Heat dissipation system for water-based energy storage battery pack and water-based energy storage system

Abstract

This invention discloses a heat dissipation system and an underwater energy storage system for a floating battery pack. The system includes a cold plate, a circulating pump, an underwater heat exchanger, connecting pipes, a temperature detection unit, and a control unit. The cold plate is attached and fixed to the surface of the battery pack. The cold plate, the circulating pump, and the underwater heat exchanger are sequentially connected through pipes to form a closed cooling medium circulation loop. The underwater heat exchanger is submerged in external water. The temperature detection unit collects the battery pack temperature signal, and the control unit controls the start and stop of the circulating pump accordingly. This invention eliminates the need for traditional liquid cooling units, solving the problems of large size, cumbersome installation, and high maintenance costs associated with liquid cooling. It utilizes the natural cooling source of water in conjunction with a temperature-controlled circulating pump to replace air-cooled fans, overcoming the shortcomings of air cooling, such as susceptibility to environmental influences, heat accumulation, high energy consumption, and insufficient reliability. It is suitable for floating distributed energy storage scenarios and can effectively ensure the long-term stable operation of the battery pack.

Description

Technical Field

[0001] This invention belongs to the field of thermal management technology for energy storage batteries, specifically relating to a heat dissipation system for an underwater energy storage battery pack and an underwater energy storage system. Background Technology

[0002] The energy storage system supporting the floating photovoltaic power station is the core support for smoothing the power station's output fluctuations and improving power generation revenue. Due to the objective limitations of water space, it is difficult to deploy centralized large-scale energy storage equipment. Therefore, the distributed column-mounted energy storage solution has become the mainstream. Specifically, it involves deploying lithium iron phosphate battery clusters or battery packs in a distributed manner on the water surface or mounted on photovoltaic support columns.

[0003] In this distributed installation mode, the heat dissipation effect of the battery pack directly determines the operational stability of the entire energy storage system. Currently, the mainstream heat dissipation methods for lithium iron phosphate energy storage systems are divided into two categories: air cooling and traditional liquid cooling. Air cooling relies on forced ventilation by fans to dissipate heat, and its heat dissipation efficiency is significantly affected by ambient wind speed and temperature. Heat accumulation is likely to occur under high temperature and no wind conditions, and the operation of the fan consumes additional energy, resulting in insufficient reliability. Traditional liquid cooling requires the configuration of a complete liquid cooling unit with complex piping. Not only is the equipment large in size and cumbersome to install, but it also has prominent drawbacks such as high energy consumption and high maintenance costs. Summary of the Invention

[0004] The purpose of this invention is to provide a heat dissipation system and an aquatic energy storage system for aquatic energy storage battery pack, in order to solve the technical defects of existing aquatic distributed energy storage battery packs, such as air cooling efficiency being greatly affected by the environment, additional energy consumption and insufficient reliability, and traditional liquid cooling equipment being large in size, cumbersome to install, high in energy consumption and high in maintenance cost.

[0005] To achieve the above objectives, the present invention employs the following technical solutions.

[0006] In a first aspect, this application provides a heat dissipation system for an underwater energy storage battery pack, comprising: At least one cold plate is attached and fixed to the surface of the energy storage battery pack; Circulating pump; Submersible heat exchangers are installed submerged in external water bodies. The cold plate, circulating pump and underwater heat exchanger are connected in sequence through connecting pipes to form a closed cooling medium circulation loop. The temperature detection unit is fixedly installed on the energy storage battery pack and is used to collect and output the temperature signal of the battery pack in real time. The control unit is electrically connected to the temperature detection unit and the circulating pump, respectively, and is used to control the start and stop of the circulating pump according to the temperature signal output by the temperature detection unit.

[0007] In one optional embodiment, the circulating pump is a miniature DC brushless circulating pump; The power supply terminal of the micro DC brushless circulating pump is electrically connected to the power output terminal of the photovoltaic module. Alternatively, the power supply terminal of the micro DC brushless circulating pump is electrically connected to the power output terminal of the energy storage battery pack.

[0008] In one optional embodiment, the control unit is configured to receive a temperature signal output by the temperature detection unit, and control the circulation pump to start when the temperature signal is higher than a first preset threshold, and control the circulation pump to stop running when the temperature signal is lower than a second preset threshold.

[0009] In an optional embodiment, the control unit is further configured to: When the battery pack temperature detected by the temperature detection unit is between the first preset threshold and the second preset threshold, the current operating state of the circulation pump is maintained unchanged.

[0010] In one optional embodiment, a thermally conductive interface material is sandwiched between the cold plate and the bonding surface of the energy storage battery pack, the thermally conductive interface material being used to reduce the contact thermal resistance between the cold plate and the energy storage battery pack.

[0011] In one alternative embodiment, the underwater heat exchanger is a finned tube heat exchanger made of copper alloy or stainless steel.

[0012] In one optional embodiment, multiple cold plates are provided, and the multiple cold plates are attached to multiple energy storage battery packs in a one-to-one correspondence. The liquid inlets of each cold plate are connected in parallel to the liquid outlet of the circulating pump, and the liquid outlets of each cold plate are connected in parallel to the liquid inlet of the underwater heat exchanger, forming a parallel cooling circulation loop.

[0013] In one alternative embodiment, the cooling medium is one or a mixture of heat transfer oil, water, and ethylene glycol.

[0014] In one optional embodiment, the first preset threshold is 35℃~45℃, and the second preset threshold is 15℃~25℃.

[0015] A second aspect of this application provides a floating energy storage system, comprising: Energy storage battery packs, photovoltaic modules, and the heat dissipation system for floating energy storage battery packs as described above; The energy storage battery pack includes at least one energy storage battery pack; The cooling plate of the heat dissipation system is attached and fixed to the surface of each energy storage battery pack; The power output terminal of the photovoltaic module is electrically connected to the charging terminal of the energy storage battery pack, the control unit of the heat dissipation system, and the power supply terminal of the circulation pump, respectively, for charging the energy storage battery pack. The underwater heat exchanger of the heat dissipation system is submerged in external water. Its inlet and outlet are connected to the circulating pump and the cold plate respectively through connecting pipes to form a closed heat dissipation cycle. The control unit of the heat dissipation system is electrically connected to the temperature detection unit and the circulation pump. Based on the battery pack temperature signal collected by the temperature detection unit, the control unit controls the start-up, shutdown and operation status of the circulation pump. The energy storage battery pack's power output terminal is electrically connected to the control unit and circulation pump of the heat dissipation system, used to store the electrical energy generated by the photovoltaic module and provide backup power to the heat dissipation system when the photovoltaic module's power supply is abnormal.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By constructing a closed cooling medium circulation loop through a cold plate, circulating pump, underwater heat exchanger, and connecting pipelines, the traditional liquid cooling unit is eliminated, effectively solving the technical problems of large size, complicated installation, and high maintenance cost of traditional liquid cooling systems. The underwater heat exchanger, submerged in water, fully utilizes natural cold sources for heat dissipation. Combined with a temperature detection unit and control unit, the circulating pump can be started and stopped on demand, replacing the traditional air-cooled fan. This solves the defects of air-cooled heat dissipation, such as significant influence from the environment, easy heat accumulation, high energy consumption, and insufficient reliability. The system has efficient and stable heat dissipation, is not limited by environmental wind speed and temperature, and has a simple overall structure, making it suitable for floating distributed energy storage installation scenarios. The circulating pump operates on demand, which can reduce energy consumption, extend service life, reduce maintenance frequency, and effectively ensure the long-term stable operation of the floating energy storage battery pack.

[0017] 2. It adopts a miniature DC brushless circulating pump, which is small in size, low in power consumption, long in life and maintenance-free, and is suitable for long-term unattended operation on water. The circulating pump is powered by photovoltaic modules or energy storage battery packs. When there is sufficient sunlight, it is directly driven by photovoltaic power generation. When there is insufficient sunlight or at night, it can be powered by battery packs to ensure the continuous and stable operation of the heat dissipation system.

[0018] 3. The control unit automatically starts and stops the circulating pump based on the temperature signal. It starts when the temperature is higher than the first threshold and stops when the temperature is lower than the second threshold, so as to achieve heat dissipation on demand, avoid continuous operation of the circulating pump, significantly reduce system energy consumption, fit the intermittent charging and discharging characteristics of the water storage system, effectively reduce energy consumption and component wear, avoid ineffective heat dissipation under low temperature conditions, take into account heat dissipation needs and energy saving goals, and improve the economy and service life of the heat dissipation system.

[0019] 4. The control unit maintains the current state of the circulating pump when the temperature is between two threshold values, avoiding frequent start-stop cycles that could cause pump wear and system fluctuations, improving operational stability, reducing control jitter, and extending the service life of the circulating pump. Simultaneously, it keeps the battery pack temperature within a reasonable range, preventing both overheating and excessive heat dissipation, improving temperature control accuracy, ensuring stable operating temperature of the energy storage battery pack, and further enhancing system reliability and range.

[0020] 5. A thermally conductive interface material is placed between the cold plate and the battery pack to effectively fill the contact gap, reduce contact thermal resistance, improve heat transfer efficiency, ensure uniform battery pack temperature, and improve heat dissipation and operational safety.

[0021] 6. The underwater heat exchanger adopts a finned tube structure to increase the heat exchange area, improve the heat exchange efficiency with the water body, and enhance the heat dissipation capacity. It is made of copper alloy or stainless steel, which is resistant to water corrosion, has a long service life, and can be used for a long time in various water environments such as fresh water and seawater.

[0022] 7. Multiple cold plates are connected in parallel with multiple battery packs to form a parallel cooling circuit, achieving centralized heat dissipation for multiple battery packs.

[0023] 8. The cooling medium can be one or a mixture of heat transfer oil, water, and ethylene glycol. Heat transfer oil has good insulation and high safety, while water and ethylene glycol have high heat exchange efficiency and low cost. It can be flexibly configured according to ambient temperature, heat dissipation requirements and safety requirements.

[0024] 9. Setting the first threshold to 35℃~45℃ and the second threshold to 15℃~25℃ closely matches the optimal operating temperature range of lithium iron phosphate batteries, achieving precise temperature control. This ensures timely heat dissipation at high temperatures to prevent battery overheating and damage, while avoiding excessive heat dissipation at low temperatures to maintain battery performance. Reasonable threshold settings balance heat dissipation requirements and energy-saving effects, improving battery cycle life and system stability, and ensuring the long-term safe and efficient operation of the floating energy storage system.

[0025] 10. The floating energy storage system integrates a heat dissipation system, photovoltaic modules and energy storage battery packs, and is suitable for distributed and platform-based deployment on water. The photovoltaic modules charge the battery packs and power the heat dissipation system, while the battery packs provide backup power, forming a clean energy self-sufficient system. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1A schematic diagram of the longitudinal arrangement of the energy storage battery pack in the first embodiment of a heat dissipation system for an underwater energy storage battery pack provided by the present invention; Figure 2 A schematic diagram of the horizontal arrangement of the energy storage battery pack in the first embodiment of a heat dissipation system for an underwater energy storage battery pack provided by the present invention; Figure 3 A schematic diagram of a phase change material layer structure added between the energy storage battery pack and the heat transfer oil cooling plate in a second embodiment of the heat dissipation system for a floating energy storage battery pack provided by the present invention. Figure 4 This is a schematic diagram of the oil inlet pipe connection in a third embodiment of a heat dissipation system for an aquatic energy storage battery pack provided by the present invention; In the diagram: 1. Photovoltaic module; 2. Support column; 3. Triangular bracket; 4. Energy storage battery pack; 5. Cold plate; 6. Oil outlet pipe; 7. Underwater heat exchanger; 8. Oil inlet pipe; 9. Circulation pump; 10. Phase change thermal storage material; 11. Water body; 12. Water surface platform. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] To address the technical deficiencies mentioned in the background section, this embodiment provides a heat dissipation system for a floating energy storage battery pack and a floating energy storage system. The invention will be further described in detail below with reference to the accompanying drawings: In a first aspect, the present invention provides a heat dissipation system for a floating energy storage battery pack, such as... Figure 1 As shown, it includes: at least one cold plate 5, which is attached and fixed to the surface of the energy storage battery pack 4; a circulation pump 9; an underwater heat exchanger 7, which is submerged in an external water body 11; the cold plate 5, the circulation pump 9, and the underwater heat exchanger 7 are connected in sequence through connecting pipes to form a closed cooling medium circulation loop; a temperature detection unit, which is fixedly installed on the energy storage battery pack 4, for real-time acquisition and output of battery pack temperature signals; and a control unit, which is electrically connected to the temperature detection unit and the circulation pump 9 respectively, for controlling the start and stop of the circulation pump 9 according to the temperature signal output by the temperature detection unit.

[0030] Example 1 like Figure 1 and Figure 2As shown, it can be installed in both longitudinal and transverse configurations. The entire heat dissipation system is mounted on the photovoltaic support structure on the water surface and mainly includes photovoltaic modules 1, support columns 2, triangular brackets 3, energy storage battery packs 4, cold plates 5, oil outlet pipes 6, underwater heat exchangers 7, oil inlet pipes 8, circulation pumps 9, temperature detection units, and control units. The components are arranged in layers along the support columns 2 to form an integrated structure for water power generation, water energy storage, and underwater heat dissipation. It makes full use of the vertical space on the water surface, does not occupy additional water area, and solves the technical problem of limited water space making it difficult to install large heat dissipation equipment.

[0031] Furthermore, the support column 2 is vertically fixed in the external water body 11, serving as the load-bearing structure for the floating photovoltaic system and energy storage system. It is made of steel or high-strength composite materials, possessing sufficient structural strength, anti-overturning ability, and wind and wave resistance. It can serve stably for a long time in different aquatic environments such as freshwater and nearshore, without corrosion, deformation, or subsidence, providing a stable installation foundation for the entire system.

[0032] The burial depth and diameter of the support column 2 are reasonably selected based on the water depth, wind and wave level and the total weight of the system to ensure safe and stable operation under extreme weather conditions; the photovoltaic module 1 is fixedly installed on the top of the support column 2, at the highest position above the water surface, to ensure unobstructed and sufficient sunlight, and to maximize the conversion of solar energy into DC power.

[0033] Furthermore, the power output of the photovoltaic module 1 is divided into two paths. One path is electrically connected to the charging end of the energy storage battery pack 4 to continuously charge the energy storage battery pack 4, realizing the storage of light energy into electrical energy and then into chemical energy. The other path is electrically connected to the circulation pump 9 and control unit of the heat dissipation system to directly provide working power to the heat dissipation system, realizing the self-driven operation of clean energy without the need for external municipal power grid or additional power supply equipment, greatly improving the system's independence and environmental adaptability.

[0034] In this embodiment, the triangular bracket 3 is fixedly connected to the middle position of the support column 2. It is connected to the support column 2 by metal welding or bolt fastening. The triangular bracket 3 is used to support and fix the energy storage battery pack 4, so that the energy storage battery pack 4 maintains a horizontal or vertical posture, ensuring that it does not shake, shift, flip or fall off under the disturbance of wind and waves or the impact of water flow. At the same time, it provides a stable mounting surface for the cold plate 5, ensuring that the cold plate 5 and the energy storage battery pack 4 are always in close contact and maintain a state of efficient heat transfer.

[0035] The energy storage battery pack 4 uses lithium iron phosphate battery packs, which have advantages such as high safety, long cycle life, high charge and discharge efficiency, and wide applicable temperature range. It is the energy storage carrier of the floating photovoltaic energy storage system. During the charging and discharging process, the internal cells of the energy storage battery pack 4 will continuously generate heat. If the heat cannot be dissipated in a timely and even manner, it will lead to an increase in the internal temperature of the battery pack and uneven temperature distribution, which will cause battery capacity decay, shorten cycle life, increase internal resistance, and even lead to the risk of thermal runaway in severe cases.

[0036] In this embodiment, the cold plate 5 is tightly attached to the surface of the energy storage battery pack 4. Specifically, it can be attached to the bottom or back of the energy storage battery pack 4 depending on the installation method. It is made of high thermal conductivity materials such as aluminum alloy, and the surface is flat and smooth to ensure full contact with the outer shell of the energy storage battery pack 4.

[0037] The cold plate 5 has a serpentine or direct flow channel inside. The inner wall of the channel is smooth and the flow resistance is small. It is used to circulate the cooling medium and directly absorb the heat generated by the energy storage battery pack 4 during operation, so as to realize the efficient transfer of heat from the battery pack to the cooling medium.

[0038] Furthermore, a thermally conductive interface material can be provided between the mating surfaces of the cold plate 5 and the energy storage battery pack 4. The thermally conductive interface material can be thermally conductive silicone, thermally conductive gel, or graphite sheet, which can fill the tiny gaps and air layers between the mating surfaces, significantly reduce the contact thermal resistance between the cold plate 5 and the energy storage battery pack 4, improve the heat conduction efficiency, avoid the generation of local hot spots, and ensure uniform battery pack temperature.

[0039] The circulating pump 9 adopts a miniature DC brushless circulating pump 9, which has outstanding features such as small size, light weight, low power consumption, low operating noise, long service life, and brushless maintenance-free operation. The power supply end of the miniature DC brushless circulating pump 9 has dual power supply modes. It can be electrically connected to the power output end of the photovoltaic module 1 and directly driven by the photovoltaic power generation energy; or it can be electrically connected to the power output end of the energy storage battery pack 4 and provided with backup power by the energy storage battery pack 4. The dual power supply mode can ensure that the circulating pump 9 can still start and operate normally under conditions such as insufficient sunlight, nighttime, or photovoltaic power generation failure, avoiding heat dissipation failure due to power interruption and improving the reliability of system operation.

[0040] In this embodiment, the underwater heat exchanger 7 is submerged in the external water body 11, with an installation depth of 1 to 2 meters below the water surface. It makes full use of the natural water body as a natural cold source, eliminating the need for additional traditional heat dissipation equipment such as heat dissipation fans, heat dissipation towers, and compressor condenser units. This greatly simplifies the system structure, reduces equipment costs, and reduces system energy consumption and maintenance costs.

[0041] The underwater heat exchanger 7 is a finned tube heat exchanger made of water-corrosion-resistant copper alloy or stainless steel. It has good thermal conductivity and corrosion resistance, and can be used for a long time in different water quality environments such as fresh water and seawater without rusting, clogging or failure. The outer wall of the underwater heat exchanger 7 is equipped with a dense fin structure, which significantly increases the heat exchange area between the heat exchanger and the water body, enhances the convective heat transfer effect, and ensures that the cooling medium carrying heat can be cooled down quickly and restore its low-temperature heat dissipation capacity.

[0042] In this embodiment, the cold plate 5, the circulating pump 9 and the underwater heat exchanger 7 are connected in sequence through connecting pipes to form a closed cooling medium circulation loop. The cooling medium flows in a closed loop and does not come into contact with the outside air or water, thus avoiding leakage, pollution and medium loss.

[0043] The oil outlet pipe 6 is connected at one end to the liquid outlet of the cold plate 5 and at the other end to the liquid inlet of the underwater heat exchanger 7, used to transport the high-temperature cooling medium after absorbing heat to the underwater heat exchanger 7; the oil inlet pipe 8 is connected at one end to the liquid outlet of the underwater heat exchanger 7 and at the other end to the liquid inlet of the cold plate 5, used to return the cooled low-temperature cooling medium to the cold plate 5 to continue absorbing heat from the battery pack; the circulating pump 9 is connected in series to the oil inlet pipe 8 or the oil outlet pipe 6 to provide stable power for the circulation of the cooling medium and ensure that the medium flow rate meets the heat dissipation requirements. The outer wall of the connecting pipes is covered with heat insulation material to reduce heat loss during transportation and improve heat dissipation efficiency.

[0044] In practice, the cooling medium is selected from one or more mixtures of heat transfer oil, water, and ethylene glycol, which can be flexibly chosen according to the ambient temperature, heat dissipation requirements, and safety requirements. Among them, heat transfer oil has the characteristics of good insulation, stable flow, high temperature resistance, and non-corrosion of metal flow channels, making it suitable for scenarios with high insulation requirements. Water and ethylene glycol have the advantages of low cost, high heat transfer coefficient, and good flow, making them suitable for ambient temperature water environments. The use of multiple media in combination can balance heat transfer efficiency, low temperature flow, and safety, meeting the needs of different working conditions.

[0045] In this embodiment, the temperature detection unit is fixedly installed on the energy storage battery pack 4. It can be attached to the surface of the battery pack shell or implanted near the cells inside the battery pack. It is used to collect and output the temperature signal of the energy storage battery pack 4 in real time, and transmit the temperature data stably and accurately to the control unit, providing real-time basis for the control of the circulating pump 9. The temperature detection unit has a fast response speed and high measurement accuracy, and can reflect the real temperature of the battery pack in real time, avoiding untimely control due to temperature detection lag.

[0046] The control unit is electrically connected to the signal output terminal of the temperature detection unit and the control terminal of the circulating pump 9, respectively. It is used to receive temperature signals and execute preset control logic to realize automatic start and stop control of the circulating pump 9 without manual operation, thus truly realizing automated heat dissipation management.

[0047] The control unit has a first preset threshold and a second preset threshold. The first preset threshold is 35℃~45℃, and the second preset threshold is 15℃~25℃. The first preset threshold is higher than the second preset threshold. The thresholds can be flexibly adjusted according to the battery type, usage environment and operating strategy.

[0048] In this embodiment, the specific control logic of the control unit is as follows: when the temperature signal collected by the temperature detection unit is higher than the first preset threshold, it is determined that the battery pack temperature is too high. The control unit immediately starts the circulation pump 9 to drive the cooling medium to circulate in a closed loop, quickly transferring the heat of the energy storage battery pack 4 to the underwater heat exchanger 7 for continuous heat dissipation through the natural water body; when the temperature signal is lower than the second preset threshold, it is determined that the battery pack temperature is too low. The control unit controls the circulation pump 9 to stop running, and the cooling medium remains stationary to reduce the heat loss of the energy storage battery pack 4 and avoid the battery temperature being too low, which would affect the charging and discharging performance and cycle life; when the temperature signal is between the first preset threshold and the second preset threshold, the control unit maintains the current operating state of the circulation pump 9 unchanged and does not perform start or stop actions to avoid frequent start and stop of the circulation pump 9 causing losses and ensure stable and reliable system operation.

[0049] like Figure 1 The diagram shows a longitudinal arrangement of the energy storage battery pack 4. The energy storage battery pack 4 is installed vertically along the axis of the support column 2. The cold plate 5 is attached to the back of the energy storage battery pack 4. The oil outlet pipe 6 and the oil inlet pipe 8 are arranged longitudinally along the support column 2. The overall structure occupies little lateral space, has a small wind resistance area, and has excellent wind resistance performance. It is suitable for water scenarios with large waves and narrow installation space.

[0050] like Figure 2 The diagram shows a horizontal arrangement of the energy storage battery pack 4. The energy storage battery pack 4 is installed horizontally perpendicular to the support column 2. The cold plate 5 is attached to the bottom surface of the energy storage battery pack 4. The pipeline extends horizontally and then connects downward to the underwater heat exchanger 7. The pipeline layout is simpler, and the installation and maintenance are more convenient. It is suitable for scenarios with good construction conditions and easy inspection and maintenance.

[0051] The two heat dissipation systems described above are completely identical in composition, connection, piping routing, medium flow direction, and control logic. They can be flexibly selected based on on-site installation space, construction conditions, wind and wave environment, and maintenance needs, and have good scene adaptability and flexibility.

[0052] In this embodiment, the energy storage battery pack 4 continuously generates heat during charging and discharging, and the heat is quickly transferred to the cold plate 5 through the bonding surface. The temperature detection unit collects the temperature of the energy storage battery pack 4 in real time and sends the signal to the control unit. The control unit compares the real-time temperature with a preset threshold and controls the start and stop of the circulation pump 9 according to preset logic. When the circulation pump 9 starts, the cooling medium absorbs heat and rises in temperature in the cold plate 5. It flows into the underwater heat exchanger 7 through the oil outlet pipe 6, undergoes forced convection heat exchange with the low-temperature water, and then cools down rapidly. It then flows back to the cold plate 5 through the oil inlet pipe 8, continuously removing heat from the battery pack and achieving closed-loop heat dissipation. When the battery pack temperature drops below the second preset threshold, the circulation pump 9 stops running, and the system enters a low-power standby state, waiting for the temperature to rise before restarting. This achieves the technical effects of on-demand heat dissipation and energy saving.

[0053] Compared to traditional air-cooling and conventional liquid-cooling technologies, this embodiment has significant advantages: it eliminates the traditional fan component, avoiding the additional energy consumption, mechanical failures, and reliability issues caused by fan operation, thus greatly improving the overall reliability of the system; it eliminates the need for complex liquid-cooling units and large piping systems, resulting in smaller, lighter, and easier-to-install equipment that perfectly suits column-mounted distributed installation requirements; it fully utilizes the natural heat dissipation of the water body, with the heat dissipation effect unaffected by ambient wind speed and temperature, and no heat accumulation even under high-temperature, windless conditions; the circulating pump 9 can be started and stopped on demand, significantly reducing ineffective operating time, extending the pump's service life, and reducing the frequency and cost of waterborne maintenance, perfectly meeting the requirements for long-term stable and low-maintenance operation of waterborne energy storage systems.

[0054] Example 2 like Figure 3 As shown, the system is optimized and improved based on Example 1. The remaining unmentioned system structure, component connection relationship, material selection, power supply method, threshold setting and control logic are consistent with Example 1.

[0055] The improvement of this embodiment is that a phase change thermal storage material 10 is added between the cold plate 5 and the bonding surface of the energy storage battery pack 4 to form a stable thermal buffer layer, which further improves the thermal stability, temperature uniformity and thermal shock resistance of the heat dissipation system. It is suitable for water-based energy storage conditions where the battery charging and discharging power fluctuates greatly and the instantaneous heat release is strong.

[0056] Specifically, the phase change thermal storage material 10 is sandwiched between the energy storage battery pack 4 and the cold plate 5, with the three tightly bonded together without air gaps or misalignment, ensuring stable and efficient heat conduction. The phase change thermal storage material 10 is a solid-liquid phase change material, and its phase change temperature range matches the optimal operating temperature range of the energy storage battery pack 4. When the temperature of the energy storage battery pack 4 rises rapidly, a solid-to-liquid phase change occurs, absorbing a large amount of latent heat and instantly storing excess heat, suppressing sudden temperature rises and fluctuations in the battery pack. When the battery pack temperature decreases and heat output decreases, a liquid-to-solid phase change occurs, slowly releasing the stored heat and preventing a sudden drop in battery pack temperature. This acts as a temperature buffer and peak shaving, ensuring that the battery pack always operates within a stable, safe, and efficient temperature range.

[0057] In this embodiment, the photovoltaic module 1 is located at the highest point of the support column 2 to ensure sufficient sunlight; the energy storage battery pack 4 is fixed to the middle of the support column 2 by the triangular bracket 3; the cold plate 5 is attached to the outside of the phase change thermal storage material 10 to form a three-layer thermally conductive structure of battery pack, phase change layer and cold plate; the underwater heat exchanger 7 is immersed in the external water body 11 to dissipate heat using natural cold source; the cold plate 5, the circulation pump 9 and the underwater heat exchanger 7 form a closed cooling circulation loop through pipelines; the circulation pump 9 is powered by either the photovoltaic module 1 or the energy storage battery pack 4 in dual mode to ensure continuous operation; the control unit controls the start and stop of the circulation pump 9 according to the real-time signal of the temperature detection unit to realize automated temperature control heat dissipation.

[0058] The heat dissipation process in this embodiment is as follows: During the charging and discharging process, the energy storage battery pack 4 generates instantaneous heat, especially under high-rate charging and discharging conditions, where the heat release rate is fast and the heat is large, and it is first transferred to the phase change thermal storage material 10; the phase change thermal storage material 10 quickly absorbs the excess heat, suppresses the rapid rise in battery pack temperature, and allows the heat to be conducted smoothly and evenly to the cold plate 5, avoiding local overheating and sudden temperature changes; the temperature detection unit continuously collects the battery pack temperature and transmits the signal to the control unit; the control unit judges according to the preset threshold and controls the circulation pump 9 to start or stop; when the circulation pump 9 is running, it drives the cooling medium to circulate in a closed loop, transferring the heat from the cold plate 5 to the underwater heat exchanger 7, and finally releasing it to the external water body; when the battery pack temperature decreases and the heat decreases, the phase change thermal storage material 10 slowly releases the stored heat to prevent the battery pack temperature from becoming too low. In conjunction with the temperature control start-stop logic of the circulation pump 9, the energy storage battery pack 4 is always maintained within a safe, stable, and efficient operating temperature range, improving battery operation consistency and service life.

[0059] Compared with Example 1, this example adds phase change thermal storage material 10, which enhances the heat dissipation system's resistance to thermal shock and temperature regulation capabilities. This effectively reduces the temperature fluctuation of the battery pack, eliminates the thermal risks caused by instantaneous high-power charging and discharging, improves the internal temperature uniformity of the battery pack, and significantly extends battery life. At the same time, the phase change thermal storage layer can absorb excess heat in a short period of time, reducing the start-stop frequency of the circulating pump 9, further reducing system energy consumption, reducing pump wear, and improving the overall stability and reliability of the system. It is more suitable for high-power, high-dynamic, and intermittent charging and discharging of floating photovoltaic energy storage scenarios, with a wider range of applications and better heat dissipation effect.

[0060] Example 3 like Figure 4 As shown, this embodiment can simultaneously provide unified and centralized heat dissipation for multiple energy storage battery packs 4, forming a battery cluster-level large-scale heat dissipation solution. It is suitable for large-capacity, high-density, and centralized large-scale floating photovoltaic energy storage power stations, solving the technical problem of limited water space and difficulty in deploying centralized large-scale energy storage equipment.

[0061] Specifically, the water surface platform 12 floats on the surface of the external water body 11. It adopts a floating platform structure with sufficient buoyancy, stable structure and strong wind and wave resistance, providing a large area and stable installation foundation. It can support all equipment such as large-capacity battery clusters, heat dissipation pipes, circulation pumps 9 and underwater heat exchangers 7, realizing an integrated layout of centralized energy storage and centralized heat dissipation on the water, which is convenient for centralized management and maintenance, and improves system integration and economy.

[0062] Multiple energy storage battery packs 4 are neatly arranged on the water surface platform 12 in a stacked or arrayed manner to form a battery cluster structure. This structure has high energy storage capacity density and occupies little space, enabling large-capacity energy storage within a limited water area. Each energy storage battery pack 4 has a corresponding cold plate 5 attached to its surface. The multiple cold plates 5 are set one-to-one with the multiple energy storage battery packs 4 to ensure that each battery pack can dissipate heat independently, efficiently, and uniformly, avoiding problems such as uneven temperature or localized overheating inside the battery cluster.

[0063] The liquid inlets of each cold plate 5 are connected in parallel to the liquid outlet of the circulating pump 9 via connecting pipes, and the liquid outlets of each cold plate 5 are connected in parallel to the liquid inlet of the underwater heat exchanger 7 via connecting pipes, forming a parallel cooling circulation loop. The main oil outlet pipe 6 and the main oil inlet pipe 8 adopt a confluence design, extending vertically downward along the edge of the water surface platform 12 to the underwater heat exchanger 7.

[0064] The underwater heat exchanger 7 still adopts a finned tube heat exchanger 7, which is made of copper alloy or stainless steel that is resistant to seawater corrosion. It is immersed in the external water body 11 and serves as a centralized heat dissipation terminal. It has a large heat exchange area and strong heat dissipation capacity, and can simultaneously meet the heat dissipation needs of multiple cold plates 5. It enables a single heat exchanger to drive the heat dissipation of the entire battery pack, significantly reducing the number of devices and lowering system costs and installation complexity.

[0065] The circulating pump 9 adopts a high-flow micro DC brushless circulating pump 9, and the power supply method is the same as that in Example 1. It can be powered by photovoltaic module 1 or energy storage battery pack 4 in dual mode to ensure stable and uniform circulation of cooling medium in parallel circuit and provide sufficient cooling medium flow for each cold plate 5.

[0066] Temperature detection units are installed on each energy storage battery pack 4 to collect temperature signals from each battery pack in real time and transmit them synchronously to the control unit, enabling comprehensive temperature monitoring of all battery packs within the battery cluster. The control unit receives multiple temperature signals and executes centralized control logic according to a unified preset threshold: when the temperature of any one or more energy storage battery packs 4 exceeds the first preset threshold, the circulation pump 9 is immediately started to provide heat dissipation for the entire battery pack cluster; when the temperature of all energy storage battery packs 4 is below the second preset threshold, the circulation pump 9 is stopped and the system enters standby mode; when the temperature is within the threshold range, the current operating state is maintained to ensure system stability.

[0067] The parameters such as the selection of cooling medium, threshold range, control logic, and setting of thermal interface material are consistent with those in Example 1: the cooling medium is selected from one or more mixtures of thermal oil, water, and ethylene glycol; the first preset threshold is 35℃~45℃, and the second preset threshold is 15℃~25℃; a thermal interface material can be set between the cold plate 5 and the energy storage battery pack 4 to further reduce the contact thermal resistance and improve the heat dissipation effect.

[0068] The workflow of this embodiment is as follows: Multiple energy storage battery packs 4 are charged and discharged simultaneously, and the heat generated is quickly transferred to the corresponding cold plates 5; after the circulation pump 9 starts, it drives the cooling medium to flow evenly into each parallel cold plate 5, absorbs the heat of the battery pack, and then flows into the main oil outlet pipe 6, and flows into the underwater heat exchanger 7 for centralized heat dissipation; the cooled cooling medium is distributed to each cold plate 5 through the main oil inlet pipe 8 to complete one cycle; the control unit centrally controls the start and stop of the circulation pump 9 according to the overall temperature status of the battery pack, so as to realize unified temperature control, centralized heat dissipation, and efficient and stable operation of the entire battery pack.

[0069] Compared to Embodiments 1 and 2, this embodiment features higher energy storage capacity density, stronger heat dissipation capability, and higher system integration. It is highly modular and expandable, allowing for flexible adjustments to the number of battery packs and cold plates 5 based on energy storage capacity requirements, making it suitable for floating photovoltaic energy storage power stations of different scales. Multiple battery packs share a single circulating pump 9 and underwater heat exchanger 7, resulting in high equipment utilization and significantly reduced equipment, installation, and maintenance costs. The internal temperature distribution of the battery clusters is more uniform, with no localized overheating or uneven temperature distribution, ensuring stable and reliable heat dissipation. It perfectly meets the centralized, large-scale, and high-capacity application requirements of large-scale floating photovoltaic energy storage power stations, possessing extremely high practical value and promising prospects for promotion.

[0070] During system implementation, after the system is powered on and initialized, the temperature detection unit immediately starts, continuously and in real-time acquiring the temperature signal of the energy storage battery pack 4 and transmitting the signal stably to the control unit. The control unit receives the temperature signal in real time and first determines whether the real-time temperature is higher than the first preset threshold. If so, it immediately outputs a start command to control the circulation pump 9 to start running, and the cooling medium begins to circulate and dissipate heat. Otherwise, it continues to the next step of judgment. The control unit then determines whether the real-time temperature is lower than the second preset threshold. If so, it outputs a stop command to control the circulation pump 9 to stop running, and the system enters standby mode. Otherwise, it maintains the current operating state. When the temperature is between the second preset threshold and the first preset threshold, the control unit maintains the current operating state of the circulation pump 9 and does not perform start or stop actions to avoid frequent start and stop causing pump wear and increased system energy consumption. During the continuous operation of the circulation pump 9, the cooling medium circulates stably in a closed loop, continuously transferring the heat from the battery pack to the underwater heat exchanger 7 for release, until the battery pack temperature drops below the second preset threshold. At this point, the control unit controls the circulation pump 9 to stop, completing one temperature control and heat dissipation cycle.

[0071] In summary, this system discloses three technical solutions through three specific embodiments: longitudinal / lateral column-mounted heat dissipation for single battery packs, enhanced heat dissipation with phase change thermal storage materials, and clustered parallel heat dissipation for multiple battery packs. These solutions comprehensively cover various scales of floating photovoltaic energy storage applications, including small-scale distributed, medium-scale enhanced, and large-scale centralized systems. The system features a simple structure, convenient installation, low energy consumption, minimal maintenance, and stable and reliable heat dissipation. It completely solves the technical shortcomings of existing air-cooled systems, such as susceptibility to environmental influences, easy heat accumulation, and poor reliability, as well as the technical deficiencies of traditional liquid cooling systems, such as large volume, complex installation, high energy consumption, and high maintenance costs. This system meets the thermal management requirements of floating energy storage battery packs, improves battery operation safety, stability, and lifespan, and provides an efficient, reliable, and low-cost thermal management solution for the floating photovoltaic energy storage industry. It possesses good practicality, economic efficiency, and broad promotional value.

[0072] In a second aspect, this invention provides an underwater energy storage system, comprising: an energy storage battery pack, a photovoltaic module 1, and a heat dissipation system for the underwater energy storage battery pack as described above; the energy storage battery pack includes at least one energy storage battery pack 4; the cold plate 5 of the heat dissipation system is attached and fixed to the surface of each energy storage battery pack 4; the power output terminal of the photovoltaic module 1 is electrically connected to the charging terminal of the energy storage battery pack, the control unit of the heat dissipation system, and the power supply terminal of the circulation pump 9, respectively, for charging the energy storage battery pack; the underwater heat exchanger 7 of the heat dissipation system is submerged in an external water body 11, and its inlet and outlet are connected to the circulation pump 9 and the cold plate 5 respectively through connecting pipes to form a closed heat dissipation cycle; the control unit of the heat dissipation system is electrically connected to a temperature detection unit and the circulation pump 9, and controls the operating state of the circulation pump 9 according to the battery pack temperature signal collected by the temperature detection unit; the power output terminal of the energy storage battery pack is electrically connected to the control unit of the heat dissipation system and the circulation pump 9, for storing the electrical energy generated by the photovoltaic module 1 and providing backup power for the heat dissipation system.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. A heat dissipation system for a floating energy storage battery pack, characterized in that, include: At least one cold plate is attached and fixed to the surface of the energy storage battery pack; Circulating pump; Submersible heat exchangers are installed submerged in external water bodies. The cold plate, circulating pump and underwater heat exchanger are connected in sequence through connecting pipes to form a closed cooling medium circulation loop. The temperature detection unit is fixedly installed on the energy storage battery pack and is used to collect and output the temperature signal of the battery pack in real time. The control unit is electrically connected to the temperature detection unit and the circulating pump, respectively, and is used to control the start and stop of the circulating pump according to the temperature signal output by the temperature detection unit.

2. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, The circulating pump is a miniature DC brushless circulating pump; The power supply terminal of the micro DC brushless circulating pump is electrically connected to the power output terminal of the photovoltaic module. Alternatively, the power supply terminal of the micro DC brushless circulating pump is electrically connected to the power output terminal of the energy storage battery pack.

3. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, The control unit is used to receive the temperature signal output by the temperature detection unit, and to control the circulation pump to start when the temperature signal is higher than a first preset threshold, and to control the circulation pump to stop running when the temperature signal is lower than a second preset threshold.

4. The heat dissipation system for an underwater energy storage battery pack according to claim 3, characterized in that, The control unit is also configured to: When the battery pack temperature detected by the temperature detection unit is between the first preset threshold and the second preset threshold, the current operating state of the circulation pump is maintained unchanged.

5. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, A thermally conductive interface material is sandwiched between the cold plate and the mounting surface of the energy storage battery pack to reduce the contact thermal resistance between the cold plate and the energy storage battery pack.

6. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, The underwater heat exchanger is a finned tube heat exchanger made of copper alloy or stainless steel.

7. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, The cold plate is configured as a plurality of them, and the plurality of cold plates are fitted together with the plurality of energy storage battery packs in a one-to-one correspondence; The liquid inlets of each cold plate are connected in parallel to the liquid outlet of the circulating pump, and the liquid outlets of each cold plate are connected in parallel to the liquid inlet of the underwater heat exchanger, forming a parallel cooling circulation loop.

8. The heat dissipation system for an underwater energy storage battery pack according to claim 1, characterized in that, The cooling medium is one or a mixture of heat transfer oil, water, and ethylene glycol.

9. The heat dissipation system for an underwater energy storage battery pack according to claim 3, characterized in that, The first preset threshold is 35℃~45℃, and the second preset threshold is 15℃~25℃.

10. A floating energy storage system, characterized in that, include: Energy storage battery pack, photovoltaic module, and heat dissipation system for a floating energy storage battery pack as described in any one of claims 1-9; The energy storage battery pack includes at least one energy storage battery pack; The cooling plate of the heat dissipation system is attached and fixed to the surface of each energy storage battery pack; The power output terminal of the photovoltaic module is electrically connected to the charging terminal of the energy storage battery pack, the control unit of the heat dissipation system, and the power supply terminal of the circulation pump, respectively, for charging the energy storage battery pack. The underwater heat exchanger of the heat dissipation system is submerged in external water. Its inlet and outlet are connected to the circulating pump and the cold plate respectively through connecting pipes to form a closed heat dissipation cycle. The control unit of the heat dissipation system is electrically connected to the temperature detection unit and the circulation pump. Based on the battery pack temperature signal collected by the temperature detection unit, the control unit controls the start-up, shutdown and operation status of the circulation pump. The energy storage battery pack's power output terminal is electrically connected to the control unit and circulation pump of the heat dissipation system, used to store the electrical energy generated by the photovoltaic module and provide backup power to the heat dissipation system when the photovoltaic module's power supply is abnormal.

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