection conditions are met, and whether the storage requirements are met. If the requirements are met, it sends a storage command to the quality inspection and enhancement module; if the requirements are not met, it sends a corresponding enhancement execution command to the quality inspection and enhancement module for the corresponding season. It also monitors the water stored in the energy storage module based on the signal data sent by the energy storage module. When the preset detection conditions are not met, it sends a post-processing command to the energy storage module.

[0015] Furthermore, the power supply module includes a PVT photovoltaic panel, a photovoltaic controller, a storage battery, an inverter, and a second water pump. The power generation interface of the PVT photovoltaic panel is connected to the storage battery through the photovoltaic controller. The storage battery is electrically connected to the control module. The second water pump is installed on the pipe connecting the PVT photovoltaic panel and the first plate heat exchanger.

[0016] Furthermore, the energy conversion module includes a pipeline, a first plate heat exchanger, a first water pump, and a first temperature sensor; wherein, the antifreeze of the first plate heat exchanger forms a closed antifreeze circulation with the PVT photovoltaic panel through the pipeline; the inlet end of the water circuit of the first plate heat exchanger is connected to the water supply module, the quality inspection and enhancement module, and the energy storage module through pipelines; the outlet end of the water circuit of the first plate heat exchanger and the inlet end of the quality inspection and enhancement module are connected through pipelines; the first water pump is installed on the pipeline at the inlet end of the water circuit of the first plate heat exchanger; and the first temperature sensor is installed inside the pipeline at the outlet end.

[0017] Furthermore, the quality inspection and enhancement module includes a water storage tank, an electric heater, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a third water pump, a fourth water pump, and a seventh water pump. The electric heater is located at the bottom of the water storage tank. The second, third, fourth, and fifth temperature sensors are all located at preset key nodes on the inner wall of the water storage tank. The inlet end of the water storage tank is connected to the energy transducer module via a pipe, and the outlet end of the water storage tank is connected to the inlet ends of both the energy storage module and the energy transducer module via pipes. The fourth water pump is located on the pipe connected to the inlet end of the energy storage module, the seventh water pump is located on the pipe connected to the inlet end of the energy transducer module, and the sixth sensor is located at the outlet end of the water storage tank.

[0018] Furthermore, when the summer quality inspection conditions are not met, the control module combines the magnitude of the current generated by the photovoltaic panel to determine whether the current light intensity meets the conditions for starting the electric heater: if it does, it sends a start command to the electric heater to start the electric heater until the received temperature data reaches the storage requirements; if it does not meet the conditions, it sends an enhanced execution command, that is, sends a pumping command to the seventh water pump in the quality inspection and enhancement module to pump the water back to the energy conversion module.

[0019] Furthermore, when the winter quality inspection conditions are not met, the control module combines the current generated by the photovoltaic panel to determine whether it is nighttime based on the current intensity. If so, it sends an enhanced execution command, that is, sends a pumping command to the seventh water pump in the quality inspection and enhancement module to pump water back to the energy conversion module. If not, it continues to judge the light intensity until it is met.

[0020] Furthermore, each connecting pipe exposed to the outside of the water supply module, energy supply module, heat exchange module, quality inspection and enhancement module, and energy storage module is equipped with a heating belt that can limit the temperature. The heating belt is wrapped with an insulation layer and a protective layer in sequence. The heating belt is controlled by the control module and powered by the energy supply module.

[0021] Furthermore, when the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the antifreeze cycle threshold, the control module sends a flow reduction adjustment command to the third water pump, shuts down some of the PVT photovoltaic panels in the energy supply module to reduce the heat exchange intensity, and starts the heating belt. The heating belt is shut down when the temperature data detected by the first temperature sensor reaches the preset safety threshold. When the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the emergency shutdown threshold, the control module sends a stop command to all water pumps and simultaneously sends an alarm to the monitoring center staff, waiting for manual intervention.

[0022] Furthermore, the energy storage module is installed in an abandoned mine shaft or pit that has undergone specialized engineering treatment. After the abandoned mine shaft is leveled and compacted, a comprehensive seepage-proof layer composed of geotextile and high-performance impermeable membrane is laid. Gaps are sealed and reinforced with concrete masonry or shotcrete to form a stable, sealed underground thermal storage space. Multiple temperature sensors are installed at pre-set key points on the inner wall of the underground thermal storage space. A horizontal annular pipe or porous diffuser pipe is laid near the top and bottom walls inside the underground thermal storage space, serving as the inlet and outlet of the energy storage module, respectively. The outlet of the energy storage module is connected to the energy exchanger via a pipeline. The module's inlet is connected to and a sixth water pump is installed on it. Inside the underground thermal storage space, near the top and bottom walls, there are corresponding top composite ports and bottom composite ports. Hot / cold water from the mine is taken through the bottom composite port. After exchanging heat with the circulating water at the user end 18 in the second plate heat exchanger 17, the water from the mine is sent back to the cold / heat storage module through the top composite port. Then, it is cooled / heated through the first plate heat exchanger 7 to prepare cold / hot water at the required temperature. Finally, it is stored in the cold / heat storage module. The circulating water is heated / cooled and then sent to the user end 18 for heating / cooling.

[0023] Furthermore, an insulation layer is also installed on the outside of the impermeable layer.

[0024] Compared with existing technologies, the solar photovoltaic / thermal / cold conversion and cross-seasonal energy storage system provided by this invention, suitable for the transformation of abandoned mines, has the following advantages:

[0025] 1) Achieving large-scale, cross-seasonal energy storage at a lower cost: Traditional battery-based energy storage solutions involve huge investments and have limited lifespans; constructing large artificial storage tanks or using soil for thermal storage is costly and requires a large land area. This invention transforms abandoned mine shafts into final thermal storage facilities, utilizing previously worthless abandoned spaces left over from mines, replacing artificial thermal storage facilities or battery packs that require high construction costs. Mine shafts, as natural underground water reservoirs, have surrounding rock with excellent thermal insulation properties, making the marginal cost of the system in terms of energy storage media and insulation structure approach zero. This significantly reduces the initial investment and life-cycle cost of the entire energy storage system, making large-scale promotion of solar cross-seasonal thermal storage heating technology economically feasible, and providing a new solution to address the core "economic" obstacle faced by existing energy storage technologies.

[0026] 2) Reduced land occupation and soil thermal accumulation effects, achieving environmentally friendly synergy: Traditional soil thermal storage systems require large-scale buried pipes, occupying significant land resources and potentially causing a "thermal accumulation effect" due to imbalances in heat extraction and release, disrupting the underground soil temperature field ecosystem. This invention places the thermal storage unit within an underground mine, without occupying additional surface land, minimizing the impact of solar energy facilities on the surface ecosystem. The entire thermal storage and release process takes place entirely within a sealed mine water body, exchanging heat only with the surrounding soil. Temperature stratification technology (e.g., hot water extraction from the top, cold water return from the bottom) and insulation treatment effectively manage the thermal field. This avoids long-term, disorderly heat diffusion into the surrounding soil and rock, greatly reducing the impact of the "soil thermal accumulation effect." It achieves the dual goals of "turning waste into treasure" and environmental protection, providing a novel method for resolving "land use conflicts" and potential ecological impacts of renewable energy facilities.

[0027] 3) Based on the core concept of “turning waste into treasure”, the disadvantages of abandoned mines can be transformed into unique advantages, and the environmental burden can be transformed into high-quality assets. This can significantly reduce land use, infrastructure and energy storage costs, and provide novel energy solutions for mine transformation.

[0028] 4) A complete energy closed loop and waste resource recycling are formed, making the system self-consistent and sustainable: Traditional "photovoltaic + mining" projects only output electricity and fail to form a complete energy cycle, with the utilization of abandoned mines remaining superficial. This invention uses a water pump to return low-temperature water from the bottom of the mine to a plate heat exchanger for reheating during summer heat storage, forming a complete material and energy closed loop of "heat collection-heat storage-heat use-recirculation". During winter cold storage, the water pump re-pumps cold water that has not reached the target temperature back into the plate heat exchanger for further cooling, forming a cycle of "cold collection-detection-recooling". This system simultaneously realizes "space recycling" (utilizing abandoned space) and "energy recycling" (utilizing renewable energy), forming a highly self-consistent system.

[0029] The system proposed in this invention significantly reduces the system's dependence on external water and energy sources, enhancing its self-sustaining capacity and overall energy efficiency. It organically combines energy problem-solving with mine environmental remediation, creating a replicable and scalable sustainable development model. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced 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.

[0031] Figure 1 This is a schematic diagram of a solar energy conversion and cross-seasonal energy storage system suitable for the transformation of abandoned mines, provided by an embodiment of the present invention.

[0032] Figure 2 This is a cross-sectional view of the temperature distribution of hot water stored in summer over one day, provided in an embodiment of the present invention.

[0033] Figure 3 This is a temperature distribution profile of hot water stored in summer over 180 days, provided in an embodiment of the present invention.

[0034] Figure 4 This is a temperature probe diagram of hot water stored in summer for 180 days, provided in an embodiment of the present invention.

[0035] Figure 5 This is a temperature distribution profile of hot water stored in winter over one day, provided in an embodiment of the present invention.

[0036] Figure 6 This is a temperature distribution profile of hot water stored in winter over 180 days, provided in an embodiment of the present invention.

[0037] Figure 7 This is a temperature probe diagram of hot water stored in winter for 180 days, provided in an embodiment of the present invention.

[0038] In the diagram: 1. Water supply module; 2. PVT photovoltaic panel; 3. Photovoltaic controller; 4. Battery; 5. Inverter; 6. Control module; 7. First plate heat exchanger; 8. Top composite port; 9. Mine tunnel; 10. Inlet of energy storage module; 11. Electric heater; 12. Insulation layer; 13. Anti-seepage layer; 14. Bottom composite port; 15. Outlet of energy storage module; 16. Water storage tank; 17. Second plate heat exchanger; 18. User end; P-1. First water pump; P-2. Second water pump; P-3. Third water pump; P-4. Fourth water pump; P-5. Fifth water pump; P-6. Sixth water pump; P-7. Seventh water pump; T-1. First temperature sensor; T-2. Second temperature sensor; T-3. Third temperature sensor; T-4. Fourth temperature sensor; T-5. Fifth temperature sensor; T-6. Sixth temperature sensor; T-7. Seventh temperature sensor; T-8. Eighth temperature sensor. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] Example 1

[0041] like Figure 1 As shown, this embodiment provides a solar-thermal / cold conversion and cross-seasonal energy storage system suitable for the transformation of abandoned mines. This system converts solar energy into thermal energy and utilizes abandoned mine shafts for large-scale, cross-seasonal storage. Its core lies in constructing a complete closed loop from "energy harvesting" → "heating and buffering" → "quality detection and enhancement" → "final storage" → "refrigerant circulation". The system is intelligently controlled through a control module, maximizing the utilization of solar energy and the resource-based application of abandoned mine shafts.

[0042] The system specifically includes a water supply module 1, an energy supply module, an energy conversion module, a quality inspection and enhancement module, an energy storage module, and a control module 6;

[0043] The water supply module 1 is used to provide initial and supplementary water for the system. In specific implementations, it can be a municipal water supply network or a mine's own water source, without limitation.

[0044] The power supply module is used to collect energy from the energy unit and convert it into energy to provide energy drive for each module.

[0045] Specifically, further, the power supply module includes a PVT photovoltaic panel 2, a photovoltaic controller 3, a storage battery 4, an inverter 5, and a second water pump P-2. The power generation interface of the PVT photovoltaic panel 2 is connected to the storage battery 4 through the photovoltaic controller 3. The storage battery 4 is electrically connected to the control module 6. The second water pump P-2 is installed on the pipe connecting the PVT photovoltaic panel 2 and the first plate heat exchanger 7 in the energy conversion module.

[0046] It should be noted that the PVT photovoltaic panel 2 is the core energy harvester of the system, laid on sunny slopes or idle sites in the mining area, simultaneously converting solar energy into DC electricity and heat. The PVT photovoltaic panel 2's power generation interface outputs DC power to supply power to subsequent electrical equipment. Its fluid loop circulates antifreeze and other heat exchange media to collect solar heat and absorb and remove waste heat generated by the photovoltaic chips, achieving the dual purpose of cooling the power generation chips (improving power generation efficiency) and collecting heat energy. Furthermore, in winter, the PVT photovoltaic panel 2 does not perform heat recovery but is used as a "heat exchanger." The antifreeze inside the PVT photovoltaic panel 2 cools down with the outdoor air in winter, lowering the antifreeze temperature.

[0047] The photovoltaic controller 3, the "core regulator" of solar power generation, is connected between the PVT photovoltaic panel 2 and the battery 4. Its core function is to ensure the safe and stable operation of the system and extend the life of the battery and the entire system. Specifically, it includes the following functions: (a) Overcharge protection: Prevents the battery voltage from becoming too high, avoiding damage to the battery. (b) Over-discharge protection: Prevents the battery voltage from becoming too low, avoiding damage from deep discharge. (c) Stabilizing charging voltage / current and optimizing charging efficiency: The output characteristics of the PVT photovoltaic panel are non-linear (voltage changes with light and temperature), while the battery requires a "stable and matched" voltage / current for efficient charging.

[0048] Battery 4 is electrically connected to PVT photovoltaic panel 2 to store the electrical energy generated by PVT photovoltaic panel and provide stable power to all electrical equipment in the system.

[0049] Inverter 5 is connected between battery 4 and control module 6, converting the direct current (DC) output from battery into alternating current (AC) for use by electrical equipment in the system.

[0050] The energy conversion module is used to convert the water supplied by the water supply module, quality inspection and enhancement module, and energy storage module received at the inlet using the energy provided by the energy supply module; it is also used to send the temperature data collected at the outlet to the control module.

[0051] Furthermore, the energy conversion module includes a piping system, a first plate heat exchanger 7, a first water pump P-1, and a first temperature sensor T-1. The antifreeze of the first plate heat exchanger 7 forms a closed antifreeze circulation loop with the PVT photovoltaic panel 7 via piping. The inlet end of the water circuit of the first plate heat exchanger 7 is connected to a water supply module, a quality inspection and enhancement module, and an energy storage module via piping. The outlet end of the water circuit of the first plate heat exchanger 7 is connected to the inlet end of the quality inspection and enhancement module via piping. The first water pump P-1 is installed on the piping at the inlet end of the water circuit of the first plate heat exchanger 7. The first temperature sensor T-1 is installed on the piping at the outlet end. Inside .

[0052] It should be noted that the antifreeze in the first plate heat exchanger 7 forms a closed antifreeze circulation with the PVT photovoltaic panel 2 through pipes. The antifreeze absorbs heat within the PVT panel (partly from direct sunlight and partly from heat generated by photovoltaic power generation), becoming a high-temperature antifreeze. It then exchanges heat with the water from the water supply module 1, transferring heat to the water in the water supply module 1. Essentially, it acts as an energy exchange hub between the PVT photovoltaic panel 2 and the water storage module, achieving isolated heat exchange between the "antifreeze loop" and the "water loop". In specific implementation, during summer, the high-temperature antifreeze transfers heat to the water supplied from the water supply module 1 within the first plate heat exchanger 7, cools down, and returns to the PVT photovoltaic panel 2 to continue absorbing heat. During winter, the antifreeze exchanges heat with the water from the water supply module 1, lowering the temperature of the water from the water supply module 1 (in this specific implementation, it is lowered to about 5°C), producing chilled water for winter cooling storage.

[0053] The first water pump P-1 is a DC water pump, and its power input terminal is connected to the storage battery 4. It is connected between the water supply module 1 and the water inlet of the first plate heat exchanger 7 through a pipe. Under the command of the control module 6, it pumps the water from the water supply module into the first plate heat exchanger 7.

[0054] The quality inspection and enhancement module is used to collect water temperature data from the quality inspection and enhancement module and send it to the control module; it is also used to receive instructions from the control module and execute corresponding operations.

[0055] The quality inspection and enhancement module includes a water storage tank 16, an electric heater 11, a second temperature sensor T-2, a third temperature sensor T-3, a fourth temperature sensor T-4, a fifth temperature sensor T-5, a sixth temperature sensor T-6, a third water pump P-3, a fourth water pump P-4, and a seventh water pump P-7. The electric heater 11 is located at the bottom of the water storage tank 16. The second, third, fourth, and fifth temperature sensors are all located at preset key nodes on the inner wall of the water storage tank 16. The inlet end of the water storage tank 16 is connected to the energy transducer module via a pipe, and the outlet end of the water storage tank is connected to the inlet ends of both the energy storage module and the energy transducer module via pipes. The fourth water pump P-4 is located on the pipe connected to the inlet end of the energy storage module, the seventh water pump P-7 is located on the pipe connected to the inlet end of the energy transducer module, and the sixth sensor T-6 is located at the outlet of the water storage tank 16.

[0056] It should be noted that the water storage tank 16 is an intermediate water storage container with heat preservation function, serving as a transfer and buffer station for hot (or cold) water.

[0057] The first temperature sensor T-1 is installed at the outlet of the first plate heat exchanger 7. The second temperature sensor T-2, the third temperature sensor T-3, the fourth temperature sensor T-4, and the fifth temperature sensor T-5 are all installed inside the water storage tank 16. Their specific locations are not limited. The sixth temperature sensor T-6 is installed on the pipe leading from the water storage tank 16 to the outlet of the energy storage module in the mine tunnel 9. It serves as the final determining sensor for whether hot water (cold water in winter) can be stored in the energy storage module in the mine tunnel 9.

[0058] The electric heater 11 is vertically installed at the center of the bottom of the water storage tank 16, with its heating element (electric heating rod) extending upwards from the bottom. Multiple sets of U-shaped or straight rod-shaped electric heating tubes are evenly distributed on the bottom cross-section of the water storage tank 16 in a concentric ring or symmetrical layout. When the heater is activated, the water heated at the center of the bottom of the water storage tank 16 will form a strong, upward-flowing central heat jet due to the decrease in density. This heat jet will impact the relatively cooler water layer at the top of the water storage tank 16, causing the water inside the tank to circulate, thereby enhancing the convective heat transfer of the water flow inside the tank and effectively breaking down temperature stratification. This layout avoids heat accumulation on the side walls or in localized areas, allowing the water temperature inside the tank to rise rapidly and evenly, solving the "hot at the top, cold at the bottom" problem caused by side wall heating, and enabling the temperature detected by the temperature sensor inside the water storage tank to reach the target temperature more quickly.

[0059] The energy storage module is used to store the water transmitted by the quality inspection and enhancement module; to collect the temperature data of the water at preset time intervals and send it to the control module; and to receive post-processing instructions sent by the control module and perform post-processing operations.

[0060] Furthermore, the energy storage module is installed in an abandoned mine shaft or pit that has undergone specialized engineering treatment. After the abandoned mine shaft is leveled and compacted, an all-around impermeable layer 13 composed of geotextile and high-performance impermeable membrane is laid. The gaps are sealed and reinforced with concrete masonry or shotcrete to form a stable, sealed underground thermal storage space. Multiple temperature sensors are installed at preset key points on the inner wall of the underground thermal storage space. A set of horizontal annular pipes or porous diffusers is laid near the top and bottom walls inside the underground thermal storage space, serving as the inlet end 10 and outlet end 15 of the energy storage module, respectively. The outlet end 15 of the energy storage module is connected to... The inlet of the transducer module is connected to and a sixth water pump P-6 is installed on it. Inside the underground thermal storage space, near the top and bottom walls, there are also corresponding top composite port 8 and bottom composite port 14. Hot / cold water in the mine is taken through the bottom composite port 8, and after exchanging heat with the circulating water at the user end in the second plate heat exchanger 17, the water in the mine is sent back to the cold / heat storage module through the top composite port 14. Then it will be cooled / heated through the first plate heat exchanger 7 to prepare cold / hot water at the standard temperature, and finally stored in the cold / heat storage module. The circulating water is heated / cooled and then sent to the user end 18 for heating / cooling. In practice, during the summer when using the cold water from the mine's cooling storage module, the cold water exchanges heat with the circulating water in the second plate heat exchanger 17. After the cold water in the mine's cooling storage module is heated, it is sent to the heat storage module for heat exchange in the first plate heat exchanger 7. After reaching the heat storage temperature (70℃), this portion of hot water is stored in the heat storage module, while the circulating water is cooled after heat exchange and then sent to the user end for cooling. The opposite is true in winter.

[0061] It should be noted that Mine 9 is an abandoned mine shaft or pit that has undergone specialized engineering treatment. After its inner walls were leveled and compacted, an all-around impermeable layer 13 composed of geotextile and high-performance impermeable membrane (such as HDPE membrane) was laid. Key areas such as the entrance and tunnels were sealed and reinforced with concrete masonry or shotcrete, ultimately forming a stable and sealed underground thermal storage space. Near the top wall inside the underground thermal storage space, a horizontal ring pipe or porous diffuser pipe is laid as the inlet end 10 of the energy storage module. The inlet end 10 of the energy storage module is connected to the fourth water pump P-4 via a pipeline, used to uniformly inject hot water into the upper part of the mine shaft at a low flow rate and over a large area, utilizing the low density of hot water to form a stable temperature stratification (climatic layer) and reduce thermal disturbance. Near the bottom wall inside the underground thermal storage space, a ring pipe or water collection pipe is laid as the outlet end 15 of the energy storage module. The outlet end 15 of the energy storage module is connected to the sixth water pump P-6 via a pipeline, used to extract the coldest water from the bottom of the mine shaft. The seventh temperature sensor T-7 is installed in the middle of the underground thermal storage space, the eighth temperature sensor T-8 is installed in the upper part of the underground thermal storage space, and the ninth temperature sensor T-9 is installed in the lower part of the underground thermal storage space.

[0062] Preferably, an insulation layer 12 is also provided on the outside of the impermeable layer 13. In this embodiment, a high-efficiency insulation material (such as polyurethane foam board) is added to the outside of the impermeable layer as the insulation layer 12.

[0063] The control module 6 is used to analyze the temperature data sent by the transducer module. When the temperature data meets the preset conditions, it sends a pumping command to the quality inspection and enhancement module. Based on the temperature data sent by the quality inspection and enhancement module, it determines whether the corresponding preset summer and winter quality inspection conditions are met, and whether the storage requirements are met. If the requirements are met, it sends a storage command to the quality inspection and enhancement module. If the requirements are not met, it sends a corresponding enhancement execution command to the quality inspection and enhancement module according to the season. It is also used to monitor the water stored in the energy storage module based on the signal data sent by the energy storage module. When the preset detection conditions are not met, it sends a post-processing command to the energy storage module.

[0064] In practice, the temperature values ​​in this embodiment are not limited and can be adjusted according to actual needs.

[0065] Among them, the summer quality inspection condition is that the temperature data at the outlet of the quality inspection and strengthening module, i.e., the temperature data collected by the six temperature sensors T-6, T6 ≥ the preset summer target storage temperature of 70℃; the winter quality inspection condition is that the temperature data at the outlet of the quality inspection and strengthening module, i.e., the temperature data collected by the six temperature sensors T-6, the first winter target storage temperature (3℃) ≤ T6 ≤ the second winter target storage temperature (5℃).

[0066] Furthermore, when the summer quality inspection conditions are not met, control module 6 determines whether the current light intensity meets the conditions for starting the electric heater based on the magnitude of the current generated by the photovoltaic panel. If it does, a start command is sent to the electric heater, which continues to operate until the received temperature data reaches the storage requirements. If it does not meet the conditions, an enhanced execution command is sent, i.e., a pumping command is sent to the seventh water pump P-7 in the quality inspection and enhancement module, to pump the water back to the energy exchange module. The electric heater is only activated when the light intensity is weak (the power comes from the previously stored electricity in the battery); when the light intensity is strong, heat exchange can be carried out directly in the heat exchange plate.

[0067] In practical implementation, during summer, when the temperature data T1 collected by the first temperature sensor T-1 is greater than or equal to the preset summer target storage temperature (not limited, but 70℃ in this embodiment), the control module sends a command to start the third water pump P-3. The third water pump P-3 receives the command and transports the hot water heated by the first plate heat exchanger 7 to the water storage tank 16. When the light intensity is weak at night or during the day, the control module 6 will determine that the current light intensity is low based on the current generated by the photovoltaic panel. The temperature data T2, T3, T4, and T5 obtained by the second temperature sensor T-2, the third temperature sensor T-3, the fourth temperature sensor T-4, and the fifth temperature sensor T-5 will be lower than the set lower limit (70℃). Even if the seventh water pump P-7 pumps this part of the substandard water back to the first plate heat exchanger 7 for reheating, the effect will be negligible. Therefore, the control module 6 sends a start command to the electric heater 11, and the electric heater 11 performs auxiliary heating. When control module 6 reads the temperature data T6 collected by the sixth temperature sensor T-6: if T6 ≥ the target storage temperature (70℃), then the fourth water pump P-4 is started to pump hot water into the energy storage module; if T6 < the target storage temperature (70℃), then P-4 is prohibited from starting. After P-4 is prohibited, control module 6 will re-evaluate the value of T6 to determine whether to lift the prohibition when any of the following conditions are met: a. Delayed retry: after a preset delay period (e.g., 30 minutes); b. Energy input optimization: when new high-temperature hot water is detected being injected into the storage tank (manifested as a significant increase in T1 and the start of water pump P-3) or the electric heater has been working continuously for a preset period of time.

[0068] Furthermore, when the winter quality inspection conditions are not met, the control module 6 determines whether it is nighttime based on the magnitude of the current generated by the photovoltaic panel and the current light intensity: if so, it sends an enhanced execution command, that is, sends a pumping command to the seventh water pump P-7 of the quality inspection and enhancement module, and pumps the water back to the energy conversion module; if not, it continues to judge the light intensity until it is met.

[0069] In practice, during winter, heat exchange and energy storage operations are only carried out at night to avoid the negative impact of heat generated by the PVT photovoltaic panels themselves during daytime photovoltaic power generation on cooling efficiency. Simultaneously, the lower ambient temperature at night facilitates efficient heat exchange between the PVT photovoltaic panels 2 and the cold air. During the day, the PVT photovoltaic panels 2 focus on photovoltaic power generation, storing the generated electricity in the battery 4 to power the various water pumps and control modules 6 that operate at night. When the energy exchanger is working at night, when the first winter target storage temperature (3℃) ≤ T1 ≤ the second winter target storage temperature (5℃), the controller starts the third water pump P-3 to deliver the cooled water from the first plate heat exchanger 7 to the water storage tank 16. After the water is delivered to the water storage tank, the control module 5 further checks whether the water temperature is qualified based on the temperature data collected by the sixth temperature sensor T-6 (qualified when the first winter target storage temperature (3℃) ≤ T6 ≤ the second winter target storage temperature (5℃)): if qualified, a pumping command is sent to the fourth water pump P-4; if T6 > the second winter target storage temperature (5℃), the control module 6 sends a pumping command to the seventh water pump P-7 to pump the water back to the first plate heat exchanger 7.

[0070] More specifically, when the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the antifreeze cycle threshold (1℃), the control module sends a flow reduction adjustment command to the third water pump, shuts down some of the PVT photovoltaic panels in the energy supply module to reduce the heat exchange intensity, and starts the heating belt to heat. When the temperature data detected by the first temperature sensor reaches the preset safety threshold (3℃), it shuts down. When the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the emergency shutdown threshold (0℃), the control module sends a stop command to all water pumps and sends an alarm to the monitoring center staff, waiting for manual intervention.

[0071] Specifically, when the temperature T1 obtained by the first temperature sensor T-1 is lower than the antifreeze cycle threshold (1℃), the electric heating tape is automatically activated for low-temperature insulation, regardless of whether the system is running. Simultaneously, the control module 6 reduces the flow rate of the third water pump P-3 and adjustably shuts down part of the PVT loop to reduce heat exchange intensity and prevent the water temperature from further dropping to freezing point. Its core objective is to prioritize preventing the system from freezing, followed by cooling efficiency. When T1 displays a temperature higher than the preset safety threshold (3℃), it automatically shuts down to save energy. When T1 detects a water temperature lower than the emergency shutdown threshold (0℃), the control module determines there is an immediate risk of freezing, forcibly stops all water pumps, and activates the heating tape at maximum power for heating. Simultaneously, an alarm is sent to the monitoring center, awaiting manual intervention.

[0072] It should be noted that the power input terminal of the control module 6 is electrically connected to the battery 4, its signal input terminal is connected to each temperature sensor, and its control output terminal is connected to each water pump and electric heater 11. It is the "brain" of the entire system and is configured to execute the above-mentioned complete intelligent control logic, which includes decision-making and recovery mechanisms, to regulate the operation of the entire system.

[0073] The second water pump P-2 is installed on the pipeline connecting the antifreeze inlet of the PVT photovoltaic panel 2 and the antifreeze outlet of the first plate heat exchanger 7. Under the command of the control module 6, it drives the antifreeze to circulate in a closed loop of "PVT photovoltaic panel 2 → first plate heat exchanger 7 → PVT photovoltaic panel 2".

[0074] The third water pump P-3 is installed on the pipe connecting the outlet of the first plate heat exchanger 7 and the inlet of the water storage tank 16. When the temperature data sent to the control module by the first temperature sensor T-1 meets the storage conditions, the control module sends a command to start the pump, which delivers the hot water (or cold water prepared in winter) heated by the first plate heat exchanger 7 to the water storage tank 16.

[0075] The fourth water pump P-4 is installed on the pipe connecting the outlet of the water storage tank 16 and the inlet of the energy storage module 10. When the temperature data detected by the sixth temperature sensor T-6 confirms that the water temperature meets the standard (T6≥ target temperature), the control module 6 sends a start command, and the fourth water pump P-4 pumps the qualified hot water into the energy storage module for storage.

[0076] The seventh water pump P-7 is installed on the pipe connecting the outlet of the water storage tank 16 and the inlet of the first plate heat exchanger 7. In summer, if the hot water temperatures T2, T3, and T4 collected by the second temperature sensor T-2, third temperature sensor T-3, and fourth temperature sensor T-4 are lower than the set lower limit (70℃), the control module 6 will immediately start the seventh water pump P-7 to pump this portion of substandard hot water back to the inlet of the first plate heat exchanger 7 for reheating. In winter, if the hot water temperature T6 collected by the sixth temperature sensor T-6 is greater than 5℃, it indicates that the water temperature is not up to standard. The control module 6 will immediately send a start command to the seventh water pump P-7, which will pump this portion of substandard cold water back to the inlet of the first plate heat exchanger 7 for further cooling, forming an internal circulation until the temperature reaches the standard (3℃≤T8≤5℃) before it is allowed to enter the energy storage module for storage.

[0077] The sixth water pump P-6 is installed on the pipe connecting the outlet of the energy storage module and the inlet of the first plate heat exchanger 7. In summer, when the temperature T7 collected by the seventh temperature sensor T-7 is less than or equal to the target temperature (70℃), the control module 6 issues a start command to the sixth water pump P-6. The sixth water pump P-6 pumps the low-temperature water from the bottom of the mine back to the first plate heat exchanger 7, starting a new heating cycle, thus forming a complete working fluid circulation loop. In winter, when the temperature T7 collected by the seventh temperature sensor T-7 is greater than or equal to the target temperature (5℃), and it is necessary to cool the substandard cold water in the mine again, the control module 6 issues a start command to the sixth water pump P-6. The sixth water pump P-6 then pumps the substandard water from the bottom of the mine back to the first plate heat exchanger 7, starting a new cooling cycle, thus forming a complete working fluid circulation loop.

[0078] More specifically, each connecting pipe exposed to the outside of the water supply module, energy supply module, heat exchange module, quality inspection and enhancement module, and energy storage module is equipped with a heating band capable of limiting temperature. The heating band is then wrapped with an insulation layer and a protective layer. The heating band is controlled by a control module and powered by energy provided by the energy supply module. In this embodiment, all water circuit and antifreeze circuit pipes are further wrapped with a high-efficiency insulation material (including but not limited to rubber-plastic insulation cotton or polyurethane insulation pipe shell) outside the heating band. Finally, aluminum or galvanized iron sheet is added as a protective layer, forming a composite structure of "pipeline-electric heat tracing-insulation layer-protective layer," enhancing insulation and protection, greatly reducing heat loss from the pipes, slowing down water temperature drop, and protecting the heating band.

[0079] The operation process of the system provided by this invention in specific implementation 2 is as follows: The water supply module 1 provides the initial and supplementary water for the system, which is then heated by the high-temperature refrigerant from the PVT photovoltaic panel 2 in the first plate heat exchanger 7. The PVT photovoltaic panel 2 heats the antifreeze on one hand and generates DC power on the other, which is regulated by the photovoltaic controller 3 and stored in the battery 4, and then supplied to all equipment in the system that requires electricity through the inverter 5. The hot water obtained after heat exchange in the first plate heat exchanger 7 meets the storage conditions and is pumped into the water storage tank 16 by the third water pump P-3, where it undergoes quality inspection. In summer, if the temperature of the water storage tank meets the standard (70°C), it is directly pumped into the energy storage module by the fourth water pump P-4. If it does not meet the standard, the seventh water pump P-7 is started first to pump the substandard hot water back to the inlet of the first plate heat exchanger 7 for reheating. If it is during the day or night when the light intensity is relatively weak, the substandard water is heated to the standard by the electric heater 11 and then pumped into the heat storage module. The energy storage module inside mine shaft 9 is insulated and seepage-proofed, with a seepage-proof layer 13 and an insulation layer 12. The hot water in the heat storage module will cool down over time. When the temperature sensor in the mine shaft detects that the water temperature is not up to standard, the sixth water pump P-6 is activated to send the cooler water from the bottom back to the first plate heat exchanger 7 for heating.

[0080] Winter Cooling: During the day, PVT photovoltaic panel 2 focuses on photovoltaic power generation, storing the generated electricity in battery 4 to power the water pumps and control module 6 that operate at night. The core reason for choosing nighttime operation is to avoid the negative impact of the heat generated by the PVT photovoltaic panel itself during daytime photovoltaic power generation on cooling efficiency. Simultaneously, the lower ambient temperature at night facilitates efficient heat exchange between the PVT photovoltaic panel 2 as a radiator and the cold air. At night, control module 6 starts the second water pump P-2, driving the antifreeze to circulate in a closed loop: "PVT photovoltaic panel 2 → first plate heat exchanger 7 → PVT photovoltaic panel 2". Under the low-temperature environment at night, the PVT photovoltaic panel 2 acts as a highly efficient radiator, cooling the flowing antifreeze. Simultaneously, ambient temperature water supplied by water supply module 1 is pumped into the first plate heat exchanger 7 by the first water pump P-1. Inside the first plate heat exchanger 7, the ambient temperature water undergoes isolated heat exchange with the low-temperature antifreeze from the PVT loop, thus lowering the water temperature.

[0081] The cooled target low-temperature water is first pumped into the storage tank 16 by the third water pump P-3 for temporary storage and buffering. Then, the fourth water pump P-4 pumps the cold water from the storage tank 16 to the leak-proof and insulated cold storage module for final storage. Before the cold water enters the cold storage module, the sixth temperature sensor T-6 performs a final temperature check on its data T6. If T6 > 5℃, it indicates that the water temperature has not reached the standard. The control module 6 will immediately start the seventh water pump P-7 to pump this portion of the substandard cold water back to the inlet of the first plate heat exchanger 7 for further cooling, forming an internal circulation until the temperature reaches the standard (3℃ ≤ T8 ≤ 5℃) before it is allowed to enter the cold storage module for storage.

[0082] Assuming the underground cavern is a cylinder, we can approximate its heat storage capacity by taking a radius of 5m and a height of 15m. The cavern's internal volume would then be approximately 1178m³. 3 The thermophysical properties of saturated water at 70℃ are as follows: density 977.8 kg / m³, thermal conductivity 0.668 W / (m·K); specific heat 4.187 kJ / (kg·K). The thermophysical properties of saturated water at 5℃ are as follows: density 999.6 kg / m³, thermal conductivity 0.5625 W / (m·K); specific heat 4.202 kJ / (kg·K). The rock wall parameters are set as general granite with a density of 2700 kg / m³; the constant-pressure heat capacity is set to Cp = 900 J / kg·K. Considering the influence of heat exchange pipes within the water body and the insulation materials on the cave walls, the heat transfer coefficient is taken as 0.25 W / (m²·K). Comsol software is used to simulate transient heat transfer changes. Figure 2 , Figure 3 , Figure 4 These are temperature distribution profiles for hot water stored in summer over 1 day, 180 days, and 180 days, respectively. Figure 5 , Figure 6 , Figure 7 The figures show temperature distribution profiles for 1 day, 180 days, and a temperature probe diagram for 180 days of stored cold water in winter. The temperature distribution and probe diagrams show that the 70℃ hot water produced in summer still maintains a temperature of approximately 36℃ after 180 days, and the 5℃ cold water produced in winter still maintains a temperature of 6℃ after 180 days. These results are based solely on the insulation effect of the mine after insulation measures have been implemented, without considering the reheating / cooling of substandard hot / cold water using pumps. Even without pumping substandard water back into the plate heat exchanger, the water still maintains the above temperatures. Furthermore, if the sixth and seventh pumps in the system (P-6 and P-7) can reheat / cool the water that has not reached the standard temperature (below 70℃ in summer and above 5℃ in winter), excessive heat / cold loss will not occur during long-term heat storage, enabling cross-seasonal energy storage.

[0083] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0084] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. This invention provides a solar photovoltaic-thermal / cold conversion and interseasonal energy storage system suitable for the transformation of abandoned mines, characterized in that, The system includes a water supply module, an energy supply module, an energy conversion module, a quality inspection and enhancement module, an energy storage module, and a control module. The water supply module is used to provide initial and supplemental water for the system; The power supply module is used to collect energy from the energy unit and convert it into energy to provide energy drive for each module; The energy conversion module is used to convert the water supplied by the water supply module, quality inspection and enhancement module and energy storage module received at the inlet into energy using the energy provided by the energy supply module; and is used to send the temperature data collected at the outlet to the control module. The quality inspection and enhancement module is used to collect water temperature data in the quality inspection and enhancement module and send it to the control module; it is also used to receive instructions from the control module and execute corresponding operations. The energy storage module is used to store the water transmitted by the quality inspection and enhancement module; to collect the temperature data of the water at preset time intervals and send it to the control module; and to receive post-processing instructions sent by the control module and perform post-processing operations. The control module analyzes the temperature data sent by the transducer module. When the temperature data meets preset conditions, it sends a pumping command to the quality inspection and enhancement module. Based on the temperature data sent by the quality inspection and enhancement module, it determines whether the corresponding preset summer and winter quality inspection conditions are met, and whether the storage requirements are met. If the requirements are met, it sends a storage command to the quality inspection and enhancement module; if the requirements are not met, it sends a corresponding enhancement execution command to the quality inspection and enhancement module for the corresponding season. It also monitors the water stored in the energy storage module based on the signal data sent by the energy storage module. When the preset detection conditions are not met, it sends a post-processing command to the energy storage module.

2. The system according to claim 1, characterized in that, The power supply module includes a PVT photovoltaic panel, a photovoltaic controller, a storage battery, an inverter, and a second water pump. The power generation interface of the PVT photovoltaic panel is connected to the storage battery through the photovoltaic controller. The storage battery is electrically connected to the control module. The second water pump is installed on the pipeline connecting the PVT photovoltaic panel and the first plate heat exchanger.

3. The system according to claim 1, characterized in that, The energy conversion module includes a pipeline, a first plate heat exchanger, a first water pump, and a first temperature sensor. The antifreeze of the first plate heat exchanger forms a closed antifreeze circulation loop with the PVT photovoltaic panel via a pipeline. The inlet end of the water circuit of the first plate heat exchanger is connected to a water supply module, a quality inspection and enhancement module, and an energy storage module via pipelines. The outlet end of the water circuit of the first plate heat exchanger is connected to the inlet end of the quality inspection and enhancement module via a pipeline. The first water pump is installed on the pipeline at the inlet end of the water circuit of the first plate heat exchanger. The first temperature sensor is installed inside the outlet end pipeline.

4. The system according to claim 3, characterized in that, The quality inspection and enhancement module includes a water storage tank, an electric heater, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a third water pump, a fourth water pump, and a seventh water pump. The electric heater is located at the bottom of the water storage tank. The second, third, fourth, and fifth temperature sensors are all located at preset key nodes on the inner wall of the water storage tank. The inlet of the water storage tank is connected to the energy transducer module via a pipe, and the outlet of the water storage tank is connected to the inlet of both the energy storage module and the energy transducer module via pipes. The fourth water pump is located on the pipe connected to the inlet of the energy storage module, the seventh water pump is located on the pipe connected to the inlet of the energy transducer module, and the sixth sensor is located at the outlet of the water storage tank.

5. The system according to claim 4, characterized in that, When the summer quality inspection conditions are not met, the control module checks whether the current solar intensity meets the conditions for starting the electric heater: if it does, it sends a start command to the electric heater to start the electric heater until the received temperature data reaches the storage requirements; if it does not meet the conditions, it sends an enhanced execution command, that is, sends a pumping command to the seventh water pump in the quality inspection and enhancement module to pump the water back to the energy conversion module.

6. The system according to claim 4, characterized in that, When the winter quality inspection conditions are not met, the control module combines the current generated by the photovoltaic panel to determine the current light intensity and whether it is nighttime. If so, it sends an enhanced execution command, which sends a pumping command to the seventh water pump of the quality inspection and enhancement module to pump water back to the energy conversion module. If not, it continues to judge the light intensity until it is met.

7. The system according to claim 6, characterized in that, The external connecting pipes of the water supply module, energy supply module, heat exchange module, quality inspection and enhancement module and energy storage module exposed to the outside are also equipped with heating belts that can limit the temperature. The heating belts are wrapped with insulation layers and protective layers in sequence. The heating belts are controlled by the control module and driven by the energy supply module.

8. The system according to claim 7, characterized in that, When the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the antifreeze cycle threshold, the control module sends a flow reduction adjustment command to the third water pump, shuts down some of the PVT photovoltaic panels in the energy supply module to reduce the heat exchange intensity, and starts the heating belt. The heating belt is shut down when the temperature data detected by the first temperature sensor reaches the preset safety threshold. When the temperature data detected by the first temperature sensor at the outlet of the energy converter module is lower than the emergency shutdown threshold, the control module sends a stop command to all water pumps and sends an alarm to the monitoring center staff, waiting for manual intervention.

9. The system according to claim 1, characterized in that, The energy storage module is installed in an abandoned mine shaft or pit that has undergone special engineering treatment. After the abandoned mine shaft is leveled and compacted, an all-round seepage-proof layer composed of geotextile and high-performance seepage-proof membrane is laid. The gaps are sealed and reinforced by concrete masonry or shotcrete to form a stable and sealed underground heat storage space. The energy storage module consists of two modules: a thermal storage module and a cold storage module. Multiple temperature sensors are installed at key points on the inner wall of the underground thermal storage space. A horizontal annular pipe or porous diffuser is laid near the top and bottom walls of the underground thermal storage space, serving as the inlet and outlet of the energy storage module, respectively. The outlet of the energy storage module is connected to the inlet of the energy exchange module via a pipe, and a sixth water pump is installed on it. A top composite port and a bottom composite port are also installed near the top and bottom walls of the underground thermal storage space. Hot / cold water is drawn from the mine through the bottom composite port, exchanged with circulating water at the user end in the second plate heat exchanger, and then returned to the cold / heat storage module through the top composite port. Afterward, the water is cooled / heated by the first plate heat exchanger 7 to produce cold / hot water at the required temperature, which is then stored in the cold / heat storage module. The circulating water, after being heated / cooled, is sent to the user end for heating / cooling.

10. The system according to claim 9, characterized in that, An insulation layer is also installed on the outside of the seepage-proof layer.

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