Modular photovoltaic or wind-solar complementary lithium-sodium battery energy storage underground water indirect cooling heat pump air conditioning device

Abstract

The application discloses a modular photovoltaic / wind-solar complementary lithium-sodium battery energy storage underground water indirect cooling heat pump air conditioning device, which comprises a modular mainframe, a photovoltaic or wind-solar complementary power generation unit, a lithium-sodium hybrid energy storage unit, an underground water indirect heat exchange unit, a water source heat pump unit, a battery active thermal management unit and an intelligent control system. The core innovation lies in that the closed secondary circulating medium is formed by using underground water through a plate heat exchanger, the medium is used as the water source heat pump heat exchange medium and the energy storage battery liquid cooling medium at the same time, and the integration and coupling of the underground cold and heat sources and the new energy storage system are realized; the intelligent control system adjusts the flow of the heat pump branch and the battery cooling branch through a valve group according to the battery temperature, the heat pump load and the temperature difference of the water to be taken, lithium ion and sodium ion batteries are connected to a common DC bus through independent bidirectional DC / DC conversion modules, and the direct parallel connection risk is avoided. The recharge well is provided with a porous diffuser and is linked to a temperature sensor for linkage control, and the heat penetration risk is reduced. The application realizes the integration of new energy power generation, energy storage regulation, building cold and heat supply and battery temperature control, has the advantages of complementary energy storage performance, efficient battery thermal management, modular rapid installation, heat penetration reduction and the like, and is suitable for distributed scenes such as rural self-built houses.

Description

Technical Field

[0001] This invention belongs to the fields of new energy comprehensive utilization, energy storage system thermal management and building heating and cooling supply technology. Specifically, it relates to a comprehensive energy device that deeply structurally couples and modularly integrates photovoltaic power generation or wind-solar hybrid power generation, lithium-sodium hybrid energy storage, active battery thermal management, groundwater indirect heat exchange and water source heat pump air conditioning system.

[0002] More specifically, the present invention relates to a modular integrated energy device that utilizes the relatively stable temperature characteristics of groundwater throughout the year, provides a cold and heat source for a water source heat pump system through a closed-loop secondary circulation medium, and further utilizes the same closed-loop cooling medium to actively manage the energy storage battery, thereby realizing the bidirectional coupling of the underground stable cold and heat source and the new energy storage system.

[0003] This device is particularly suitable for: self-built houses in rural areas, villas, small commercial buildings, agricultural facilities, independent energy supply scenarios in remote areas, and distributed energy systems under conditions without a stable power grid. Background Technology

[0004] With the development of new energy technologies, the application of renewable energy sources, such as photovoltaic and wind power, in building energy systems is constantly increasing. However, due to the significant intermittency and volatility of solar and wind power, there is a mismatch between the timing of new energy power generation and user energy demand. To improve the utilization rate of new energy sources, energy storage batteries are currently commonly used to store excess electricity and release it during periods of insufficient photovoltaic power or peak load.

[0005] Existing distributed renewable energy systems typically include photovoltaic modules, wind power generation equipment, energy storage battery systems, inverter equipment, and building loads. However, these systems primarily address the issue of electricity supply and demand; the cooling and heating loads of buildings still require traditional air conditioning equipment.

[0006] Traditional air-source heat pump air conditioning systems use air as the heat exchange medium, and their operating efficiency is significantly affected by ambient temperature. In high-temperature summer environments, the outdoor air temperature rises, the temperature difference between the air and the condenser decreases, the compressor operating pressure increases, and the system's energy efficiency ratio drops. In low-temperature winter environments, the air's heat capacity decreases, the evaporation temperature drops, the heat pump's heat absorption capacity decreases, and the heating efficiency decreases. Therefore, air-source heat pumps suffer from reduced operating efficiency under extreme weather conditions.

[0007] In contrast, groundwater, due to the moderating effect of the underground environment, has a smaller temperature range throughout the year, providing a stable source of heat and cold. Groundwater source heat pumps utilize groundwater as a heat exchange medium, offering advantages such as stable heat exchange temperature, high operating efficiency, minimal performance fluctuations in winter and summer, and significant energy savings.

[0008] However, existing groundwater source heat pump systems and energy storage systems still have the following prominent problems:

[0009] First, the system equipment is dispersed and installation is complex. Traditional groundwater source heat pump systems typically consist of multiple independent parts, such as groundwater well systems, water pumps, heat exchange equipment, heat pump main units, control equipment, and terminal equipment. Each piece of equipment requires on-site layout, connection, and commissioning. For application scenarios such as rural residences and small buildings, the construction period is long, the professional requirements are high, and maintenance is difficult, which is not conducive to rapid promotion.

[0010] Secondly, the independent configuration of thermal management for energy storage batteries leads to energy waste and system complexity. Energy storage batteries generate heat during charging and discharging, especially at high rates, in high-temperature summer environments, and under continuous operation, resulting in significant temperature rises. Currently, energy storage systems typically employ air cooling, independent liquid cooling units, or air conditioning, leading to issues such as increased equipment, higher energy consumption, more complex structures, and higher system costs. On the other hand, underground water source heat pump systems inherently possess a stable low-temperature cold source, but existing technologies typically only utilize them for building heating and cooling, failing to fully leverage their potential as a cold source for energy storage battery thermal management, thus hindering the cascade utilization of underground cold source resources.

[0011] Third, groundwater recharge is prone to thermal runaway problems. During the operation of a groundwater source heat pump, the heat-exchanged groundwater needs to be recharged. However, in rural areas and small-scale construction sites, due to limited space, the distance between the intake well and the recharge well is often close (commonly 15–30 meters), which usually cannot meet the requirements of large-scale projects. The temperature of the recharged water differs from the original groundwater temperature. Over long-term operation, the heat plume formed by the recharge may gradually affect the intake area, causing thermal runaway, reduced heat exchange capacity, and decreased system efficiency. Existing solutions mainly include increasing the distance between wells, increasing the scale of underground engineering, or optimizing the groundwater model, but these methods are costly and unsuitable for small-scale distributed applications.

[0012] Fourth, a single energy storage system cannot adequately handle diverse environmental conditions, and directly connecting batteries with different chemical systems in parallel poses safety risks. Lithium-ion batteries offer advantages such as high energy density, high efficiency, and long cycle life, but their internal resistance increases and charge / discharge capacity decreases at low temperatures. Sodium-ion batteries, on the other hand, have better low-temperature performance, abundant resources, and lower costs, but their energy density is relatively low. Existing energy storage systems typically employ a single battery system, making it difficult to simultaneously meet the demands of high-temperature environments, low-temperature environments, long-term energy storage, high-power output, and multi-condition operation. Simply connecting lithium and sodium batteries directly in parallel can easily lead to circulating currents, SOC imbalance, and even overcharging risks due to differences in nominal voltage platforms, SOC-OCV curves, and internal resistance characteristics.

[0013] Fifth, existing technologies are mostly simple system superpositions, lacking deep structural coupling and dynamic energy management. Simply connecting mature modules such as photovoltaics, energy storage, underground water heat pumps, and battery liquid cooling is a conventional combination of technologies and is unlikely to create irreplaceable technological effects. There is an urgent need for a modular device that uses the same closed-loop circulation medium as a link to achieve deep coupling between stable underground cold and heat sources and new energy storage systems, and that possesses intelligent flow distribution and heat penetration early warning capabilities. Summary of the Invention

[0014] To address the aforementioned problems with existing new energy building energy systems, this invention proposes a modular photovoltaic or wind-solar hybrid lithium-sodium battery energy storage groundwater indirect cooling heat pump air conditioning device.

[0015] The core objective of this invention is to provide a bidirectional coupling energy management device for new energy storage and building heating / cooling loads based on a stable underground cold and heat source. By deeply coupling photovoltaic or wind-solar hybrid power generation, lithium-sodium hybrid energy storage (accessed via an independent DC / DC converter), indirect heat exchange with groundwater, a water source heat pump, and active battery thermal management, the same closed-loop secondary circulation medium simultaneously performs both heat pump heat exchange and battery liquid cooling functions. This enables intelligent flow distribution and heat transfer warning, thereby achieving comprehensive technical effects such as reduced auxiliary energy consumption, extended battery life, and improved system adaptability and long-term stability throughout the year.

[0016] A further objective of this invention is to achieve active thermal management of energy storage batteries by utilizing the closed-loop cooling medium in an underground water source heat pump system, without adding independent battery cooling equipment, thereby realizing the cascade utilization of underground cold and heat sources.

[0017] A further objective of this invention is to connect lithium-ion batteries and sodium-ion batteries to a common DC bus via independent bidirectional DC / DC conversion modules, and to dynamically switch between them based on temperature, state of charge, and load requirements. This approach avoids the safety risks of direct parallel connection and improves the year-round operational adaptability of the energy storage system.

[0018] A further objective of this invention is to make the groundwater recharge process more uniform by setting up a porous diffusion recharge structure and combining it with temperature feedback control, thereby reducing local temperature differences and heat plume concentration, and improving the long-term operational stability of the groundwater source heat pump.

[0019] To achieve the above objectives, the present invention adopts the following technical solution:

[0020] A modular photovoltaic or wind-solar hybrid lithium-sodium battery energy storage groundwater indirect cooling heat pump air conditioning device includes: a modular main frame; a photovoltaic or wind-solar hybrid power generation unit; a lithium-sodium hybrid energy storage unit; a groundwater indirect heat exchange unit; a water source heat pump air conditioning unit; a battery active thermal management unit; and an intelligent control system.

[0021] Each functional unit is deeply integrated through mechanical structure, electrical connection, and closed-loop heat exchange pipeline, making the entire system a comprehensive energy device with functions of new energy generation, electrical energy storage, building heating and cooling supply, energy storage thermal management, long-term stable operation of groundwater, and multi-energy coordinated regulation. The core lies in the integrated coupling of heat pump heat exchange and battery thermal management through the same closed-loop circulating medium on the secondary side of the plate heat exchanger.

[0022] 1. Modular host frame structure

[0023] The modular main frame serves as the main load-bearing structure of the entire device and is manufactured using steel, aluminum alloy profiles, or composite structural frames. The interior of the frame is divided into multiple independent functional areas by partitions, including: (1) an energy storage compartment; (2) a heat exchange compartment; (3) a heat pump main unit compartment; and (4) a control compartment.

[0024] The system includes: an energy storage compartment for installing lithium-sodium hybrid energy storage units; a heat exchange compartment for installing plate heat exchangers, circulating water pumps, and valve assemblies; a heat pump unit compartment for installing water source heat pump units; and a control compartment for installing energy storage controllers, heat pump controllers, energy management systems, and communication modules.

[0025] Each functional compartment adopts a modular installation method, enabling the equipment to complete mechanical installation, piping connection, electrical commissioning, and control program configuration in the factory. During on-site installation, only the connection of underground water pipes, building end hot and cold water pipes, power interface, and communication interface needs to be completed, allowing for rapid deployment. Compared to traditional underground water source heat pump systems that require item-by-item on-site construction, this invention reduces construction complexity and improves equipment standardization through modular prefabrication.

[0026] The modular main unit frame has multiple lifting holes and rubber or spring shock-absorbing supports at the bottom. The sides and ends are pre-drilled with standardized quick-connect interfaces for underground water pipes, terminal air conditioning water pipe interfaces, cable threading holes, and grounding terminals. The exterior of the frame is equipped with openable maintenance doors or covers corresponding to the energy storage compartment, heat exchange compartment, and main unit compartment, facilitating battery replacement, heat exchanger cleaning, and equipment maintenance.

[0027] 2. Photovoltaic or wind-solar hybrid power generation unit

[0028] The photovoltaic or wind-solar hybrid power generation unit includes a photovoltaic module array, a small wind turbine, an anti-reverse current control module, and a power generation controller. Specifically, the photovoltaic modules convert solar energy into direct current (DC), and the wind turbine converts wind energy into DC. The two power sources are combined and controlled before being input into an energy storage inverter system. The generated electricity is distributed according to the system's operating status: the first part directly supplies the water source heat pump unit, circulating water pump, control system, and other equipment; the second part is stored in a lithium-sodium hybrid energy storage unit; and the third part is released by the energy storage unit when photovoltaic and wind power are insufficient, providing continuous energy to the system. Through this method, the utilization rate of renewable energy is improved, and the building's dependence on the external power grid for heating and cooling is reduced.

[0029] 3. Lithium-Sodium Hybrid Energy Storage Unit Structure (Key Improvements)

[0030] The lithium-sodium hybrid energy storage unit includes a lithium-ion battery pack, a sodium-ion battery pack, a battery housing, a battery management system, and a group switching control device.

[0031] To mitigate the safety risks of directly connecting batteries with different chemical systems in parallel, this invention employs the following structure: the lithium-ion battery pack and the sodium-ion battery pack are each connected to a common DC bus via independent bidirectional DC / DC converter modules. The bidirectional DC / DC converter achieves voltage matching, electrical isolation, and bidirectional energy flow, fundamentally eliminating the risks of circulating current, SOC imbalance, and overcharging.

[0032] The group switching control device is communicatively connected to the ambient temperature sensor, the bidirectional DC / DC converter module of the lithium-ion battery pack, and the bidirectional DC / DC converter module of the sodium-ion battery pack, respectively. The intelligent control system has a built-in switching module that triggers the corresponding DC / DC module to turn on or simultaneously turn on based on the received temperature and load signals, thereby achieving dynamic switching.

[0033] The operating logic for lithium-sodium hybrid energy storage includes:

[0034] (1) Low temperature operation mode: When the ambient temperature is low, the sodium-ion battery has better low temperature charging and discharging performance. The control system will prioritize triggering the DC / DC module of the sodium battery pack to turn on, thereby reducing the problems of battery polarization, limited charging and capacity reduction in low temperature environment.

[0035] (2) High-efficiency operation mode: When the ambient temperature is suitable and the system requires high energy density output, the DC / DC module of the lithium-ion battery pack is triggered to turn on first, making full use of the advantages of high energy density, high rate performance and high cycle efficiency of lithium battery.

[0036] (3) High load operation mode: When the building's heating and cooling load increases and the heat pump power increases, the control system triggers two sets of DC / DC modules to simultaneously conduct power to the common DC bus, thereby improving instantaneous power capacity and system stability.

[0037] Through the above structure and control methods, the energy storage system can adapt to different climatic conditions throughout the year while ensuring electrical safety.

[0038] 4. Groundwater indirect heat exchange unit

[0039] The groundwater indirect heat exchange unit includes an intake well, a reinjection well, a groundwater delivery pipeline, a pre-filter, a plate heat exchanger, and a closed-loop cooling water circuit. After being extracted from the intake well, the groundwater is first filtered before entering the primary side channel of the plate heat exchanger, where it exchanges heat with the secondary side closed-loop cooling water. The heat-exchanged groundwater is then transported to the reinjection well via the reinjection pipe.

[0040] Unlike traditional direct groundwater utilization methods, this invention employs a primary groundwater system and a closed-loop secondary circulating water system, completely isolating the two. Therefore, silt, minerals, and corrosive substances from the groundwater will not enter the equipment, improving system reliability, ease of maintenance, and service life. The plate heat exchanger uses a detachable plate structure, with plates made of 316L stainless steel or titanium alloy. The primary and secondary flow channels are arranged in a counter-current or cross-flow configuration.

[0041] 5. Core Innovative Structure: A coupling unit that uses the same closed-loop circulation medium to simultaneously serve both the heat pump and the battery.

[0042] One of the core technical solutions of this invention is that the stable cold and heat source closed-loop circulating water formed by the groundwater indirect heat exchange system is used as both the heat exchange medium of the water source heat pump and the cooling medium of the energy storage battery, and priority control is achieved through intelligent flow distribution.

[0043] The specific structure is as follows: The secondary outlet of the plate heat exchanger is connected to the closed-loop main pipeline. The main pipeline is divided into two branches: the first branch connects to the heat exchange end of the water source heat pump unit; the second branch connects to the cooling channels inside the energy storage battery housing. The battery cooling channels are located at the bottom, side walls, module support structure, or inside an independent liquid cooling plate of the battery housing. When the cooling medium flows through the battery cooling structure, it absorbs the Joule heat, polarization heat, and reaction heat generated by the battery charging and discharging, and then returns to the closed-loop system.

[0044] Summer cooling mode: The closed-loop circulating medium is cooled by the plate heat exchanger and then flows into the condenser side of the water source heat pump, carrying away the heat of condensation. Winter heating mode: The closed-loop circulating medium is heated by the plate heat exchanger and then flows into the evaporator side of the water source heat pump, providing a stable heat source. During transitional seasons, it can be switched to a direct cooling mode using natural cold source, shutting down the compressor and reducing energy consumption.

[0045] The intelligent control system is electrically connected to the lithium-sodium hybrid energy storage unit, the groundwater indirect heat exchange unit, and the water source heat pump host. By collecting signals of battery temperature, heat pump load, and return water temperature difference, it controls the regulating valve group to distribute the flow between the heat pump branch and the battery cooling branch: when the battery temperature is close to the upper limit, the flow of the battery branch is increased first; when the building load suddenly increases, the heat pump branch is prioritized; when the temperature difference is abnormal, a heat penetration warning is triggered and the total flow is reduced.

[0046] The cooling water channels of the battery housing adopt a serpentine flow channel, parallel multi-channel, or harmonica tube structure. A thermally conductive silicone or phase change material layer is provided between the cooling water channels and the battery modules. The inlet and outlet of the cooling water channels are connected to the closed cooling water circulation loop on the secondary side of the plate heat exchanger through quick-connect couplings or flanges, forming an active thermal management loop for the battery.

[0047] 6. Battery active thermal management structure The battery casing is equipped with a liquid cooling structure. This liquid cooling structure includes a serpentine flow channel, parallel multi-channel flow channels, a harmonica-tube flow channel, and a liquid cooling plate structure. Thermally conductive silicone, high thermal conductivity pads, and a phase change material layer are placed between the cooling channels and the battery cells to improve heat transfer efficiency and cell temperature uniformity.

[0048] Temperature control method: The system is equipped with a temperature sensor, an electric regulating valve, and a circulating water pump. The control system collects real-time data on the temperature of individual battery cells, module temperature, cooling water inlet temperature, and cooling water outlet temperature. Based on the temperature difference, it automatically adjusts the circulation flow rate, cooling power, and operating mode to maintain the battery within the 10–45℃ operating range (this parameter is a preferred operating range and not structurally limited, and can be differentiated for lithium-ion and sodium-ion batteries depending on their system differences). The battery's active thermal management loop includes an independent closed-loop cooling water circulation pump or a main loop shunt structure, equipped with a temperature sensor and an electric regulating valve for precise control of the water flow entering the battery cooling channels.

[0049] 7. Heat pump operation mode switching structure

[0050] The closed-loop circulating water pipeline is equipped with a three-way electric valve assembly and a bypass pipeline. By controlling the valve status, the following can be achieved:

[0051] Mode 1: Mechanical refrigeration / heating mode - In summer, groundwater is cooled by the heat exchanger and then enters the condenser to dissipate heat; in winter, groundwater is heated by the heat exchanger and then enters the evaporator to absorb heat.

[0052] Mode 2: Direct cooling from natural cold source – When the groundwater temperature meets the requirements, the compressor is turned off, and the groundwater cooling capacity is directly transferred to the building terminal through the heat exchanger, reducing operating energy consumption.

[0053] Mode 3: Battery thermal management priority mode - When the temperature of the energy storage battery rises, increase the flow rate in the battery branch to prioritize reducing the battery temperature.

[0054] 8. Intelligent control system and heat penetration early warning

[0055] The intelligent control system includes a battery management system, an energy management system, a heat pump controller, a communication module, and a data acquisition module. It collects real-time data on battery SOC, battery temperature, ambient temperature, groundwater temperature, retrieved water temperature difference, flow rate, and building load. Based on the collected data, it performs energy storage scheduling, lithium-sodium switching, cooling flow distribution, heat pump start / stop, and groundwater protection.

[0056] The system is electrically connected to the temperature sensor and circulating water pump of the wellhead monitoring device and is equipped with a thermal breakthrough early warning threshold. When the received temperature difference signal between water intake and reinjection meets the threshold, a frequency reduction or shutdown command is sent to the circulating water pump to protect the long-term heat exchange capacity of the groundwater.

[0057] The integrated control cabinet houses a battery management system, a wind-solar hybrid controller, and a heat pump controller, and is connected to the wellhead monitoring device via signal lines. The integrated control cabinet panel or internal components include a display unit and a communication module. The display unit can show in real-time the state of charge, voltage, temperature, intake water temperature, reinjection temperature, temperature difference, flow rate, cooling branch allocation ratio, and system operating mode of the lithium and sodium batteries.

[0058] 9. Porous diffuser and wellhead monitoring device

[0059] The groundwater intake and recharge pipeline includes an intake well, a recharge well, an intake pipe, and a recharge pipe. The wellheads of both the intake and recharge wells are equipped with identical wellhead monitoring devices, which include flanges, flow meters, and temperature sensors. A pre-filter for removing sand is installed on the intake pipe, and a porous diffuser is connected to the lower end of the recharge pipe. Multiple rows of through holes are evenly distributed on the sidewalls of the porous diffuser.

[0060] The porous diffuser is a cylindrical or irregularly shaped polygonal shell with an opening ratio of 25%–40% and a through-hole diameter of 3–8 mm. The bottom of the diffuser is closed or equipped with a one-way check valve. The diffuser and the reinjection pipe are detachably connected by threads, clamps, or flanges. The reinjection pipe adopts a segmented threaded connection pipe or a telescopic sleeve structure, allowing the burial depth of the porous diffuser to be adjusted on-site.

[0061] Furthermore, the porous diffuser is linked with the wellhead temperature sensor, and the intelligent control system can dynamically adjust the reinjection flow rate or the effective opening flow capacity according to the temperature difference between the reinjection temperature and the intake water temperature, forming a temperature feedback-type heat-resistant through-flow control, which significantly improves long-term operational stability.

[0062] The wellhead monitoring device is also equipped with a pressure sensor interface and a protective cover on its flange. A sealing ring is provided between the protective cover and the flange, and the overall protection level is not lower than IP68.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. This invention achieves deep coupling between stable underground heat and cold sources and energy storage thermal management, resulting in irreplaceable technological benefits. Unlike the traditional simple superposition of "photovoltaics + energy storage + heat pump + liquid cooling," this invention uses the same closed-loop circulating medium on the secondary side of a plate heat exchanger as a link, enabling the underground heat and cold source to simultaneously serve heat pump heat exchange and active battery thermal management, with priority control achieved through intelligent flow allocation. This structural coupling produces a comprehensive effect of reducing investment in additional battery cooling equipment, reducing system auxiliary energy consumption, and improving overall energy utilization efficiency—a technological contribution that cannot be directly obtained through conventional combinations in existing technologies.

[0065] 2. Improve the year-round environmental adaptability and electrical safety of energy storage batteries, and extend battery life. This invention adopts a structure in which lithium-ion batteries and sodium-ion batteries are connected to a common DC bus via independent bidirectional DC / DC converter modules. This avoids the risks of circulating current and SOC imbalance associated with direct parallel connection, and allows for dynamic switching based on ambient temperature, battery temperature, SOC, and building load requirements. Sodium batteries are prioritized at low temperatures, lithium batteries are prioritized for high energy density requirements, and both are used under high loads. Simultaneously, active temperature control of the batteries is achieved through a stable groundwater heating and cooling source, maintaining the battery operating temperature within a suitable range. This reduces high-temperature capacity decay, low-temperature performance degradation, and reduced consistency due to temperature unevenness, significantly improving cycle life and operational reliability.

[0066] 3. This invention addresses the thermal runaway problem in small-space groundwater source heat pump systems and introduces temperature feedback control to improve long-term operational stability. For scenarios such as rural residences and small buildings where the intake and reinjection wells are close together, this invention incorporates a porous diffuser at the end of the reinjection pipe. This transforms the reinjection water from a concentrated jet to a multi-directional, uniform diffusion, reducing local flow velocity and the concentration of the heat plume. Furthermore, by combining wellhead temperature monitoring and intelligent control, a temperature feedback-based anti-thermal runaway system is formed. This system can automatically adjust the flow rate or enter an intermittent mode when temperature differences are abnormal, significantly delaying the occurrence of thermal runaway and ensuring the long-term efficient operation of the groundwater source heat pump.

[0067] 4. Improved modularity for rapid installation and maintenance. This invention employs a modular mainframe, integrating the energy storage system, heat exchange system, heat pump main unit, and control system into a unified equipment unit. Each functional area is independently configured. The equipment can be prefabricated and installed in the factory. On-site deployment requires only groundwater interfaces, building hot and cold water interfaces, and electrical connections. It is particularly suitable for applications such as rural residences and distributed energy stations.

[0068] 5. Improved system safety and maintenance convenience. This invention employs an isolation structure between the primary groundwater side and the secondary closed-loop circulating water side, preventing silt, minerals, and corrosive ions from the groundwater from entering the equipment. The battery cooling channels, heat exchange equipment, and valve components all utilize modular installation, facilitating maintenance, replacement, and capacity expansion.

[0069] 6. Achieve multi-energy coordinated control and improve the capacity for renewable energy absorption. This invention unifies the scheduling of photovoltaic energy, wind energy, energy storage batteries, building heating and cooling loads, and groundwater heating and cooling resources. During periods of sufficient sunlight, photovoltaic power is prioritized to drive heat pumps, with surplus electricity stored. At night or during cloudy / rainy weather, the energy storage system replenishes energy. During transitional seasons, the natural temperature of groundwater is used for direct cooling or heating. This increases the proportion of renewable energy utilization and reduces the consumption of traditional energy sources.

[0070] 7. Achieving comprehensive technical effects distinct from existing technologies. Because this invention does not simply combine photovoltaic, energy storage, and heat pump systems, but rather forms an interconnected system structure through groundwater heat exchange loops, a single closed-loop circulating medium, battery liquid cooling thermal management, independent lithium-sodium DC / DC connection and dynamic switching, and a temperature feedback diffusion reinjection structure, it achieves comprehensive technical effects such as reduced energy consumption for energy storage thermal management, improved heat pump operational stability, extended battery life, reduced risks of groundwater thermal penetration, and enhanced applicability of distributed energy systems, demonstrating high inventiveness. Attached Figure Description

[0071] To more clearly illustrate the embodiments of the present invention, the structure of the present invention will be described below with reference to the accompanying drawings.

[0072] Figure 1 This is a schematic diagram of the overall system connection according to an embodiment of the present invention;

[0073] Figure 2 This is a schematic diagram of the internal layout of the modular host frame according to an embodiment of the present invention;

[0074] Figure 3 This is a schematic diagram of the lithium-sodium battery energy storage unit and cooling water channel structure according to an embodiment of the present invention;

[0075] Figure 4 This is a partial structural diagram of the plate heat exchanger and three-way electric valve assembly according to an embodiment of the present invention;

[0076] Figure 5 This is a schematic diagram of the porous diffuser structure according to an embodiment of the present invention;

[0077] Figure 6 This is a schematic diagram of the wellhead monitoring device according to an embodiment of the present invention;

[0078] Figure 7This is a schematic diagram of the battery thermal management circuit connection according to an embodiment of the present invention.

[0079] Explanation of reference numerals in the attached figures:

[0080] Figure 1 The system consists of: 1-Photovoltaic module array, 2-Small wind turbine, 3-Exhaust and pressure relief riser, 4-Energy storage inverter, 5-Lithium-sodium energy storage battery cabinet, 6-Water source heat pump main unit cabinet, 7-Wellhead valve assembly, 8-User-side air conditioning supply and return water inlets, 9-Intake well and reinjection well, 10-Porous diffuser. The overall system structure and external connections are as follows: The central part is a modular main unit frame; the left side connects to the wind-solar hybrid power generation unit; the right side connects to the groundwater intake well and reinjection well via pipelines; and the lower or side part connects to the indoor terminal air conditioning equipment. Power flow: Wind and solar power generation → Lithium-sodium battery energy storage → Heat pump main unit; Water flow: Groundwater → Lithium-sodium battery pack and plate heat exchanger → Reinjection.

[0081] Figure 2 The modular main unit frame consists of: 1-Integrated control cabinet, 2-Water source heat pump main unit module, 3-Axial flow cooling fan, 4-Circulating water pump set and plate heat exchanger, 5-Lithium-sodium energy storage battery pack. The internal space of the modular main unit frame is divided into four functional compartments by partitions: the left side is the energy storage compartment, housing the lithium-sodium battery energy storage unit; the middle section is the heat exchange compartment, housing the plate heat exchanger and closed-loop cooling water circulation pump; the right side is the main unit compartment, housing the water source heat pump main unit; and the top or front section is the control compartment, housing the integrated control cabinet.

[0082] Figure 3 Components: 1-Battery housing cover, 2-Cell module (lithium battery module and sodium battery module are connected via independent DC / DC converters), 3-Electrode terminals, 4-Cooling water pipe interface, 5-Battery unit outer frame. Structural layout and thermal management of the lithium-sodium hybrid battery: Lithium-ion battery packs and sodium-ion battery packs are installed side-by-side or in layers within the battery housing, both connected to a common DC bus via independent bidirectional DC / DC converter modules. The bottom and side walls of the battery housing are equipped with serpentine or parallel cooling water channels. The inlet and outlet of the cooling water channels are led out via quick-connect fittings for connection to the closed-loop cooling water circuit on the secondary side of the plate heat exchanger.

[0083] Figure 4 Components: 1-Plate heat exchanger frame, 2-Groundwater pre-sand filter, 3-Heat exchange plate assembly, 4-Secondary side outlet pipe, 5-Closed-loop cooling water circulation pump, 6-Bypass regulating valve assembly (three-way electric valve assembly). Connection relationship between the primary and secondary sides of the plate heat exchanger: The primary side (groundwater side) inlet and outlet pipes connect to the water intake pipe and the reinjection pipe; the secondary side (cooling water side) inlet and outlet pipes connect to the heat exchange end of the water source heat pump unit (condenser side in summer, evaporator side in winter); the secondary side pipeline is equipped with a three-way electric valve assembly and a bypass pipeline, which can realize the conversion between mechanical refrigeration / heating mode and direct cooling mode from natural cold source.

[0084] Figure 5 Components: 1-Reinjection water supply bend, 2-Porous diffuser shell, 3-Radial water distribution holes, 4-Bottom sealing plate. The porous diffuser is installed at the lower end of the reinjection pipe. The diffuser is a cylindrical shell with multiple rows of evenly spaced holes (open area ratio 25%–40%) on its sidewalls. The bottom is closed or has a unidirectional structure. Reinjection water diffuses into the aquifer at a low flow rate through the small holes in the sidewalls in multiple directions, thereby reducing the local water flow velocity and temperature gradient, and mitigating thermal penetration. This component, combined with temperature feedback control, forms an intelligent anti-thermal penetration reinjection system.

[0085] Figure 6 Components: 1-Flow detection probe, 2-Temperature sensor, 3-Wellhead flange, 4-Well pipe, 5-Protective top cover, 6-Flow transmitter module, 7-Signal cable. Monitoring device for intake and reinjection wellheads: The main body is a flange, fixed to the top of the well pipe; a flow meter and temperature sensor are installed on the flange for real-time monitoring of intake / reinjection flow and temperature; the top is equipped with an openable protective cover with a protection level of not less than IP68; the signal cable is led out from the device and connected to the integrated control cabinet. Intake and reinjection wells use the same wellhead monitoring device for standardized production and interchangeability.

[0086] Figure 7 In the diagram: 1-Plate heat exchanger, 2-Heat pump heat exchange end branch (summer condenser, winter evaporator), 3-Battery energy storage box, 4-Battery cell cooling channel, 5-Battery cooling circulation pump or diverter valve. The connection between the closed-loop cooling water circuit on the secondary side of the plate heat exchanger and the battery cooling water channel: Part of the cooling water from the secondary side outlet of the plate heat exchanger is supplied to the heat exchange end of the water source heat pump host, and the other part enters the cooling water channel of the battery box through branch pipes, actively cooling the lithium battery pack and sodium-ion battery pack before returning. This forms a structure of underground water cooling heat source → closed-loop circulating water → heat pump + battery dual-load utilization → recycling, and priority control is achieved through intelligent flow distribution. This is the core technical structure that distinguishes this invention from traditional energy storage systems and traditional heat pump systems. Detailed Implementation

[0087] The following is in conjunction with the appendix Figures 1-7 The present invention will be further described in detail below:

[0088] It should be noted that the following embodiments are only used to illustrate the technical solutions of the present invention and do not limit the scope of protection of the present invention. Without changing the core technical concept of the present invention, those skilled in the art can adjust the device size, capacity parameters and connection form according to the actual application scenario.

[0089] 1. Overall System Composition

[0090] Reference Figure 1The wind-solar hybrid power generation unit includes a photovoltaic module array 1 and at least one small wind turbine 2, located outdoors in a location with good sunlight and ventilation. The photovoltaic module array 1 uses the photoelectric effect to convert solar energy into direct current (DC), and the small wind turbine 2 uses wind energy to convert it into DC. The two DC outputs are combined by anti-reverse current diodes and connected to the DC input terminal of the energy storage inverter 4. The energy storage inverter 4 converts the DC power into industrial frequency AC power, which supplies power to the water source heat pump main unit cabinet 6 and auxiliary loads such as circulating pumps and control valves. It also connects to the lithium-sodium energy storage battery cabinet 5 (via an independent DC / DC module) to realize the storage and scheduling of electrical energy. Excess energy is charged into the battery, and the battery discharges to replenish energy when the battery is low.

[0091] The water source heat pump main unit cabinet 6 is a modular integrated cabinet, internally integrating a plate heat exchanger, the water source heat pump main unit, a circulating pump set, and control valves. One side of the cabinet connects to the intake well and the reinjection well 9 via pipelines. Groundwater is drawn by a submersible pump and enters the main unit cabinet for heat exchange, then is transported through the reinjection pipeline to the porous diffuser 10 in the well for uniform reinfiltration into the aquifer. The other side of the cabinet connects to indoor fan coil units, underfloor heating, and other air conditioning terminals via the user-side air conditioning supply and return water inlets 8, delivering cooling or heating to the room. An exhaust and pressure relief riser 3 is located at the highest point of the groundwater circuit to expel accumulated air from the pipeline, ensuring stable water circulation. A wellhead valve assembly 7 is located at the wellhead, integrating a shut-off valve, a check valve, and monitoring elements for controlling the on / off state of individual wells and collecting operating parameters.

[0092] 2. Modular host frame internal layout

[0093] Reference Figure 2 The modular main frame is constructed from hot-dip galvanized steel or welded aluminum alloy profiles. Internally, it is divided into four functional compartments by galvanized steel plate partitions. Each unit is fixedly installed in its own compartment, resulting in a compact layout and independent maintenance. The left side of the frame houses the energy storage compartment, which contains a fixed lithium-sodium energy storage battery pack 5 (including an independent DC / DC module) for storing wind and solar energy and discharging to supply power during power outages. The middle section of the frame is the heat exchange compartment, housing a circulating water pump set and a plate heat exchanger 4, serving as the core area for indirect heat exchange between groundwater and closed-loop cooling water. The right side of the frame is the main unit compartment, where a fixed water source heat pump main unit module 2 is installed, along with an axial flow cooling fan 3 for auxiliary cooling of the main unit's electrical components. The top of the frame houses the control compartment, containing an integrated control cabinet 1. This cabinet integrates a battery management system, a wind-solar hybrid controller, a heat pump controller, and a communication module, enabling automated control of the entire system.

[0094] The frame is equipped with multiple hoisting holes and rubber / spring shock-absorbing supports at the bottom. Standardized quick interfaces for underground water pipes, terminal air conditioning water pipe interfaces, cable threading holes and grounding terminals are reserved on the sides and ends for easy on-site connection. Openable maintenance doors or covers are provided on the outside of the frame for each compartment to facilitate battery replacement, heat exchanger cleaning and equipment maintenance.

[0095] 3. Structure of Lithium-Sodium Battery Energy Storage Unit

[0096] Reference Figure 3 The lithium-sodium battery energy storage unit uses the outer frame 5 of the battery cell as the supporting base, and internally installs lithium battery modules and sodium battery modules 2 side by side or in layers. The two types of cells are connected to a common DC bus through independent bidirectional DC / DC conversion modules. The battery management system realizes independent or proportional switching according to the real-time state of charge, cell temperature and end load requirements. The top of the battery box is equipped with a cover 1, and electrode terminals 3 are led out from the cover for external electrical connection.

[0097] The battery casing has built-in cooling water channels at the bottom and side walls, which can adopt a serpentine flow channel, parallel multi-channel, or harmonica tube structure. Cooling water pipe interfaces 4 are led out from both ends of the water channels, which are connected to the closed cooling water loop on the secondary side of the plate heat exchanger through quick-connect couplings or flanges to form an active thermal management loop for the battery. Thermally conductive silicone pads or phase change material layers are filled between the cooling water channels and the cell modules to enhance heat transfer and ensure temperature uniformity between the cells.

[0098] 4. Plate heat exchanger and three-way valve assembly structure

[0099] Reference Figure 4 The plate heat exchanger is supported by a frame 1, and internally contains multiple detachable metal heat exchange plates 3. The plates are made of 316L stainless steel or titanium alloy. The plates are separated by sealing strips, forming two completely independent sealed flow channels, one for groundwater and the other for closed-loop cooling water. Heat is transferred solely through the metal plates, achieving indirect heat exchange with water and soil isolation. The primary and secondary flow channels are arranged in counter-current or cross-flow to improve heat exchange efficiency.

[0100] A pre-filter 2 is installed on the primary side groundwater inlet pipe to filter sand and impurities in the groundwater, preventing blockage of the plate flow channels. A closed-loop cooling water circulation pump 5 is installed on the secondary side return water pipe to provide circulation power for the closed loop. A bypass regulating valve assembly 6 and a bypass pipe are integrated into a three-way electric valve assembly. By adjusting the valve core opening, the flow path of the closed-loop cooling water can be switched: the main path flows through the heat exchange end of the water source heat pump unit (condenser side in summer, evaporator side in winter), corresponding to mechanical refrigeration / heating mode; the bypass path bypasses the heat pump unit, corresponding to direct cooling / heating mode from the natural cold source during the transition season. The secondary side outlet pipe 4 delivers the cooled water after heat exchange to the heat pump unit or the terminal loop. The valve assembly is integrated and installed in the valve box on one side of the plate heat exchanger, with a compact structure suitable for modular compartment layouts.

[0101] 5. Porous diffuser structure

[0102] Reference Figure 5The porous diffuser is connected to the lower end of the reinjection pipe and lowered into the aquifer section of the reinjection well. Its core function is to slow down thermal penetration between the pumping and injection wells. Its main body is a cylindrical porous diffuser shell 2, which can also be an irregular polygonal prism shape depending on the well structure. The top is connected to the reinjection water delivery bend 1, which connects to the surface reinjection pipeline. A detachable connection can be achieved using threads, clamps, or flanges. Multiple rows of radial water distribution holes 3 are evenly distributed on the sidewalls of the shell, with an opening rate controlled at 25%–40% and a single hole diameter of 3–8 mm. A bottom sealing plate 4 is installed at the bottom of the shell, forming a closed structure at the lower end. A one-way check structure can also be installed as needed to prevent sand inrush.

[0103] After the reinjection water enters the diffuser cavity through the top bend, it is blocked by the bottom sealing plate and cannot flow straight downwards. Instead, it is forced to diffuse evenly in all directions (360°) through the radial water distribution holes on the sidewall, slowly seeping into the aquifer at a low flow rate. This structure significantly expands the seepage area, reduces the local seepage velocity and temperature gradient, and avoids the formation of a directional hot plume from concentrated water outflow, thus significantly delaying thermal penetration. Furthermore, combined with wellhead temperature monitoring and intelligent control, the reinjection flow rate or effective orifice flow capacity can be dynamically adjusted to form a temperature feedback-based anti-thermal penetration control system. The reinjection pipe can adopt a segmented threaded connection pipe or a telescopic sleeve structure, and the burial depth of the porous diffuser can be flexibly adjusted on-site to adapt to the aquifer thickness.

[0104] 6. Wellhead Monitoring Device Structure

[0105] Reference Figure 6 Both the intake and reinjection wells are equipped with identical wellhead monitoring devices to facilitate standardized production and on-site interchangeability. The device uses the wellhead flange 3 as its base and is bolted to the top of the well pipe 4, matching the PN10 / PN16 flange standard. A sealing ring is installed at the joint between the flange and the well pipe.

[0106] The flange integrates a flow detection probe 1 and a temperature sensor 2 to collect real-time data on the instantaneous flow rate, cumulative flow rate, and water temperature of the water in the well. A flow transmitter module 6 is also included to convert the physical flow signal into a standard electrical signal. A pressure sensor interface is provided on the flange, allowing for expansion of pressure monitoring functionality as needed. An openable protective cover 5 is installed on the top of the device, with a sealing ring between the cover and the flange. The overall protection level is no less than IP68, suitable for outdoor use and preventing rainwater and dust from damaging the sensing elements. A signal cable 7 is sealed and led out from the side of the device, transmitting the flow and temperature monitoring signals to the ground-based integrated control cabinet for remote data acquisition and operational management.

[0107] Battery thermal management circuit working principle

[0108] Reference Figure 7The battery active thermal management loop is constructed based on the closed-loop cooling water on the secondary side of the plate heat exchanger 1, realizing the dual use and intelligent distribution of underground cold and heat sources. The low-temperature (or suitable temperature) cooling water at the secondary side outlet of the plate heat exchanger is divided into two paths: one path flows into the water source heat pump host through the heat pump heat exchange end branch 2 (in summer, the condenser side removes condensation heat, and in winter, the evaporator side provides a heat source); the other path branches into the battery energy storage box 3, flows through the cell cooling channel 4, absorbs the Joule heat and reaction heat generated by the charging and discharging of lithium and sodium batteries, and maintains the battery operating temperature within the suitable range of 10–45℃.

[0109] An independent battery cooling circulation pump 5 can be installed in the loop, or the main loop closed-loop cooling water circulation pump can be used for water supply. A temperature sensor and electric regulating valve are also included, allowing the control system to adjust the cooling water flow distribution ratio in real time based on the battery's highest temperature, heat pump load, and groundwater temperature difference, achieving precise temperature control and priority control. The cooled water, after absorbing heat and heating up, flows back to the secondary inlet of the plate heat exchanger, where it is recooled (or reheated) by the primary side groundwater, completing the closed-loop cycle. This design reuses the natural heat source of groundwater, eliminating the need for separate cooling equipment for the battery, thus reducing system complexity and operating energy consumption.

[0110] Example 1 (Complete application example for a 200-square-meter self-built rural house)

[0111] This example uses a two-story self-built house in a rural area with a building area of ​​approximately 200 square meters as the subject.

[0112] The modular main frame has external dimensions of 2200mm (length) × 1200mm (width) × 1800mm (height), with main load-bearing pipes measuring 80×80×4mm. The bottom is equipped with four M20 hoisting holes and rubber shock-absorbing pads.

[0113] The lithium-sodium battery energy storage unit is configured as follows: a 51.2V / 200Ah lithium iron phosphate battery pack (approximately 10.24kWh) + a 51.2V / 150Ah sodium battery pack (approximately 7.7kWh), each connected to a common DC bus via an independent bidirectional DC / DC converter module, achieving safe isolation and dynamic switching. The battery enclosure cooling water channel is designed with a flow rate of 0.8–1.5 m³ / h.

[0114] The water source heat pump unit has a nominal cooling capacity of 18kW and a heating capacity of 20kW. The plate heat exchanger has a heat exchange area of ​​4.5m², and the plates are made of 316L stainless steel. The closed-loop cooling water circulation pump has a rated flow rate of 3.5m³ / h.

[0115] The intake and reinjection wells are 60m deep and 22m apart. The porous diffuser is 110mm in diameter and 1500mm in length, made of 304 stainless steel, with an opening rate of approximately 33%. The wellhead monitoring device has an IP67 protection rating.

[0116] The photovoltaic system has a capacity of 10kWp, and the small wind turbine has a capacity of 3kW. The total transport weight is approximately 980kg, and two workers can complete the main on-site installation and commissioning within one day.

[0117] Operating mode description: During the summer daytime, photovoltaic power is used to drive the heat pump first, and excess electricity is stored in the lithium-sodium battery. The closed cooling water simultaneously cools the battery (prioritizing battery temperature); at night or on cloudy days, the sodium battery discharges first (good low-temperature performance), and the lithium battery is used as a supplement; during the transition season, the three-way valve is switched to bypass, and natural cold source is used for direct cooling; when the temperature difference between water intake and reinjection is abnormal for 2 consecutive hours, the system will automatically prompt to enter intermittent operation mode or reduce the load to protect the long-term heat exchange capacity of groundwater.

[0118] Example 2: Application of Industrial and Commercial Micro Energy Stations This embodiment is applicable to small factories, agricultural greenhouses, and commercial buildings. System configuration: 50-200kW photovoltaic system, 100-500kWh energy storage (lithium and sodium connected via independent DC / DC converters), 30-100kW heat pump, and a multi-well groundwater circulation system. Compared to traditional photovoltaic + energy storage + air conditioning systems, this embodiment simultaneously handles building heating and cooling supply and battery thermal management through a closed-loop groundwater heat exchange system, achieving intelligent flow distribution and reducing the need for additional liquid cooling equipment.

[0119] Example 3: Independent Energy Application in Areas Without Power Grid In remote areas, an independent energy system is formed by photovoltaics, wind turbines, lithium-sodium energy storage (independent DC / DC), and groundwater heat pumps. During the day, renewable energy supplies power the system, while at night, energy storage provides power. Groundwater provides a stable source of heat and cold throughout the year, and battery thermal management is achieved through a single closed-loop circulation medium, thus enhancing energy self-sufficiency.

[0120] To facilitate implementation and ensure long-term reliability, the following key material and parameter ranges are recommended:

[0121] Modular host framework Hot-dip galvanized rectangular steel pipe + galvanized steel sheet Main load-bearing pipe ≥ 80×80×4mm Corrosion protection life ≥ 15 years lithium battery pack <![CDATA[Lithium iron phosphate (LiFePO4)]]> 51.2V, 8–15kWh per unit Cycle life ≥ 4000 cycles Sodium battery pack Layered oxides or polyanionic types Around 51.2V, 5-10kWh per unit Focus on improving low-temperature performance Bidirectional DC / DC Isolated bidirectional DC / DC module Matching battery voltage with bus voltage Electrical isolation key Battery cooling water channel 6063 / 6061 aluminum alloy or 316L stainless steel Wall thickness 1.5–2.5 mm, pressure ≥0.6 MPa Preferred aluminum alloy Thermal interface materials High thermal conductivity silicone pads or phase change materials Thermal conductivity ≥ 3.0 W / (m·K) Thickness 1–2mm Plate heat exchanger plates 316L stainless steel or titanium alloy Plate thickness 0.4–0.6 mm, pressure 1.6 MPa Use titanium plates when the water quality is poor. Closed cooling water pipes PPR (S3.2) or thin-walled stainless steel Nominal pressure ≥1.6MPa PPR can be used indoors. Porous diffuser 304 or 316L stainless steel Aperture ratio 25%–40%, aperture diameter 3–8 mm Carbon steel is strictly prohibited. Wellhead monitoring flange 304 stainless steel Matching PN10 / PN16 flange standards With sealing groove Flow meter Turbine type or stainless steel electromagnetic type Accuracy ≤±1%, IP68 or above Adapt to groundwater quality Temperature sensor PT100 or NTC Accuracy ≤ ±0.3℃, IP67 Insert type with protective sleeve quick connector Stainless steel or nickel-plated brass quick connectors With anti-return function Easy to maintain shock-absorbing pads Nitrile rubber or spring shock absorbers Single unit can carry ≥200kg Reduce noise

[0122] Material selection principles: Components that come into direct or indirect contact with groundwater should preferably be made of 316L stainless steel or titanium to prevent corrosion; battery-related structures should be made as lightweight as possible while meeting strength requirements; all seals are recommended to be made of EPDM or fluororubber to withstand water temperature changes and long-term immersion; bidirectional DC / DC modules must have high efficiency and electrical isolation functions.

[0123] The above embodiments and material recommendations are merely preferred implementations of the present invention. Any equivalent structural modifications made based on the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A modular photovoltaic or wind-solar hybrid lithium-sodium battery energy storage groundwater indirect cooling heat pump air conditioning device, characterized in that, It includes a modular main frame, a photovoltaic or wind-solar hybrid power generation unit, a lithium-sodium hybrid energy storage unit, a groundwater indirect heat exchange unit, a battery active thermal management unit, and an intelligent control system. The modular main frame is internally equipped with an independent and maintainable energy storage compartment, heat exchange compartment, heat pump main unit compartment and control compartment. The lithium-sodium hybrid energy storage unit is installed in the energy storage compartment and includes a lithium-ion battery pack, a sodium-ion battery pack, a battery housing, a battery management system, and a group switching control device. The lithium-ion battery pack and the sodium-ion battery pack are respectively connected to a common DC bus through independent bidirectional DC / DC conversion modules to achieve electrical isolation and bidirectional energy flow. The groundwater indirect heat exchange unit includes a groundwater intake well, a groundwater reinjection well, a plate heat exchanger, a closed-loop cooling water pipeline, and a water source heat pump unit. The groundwater exchanges heat through the primary side channel of the plate heat exchanger, and the closed-loop cooling water obtains a stable underground cold and heat source through the secondary side channel of the plate heat exchanger. The closed-loop cooling water circuit formed on the secondary side of the plate heat exchanger is simultaneously connected to the heat exchange end of the water source heat pump host and the battery cooling channel of the lithium-sodium hybrid energy storage unit, so that the same closed-loop medium can be used as both the heat exchange medium of the heat pump system and the battery liquid cooling medium. The battery box is equipped with a liquid cooling heat exchange structure inside or outside, and the liquid cooling heat exchange structure is connected to the secondary side closed-loop cooling water circuit of the plate heat exchanger through a circulation pipeline. The closed-loop cooling water circuit is equipped with a regulating valve group. The intelligent control system is electrically connected to the lithium-sodium hybrid energy storage unit, the groundwater indirect heat exchange unit and the water source heat pump host respectively. By collecting battery temperature, heat pump load and return water temperature difference signals, the regulating valve group is controlled to distribute the flow between the heat pump branch and the battery cooling branch.

2. The apparatus according to claim 1, characterized in that: The modular main frame is made of steel or aluminum alloy profiles. The interior is divided into energy storage compartment, heat exchange compartment, main unit compartment and control compartment by partitions. Each functional unit is fixedly installed in the factory by prefabrication and can be quickly connected on site through standardized interfaces. The bottom of the frame is equipped with hoisting holes and shock-absorbing supports, and the exterior is equipped with maintenance doors, standardized water pipe interfaces, cable interfaces and grounding interfaces.

3. The apparatus according to claim 1, characterized in that: The group switching control device is communicatively connected to the ambient temperature sensor, the bidirectional DC / DC converter module of the lithium-ion battery pack, and the bidirectional DC / DC converter module of the sodium-ion battery pack, respectively. The intelligent control system has a built-in switching module, which is used to trigger the DC / DC module of the sodium-ion battery pack to conduct when a low temperature signal is received, and to trigger both groups of DC / DC modules to conduct simultaneously to supply power to the common DC bus when a high load signal is received.

4. The apparatus according to claim 1, characterized in that: The battery housing is provided with one or more liquid cooling structures, such as serpentine flow channels, parallel multi-flow channels, and harmonica tube flow channels. A thermally conductive silicone layer, thermally conductive pad, or phase change material layer is provided between the liquid cooling flow channels and the battery cell modules to improve the temperature uniformity between the battery cells.

5. The apparatus according to claim 1, characterized in that: A porous diffuser is installed at the lower end of the groundwater recharge well. The porous diffuser includes a shell, radial water distribution holes, and a bottom closed structure. After passing through the porous diffuser, the groundwater diffuses evenly into the aquifer in a circumferential direction. The porous diffuser is linked to the wellhead temperature sensor. The intelligent control system controls the recharge flow rate or the effective opening flow capacity by adjusting valves or pumps based on the difference between the recharge temperature and the intake temperature signal.

6. The apparatus according to claim 5, characterized in that: The porous diffuser adopts a cylindrical, polygonal, or combined structure, with multiple rows of radial through holes on the side wall. The diameter of the through holes is 3-8 mm, and the opening rate is 25%-40%. The recharge pipe adopts a segmented threaded connection pipe or a telescopic sleeve structure, so that the burial depth of the porous diffuser can be adjusted on site.

7. The apparatus according to claim 1, characterized in that: Both the intake well and the reinjection well are equipped with standardized wellhead monitoring devices. The wellhead monitoring devices include a flange connection structure, a flow detection module, a temperature detection module, and a pressure detection interface. The protection level is not lower than IP65. They are used to monitor the groundwater operation status in real time and transmit the signals to the intelligent control system.

8. The apparatus according to claim 1, characterized in that: The plate heat exchanger adopts a detachable plate structure, and the plate material is 316L stainless steel or titanium alloy. The primary side underground water flow channel and the secondary side closed circulating water flow channel are isolated from each other. Heat exchange is completed through metal plates. The primary side and secondary side flow channels are arranged in counter-current or cross-flow.

9. The apparatus according to claim 1, characterized in that: The closed-loop cooling water circuit is equipped with a three-way electric valve group and a bypass pipeline. The valve group is controlled to switch between mechanical refrigeration mode, direct cooling mode from natural cold source, and battery thermal management priority mode.

10. The apparatus according to claim 1, characterized in that: The photovoltaic or wind-solar hybrid power generation unit includes a photovoltaic module array and at least one small wind turbine. The generated electricity is connected to the energy storage inverter after being controlled to prevent backflow, and then supplied to the heat pump host, circulating pump, electrical control equipment and lithium-sodium hybrid energy storage unit via a common DC bus.

11. The apparatus according to claim 1, characterized in that: The intelligent control system is electrically connected to the battery voltage / current / temperature sensor, the temperature sensor and flow sensor of the wellhead monitoring device, and the heat pump load sensor, respectively. After collecting the above signals, it outputs control commands to the regulating valve group, the circulating water pump, and the group switching control device.

12. The apparatus according to claim 1, characterized in that: The modular main frame is equipped with maintenance doors, hoisting holes, shock-absorbing supports, and standardized water pipe interfaces, cable interfaces, and grounding interfaces, enabling the entire device to be transported and installed quickly in prefabricated modular form.

13. The apparatus according to claim 4, characterized in that, The battery active thermal management circuit is equipped with an independent closed-loop cooling water circulation pump or a main circuit diversion structure, and is equipped with a temperature sensor and an electric regulating valve to precisely control the water flow rate entering the battery cooling water channel.

14. The apparatus according to claim 1, characterized in that: The intelligent control system is electrically connected to the temperature sensor and circulating water pump of the wellhead monitoring device. The intelligent control system is equipped with a thermal penetration early warning threshold. When the received water intake and reinjection temperature difference signal meets the threshold, it outputs a frequency reduction or shutdown command to the circulating water pump.

15. The apparatus according to claim 7, characterized in that, The wellhead monitoring device is also equipped with a pressure sensor interface and a protective cover on its flange, and a sealing ring is provided between the protective cover and the flange.

16. The apparatus according to claim 1, characterized in that, The integrated control cabinet panel or interior is equipped with a display unit and a communication module. The display unit can display the state of charge, voltage, temperature, water intake temperature, recharge temperature, temperature difference, flow rate, cooling branch allocation ratio, and system operation mode of the lithium battery and sodium battery in real time.

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