Buried energy storage sealing structure, control method and system

Abstract

The application discloses a buried energy storage sealing structure, a control method and a system, and relates to the technical field of energy storage equipment. The structure comprises: a pressure adjusting unit, which is connected with the inside and outside of an energy storage bin and is used for adjusting air pressure balance in a passive mode or an active mode; a composite sealing unit, which is arranged at the joint of a bin cover and a bin body of the energy storage bin; a pressure charging unit, which is arranged on one side of the composite sealing unit facing the inside of the bin body, is used for receiving external gas to enhance the sealing contact pressure of the composite sealing unit, and represents the sealing deterioration degree through the change of the internal air pressure; and a control unit, which is used for controlling the pressure adjusting unit to work in the passive mode or the active mode based on the air pressure difference between the inside and outside of the energy storage bin, executing early warning based on the sealing deterioration degree, and executing air supplement based on the internal air pressure of the pressure charging unit. In this way, the passive / active dual-mode pressure adjustment considers the energy consumption and the adjusting capacity, and solves the technical problems that the sealing state of the buried energy storage is unknown and early warning cannot be performed in advance.

Description

Technical Field

[0001] This application relates to the field of energy storage equipment technology, and in particular to a buried energy storage sealing structure, control method and system. Background Technology

[0002] Buried energy storage systems, which bury batteries and electrical equipment underground, offer advantages such as saving surface space and good concealment, and have been gradually applied in fields such as distributed energy storage and base station backup power. However, the underground environment is complex, and the energy storage compartment is subjected to the hydrostatic pressure of groundwater, as well as the periodic fluctuations in internal air pressure caused by diurnal temperature differences and equipment heating. This makes the sealing structure at the junction of the compartment cover and the compartment body a weak link in the entire system.

[0003] Currently, underground energy storage silos mainly use a single rubber sealing ring combined with a common breather valve. This solution has the following technical defects: (1) The breather valve can only passively exhaust or inhale air, and cannot accurately balance the pressure difference in both directions. Under extreme working conditions, the pressure difference that the seal can withstand can be several times the design value, which accelerates the aging of the seal; (2) The sealing status is unknown and can only be discovered after a water seepage accident occurs, lacking early warning means; (3) Some high-end solutions introduce inflatable seals to enhance contact pressure, but inflatable seals are only used for static compression, and the decrease in internal pressure is simply regarded as pipeline leakage, and has never been used to assess the deterioration trend of the sealing material itself.

[0004] Therefore, existing technologies cannot achieve low-energy pressure balance, nor can they monitor the sealing health status online, making it difficult to meet the requirements of underground energy storage for long-term maintenance-free operation and high reliability waterproofing. Summary of the Invention

[0005] This application provides a buried energy storage sealing structure, control method and system, which aims to solve the problems of unknown sealing status and inability to provide early warning of sealing aging failure in the prior art, while achieving low energy consumption pressure balance and graded waterproof protection.

[0006] On one hand, embodiments of this application provide a buried energy storage sealing structure, including: The pressure regulating unit connects the interior and exterior of the energy storage chamber and is used to regulate the gas pressure balance in a passive or active manner. The composite sealing unit is located at the junction of the chamber cover and the chamber body. The pressurizing unit is located on the side of the composite sealing unit facing the interior of the chamber and is used to receive external gas to enhance the sealing contact pressure of the composite sealing unit and to characterize the degree of seal deterioration through changes in its internal gas pressure. The control unit is used to control the pressure regulating unit to select passive or active operation based on the pressure difference between the interior and exterior of the energy storage chamber; to issue early warnings based on the degree of seal deterioration; and to perform gas replenishment based on the internal gas pressure of the pressurizing unit.

[0007] In one possible embodiment, the pressure regulating unit includes a breathing channel connecting the interior and the exterior, a one-way valve installed on the breathing channel, and an active air pump that can be selectively activated; in the passive mode, the active air pump is turned off, and the gas flows naturally by utilizing the thermal pressure difference between the interior and the surrounding soil; in the active mode, the active air pump is activated to force pressure regulation.

[0008] In one possible embodiment, the composite sealing unit includes a water-swellable layer and a shape memory layer stacked sequentially along the sealing direction; wherein, the water-swellable layer is used to expand in volume when exposed to water to fill the gap between the sealing surfaces; and the shape memory layer is used to restore the water-swellable layer to its initial thickness by means of the shape memory effect when dry.

[0009] In one possible embodiment, the pressurization unit includes a sealable cavity and an inflation port communicating with the cavity; wherein the control unit obtains the degree of seal deterioration by monitoring the rate of decrease of the air pressure inside the cavity.

[0010] In one possible embodiment, the sealing structure further includes: a pressure sensor for detecting the internal and external pressure difference; and a water immersion sensor for detecting water accumulation; wherein the pressure sensor and the water immersion sensor are respectively connected to the control unit.

[0011] In one possible embodiment, the control unit is also configured to: perform graded protection based on the water immersion signal detected by the water immersion sensor, including: starting the drainage pump when the water immersion signal reaches a first water level threshold; cutting off the main power supply when the water immersion signal reaches a second water level threshold; and issuing a remote alarm signal when the water immersion signal continues for more than a set time or reaches a third water level threshold.

[0012] In one possible embodiment, the control unit also includes a wireless communication module for transmitting information such as seal deterioration level, gas replenishment records, or early warning information to a remote operation and maintenance platform.

[0013] On one hand, this application provides a method for controlling the sealing of an underground energy storage system based on any of the above-mentioned sealing structures, including: acquiring the internal and external air pressure difference of the energy storage chamber; if the internal and external air pressure difference exceeds a preset difference value, controlling the pressure regulating unit to operate in an active mode, otherwise operating in a passive mode, until the internal and external air pressure difference is within the preset difference value; acquiring the internal air pressure of the pressurization unit; if the rate of decrease of the internal air pressure exceeds a preset value, determining that there is a leak in the pressurization unit or the composite sealing unit, and issuing a seal aging warning; if the internal air pressure is lower than the lower limit value, controlling the replenishment of air to the pressurization unit until the internal air pressure is restored to a safe pressure.

[0014] In one possible embodiment, the method further includes: after the air replenishment is completed, the rate of decrease of the internal air pressure is reacquired; if the rate of decrease of the newly acquired internal air pressure still exceeds the preset value, it is determined that the composite sealing unit has irreversibly aged and a replacement warning is issued.

[0015] On the one hand, embodiments of this application provide a buried energy storage system, including an energy storage battery and a buried energy storage sealing structure as described above.

[0016] The beneficial effects of this application are as follows: This application provides a buried energy storage sealing structure, control method, and system. First, the pressure regulating unit prioritizes passive pressure regulation, switching to active mode only when the pressure difference exceeds a threshold. This avoids the insufficient regulation capacity of a purely passive breathing valve under extreme conditions and overcomes the continuous energy consumption of a purely active solution, thereby reducing the cyclic pressure difference impact on the sealing components and delaying seal aging. Second, while receiving external gas to enhance the sealing contact pressure, the pressurizing unit directly characterizes the degree of seal deterioration through changes in its internal air pressure (especially the decay rate). This transforms the pressurizing unit, which was originally just an actuator, into a self-sensing element—when the sealing material ages or is damaged, leading to accelerated leakage, the air pressure decay rate increases, and the control unit issues an early warning accordingly. This dual function solves the problem of "unknown sealing status" without adding additional sensors, enabling predictive maintenance before water leakage occurs. Finally, the control unit switches the pressure regulation mode based on the internal and external air pressure difference, issues early warnings based on the degree of seal deterioration, and performs air replenishment based on the internal air pressure of the pressurizing unit. These three elements form a closed loop: air replenishment maintains the sealing pressure, early warnings indicate aging trends, and mode switching ensures regulation capability under extreme conditions. In this way, a low-energy-consumption, predictable, and automatically maintained underground energy storage seal is achieved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a buried energy storage sealing structure in an embodiment of this application.

[0019] Figure 2 This is a schematic flowchart of a buried energy storage sealing control method in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the structure of a buried energy storage system according to an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0022] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in sequences other than those illustrated or described herein.

[0023] The design concept of the embodiments of this application is briefly introduced below: Currently, underground energy storage mainly uses a single rubber sealing ring combined with a common breather valve. This solution has the following technical defects: (1) The breather valve can only passively exhaust or inhale air, and cannot accurately balance the pressure difference in both directions. Under extreme working conditions, the pressure difference that the seal can withstand can be several times the design value, accelerating the aging of the seal; (2) The sealing status is unknown and can only be discovered after a water leakage accident occurs, lacking early warning means; (3) Some high-end solutions introduce inflatable seals to enhance contact pressure, but inflatable seals are only used for static compression, and the decrease in internal pressure is simply regarded as pipeline leakage, and has never been used to assess the deterioration trend of the sealing material itself. Therefore, the existing technology can neither achieve low-energy pressure balance nor monitor the sealing health status online, and it is difficult to meet the requirements of underground energy storage for long-term maintenance-free and highly reliable waterproofing.

[0024] In view of this, embodiments of this application provide a buried energy storage sealing structure, control method, and system. The structure includes: a pressure regulating unit connecting the interior and exterior of the energy storage chamber for adjusting air pressure balance in a passive or active manner; a composite sealing unit located at the junction of the chamber cover and body; a pressurizing unit located on the side of the composite sealing unit facing the interior of the chamber for receiving external gas to enhance the sealing contact pressure of the composite sealing unit and characterizing the degree of seal deterioration through changes in its internal air pressure; and a control unit for controlling the pressure regulating unit to select passive or active operation based on the internal and external air pressure difference of the energy storage chamber; performing early warning based on the degree of seal deterioration; and performing gas replenishment based on the internal air pressure of the pressurizing unit. Thus, through the dual functions of the pressurization unit (actively enhancing sealing + self-sensing characterization of degradation) and the differentiated control of the control unit (mode switching, early warning, and gas replenishment), online monitoring and automatic maintenance of sealing health are achieved without the need for additional sensors. At the same time, the passive / active dual-mode pressure regulation balances energy consumption and regulation capability, solving the technical problem of unknowable sealing status and inability to provide early warning for buried energy storage, without relying on any hypothetical data.

[0025] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0026] refer to Figure 1 This is a schematic diagram of a buried energy storage sealing structure provided in an embodiment of this application. Figure 1 As shown, the underground energy storage sealing structure includes a pressure regulating unit 101, a composite sealing unit 103, a pressurizing unit 104, and a control unit 105.

[0027] The energy storage compartment 102 is entirely buried underground and contains electrical equipment such as battery modules, power conversion system (PCS) and battery management system (BMS). The energy storage compartment 102 has a cover 1021 and a compartment body 1022. The cover 1021 can be opened to cover the upper opening of the compartment body 1022.

[0028] The pressure regulating unit 101 connects the inside and outside of the energy storage chamber 102 and is used to selectively regulate the pressure balance inside and outside the chamber in a passive or active manner according to the pressure difference between the inside and outside of the energy storage chamber 102.

[0029] Optionally, the pressure regulating unit 101 includes a breathing channel connecting the inside and outside, a one-way valve installed on the breathing channel, and an active air pump that can be selectively activated. In the passive mode, the active air pump is turned off. Since the temperature of the soil constant temperature layer is relatively stable, when the temperature inside the chamber is higher than that of the soil, the gas is heated and rises and is discharged from the breathing tube. When the temperature inside the chamber is lower than that of the soil, the cold air sinks and is drawn in, forming natural convection, thereby making full use of the thermal pressure difference between the inside and the surrounding soil to drive the gas to flow naturally. In the active mode, the active air pump is activated to force pressure regulation. For example, when the absolute value of the air pressure difference between the inside and outside of the energy storage chamber 102 is ≤3kPa, the pressure regulating unit 101 operates in a passive mode: the active air pump remains off, and the gas is driven to flow naturally along the breathing tube by utilizing the thermal pressure difference between the inside of the energy storage chamber 102 and the surrounding soil constant temperature layer, thereby slowly balancing the internal and external air pressure. This process does not consume electricity and can maintain the air pressure inside the chamber within a safe range under normal conditions. When the absolute value of the internal and external air pressure difference is >3kPa and lasts for a certain period of time, such as 10 seconds, or when the rate of change of the air pressure difference is too fast, the pressure regulating unit 101 switches to active mode: the control unit 105 issues a command to start the active air pump, forcibly driving the gas into and out of the energy storage chamber 102, quickly reducing the air pressure difference to within a safe value, and preventing the seals from aging faster due to excessive pressure difference.

[0030] The composite sealing unit 103 is located at the junction of the cover 1021 and the body 1022 of the energy storage compartment 102; Optionally, the composite sealing unit 103 is a multi-layer composite structure, including a water-swellable layer and a shape memory layer stacked sequentially along the sealing direction (i.e., from the external environment to the interior of the chamber). The water-swellable layer expands in volume upon contact with water to fill gaps between the sealing surfaces. The shape memory layer restores its initial thickness upon drying due to the shape memory effect. The water-swellable layer can be made of water-swelling rubber (WSR). When groundwater from outside the chamber seeps into tiny gaps in the sealing surface, this layer expands in volume, automatically filling the gaps and preventing further water ingress. The shape memory layer can be made of shape memory polymer (SMP). When the environment dries, this layer uses the shape memory effect to restore the water-swellable layer to its initial thickness, thus ensuring that the sealing ring maintains effective sealing contact pressure after multiple water immersion-drying cycles.

[0031] The pressurization unit 104 is located on the side of the composite sealing unit 103 facing the interior of the chamber, i.e. the side facing away from the external environment. It is used to receive external gas to enhance the sealing contact pressure of the composite sealing unit 103 and to characterize the degree of sealing deterioration by the change in internal gas pressure.

[0032] Optionally, the pressurization unit 104 includes a sealable cavity and an inflation port communicating with the cavity. The control unit 105 obtains the degree of seal deterioration by monitoring the rate of pressure decay within the cavity. The inflation port is connected to an external compressed air source, such as a miniature air tank or air pump, via a pipe. The pressurization unit 104 has two main functions: First, it receives gas from an external source, increasing the internal pressure of the cavity and thus pressing the composite sealing unit 103 from the inside out, significantly enhancing the sealing contact pressure. When the sealing material undergoes permanent deformation due to long-term compression or when temperature changes cause a decrease in contact pressure, the sealing performance can be restored or even improved through gas replenishment, thereby extending the effective service life of the seal. Second, the pressurization unit 104 also acts as a self-sensing element: the control unit 105 monitors its internal pressure value in real time and calculates the rate of pressure decrease per unit time (i.e., the decay rate). When the sealing material ages, develops micro-cracks, or suffers installation damage, the gas inside the pressurization unit 104 leaks more rapidly, manifested as an increased rate of pressure decay. Therefore, this decay rate can directly quantify the degree of sealing degradation of the composite sealing unit 103 without the need for additional specialized sensors such as strain gauges and displacement gauges.

[0033] The control unit 105 can be installed either outside or inside the energy storage compartment 102. For example... Figure 1 As shown, the control unit 105 is installed inside the energy storage chamber 102. In this case, a protective housing, such as a sealed housing with an IP67 or higher protection rating, is required for the control unit 105. A dehumidification device, such as a miniature desiccant box or a semiconductor dehumidifier, can also be installed to prevent condensation and corrosion. This installation method results in a high degree of integration for the entire energy storage system. Alternatively, the control unit 105 can be installed in an external electrical control box outside the energy storage chamber 102 to avoid the impact of the damp underground environment on electronic components and facilitate routine inspection and maintenance. Regardless of whether the control unit 105 is installed outside or inside the chamber, its connection to the pressure regulation unit 101, the pressurization unit 104, and the sensors via signal lines remains unchanged, and both methods achieve the functions described in this application. The choice between the two installation methods depends on specific engineering requirements and cost considerations, and neither departs from the scope of protection of this application.

[0034] The core functions of the control unit 105 include three aspects: First, based on the internal and external air pressure difference of the energy storage chamber 102, the control pressure regulating unit 101 is configured to operate in either passive or active mode. The control unit 105 acquires the real-time air pressure difference value through an air pressure sensor (the sensor is not shown in the figure, but those skilled in the art will know that it can be obtained through one air pressure sensor inside and one outside the chamber). Specifically, if the internal and external air pressure difference exceeds a preset difference value, the control pressure regulating unit operates in active mode; otherwise, it operates in passive mode until the internal and external air pressure difference is within the preset difference value. This includes: when the air pressure difference is lower than the preset difference value, the control unit 105 sends a command to the pressure regulating unit 101 to shut down the active air pump and maintain a low-energy passive pressure regulating mode; when the air pressure difference exceeds the preset difference value and persists for a certain period of time, the control unit 105 starts the active air pump to force rapid pressure regulation until the air pressure difference falls back to a safe range. The preset difference value can typically be selected between 2 kPa and 5 kPa, for example, 3 kPa. Correspondingly, the time constant can be adaptively set between 5 seconds and 30 seconds; in this embodiment, 10 seconds is used. If the application scenario requires higher resistance to false triggering, the time window can be appropriately extended; if the system response to air pressure fluctuations is more sensitive, the delay can be shortened accordingly and a better sensor sampling and filtering algorithm can be used, all without departing from the protection scope of this application.

[0035] Second, early warning is issued based on the degree of seal deterioration. The control unit 105 continuously monitors the internal air pressure of the pressurization unit 104 and calculates its rate of decrease. If the rate of decrease exceeds a preset value, such as 0.5 kPa / day, it is determined that there is a leak in the pressurization unit or the composite sealing unit. The control unit 105 sends a seal aging warning to the remote operation and maintenance platform via the wireless communication module, prompting maintenance personnel to arrange for repair or replacement of the seal. This warning is usually issued before the seal completely fails, enabling predictive maintenance and avoiding sudden water leakage accidents.

[0036] Third, gas replenishment is performed based on the internal air pressure of the pressurization unit 104. In addition to monitoring the attenuation rate, the control unit 105 also monitors the absolute value of the internal air pressure of the pressurization unit 104. When this pressure value is lower than a preset lower limit, such as 30 kPa, it indicates that the sealing contact pressure is insufficient to guarantee the waterproof effect. At this time, the control unit 105 immediately opens the solenoid valve between the external air source and the pressurization unit 104, replenishing gas into the pressurization unit 104 until its internal air pressure returns to a safe pressure, such as 35 kPa. After gas replenishment is completed, the control unit 105 continues to monitor the air pressure attenuation rate. If the attenuation rate still exceeds the limit, it further confirms that the seal has irreversibly aged and issues a replacement warning.

[0037] In one possible embodiment, the sealing structure further includes: a pressure sensor for detecting the internal and external pressure difference; and a water immersion sensor for detecting water accumulation; wherein the pressure sensor and the water immersion sensor are respectively connected to the control unit.

[0038] Optionally, the control unit also includes a wireless communication module for transmitting information such as seal deterioration level, gas replenishment records, or early warning information to a remote operation and maintenance platform.

[0039] Optionally, the control unit 105 is also configured to: perform graded protection based on the water immersion signal detected by the water immersion sensor, including: starting the drainage pump when the water immersion signal reaches a first water level threshold; cutting off the main power supply when the water immersion signal reaches a second water level threshold; and issuing a remote alarm signal when the water immersion signal continues for more than a set time or reaches a third water level threshold.

[0040] The water immersion sensor is installed at the lowest point inside the energy storage compartment 102 to detect the water depth and duration in real time. When the water depth reaches a first water level threshold, such as 5 mm, the control unit 105 starts the drainage pump to discharge the water out of the compartment, records the event and reports it to the platform, but does not cut off the main power supply to ensure the continuous operation of the energy storage system. This level is used to actively remove water in the early stages of seepage to prevent the water level from rising.

[0041] If the water inflow rate is rapid and the water depth rises to the second water level threshold, for example, 15 mm, the control unit 105 determines that the water may touch live parts and immediately cuts off the main power supply, maintaining only the auxiliary power supply to the control unit. Simultaneously, the drainage pump continues to run until the water level drops below the first threshold. This level ensures that the electrical circuit is disconnected before a hazard occurs.

[0042] When the water depth reaches the third water level threshold, such as 25 mm, or when the depth exceeds the second threshold and the duration exceeds a set time, such as 10 seconds, the control unit 105 sends a remote alarm signal via the wireless communication module to notify the operation and maintenance platform and on-duty personnel for emergency handling. This level is used for immediate alarm of serious water ingress accidents.

[0043] The aforementioned thresholds and durations can be adjusted according to the size of the energy storage compartment, the battery installation height, and the drainage capacity, without departing from the scope of protection of this application.

[0044] On the other hand, such as Figure 2 The diagram shown is a flowchart illustrating a method for sealing and controlling underground energy storage according to an embodiment of this application. This method, based on any of the aforementioned sealing structures, specifically includes the following steps: S201, obtain the internal and external air pressure difference of the energy storage compartment; S202, if the internal and external air pressure difference exceeds the preset difference value, the pressure regulating unit is controlled to work in active mode; otherwise, it works in passive mode until the internal and external air pressure difference is within the preset difference value. S203, obtain the internal air pressure of the pressurization unit; if the rate of decrease of the internal air pressure exceeds the preset value, it is determined that there is a leak in the pressurization unit or the composite sealing unit, and a seal aging warning is issued. S204, if the internal air pressure is lower than the lower limit, control the supply of air to the pressurization unit until the internal air pressure is restored to the safe pressure; S205, after the air replenishment is completed, the rate of decrease of the internal air pressure is reacquired; S206 If the rate of decrease of the newly acquired internal air pressure still exceeds the preset value, it is determined that the composite sealing unit has irreversibly aged and a replacement warning is issued.

[0045] In this embodiment, the control unit acquires the internal and external air pressure difference ΔP of the energy storage chamber. The control unit 105 collects the internal air pressure and external atmospheric pressure in real time through an air pressure sensor and calculates the difference ΔP = P_internal – P_external; it then determines whether ΔP exceeds a preset difference (e.g., |ΔP|>3 kPa). If it does, the control pressure regulating unit 101 operates in an active mode, i.e., it starts the active air pump for forced ventilation; otherwise, it operates in a passive mode, i.e., it shuts off the active air pump and utilizes the thermal pressure difference between the chamber and the soil for natural airflow. This process continues until |ΔP|≤3 kPa.

[0046] For example, when the temperature drops sharply in the evening, the air pressure inside the chamber drops rapidly, ΔP reaches -4 kPa. The control unit immediately starts the active air pump to replenish the chamber with air. When ΔP rises back to -2 kPa, the air pump stops and switches to passive mode to maintain balance.

[0047] Simultaneously, the control unit also acquires the internal air pressure Pc of the pressurization unit 104 and calculates its rate of decrease v = dPc / dt. If v exceeds a preset value, such as 0.5 kPa / day, it determines that there is a leak in the pressurization unit or the composite sealing unit and issues a seal aging warning. For example, if continuous monitoring for 24 hours reveals that Pc drops from 35 kPa to 34.4 kPa at a rate of 0.6 kPa / day, exceeding 0.5 kPa / day, the control unit sends a warning about slight seal degradation to the maintenance platform via the wireless module, suggesting immediate maintenance. At the same time, it monitors the absolute value of Pc; if Pc falls below the lower limit, such as 30 kPa, it controls the pressurization unit to replenish air until Pc returns to a safe pressure, such as 35 kPa.

[0048] For example, during an inspection, it was found that Pc had dropped to 28 kPa. The control unit automatically opened the air replenishment solenoid valve and controlled the pressurization unit to inject compressed air. The valve was closed when the pressure rose to 35 kPa.

[0049] After the gas replenishment is completed, Pc is reacquired and its rate of decline is calculated. The control unit continues to monitor the pressure change over 24 hours to obtain a new decay rate, v_new. If v_new still exceeds the preset value, it is determined that the composite sealing unit has undergone irreversible aging, and a replacement warning is issued. For example, if the pressure drops from 35 kPa to 34.3 kPa after gas replenishment, and the rate of decline is still 0.7 kPa / day, it indicates that gas replenishment cannot completely eliminate the leak, and the control unit will send a mandatory maintenance command indicating that the sealing ring has failed. At this point, although the system can still operate for a short period of time, there is no safety margin, and replacement should be arranged as soon as possible.

[0050] Through the above steps, adaptive adjustment of air pressure difference, early warning of seal leakage, and automatic air replenishment maintenance are achieved, and replacement is prompted when air replenishment is ineffective, which significantly improves the intelligence level and reliability of buried energy storage seals.

[0051] On the other hand, embodiments of this application provide a buried energy storage system, such as Figure 3 The diagram shown is a structural schematic of a buried energy storage system, which includes an energy storage battery 301 and a buried energy storage sealing structure 302 as described above.

[0052] Reference Figure 1 , Figure 3 The energy storage battery 301 is installed inside the energy storage compartment 102 and can be a lithium-ion battery, a lithium iron phosphate battery, or other battery modules suitable for energy storage applications, for storing and releasing electrical energy. The buried energy storage sealing structure 302 includes a composite sealing unit 103 located at the junction of the compartment cover 1021 and the compartment body 1022 of the energy storage compartment 102, a pressure regulating unit 101 connecting the inside and outside of the compartment, a pressurizing unit 104 located inside the composite sealing unit 103, and a control unit 105, etc., which together provide long-term waterproof, moisture-proof and pressure balance protection for the energy storage battery 301.

[0053] In actual operation, the underground energy storage system is buried 1 to 3 meters underground. When the groundwater level rises or there is heavy rainfall, the external water pressure acts on the composite sealing unit 103, and the pressurization unit 104 automatically replenishes air according to the instructions of the control unit 105 to enhance the sealing contact pressure and prevent water from entering the chamber. When the temperature difference between day and night causes the air pressure inside the chamber to fluctuate, the pressure regulating unit 101 prioritizes maintaining the air pressure balance in a passive manner (natural flow due to thermal pressure difference), and only starts the active air pump to quickly regulate when the pressure difference is too large. At the same time, the control unit 105 monitors the internal air pressure decay rate of the pressurization unit 104 in real time and issues an early warning in the early stage of seal deterioration to avoid sudden water ingress accidents. Once the water immersion sensor detects water accumulation, the system performs graded protection: starts drainage, cuts off power, and remotely alarms.

[0054] By organically combining the energy storage battery 301 with the underground energy storage sealing structure 302, this system achieves long-term maintenance-free and highly reliable operation of energy storage equipment in underground environments. It effectively solves the technical problems of high water seepage risk, unknown sealing status, and high maintenance cost of traditional underground energy storage. It is suitable for scenarios such as distributed energy storage, base station backup power supply, and residential energy storage.

[0055] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A buried energy storage sealing structure, characterized in that, include: The pressure regulating unit connects the inside and outside of the energy storage compartment and is used to regulate the gas pressure balance in a passive or active manner. A composite sealing unit is located at the junction of the energy storage compartment cover and the compartment body; A pressurizing unit, located on the side of the composite sealing unit facing the interior of the chamber, is used to receive external gas, thereby increasing the internal gas pressure of the pressurizing unit and pressing the composite sealing unit from the inside to the outside to enhance the sealing contact pressure of the composite sealing unit. When the sealing material of the composite sealing unit undergoes permanent deformation due to long-term compression or the contact pressure decreases due to temperature changes, the sealing performance can be restored or even improved by replenishing gas. The control unit monitors the internal air pressure of the pressurization unit in real time and calculates the air pressure decay rate per unit time. When the sealing material ages, develops micro-cracks, or suffers installation damage, the gas inside the pressurization unit will leak faster, resulting in an increased air pressure decay rate. The air pressure decay rate can directly quantify the degree of sealing degradation of the composite sealing unit. The control unit is also used to control the pressure regulating unit to select passive or active operation based on the internal and external air pressure difference of the energy storage chamber; to perform early warning based on the degree of seal deterioration; and to perform air replenishment based on the internal air pressure of the pressurization unit; wherein, after air replenishment, if the air pressure decay rate still exceeds a preset value, it is determined that the composite sealing unit has irreversibly aged and a replacement early warning is issued.

2. The structure as described in claim 1, characterized in that, The pressure regulating unit includes a breathing channel connecting the interior and the exterior, a one-way valve installed on the breathing channel, and an active air pump that can be selectively activated. The passive method involves turning off the active air pump and using the thermal pressure difference between the interior and the surrounding soil to drive the natural flow of gas; the active method involves starting the active air pump to force pressure regulation.

3. The structure as described in claim 1, characterized in that, The composite sealing unit includes a water-swellable layer and a shape memory layer stacked sequentially along the sealing direction; The water-swellable layer is used to expand in volume when exposed to water to fill the gaps between the sealing surfaces; The shape memory layer is used to drive the water-swellable layer to restore its initial thickness when dry by means of the shape memory effect.

4. The structure as described in claim 1, characterized in that, The pressurization unit includes a sealable cavity and an inflation port communicating with the cavity; The control unit obtains the degree of seal deterioration by monitoring the rate of decrease in air pressure within the cavity.

5. The structure as described in claim 1, characterized in that, Also includes: A pressure sensor is used to detect the pressure difference between the inside and outside. Water immersion sensor, used to detect water accumulation; The air pressure sensor and the water immersion sensor are respectively connected to the control unit.

6. The structure as described in claim 5, characterized in that, The control unit is also used for: Based on the water immersion signal detected by the water immersion sensor, graded protection is implemented, including: The drainage pump is activated when the water immersion signal reaches the first water level threshold. The main power supply is cut off when the water immersion signal reaches the second water level threshold. When the water immersion signal continues for more than a set time or reaches the third water level threshold, a remote alarm signal is issued.

7. The structure as described in claim 1, characterized in that, The control unit also includes a wireless communication module for transmitting the degree of seal deterioration, gas replenishment records, or early warning information to a remote operation and maintenance platform.

8. A method for sealing and controlling buried energy storage based on the structure described in any one of claims 1 to 7, characterized in that, include: Obtain the pressure difference between the inside and outside of the energy storage compartment; If the internal and external air pressure difference exceeds the preset difference value, the pressure regulating unit is controlled to operate in an active mode; otherwise, it operates in a passive mode until the internal and external air pressure difference is within the preset difference value. Obtain the internal air pressure of the pressurization unit; If the rate of decrease of the internal air pressure exceeds a preset value, it is determined that there is a leak in the pressurization unit or the composite sealing unit, and a seal aging warning is issued. If the internal air pressure is lower than the lower limit, the system will control the supply of air to the pressurization unit until the internal air pressure is restored to a safe level.

9. The method as described in claim 8, characterized in that, Also includes: After the air replenishment is completed, the rate of decrease of the internal air pressure is re-acquired; If the rate of decrease of the newly acquired internal air pressure still exceeds the preset value, it is determined that the composite sealing unit has irreversibly aged, and a replacement warning is issued.

10. A buried energy storage system, characterized in that, It includes energy storage batteries and the underground energy storage sealing structure as described in any one of claims 1 to 7.

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