An immersed lithium battery energy storage system

Abstract

The utility model provides a kind of immersed lithium battery energy storage system, it includes: cabin body;Energy storage module, for one group or multiple groups, be set in cabin body, including battery PACK unit and PCS energy storage converter unit, battery PACK unit and PCS energy storage converter unit include box and the functional module being set in box respectively, functional module is battery module or energy storage converter module, cooling liquid for cooling functional module is loaded in box;Cooling module, including carbon dioxide storage tank, first heat exchanger and second heat exchanger, first heat exchanger is installed in box and is used to cool cooling liquid, the outlet end of carbon dioxide storage tank is sequentially connected with the inlet end of carbon dioxide storage tank after first heat exchanger and second heat exchanger and forms circulation pipeline, circulation pump is equipped on circulation pipeline.The utility model immersed lithium battery energy storage system, layout is reasonable, heat dissipation efficiency and battery conversion efficiency are high, power consumption is low and use safety is good.

Description

Technical Field

[0001] This utility model relates to an energy storage system, and more particularly to an immersion lithium battery energy storage system. Background Technology

[0002] With the rapid development of the new energy industry, lithium battery energy storage systems are widely used due to their advantages such as high energy density and fast response speed. Currently, lithium battery energy storage systems are divided into two main parts: a DC compartment and an AC compartment. The lithium battery PACK and PCS are located in the DC compartment and AC compartment, respectively. The cables connecting the two are complex, and the resulting line losses affect the battery conversion efficiency. At the same time, both the lithium battery PACK and PCS systems require heat dissipation, and the mainstream heat dissipation method for the PCS system is air cooling. The two cooling systems are independent and unrelated, which makes it inconvenient for the overall system thermal management and easily increases the system's additional energy consumption. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide an immersion lithium battery energy storage system with reasonable layout, high heat dissipation efficiency and battery conversion efficiency, low power consumption and good safety.

[0004] This utility model provides an immersion lithium battery energy storage system, which includes:

[0005] Cabin 1;

[0006] The energy storage module 2, which is one or more sets, is set inside the housing 1 and includes a battery PACK unit 2a and a PCS energy storage converter unit 2b. The battery PACK unit 2a and the PCS energy storage converter unit 2b respectively include a housing 21 and a functional module set inside the housing 21. The functional module is a battery module or an energy storage converter module. The housing 21 is filled with coolant for cooling the functional module.

[0007] The cooling module includes a carbon dioxide storage tank 3, a first heat exchanger 41 and a second heat exchanger 42. The first heat exchanger 41 is installed inside the housing 21 and is used to cool the coolant. The outlet end of the carbon dioxide storage tank 3 is connected to the inlet end of the carbon dioxide storage tank 3 through the first heat exchanger 41 and the second heat exchanger 42 in sequence to form a circulation pipeline. A circulation pump 5 is provided on the circulation pipeline.

[0008] Furthermore, the same group of energy storage modules 2 includes multiple battery PACK units 2a and one PCS energy storage converter unit 2b. The battery PACK units 2a and the PCS energy storage converter unit 2b are arranged vertically, with the PCS energy storage converter unit 2b located at the bottom.

[0009] Furthermore, it also includes a first branch pipe 311 connected to the outlet end of the carbon dioxide storage tank 3 and a second branch pipe 321 connected to the inlet end of the second heat exchanger 42, with each first heat exchanger 41 on the same energy storage module 2 connected in parallel between the first branch pipe 311 and the second branch pipe 321.

[0010] Furthermore, valves are provided at the inlet end of the first branch pipe 311 and / or the outlet end of the second branch pipe 321.

[0011] Furthermore, it also includes a first main pipe 31 connected to the outlet end of the carbon dioxide storage tank 3 and a second main pipe 32 connected to the inlet end of the second heat exchanger 42, with each of the first branch pipes 311 arranged in parallel on the first main pipe 31 and each of the second branch pipes 321 arranged in parallel on the second main pipe 32.

[0012] Furthermore, temperature sensors are provided on the first main pipe 31 and the second main pipe 32.

[0013] Furthermore, valves are provided at the inlet end of the first main pipe 31 and / or the outlet end of the second main pipe 32.

[0014] Furthermore, it also includes a fire-fighting pipeline 33 connected to the carbon dioxide storage tank 3, and a sprinkler head 34 is provided on the fire-fighting pipeline 33, which is located inside the cabin 1.

[0015] Furthermore, the nozzle 34 is located at the lower end of the chamber 1 and can fill the entire chamber 1 with carbon dioxide from bottom to top, and the upper end of the chamber 1 is provided with a pressure relief port 10 for exhaust.

[0016] Furthermore, the fire-fighting pipe 33 is connected to the inlet end of the second heat exchanger 42.

[0017] This utility model relates to an immersion lithium battery energy storage system. AC and DC equipment are integrated into a single compartment, shortening cable paths, reducing line loss and electromagnetic interference, and eliminating the need for separate compartments and high-voltage boxes, thus lowering costs and installation difficulty. It employs immersion cooling, using insulating coolant to isolate airborne dust, and the phase change characteristics of carbon dioxide for efficient temperature control. A shared cooling system reduces energy consumption. The stacked layout improves space utilization, with the PCS (Pressure Packet System) positioned at the bottom for easy maintenance. Modular piping design supports flexible expansion, and valves and temperature sensors enable rapid fault isolation and location. A shared carbon dioxide storage tank serves as a fire-fighting gas source, and the lower-mounted nozzles and upper-mounted pressure relief vents form an efficient fire-extinguishing path, enhancing safety. This utility model of an immersion lithium battery energy storage system features a reasonable layout, high heat dissipation and battery conversion efficiency, low power consumption, and good operational safety. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the submersible lithium battery energy storage system of this utility model;

[0019] Figure 2 This is a schematic diagram of the energy storage module of the immersion lithium battery energy storage system of this utility model;

[0020] Figure 3 This is a schematic diagram of the installation of the first heat exchanger in the immersion lithium battery energy storage system of this utility model;

[0021] Figure 4 This is a schematic diagram of the installation of the nozzle of the immersion lithium battery energy storage system of this utility model. Detailed Implementation

[0022] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0023] See Figures 1-4 This utility model provides an immersion lithium battery energy storage system, which includes a chamber 1, an energy storage module 2 and a cooling module.

[0024] Cabin 1 serves as the installation carrier; it is a box-like structure with a hollow interior, acting as the installation cavity.

[0025] Energy storage module 2 is installed inside the housing 1. The energy storage module 2 is one or more sets. Each set includes a battery PACK unit 2a and a PCS energy storage converter unit 2b. The battery PACK unit 2a and the PCS energy storage converter unit 2b each include a housing 21 and a functional module installed inside the housing 21. The functional module is either a battery module or an energy storage converter module. That is, when the functional module installed inside the housing 21 is a battery module, it forms a battery PACK unit 2a. When the functional module installed inside the housing 21 is an energy storage converter module, it forms a PCS energy storage converter unit 2b. Coolant is installed inside the housing 21. The coolant immerses the functional module for immersion cooling.

[0026] The cooling module is used to cool the coolant inside the housing 21. It includes a carbon dioxide storage tank 3, a first heat exchanger 41, and a second heat exchanger 42. The number of first heat exchangers 41 is the same as the number of housings and they correspond one-to-one. Specifically, the first heat exchanger 41 is a coil that is installed inside the housing 21 to cool the coolant. The outlet end of the carbon dioxide storage tank 3 is connected to the inlet end of the carbon dioxide storage tank 3 after passing through the first heat exchanger 41 and the second heat exchanger 42 in sequence, thus forming a circulation pipeline. A circulation pump 5 is provided on the circulation pipeline to provide the flow power for the carbon dioxide in the pipeline.

[0027] This application integrates the battery PACK unit 2a and the PCS energy storage converter unit 2b into the same compartment 1. The close integration of DC and AC side equipment shortens the cable path, reduces resistance loss and electromagnetic interference of long-distance cables, and improves energy conversion efficiency. It eliminates the need for complex cable trays and protection designs between independent compartments, reducing equipment costs and installation difficulty. The unified heat dissipation of the battery and PCS is achieved through a carbon dioxide circulating cooling module. Compared with the traditional air-cooling + liquid-cooling cooling method, it eliminates the power consumption of the PCS air-cooling fan and reduces energy consumption. At the same time, traditional air-cooling systems are susceptible to environmental dust and have limited heat dissipation capacity, which may lead to overheating of equipment in extreme cases. Independent cooling systems have dispersed failure risks and are complex to maintain. The functional modules of the battery PACK and PCS unit are completely immersed in insulating coolant, isolating air and dust, reducing the risk of short circuits, and improving operational reliability and safety.

[0028] The battery compartment in this application adopts an integrated AC / DC design, housing both the lithium battery pack and the PCS energy storage converter. This reduces the investment in energy storage system equipment, simplifies the structure, and integrates the PCS energy storage converter into the battery compartment. During lithium battery discharge and charging, DC power is directly converted into AC power by the PCS located below the pack for generation, or the PCS converts AC power from the grid into DC power to charge the lithium battery. This eliminates the need for high-voltage box equipment in traditional battery compartments. Furthermore, the integration of the lithium battery pack and PCS within the same compartment significantly reduces cable usage, lowers line losses, and substantially enhances safety and maintainability. It is suitable for high-density, low-power scenarios in large-scale lithium battery energy storage power stations.

[0029] Both the PCS and the lithium battery PACK adopt an immersion cooling method and share a cooling system, which facilitates the thermal management of the entire system. The interior of the PCS and lithium battery PACK are immersed in coolant to dissipate heat from their respective heat-generating electrical components. Then, the first heat exchanger inside dissipates heat from the immersed coolant. The medium in the first heat exchanger is CO2. By utilizing the phase change characteristics of CO2, the temperature of the coolant inside the entire chamber is balanced, resulting in good cooling effect. At the same time, the PCS and lithium battery PACK share a cooling coil including a temperature monitoring system, which facilitates the thermal management of the entire battery compartment.

[0030] In this application, the energy storage module 2 of the same group includes multiple battery PACK units 2a and one PCS energy storage converter unit 2b. The battery PACK units 2a and PCS energy storage converter unit 2b are arranged vertically, with the PCS energy storage converter unit 2b located at the bottom. Multiple battery PACK units and one PCS unit are integrated into the same energy storage module by stacking vertically, avoiding the need for excessive space occupation due to planar dispersion, resulting in a reasonable layout and improved space utilization. The battery PACK units (DC side) and PCS units (AC side) are adjacent vertically, shortening the connection length of the DC cable and reducing resistance loss. At the same time, the short cable can reduce electromagnetic radiation generated during high-frequency switching, avoid signal distortion caused by traditional long cables, and improve the power conversion efficiency of the PCS. Meanwhile, as the control core of the system, the PCS requires regular maintenance. By arranging it at the bottom, personnel do not need to climb to heights and can operate directly on the ground, facilitating maintenance and repair without the need for tools, thus reducing the risk of falls from heights.

[0031] In this embodiment, a first branch pipe 311 and a second branch pipe 321 are also included. The first branch pipe 311 is connected to the outlet end of the carbon dioxide storage tank 3, and the second branch pipe 321 is connected to the inlet end of the second heat exchanger 42. Each first heat exchanger 41 on the same energy storage module 2 is connected in parallel between the first branch pipe 311 and the second branch pipe 321 to form an independent energy storage cooling module. In the parallel pipeline, the flow resistance of each first heat exchanger 41 is independent of each other, and the total circulation resistance is only the flow resistance of a single heat exchanger. The circulation pump 5 does not need to overcome the high resistance of the series connection, which can reduce the driving power. At the same time, the flow distribution of carbon dioxide in the parallel branch is more uniform, avoiding the flow attenuation problem of the preceding heat exchanger being too cold and the subsequent heat exchanger being too hot when connected in series. This reduces power consumption, improves the cooling uniformity of each unit, and enhances the reliability and adaptability of the system, providing key support for the safe and stable operation of the high-density energy storage system.

[0032] To improve operational flexibility, valves are installed at the inlet end of the first branch pipe 311 and the outlet end of the second branch pipe 321. When a certain energy storage module 2 malfunctions, its cooling circuit needs to be quickly cut off to avoid affecting the entire system. By setting valves, carbon dioxide can be blocked from entering the faulty module, preventing high-pressure carbon dioxide leakage or carrying pollutants into the main circulation, and avoiding the reverse flow of carbon dioxide in the main circulation into the faulty area. This allows the faulty module to be isolated independently, while other normal modules are not affected, facilitating maintenance and upkeep.

[0033] In this embodiment, a first main pipe 31 and a second main pipe 32 are also included. The first main pipe 31 is connected to the outlet end of the carbon dioxide storage tank 3, and the second main pipe 32 is connected to the inlet end of the second heat exchanger 42. The first branch pipes 311 of each energy storage module are arranged in parallel on the first main pipe 31, and the second branch pipes 321 are arranged in parallel on the second main pipe 32. The first main pipe 31 and the second main pipe 32 serve as the main circuit of the system. The first branch pipes 311 and the second branch pipes 321 of each energy storage module are connected to the main pipe through parallel branches. When adding a new energy storage module, only the branch pipes need to be connected at the reserved interface of the main pipe. There is no need to reconstruct the main circulation pipeline, which can realize modular expansion. The first main pipe 31 and the second main pipe 32 are laid along the length of the cabin 1, and the branch pipes connect vertically downward to each module. The pipeline route is clear and orderly, and the pipeline layout is reasonable and orderly, which facilitates construction and maintenance.

[0034] Temperature sensors are installed on the first main pipe 31 and the second main pipe 32 to detect problems at the inlet and outlet ends. The temperature of the first main pipe 31 can monitor the initial temperature of the coolant output from the carbon dioxide storage tank 3. If the temperature rises abnormally, it can be determined that the tank pressure is insufficient or the carbon dioxide liquefaction system is faulty. The temperature of the second main pipe 32 can monitor the temperature of the coolant returning after absorbing heat from each energy storage module. If the temperature exceeds the threshold, it indicates that the total heat generation of the system exceeds the cooling capacity, and the backup cooling unit needs to be activated immediately. This can quickly locate the source of the fault and shorten the troubleshooting time.

[0035] For ease of maintenance, valves are provided at the inlet end of the first main pipe 31 and the outlet end of the second main pipe 32, which can realize pipeline control of the first main pipe 31 and the second main pipe 32, and can control the pressure and flow rate in the circulation pipeline to adapt to different operating conditions.

[0036] To enhance safety, this application also includes a fire-fighting pipeline 33 connected to the carbon dioxide storage tank 3. The fire-fighting pipeline 33 is equipped with a sprinkler head 34 located inside the cabin 1. A valve is installed on the fire-fighting pipeline, which can be automatically triggered when a fire is detected. The fire-fighting pipeline 33 is directly connected to the carbon dioxide storage tank 3, eliminating the need for an additional independent fire-fighting gas cylinder group, thus saving equipment procurement costs and installation space inside the cabin 1. Carbon dioxide serves as both the cooling medium and the fire-fighting medium for the energy storage module, and is supplied uniformly by the storage tank 3, simplifying the pipeline layout and control system and reducing the failure rate of multi-system coordination.

[0037] In this embodiment, the nozzle 34 is located at the lower end of the chamber 1, allowing carbon dioxide to fill the entire chamber 1 from bottom to top. Simultaneously, a pressure relief port 10 for exhaust is located at the upper end of the chamber 1. Since carbon dioxide is much denser than air, when the nozzle 34 is located at the lower end of the chamber 1, the released carbon dioxide will naturally sink and diffuse outwards, forming a covering process that accumulates from the ground upwards, gradually filling the entire chamber space. If the nozzle were located at the top, the carbon dioxide would easily sink directly to the middle area due to gravity, resulting in insufficient coverage of the bottom space. Firefighting blind spots; while the bottom-mounted nozzles ensure that carbon dioxide preferentially fills the lower part of the chamber and then spreads upward to the top, achieving coverage without dead angles; at the same time, the pressure relief port at the upper end of the chamber 1 (usually equipped with a pressure-opening valve) automatically opens during the carbon dioxide filling process, quickly expelling air or flammable gas outside the chamber, avoiding excessive pressure inside the chamber that could lead to gas mixing disorder, and through the bottom-in, top-out airflow path, significantly suppressing the chain reaction of lithium battery thermal runaway, and improving the fire extinguishing speed; in this application, the fire-fighting pipeline 33 is connected to the inlet end of the second heat exchanger 42.

[0038] This application employs carbon dioxide gas fire suppression, with nozzles placed at the bottom of the battery compartment. This achieves a carbon dioxide flooding fire suppression effect, ensuring system installation. When the lithium battery pack experiences thermal runaway or fire, the valve on the branch of the CO2 pipeline is opened, and the fire suppression pipeline at the bottom of the battery compartment sprays CO2 gas through the nozzles. Since the density of CO2 is much greater than that of flammable gases such as H2 generated by the thermal runaway of the lithium battery pack, the sprayed CO2 can "flood" the entire battery compartment from bottom to top, driving the flammable gases to the top of the battery compartment and discharging them through the pressure relief port, preventing the accumulation of flammable gases and the resulting fire.

[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. An immersion lithium battery energy storage system, characterized in that, include: hull; An energy storage module, consisting of one or more units, is housed within the compartment and includes a battery pack unit and a PCS energy storage converter unit. Each battery pack unit and the PCS energy storage converter unit includes a housing and a functional module housed within the housing. The functional module is either a battery module or an energy storage converter module. The housing contains a coolant for cooling the functional module. The cooling module includes a carbon dioxide storage tank, a first heat exchanger, and a second heat exchanger. The first heat exchanger is installed inside the tank and is used to cool the coolant. The outlet end of the carbon dioxide storage tank is connected to the inlet end of the carbon dioxide storage tank in sequence through the first heat exchanger and the second heat exchanger to form a circulation pipeline. A circulation pump is provided on the circulation pipeline.

2. The immersion lithium battery energy storage system as described in claim 1, characterized in that: The same group of energy storage modules includes multiple battery PACK units and one PCS energy storage converter unit. The battery PACK units and the PCS energy storage converter unit are arranged vertically, with the PCS energy storage converter unit located at the bottom.

3. The immersion lithium battery energy storage system as described in claim 1, characterized in that: It also includes a first branch pipe connected to the outlet end of the carbon dioxide storage tank and a second branch pipe connected to the inlet end of the second heat exchanger, with each first heat exchanger on the same energy storage module connected in parallel between the first branch pipe and the second branch pipe.

4. The immersion lithium battery energy storage system as described in claim 3, characterized in that: A valve is provided at the inlet end of the first branch pipe and / or the outlet end of the second branch pipe.

5. The immersion lithium battery energy storage system as described in claim 3, characterized in that: It also includes a first main pipe connected to the outlet end of the carbon dioxide storage tank and a second main pipe connected to the inlet end of the second heat exchanger, with each of the first branch pipes arranged in parallel on the first main pipe and each of the second branch pipes arranged in parallel on the second main pipe.

6. The immersion lithium battery energy storage system as described in claim 5, characterized in that: Temperature sensors are provided on the first manifold and the second manifold.

7. The immersion lithium battery energy storage system as described in claim 5, characterized in that: A valve is provided at the inlet end of the first main pipe and / or the outlet end of the second main pipe.

8. The immersion lithium battery energy storage system as described in claim 1, characterized in that: It also includes a fire-fighting pipeline connected to the carbon dioxide storage tank, the fire-fighting pipeline being equipped with sprinklers located inside the chamber.

9. The immersion lithium battery energy storage system as described in claim 8, characterized in that: The nozzle is located at the lower end of the chamber and can fill the entire chamber with carbon dioxide from bottom to top. The upper end of the chamber is provided with a pressure relief port for exhaust.

10. The immersion lithium battery energy storage system as described in claim 8, characterized in that: The fire-fighting pipeline is connected to the inlet end of the second heat exchanger.

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