Submerged liquid-cooled energy storage battery pack and battery pack testing device

Abstract

The present application relates to the field of battery energy storage, and particularly relates to a submerged liquid-cooled energy storage battery pack and a battery pack testing device. The submerged liquid-cooled energy storage battery pack is provided with an electric core cooling cavity in the shell, a plurality of liquid inlet holes and a plurality of liquid outlet holes are respectively arranged on the two opposite side walls and staggered along the second direction, two rows of electric core modules are arranged at intervals along the second direction, a first heat dissipation flow channel is formed therebetween, and a second heat dissipation flow channel is formed between adjacent electric cores. The liquid inlet holes are arranged opposite to the first heat dissipation flow channel in the first direction and are injected in multiple points. The liquid outlet holes are staggered with the first heat dissipation flow channel and are respectively connected to each second heat dissipation flow channel. The flow cross section of the first heat dissipation flow channel decreases along the first direction to match the flow distribution along the path and approximately equalize the static pressure. This structure realizes uniform sending in the middle and uniform taking on both sides, suppresses short-circuit flow and stagnant flow, and improves the flow consistency of the gap and the gap between the electric cores and the uniformity of the heated wall surface temperature under the condition of low resistance increase.

Description

Technical Field

[0001] This invention relates to the field of battery energy storage, specifically to an immersion liquid-cooled energy storage battery pack and a battery pack testing device. Background Technology

[0002] This application relates to the field of liquid immersion thermal management technology, and particularly to flow distribution and temperature control for multi-cell modules / multi-channel cavities. With the continuous increase in power density of power batteries, energy storage batteries, and high heat flux density electronic components, higher demands are placed on the uniformity and controllability of cooling methods for heated surfaces (e.g., the large surface area, sides, and tab area of ​​the cell). Immersion thermal management, because the cooling medium is in direct contact with the heated surface, can significantly reduce interfacial thermal resistance and suppress local overheating, and has become an important technical approach in recent years. However, the flow distribution and path organization under immersion conditions are often affected by factors such as cavity geometry, component obstruction, manufacturing tolerances, gravity / buoyancy coupling, and changes in heat flux under various operating conditions. This leads to uneven flow within the cavity, unbalanced boundary layer development, and the formation of backflow / stagnant zones, which in turn cause uneven temperature distribution on the heated surface and deterioration of hydrodynamic performance.

[0003] Existing immersion thermal management systems still have significant room for improvement in the comprehensive trade-off between temperature uniformity, pressure drop / pump power, structural / assembly tolerance, and adaptability to multiple operating conditions. Particularly in the narrow channels where multiple battery cells are arranged side-by-side, a key technical challenge is how to construct a flow field with sufficient in-plane expansion, effective secondary flow disturbance, and robust recirculation organization through a more rational flow distribution strategy. This would allow for a significant improvement in the temperature uniformity of the heated walls and optimization of hydrodynamic performance (including pressure drop, energy consumption, flow-induced vibration, and scouring) without excessively increasing the system pressure drop. Summary of the Invention

[0004] The objective of this invention is to at least solve the problem of uneven temperature distribution in the battery cell during cooling. This objective is achieved through the following technical solution: This invention proposes an immersion liquid-cooled energy storage battery pack, characterized in that it comprises: The housing has a cell cooling cavity formed inside it. The cell cooling cavity has a first sidewall and a second sidewall that are disposed opposite to each other in a first direction. The first sidewall has at least one inlet hole for coolant to enter, and the second sidewall has at least one outlet hole for coolant to exit. In a second direction, the outlet hole and the inlet hole are offset from each other. The first direction and the second direction are perpendicular to each other. At least two rows of battery cell modules are arranged at intervals along the second direction. A first heat dissipation channel is formed between two adjacent battery cell modules. The first heat dissipation channel and the liquid outlet are staggered along the second direction. Along the first direction, the projection of the liquid inlet coincides with the projection of the first heat dissipation channel, and the flow cross-section of the first heat dissipation channel decreases along the first direction. Multiple battery cells in each row of battery cell modules are arranged at intervals along the first direction. A second heat dissipation channel is formed between adjacent battery cells. The water inlet end of the second heat dissipation channel is connected to the first heat dissipation channel, and the water outlet end of the second heat dissipation channel is connected to the liquid outlet.

[0005] According to the immersion liquid-cooled energy storage battery pack of the present invention, multiple liquid inlet holes are provided on the first sidewall of the cell cooling cavity, and multiple liquid outlet holes are provided on the second sidewall, with the two being staggered along the second direction. The projection of the liquid inlet holes in the first direction coincides with the projection of the first heat dissipation channel formed between the two rows of cell modules, allowing the coolant to directly enter the first heat dissipation channel (main slot channel) as a multi-point jet. The staggered arrangement of the liquid outlet holes avoids the inlet and outlet crossing each other to form a short-circuit flow, forcing the fluid to fully traverse between the two rows before orderly merging out through the second heat dissipation channel between each cell, forming a closed-loop distribution of uniform supply and uniform intake. Furthermore, the flow cross section of the first heat dissipation channel decreases along the first direction, matching the volume distribution of the continuous flow of the second heat dissipation channels along the length of the flow path. This can approximately equalize the static pressure of the flow path and stabilize the axial flow velocity of the main channel, allowing the second heat dissipation channels at different positions to obtain more consistent driving force and branch flow, reducing the bias caused by near-far effect, assembly tolerance, and geometric inconsistency. Multi-point liquid inlet and dispersed liquid outlet simultaneously increase the average residence time within the cavity and suppress stagnant and backflow zones. Thus, without significantly increasing the overall pressure drop, dual-scale flow uniformity is achieved between the gaps between the two rows of cells and between the cells themselves. This significantly improves the in-plane and friction-related temperature uniformity of the heated wall surface, reduces stress differences caused by local hot spots and temperature variations, effectively solves the technical problem of uneven cell temperature distribution under cooling conditions, and also considers hydrodynamic performance.

[0006] In addition, the submersible liquid-cooled energy storage battery pack according to the present invention may also have the following additional technical features: In some embodiments of the present invention, a plurality of second heat dissipation channels are formed within the battery cell module, and along the first direction, the flow cross-section of the second heat dissipation channel located in the middle is larger than the flow cross-section of the second heat dissipation channels located at both ends.

[0007] In some embodiments of the present invention, the first heat dissipation channel includes a plurality of tapered sections arranged sequentially along the first direction, wherein the flow cross section of the tapered section on the side away from the liquid inlet is smaller than the flow cross section of the tapered section on the side closer to the liquid inlet.

[0008] In some embodiments of the present invention, the spacing between two adjacent battery cell modules gradually decreases along the direction of the first sidewall toward the first sidewall.

[0009] In some embodiments of the present invention, the housing is provided with an outlet and two inlets arranged opposite to each other along the second direction, and along the first direction, an inlet chamber and an outlet chamber are respectively formed on both sides of the cell cooling cavity inside the housing. The inlet chamber is connected to the cell cooling cavity through the inlet hole, the outlet chamber is connected to the cell cooling cavity through the outlet hole, the inlet is connected to the inlet chamber, and the outlet is connected to the outlet chamber.

[0010] In some embodiments of the present invention, the submersible liquid-cooled energy storage battery pack further includes a separator, which is disposed within the housing and divides the housing into a first part and a second part that are isolated from each other. The first part includes the liquid inlet chamber and the cell cooling chamber, and the second part includes a tab cooling chamber, in which the tabs of the cell module are housed.

[0011] In some embodiments of the present invention, the immersion liquid-cooled energy storage battery pack further includes a liquid level regulator, which is connected to the liquid outlet and is used to adjust the liquid level in the tab cooling chamber.

[0012] In some embodiments of the present invention, the submerged liquid-cooled energy storage battery pack further includes a battery management system, which is electrically connected to the busbar of the cell module.

[0013] In some embodiments of the present invention, at least one liquid inlet hole includes a plurality of liquid inlets, at least one liquid outlet hole includes a plurality of liquid outlet holes, the plurality of liquid inlets are arranged at equal intervals along a third direction, the plurality of liquid outlet holes are arranged at equal intervals along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other. Attached Figure Description

[0014] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the structure of an immersed liquid-cooled energy storage battery pack according to an embodiment of the present invention is shown. Figure 2 A schematic front view of an immersed liquid-cooled energy storage battery pack according to an embodiment of the present invention is shown. Figure 3 A schematic diagram of the structure of a partially submerged liquid-cooled energy storage battery pack according to an embodiment of the present invention is shown. Figure 4 A left view of an immersed liquid-cooled energy storage battery pack according to an embodiment of the present invention is shown schematically. Figure 5 for Figure 4 A cross-sectional view of the AA plane; Figure 6 for Figure 4 A cross-sectional view of the BB plane; Figure 7 for Figure 6 A magnified view of a section at point C; Figure 8 for Figure 6 A magnified view of a section at point D; Figure 9 for Figure 6 A magnified view of a section at point E in the middle; Figure 10 A schematic diagram of the structure of the liquid inlet plate according to an embodiment of the present invention is shown. Figure 11 A schematic diagram of the structure of the liquid outlet plate according to an embodiment of the present invention is shown. Figure 12 A schematic diagram of the structure of a battery cell according to an embodiment of the present invention is shown. Figure 13 A schematic diagram of the structure of a liquid level regulator according to an embodiment of the present invention is shown.

[0015] The attached figures are labeled as follows: 100. Immersed liquid-cooled energy storage battery pack; 10. Housing; 101. Liquid inlet chamber; 102. Cell cooling chamber; 103. Liquid outlet chamber; 104. Tab cooling chamber; 11. Liquid inlet; 12. Liquid outlet; 13. Power harness interface; 141. First interface; 142. Second interface; 15. Communication port; 20. Liquid level regulator; 21. Outlet regulating plate; 30. Cell module; 301. First module; 302. Second module; 303. First heat dissipation channel; 304. Second heat dissipation channel; 305. Third heat dissipation channel; 31. Cell; 311. Rubber strip; 40. Separator; 50. Battery management system; 60. Liquid inlet plate; 61. Liquid inlet hole; 70. Liquid outlet plate; 71. Liquid outlet hole; 80. Busbar. Detailed Implementation

[0016] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0017] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0018] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0019] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0020] like Figures 1 to 13As shown, according to an embodiment of the present invention, an immersed liquid-cooled energy storage battery pack 100 is provided, which includes a housing 10 and a cell cooling cavity 102 disposed within the housing 10. For ease of description, the length direction of the housing 10 is defined as the first direction (e.g., Figure 1 (As indicated by the middle arrow x), the width direction of the housing 10 is defined as the second direction (e.g., Figure 1 (As indicated by the middle arrow y), the height direction of the shell 10 is defined as the third direction (e.g., Figure 1 (As indicated by the middle arrow z). The cell cooling chamber 102 has a first sidewall and a second sidewall that are arranged opposite to each other in the first direction. A plurality of inlet holes 61 for allowing coolant to enter are formed on the first sidewall, and a plurality of outlet holes 71 for allowing coolant to exit are formed on the second sidewall. The inlet holes 61 and the outlet holes 71 are staggered along the second direction, that is, their centers do not coincide in the projection along the second direction, so as to avoid short-circuit flow caused by the inlet and outlet penetrating each other.

[0021] At least two rows of battery cell modules 30 are arranged within the battery cell cooling chamber 102, with the at least two rows of battery cell modules 30 spaced apart along a second direction. The gap between adjacent rows of battery cell modules 30 forms a first heat dissipation channel 303. Along the first direction, the projection of the liquid inlet hole 61 coincides with the projection of the first heat dissipation channel 303, allowing the incoming coolant to be injected directly into the first heat dissipation channel 303 (i.e., the main channel between the gaps) between the two rows as a multi-point jet, thereby improving the coverage and uniformity of the inflow from the source. To match the branch flow along the length of the flow path, the first heat dissipation channel 303 is configured with a flow cross-section that gradually decreases along the first direction. In this specification, the flow cross-section refers to the effective cross-sectional area through which the coolant can pass, which is equivalent to or approximately equivalent to the geometric cross-sectional area.

[0022] Multiple battery cells 31 within each row of battery cell modules 30 are arranged at intervals along a first direction. A second heat dissipation channel 304 is formed between adjacent battery cells 31, and multiple second heat dissipation channels 304 are formed between multiple battery cells 31. The inlet end of each second heat dissipation channel 304 is connected to the first heat dissipation channel 303, and the outlet end is connected to the outlet hole 71 on the second side wall. By using the first heat dissipation channel 303 as the main distribution channel and the second heat dissipation channel 304 as the terminal branch, the coolant is continuously distributed to the gaps between each battery cell 31 while traversing the two rows of main gaps to flush the heated wall surface (large surface of battery cell 31) of the battery cell 31, and finally flows into the outlet hole 71 for discharge, thereby forming a distribution and collection topology of uniform delivery and uniform intake.

[0023] In a preferred embodiment, the inlet holes 61 and outlet holes 71 can be circular holes, oblong holes, or slotted holes, and are arranged in rows at equal intervals along a third direction. To further improve the flow uniformity, the diameter d of the inlet hole 61 and the hole spacing p between two adjacent inlet holes 61 are set. The ratio of d / p can be in the range of 0.2 to 0.6. The total open area of ​​the outlet holes 71 is preferably matched with the target volumetric flow rate of the entire cavity, so that the average Reynolds number of a single hole is within the desired range, so as to obtain stable convection enhancement without excessively increasing the pressure drop. The arrangement of the array of inlet holes 61 opposite to the first heat dissipation channel 303 can be achieved by limiting the coincidence of the projection of their centers in the first direction, preferably with the centerline angle ≤ 5°.

[0024] In another embodiment, to reduce the sensitivity of manufacturing tolerances to flow uniformity, rounded or slightly chamfered guide edges can be provided on both sides of the first heat dissipation channel 303 to reduce the inlet recirculation zone. The inlet of the second heat dissipation channel 304 can be provided with a short straight section or a small flared opening to stabilize the incident streamline and reduce the inlet local loss coefficient. In addition, a flow-collecting groove can be provided on the inner side of the second sidewall where the liquid outlet 71 is located. The flow-collecting groove is located between two adjacent liquid outlets 71 to reduce the flow difference between adjacent liquid outlets 71.

[0025] In operation, the battery pack supplies coolant to the inlet port 61 through the inlet pipe. The coolant flows through the first heat dissipation channel 303 across the two rows of cells 31 and is distributed to each of the second heat dissipation channels 304 along the flow path. After sufficient convective heat transfer is formed between the large surface and the side surface of the cell 31, the coolant is discharged through the staggered outlet ports 71. Since the flow cross-section of the first heat dissipation channel 303 decreases along the first direction, the static pressure and branch pressure difference along the flow path tend to be consistent, effectively suppressing near-end undercooling, far-end overheating, and through-flow short-circuit flow, significantly improving the temperature uniformity in the plane and along the flow path, while avoiding excessive increase in overall pressure drop due to passive flow equalization, thus balancing thermal performance and hydrodynamic performance.

[0026] Optionally, this embodiment can also combine temperature sensing and flow monitoring. Temperature sensors and flow meters are installed in the cell cooling chamber 102 or on the pipeline. The battery management system 50 and the thermal management controller adjust the pump speed and valve opening according to the temperature difference and the target flow value. When a large temperature rise is detected on one side, the overall flow can be increased for a short time to further improve the system's response speed to non-uniform heat loads.

[0027] In some embodiments, to improve the temperature uniformity of the heated wall surfaces of the battery cells 31 at various locations, multiple battery cells 31 within the battery cell module 30 are arranged at intervals along a first direction, forming a second heat dissipation channel between adjacent battery cells, thereby forming multiple second heat dissipation channels 304. Specifically, along the first direction, the flow cross-section of the second heat dissipation channel 304 located in the central region is larger than the flow cross-section of the second heat dissipation channels 304 located in the two end regions.

[0028] Specifically, the second heat dissipation channels 304 arranged sequentially along the first direction are defined as the j-th channel (j=1…n). Taking the midpoint of this row of cells 31 as a symmetry reference, the flow cross-section Smid of the middle channel is greater than the flow cross-section Send of the channels at both ends. Preferably, Smid / Send is in the range of 1.1 to 1.6, more preferably in the range of 1.2 to 1.4. And along the first direction, it decreases monotonically or stepwise from the middle to both ends, that is, S{j}≥S{j±1}, until the ends. The aforementioned distribution of a large flow cross-section in the middle and a small flow cross-section at both ends can be achieved through the following structures: First, using differential thickness positioning spacers (such as rubber strips 311) to make the net distance between adjacent cells 31 in the middle slightly larger than the net distance at both ends; second, setting wedge-shaped, flared, or stepped flow-limiting components at the inlet or middle section of the second heat dissipation channel 304 to make the flow channels at both ends locally contract while maintaining a larger opening in the middle; third, using module side frames or limiting ribs to pre-form small chamfers or local flanges in the areas at both ends to reduce the effective cross-section, while the middle section has no such limiting. Combined with the aforementioned connection between the first heat dissipation channel 303 and the outlet hole 71, the second heat dissipation channel 304 located in the middle obtains a relatively higher flow cross-section due to its longer path and larger local losses, thus distributing a branch flow rate closer to the design value under a given pressure difference. The second heat dissipation channels 304 located at both ends suppress short-circuit flow and near-outlet undercooling effect through their smaller flow cross-sections.

[0029] This improves the consistency of flow distribution along the first direction without significantly increasing the overall pressure drop, reduces near-end flow bias and far-end overheating, and enhances the in-plane and along-the-path temperature uniformity of the cell module 30 during charging and discharging. The aforementioned dimensions and proportions can be conventionally optimized and adjusted according to the target volumetric flow rate, dielectric properties, and allowable pressure drop window, all falling within the scope of this embodiment.

[0030] In some embodiments, a first heat dissipation channel 303 is disposed between two rows of battery cell modules 30 and includes multiple tapered sections sequentially along a first direction, with adjacent tapered sections connected by transition sections. The flow cross-section of the i-th tapered section is denoted as Si (i=1…n), satisfying S{i+1}<Si, to match the continuous flow branching along the flow path to each branch and approximately equalize the static pressure along the path. Multiple battery cells 31 within each row of battery cell modules 30 are arranged at intervals along the first direction, and a second heat dissipation channel 304 is formed between each pair of adjacent battery cells 31. Thus, multiple second heat dissipation channels 304 are sequentially formed along the first direction in this row (which can be denoted as the j-th second heat dissipation channel 304, j=1…m, where m equals the number of battery cells 31 in this row minus one). With the above structure, the coolant is injected into the first heat dissipation channel 303 between the two rows through the inlet hole 61. Along the way, it maintains a more stable axial velocity and branch pressure difference at each tapering section, and is distributed segment by segment into each of the second heat dissipation channels 304 composed of adjacent cells 31 to flush the heated wall surface of the cell 31. Finally, it is discharged through the staggered outlet holes 71, thereby achieving dual-scale (between row gap and between cell 31 gap) flow uniformity and temperature uniformity improvement without significantly increasing the pressure drop.

[0031] In some embodiments, at least two rows of battery cell modules 30 are arranged opposite each other along a second direction, forming a first heat dissipation channel 303 between them. The distance between two adjacent battery cell modules 30 gradually decreases along the first direction, thereby making the effective flow cross-section of the first heat dissipation channel 303 gradually narrow in the first direction. In this specification, the distance refers to the net distance between the two rows of battery cell modules 30 in the second direction, and the corresponding narrowing angle is preferably 1° to 5°. During operation, the coolant enters from the inlet side and propagates in the first heat dissipation channel 303 along the first direction. As the distance between the two rows of modules decreases along the path, the axial velocity of the main channel and the static pressure distribution at the lateral opening tend to be consistent, thereby providing closer driving force and flow distribution for each second heat dissipation channel 304. With the staggered exhaust on the outlet side, it can effectively suppress near-inlet short-circuit flow and far-end overheating, and improve the dual-scale flow uniformity and heat-receiving wall temperature uniformity of the gaps between the two rows and the gaps between the battery cells 31 without significantly increasing the overall pressure drop.

[0032] Multiple inlet holes 61 provided on the first sidewall are arranged in a row at equal intervals along the third direction, with the center-to-center distance between adjacent inlet holes 61 being the hole pitch p3. Multiple outlet holes 71 provided on the second sidewall are also arranged in a row at equal intervals along the third direction, with the center-to-center distance between adjacent outlet holes 71 being p3 (or the same as the inlet hole pitch / different fixed values ​​as needed). Preferably, the deviation of the center-to-center distance of each hole in the third direction is no greater than ±δ (e.g., ±0.2 mm). In a preferred embodiment, the end distance between the inlet holes 61 and the outlet holes 71 is approximately p3 / 2 to make the hole array approximately symmetrical about the cavity centerline in the third direction, reducing the flow rate offset between the upper and lower sections. The inlet holes 61 and the outlet holes 71 can be circular holes, oblong holes, or slotted holes, with the hole diameter d or equivalent width w remaining consistent within a row to ensure consistent hydraulic characteristics across vertical layers. By using the aforementioned equally spaced holes along the third direction, a uniform distribution of inlet / outlet taps is formed in the vertical height direction (third direction). Combined with the aforementioned staggered relationship along the second direction and the first heat dissipation channel 303 between the two rows of battery cell modules 30, similar local pressure difference and branch supply and drainage capacity can be obtained at different height levels, suppressing vertical flow deviation and temperature difference caused by buoyancy / thermal stratification, thereby further improving the temperature uniformity and hydrodynamic stability of the battery cell cooling cavity 102 in the plane and along the path.

[0033] Specifically, an outlet 12 and two inlets 11 arranged opposite each other along the second direction are provided on the outer wall of the housing 10. Correspondingly, an inlet chamber 101 and an outlet chamber 103 are respectively formed on both sides of the battery cell cooling cavity 102 inside the housing 10 along the first direction. The two inlets 11 are connected to the inlet chamber 101, and the outlet 12 is connected to the outlet chamber 103, forming a closed flow path.

[0034] The liquid inlet chamber 101 is formed by the liquid inlet plate 60 and the end of the housing 10, with a liquid inlet hole 61 provided on the side facing the cell cooling chamber 102 as the first sidewall. The liquid outlet chamber 103 is formed by the liquid outlet plate 70 and the other end of the housing 10, with a liquid outlet hole 71 provided on the side facing the cell cooling chamber 102 as the second sidewall. The two liquid inlets 11 are preferably symmetrical about the centerline in the second direction and are connected to the external circulation pipeline through flanges or quick connectors. The interface is provided with a medium-resistant sealing ring and a supporting rib to improve sealing and rigidity. The liquid outlet 12 is arranged at the end near the liquid outlet chamber 103, and a manifold can be provided on the inner side to balance the difference in pumping and discharging between adjacent liquid outlet holes 71.

[0035] During operation, coolant enters the inlet chamber 101 through two inlets 11, and is injected into the cell cooling chamber 102 at multiple points through the inlet holes 61 on the first sidewall. It then propels itself across the first heat dissipation channel 303 between the two rows of cells 31 and distributes to each of the second heat dissipation channels 304 to complete convective heat transfer. The heat-exchanged medium flows into the outlet chamber 103 through the outlet holes 71 on the second sidewall and is discharged through the outlet 12. Because the coolant is symmetrically supplied from both sides in the second direction and concentrated in the first direction, this arrangement reduces cross-flow and lateral flow deviation, improves the flow consistency and temperature uniformity between the gaps and the gaps between the cells 31, and facilitates the layout and maintenance of external circulation pipelines. If necessary, guide plates, filters, or anti-vortex components can be added to the inlet chamber 101 / outlet chamber 103 to further improve local flow patterns and anti-clogging performance.

[0036] Furthermore, a partition 40 is provided inside the housing 10. The partition 40 is fabricated using 3D printing technology and embedded within the housing 10, which divides the internal space into a first part and a second part that are mutually isolated, eliminating the risk of leakage caused by assembly gaps and improving structural rigidity. The first part is equipped with a liquid inlet chamber 101 and a cell cooling chamber 102, which are used to accommodate two rows of cell modules 30 and form a first heat dissipation channel 303 and a second heat dissipation channel 304 between the cell module 31. The second part forms a tab cooling chamber 104, which is only connected to the tab area of ​​the cell module 30. The cell 3 of the cell module 30 is installed in the first part, and the tab of the cell module 30 extends into the second part through a sealing perforation or window on the partition 40 and is received. The perforation is printed with a reserved assembly position during the integral forming process to fit an electrical insulation through sleeve and an elastic seal, thereby achieving complete fluid and electrical isolation between the two parts while maintaining the integrated structure.

[0037] A power harness interface 13 and a communication port 15 are provided on the outside of the housing 10. Both are installed as through-type sealed connectors on the corresponding side wall of the tab cooling cavity 104. The inner end of the power harness interface 13 is connected to a busbar 80 extending into the power harness interface 13, and the outer end of the power harness interface 13 is detachably connected to an external wiring harness. The inner end of the communication port 15 extends into the tab cooling cavity 104 and connects to the electrical system within the battery pack. The outer end of the communication port 15 is detachably connected to a test wiring harness or equipment communication wiring harness. The interface mounting area is integrally formed with a mounting platform and reinforcing ribs, and circumferential sealing is achieved with a metal flange and O-ring or flat sealing gasket. The through-hole can be supplemented with potting or a double-seal structure to ensure gas-liquid sealing and electrical insulation under long-term liquid immersion and temperature cycling conditions.

[0038] The power harness interface 13 preferably uses a high-voltage waterproof connector or a flange-type through-chamber connector, which includes at least positive and negative main contacts and HVIL interlock contacts. The housing has mechanical locking and anti-misinsertion key positions, and meets the IP67 / IP68 protection level and the required electrical clearance requirements.

[0039] Communication port 15 is used to electrically connect the voltage sampling or temperature sensing leads on the busbar 80 inside the tab cooling cavity 104 to the battery management system 50 (BMS). Communication port 15 is installed on the side wall corresponding to the tab cooling cavity. The inner end extends into the cavity and is connected to the sampling pads or inserts reserved on the busbar 80 by welding with a flexible FPC wire harness or crimping with terminals. The outer end is a standard signal socket, which can be detachably connected to the BMS terminal wire harness or onboard socket to realize reliable transmission of voltage, temperature and other signals, while maintaining cavity sealing and electrical isolation.

[0040] During operation, the first part is supplied with liquid by the liquid inlet chamber 101 and injected into the cell cooling chamber 102 at multiple points through the liquid inlet hole 61 on the first side wall. The fluid flows across the two rows of cells 31 and washes the heated wall surface along the multiple second heat dissipation channels 304 formed between adjacent cells 31. Then, it flows into the liquid outlet chamber 103 through the liquid outlet hole 71 on the second side wall and is discharged from the liquid outlet 12, forming a forced convection main circulation to bear the main heat load.

[0041] The second part is not connected to the external liquid supply equipment. During the assembly stage, the tab cooling chamber 104 is filled with liquid to the target level through the top cover. For this purpose, the top cover can be equipped with a sealable liquid filling opening (or it can be without a liquid filling opening, and liquid filling can be completed during the installation of the top cover of the housing 10). After assembly, it is in a sealed state. During operation, the liquid in the chamber is basically still or only generates slow natural convection and diffusion heat transfer to remove the heat of the tab and its connecting components, avoiding the scouring and vibration of the tab area by the high kinetic energy mainstream. When maintenance is required, liquid can be added or the medium can be replaced through the liquid filling opening. Optionally, without affecting the isolation of the chamber, the tab cooling chamber 104 can be equipped with a liquid level observation window, a liquid level sensor, or a miniature vent for maintenance and degassing, but by default, it does not form a continuous passage with the external circulation.

[0042] Specifically, a cell cooling cavity 102 is formed inside the housing 10 to accommodate at least two rows of cell modules 30. To facilitate the distribution and collection of inlet and outlet liquids, an L-shaped liquid inlet plate 60 and a liquid outlet plate 70 are provided inside the housing 10. The liquid inlet plate 60 and the first end of the housing 10 together form an inlet liquid cavity 101, and the liquid outlet plate 70 and the second end of the housing 10 together form an outlet liquid cavity 103.

[0043] In a preferred embodiment, the inlet plate 60 includes a first plate segment and a second plate segment perpendicular to each other. The second plate segment extends toward the cell cooling chamber 102, and the first plate segment extends along a third direction and serves as a first sidewall of the cell cooling chamber 102. The first sidewall has multiple inlet holes 61 for allowing coolant to enter the cell cooling chamber 102. The outlet plate 70 is disposed at the second end of the housing 10 opposite to the inlet plate 60. It forms a second sidewall toward the cell cooling chamber 102 and has multiple outlet holes 71 for allowing coolant to exit. The housing 10 is provided with an outlet port 12 for connection to an external pipeline and two inlet ports 11. The two inlet ports 11 are arranged opposite each other along a second direction and communicate with the inlet chamber 101. The outlet port 12 communicates with the outlet chamber 103.

[0044] Thus, at both ends along the first direction, an inlet chamber 101 (located on the first end side) and an outlet chamber 103 (located on the second end side) adjacent to the cell cooling chamber 102 are respectively formed in the housing 10, forming a distribution and collection structure from the inlet manifold to the cooling chamber to the outlet manifold.

[0045] During operation, coolant enters the inlet chamber 101 from outside the housing 10 through two inlet ports 11. It then enters the cell cooling chamber 102 through inlet holes 61 on the second section (i.e., the first sidewall) of the inlet plate 60, connecting with the first heat dissipation channel 303 between the two rows of cell modules 30 and the second heat dissipation channel 304 between adjacent cells 31. After completing the heat exchange by flushing the heated walls of the cell 31, the coolant flows into the outlet chamber 103 through the outlet holes 71 on the outlet plate 70, and finally exits the housing 10 through the outlet port 12.

[0046] To ensure sealing and structural strength, the peripheries of the inlet plate 60 and the outlet plate 70 can be fixed to the inner wall of the housing 10 by welding or brazing. The inlet port 11 is preferably symmetrically arranged about the mid-plane of the housing 10 in a third direction to reduce vertical flow deviation caused by gravity or thermal stratification. With the inlet chamber 101 and outlet chamber 103 respectively enclosed at both ends of the housing 10 by the inlet plate 60 and the outlet plate 70, and with the first and second sidewalls perforated as inlet control 61 and outlet holes 71 respectively, uniform distribution and orderly collection of fluid can be achieved inside the housing 10 without adding additional external manifolds. This also facilitates coordinated design with the heat dissipation channels (first heat dissipation channel 303 and second heat dissipation channel 304) within the cell cooling chamber 102, achieving low-resistance flow organization and good temperature uniformity.

[0047] Specifically, a plurality of liquid inlet holes 61 provided on the first sidewall are arranged in a row at equal intervals along the third direction, and the center distance between adjacent liquid inlet holes 61 is the hole pitch t. A plurality of liquid outlet holes 71 provided on the second sidewall are also arranged in a row at equal intervals along the third direction, and the center distance between adjacent liquid outlet holes 71 is the same t. Preferably, the spacing deviation of the center of each hole in the third direction is not greater than 0.2 mm.

[0048] In a preferred embodiment, the end distance between the inlet hole 61 and the outlet hole 71 is approximately t / 2, so that the hole array is approximately symmetrical about the centerline of the cavity in the third direction, reducing the flow offset of the upper and lower sections. Consistency within a row ensures consistent hydraulic characteristics across all vertical levels. Through the aforementioned equally spaced holes along the third direction, a uniform inlet / outlet tap distribution is formed in the vertical height direction. Combined with the aforementioned staggered arrangement along the second direction and the first heat dissipation channel 303 between the two rows of battery cell modules 30, similar local pressure differences and branch supply / discharge capabilities can be obtained at different height levels, suppressing vertical flow deviation and temperature differences caused by buoyancy or thermal stratification, thereby further improving the temperature uniformity and hydrodynamic stability of the second heat dissipation channel 304 (i.e., the channel flowing through the large surface of the battery cell 31).

[0049] In some embodiments, the battery pack is equipped with a liquid level regulator 20, which is connected to the liquid outlet 12 and is used to set and maintain the liquid level in the tab cooling chamber 104. The liquid level regulator 20 is integrally formed with the housing 10. By controlling whether the tab cooling chamber 104 is connected to the liquid outlet 12, when the tab cooling chamber 104 is connected to the liquid outlet 12, the coolant inside the tab cooling chamber 104 flows out from the liquid outlet 12, so that the tabs can obtain a predetermined immersion height under different operating conditions. This reduces the risk of flow-induced vibration and localized corrosion to the wiring harness and connection parts while ensuring electrical insulation and erosion resistance.

[0050] Furthermore, the liquid level regulator 20 is integrally formed with the housing and is located on the outer wall of the housing 10 near the liquid outlet side. The tab cooling chamber 104 is connected to the inner cavity of the liquid level regulator 20 through a connecting hole on the housing 10, and the adjustment opening of the liquid level regulator 20 is connected to the liquid outlet 12 of the battery pack. By controlling the opening or closing of the opening, the liquid level in the tab cooling chamber 104 is adjusted accordingly, thereby setting the immersion height of the tab.

[0051] The level regulator 20 can be an overflow box structure, with the box body and the housing 10 communicating with each other. The box is equipped with a liftable outlet regulating plate 21 or a rotatable baffle assembly to control the opening or closing of the opening.

[0052] The electrode cooling chamber 104 is connected to the liquid outlet 12 via a liquid level regulator 20, and the liquid level can be controllably set. This allows for flexible selection of the electrode immersion height under different charging / discharging heat loads and ambient temperatures, achieving a temperature control mode in the electrode area dominated by low-speed diffusion flow or near-natural convection, decoupled from the forced convection within the cell cooling chamber 102. This design ensures thermal and insulation safety while also considering pump power, noise, and ease of maintenance. The liquid level regulator 20 can be made of aluminum alloy, stainless steel, or media-resistant engineering plastics compatible with the cooling medium. All seals are made of media-compatible fluororubber or perfluoroether rubber, and a washable microporous filter can be added to the liquid outlet side to prevent particles from entering the valve or riser cavity.

[0053] In another embodiment, the liquid level regulator 20 is not provided, and the tab cooling chamber 104 is constructed as an independent, closed chamber, which is not connected to the cell cooling chamber 102 or the liquid inlet 11 and outlet 12 on the housing 10. The partition, the top cover, and the side wall form the tab cooling chamber, and the periphery of the chamber is circumferentially sealed by a structural sealing ring and sealant to ensure long-term fluid isolation from the main circulation path.

[0054] During assembly, a predetermined amount of coolant is injected into the electrode cooling chamber 104 through the filling opening on the top cover. After venting, the filling port is sealed with a threaded plug or welded cap. Free space is reserved for the amount of coolant added as a thermal expansion allowance. For extreme safety under abnormal operating conditions, the chamber can be equipped with an explosion-proof valve that connects to the outside environment. It is normally sealed and closed, releasing coolant only momentarily in case of overpressure.

[0055] In some embodiments, the battery pack further includes a battery management system 50 (BMS), with a dedicated mounting position on the housing 10 for the BMS. The mounting position may be formed by a partition 40 or a support integrally formed into the inner wall of the housing 10, a heat-conducting base plate, and a vibration-damping pad, allowing the BMS to operate in a low-vibration, heat-dissipating, and easily maintainable environment. To accommodate the liquid environment of the tab cooling cavity 104, the BMS preferably adopts a sealed control box structure, whose outer wall can directly conduct heat exchange with the coolant inside the cavity.

[0056] The BMS and busbar 80 are electrically connected, and the BMS and busbar 80 are used for individual cell voltage acquisition, passive or active balancing, and temperature measurement. Simultaneously, the BMS and busbar 80 are also used to acquire voltage or charge / discharge current. These electrical connections are made through waterproof and dielectric-resistant connectors located within the tab cooling chamber 104. Sealed through-holes or electrical penetration joints are provided at the locations where the wires pass through the partition 40 or housing 10 to maintain fluid isolation and electrical insulation between the first and second parts.

[0057] In some embodiments, an explosion-proof valve is provided on the housing 10. The explosion-proof valve is connected to the tab cooling chamber 104 through the communication port of the housing 10. It is used to release the gas and vapor in the chamber in a timely manner when abnormal gas release, rapid pressurization, or early thermal runaway occurs in the tab area, so as to avoid damage to the housing 10 and guide the venting in a safe direction. For ease of maintenance and monitoring, a pressure detection port or a miniature pressure sensor can be installed near the explosion-proof valve to record opening events and pressure peaks.

[0058] In some embodiments, the housing 10 is provided with a first interface 141 and a second interface 142 for liquid level measurement, which are respectively connected to the lower and upper ports of an external liquid level gauge. The first interface 141 is preferably located at the upper part of the liquid outlet chamber 103, and the second interface 142 is located at the lower part of the liquid outlet chamber 103. The two interfaces form a bypass loop with the liquid level gauge through a small-diameter connecting pipe, so that the liquid column in the liquid level gauge changes synchronously with the liquid level in the liquid outlet chamber 103, which facilitates local indication or remote monitoring.

[0059] In some embodiments, the housing 10 is provided with a first interface 141 and a second interface 142 for maintenance venting. The first interface 141 communicates with the liquid outlet chamber 103 inside the housing 10, and the second interface 142 communicates with the tab cooling chamber 104. Preferably, the first interface 141 is arranged at the lowest point of the liquid outlet chamber 103 or at a lower side position nearby, so that the coolant can be discharged smoothly by gravity, reducing residual liquid retention. To facilitate flow guidance, the bottom surface of the liquid outlet chamber 103 may be provided with a slight slope or a liquid collection groove towards the discharge port. The end of the groove connects to the communication hole of the first interface 141. A removable and washable foreign matter filter or metal sieve sleeve is provided at the communication hole to prevent larger particles from entering the valve with the liquid discharge.

[0060] In a specific embodiment, two rows of battery cell modules 30 are arranged inside the housing 10, namely a first module 301 and a second module 302, and a first heat dissipation channel 303 is formed between the two rows. The first heat dissipation channel 303 is located at the middle position of the housing 10 along the second direction, making it basically symmetrical about the center line of the housing 10. It serves as the main slot channel after entering the battery cell cooling cavity 102, and is used to perform transverse distribution and balanced heat exchange for the two rows of battery cells 31.

[0061] The liquid inlet holes 61 on the first sidewall are arranged at the middle position of the housing 10 along the second direction, preferably arranged in a row and aligned with the first heat dissipation channel 303 in the first direction. The incoming coolant is directly injected into the first heat dissipation channel 303 at multiple points through the row of liquid inlet holes 61, forming a balanced mainstream core area at the center line, and then advancing along the first direction and being distributed to both sides to the multiple second heat dissipation channels 304 between adjacent cells 31.

[0062] The liquid outlet holes 71 on the second sidewall are arranged in two rows, located on both sides of the housing 10 along the second direction, and symmetrical about the centerline. The water outlets of each second heat dissipation channel 304 converge and discharge towards the liquid outlet holes 71 on both sides. The liquid outlet holes 71 are connected to the liquid outlet chamber 103 and then guided to the liquid outlet 12. Since the liquid inlet is concentrated at the centerline and the liquid outlet is dispersed on both sides, the two form a transverse flow path in the second direction, which is injected from the center and then pumped out to both sides. This avoids short-circuit flow caused by the inlet and outlet crossing each other, and improves the average residence time and lateral coverage in the cavity.

[0063] In some embodiments, in addition to the first heat dissipation channel 303 and a plurality of second heat dissipation channels 304, a third heat dissipation channel 305 is also provided in the cell cooling cavity 102. The third heat dissipation channel 305 is arranged along the outer side of the cell module 30, preferably in the form of a strip-shaped confluence cavity parallel to the sidewall. Its projection in the first direction coincides with the projection of the liquid outlet 71 in the first direction, so that the fluid flowing out of the second heat dissipation channels 304 can enter the third heat dissipation channel 305 through the shortest path and be discharged through the liquid outlet 71, reducing local losses and temperature fluctuations caused by backflow and lateral flow. The third heat dissipation channel 305 can be formed by the inner sidewall of the housing 10 and the outer frame of the cell module 30. A confluence groove can be provided near the liquid outlet side of the channel to balance the pumping and discharging differences between adjacent liquid outlets 71.

[0064] In a specific embodiment, there are two battery modules arranged opposite each other, forming a first heat dissipation channel 303 between them. The first heat dissipation channel 303 corresponds to the position of the liquid inlet 61 in the first direction, allowing the incoming coolant to be injected directly into the main channel of the gap in a multi-point jet and then propagated along the path. Inside each battery module, a second heat dissipation channel 304 is formed between two adjacent cells 31. Multiple second heat dissipation channels 304 are sequentially formed along the first direction for end-point flushing and heat exchange of the large and side surfaces of the cells 31. The two battery modules and the housing 10 respectively enclose a third heat dissipation channel 305 located on their respective outer sides, which is used as an end-point collection channel. The outlet end of each second heat dissipation channel 304 in each battery module is connected to the third heat dissipation channel 305 on its corresponding side. The third heat dissipation channel 305 is then connected to the liquid outlet 71 provided on the corresponding side wall, completing the orderly collection path of the first heat dissipation channel 303, the second heat dissipation channel 304 and the third heat dissipation channel 305.

[0065] To reduce local recirculation and ensure uniform pumping, a short flared opening or chamfered transition can be provided at the connection between the second heat dissipation channel 304 and the third heat dissipation channel 305. The equivalent flow cross-section of the third heat dissipation channel 305 can be gradually varied or progressively increased in segments along the first direction to compensate for the increase in flow rate caused by cumulative inflow along the path. A guide lip or flow straightening rib can be provided near the outlet hole 71 to reduce secondary separation at the inlet of the outlet hole 71. The connection between the third heat dissipation channel 305 and the outlet hole 71 maintains projection alignment in the first direction, preferably with the projection deviation of the center of the connection opening being less than a predetermined tolerance. This makes the hydraulic path length from each of the second heat dissipation channels 304 through the third heat dissipation channel 305 to the outlet hole 71 more consistent with local losses, further improving pumping uniformity and temperature field stability.

[0066] In some embodiments, the battery pack is also equipped with an MSD (Manual Service Disconnect). The MSD is located in an accessible position on the outside of the housing 10 and is electrically connected to the busbar 80 through a through-sealed seat, enabling quick manual isolation and safe disconnection of the busbar 80.

[0067] This embodiment also includes a measurement method that constructs a closed-loop system by supplying a medium from the inlet 11 and then recovering the medium from the outlet 12. Furthermore, the medium before the inlet 11 is monitored, and its pressure, temperature, and volumetric flow rate before entering the cell cooling chamber 102 are measured in real time, with the data uploaded to the control system.

[0068] To achieve stable inlet temperature and efficient heat removal, the external cooling cycle employs a two-stage heat exchange structure. The high-temperature medium at the battery pack outlet undergoes a primary heat exchange, followed by pressurization and a secondary heat exchange and precise temperature control before returning to the battery pack. This two-stage heat exchange arrangement allows the system to quickly reduce peak temperatures and stabilize the inlet temperature near the set value even under significant disturbances, with a preferred temperature control accuracy of ±0.1℃.

[0069] To facilitate liquid replenishment, venting, and immersion height adjustment, an independent liquid storage tank is installed below the test platform and connected to an external circulation system via a hose. A small-power centrifugal pump can be installed between the storage tank and the prototype to achieve liquid replenishment and fine-tuning of the liquid level. The top of the storage tank is equipped with a venting and liquid level observation window, while the bottom is equipped with a drain valve and a filter unit to remove particulate impurities, ensuring that the medium entering the battery pack is clean and does not clog the vents.

[0070] The detection equipment may consist of a pressure sensor, a temperature sensor, and a volumetric flow meter. Ideally, sufficient straight pipe sections should be reserved upstream and downstream of the measurement section to ensure measurement accuracy. To cover different operating conditions, the flow meter can be configured with dual ranges, with the upper and lower flow meters operating separately for different flow ranges. The control system automatically switches or merges the readings. Several temperature points, voltages, and currents of the battery module can be acquired through the auxiliary acquisition channel of the charging / discharging device or external data acquisition equipment, achieving synchronous recording of thermoelectric parameters.

[0071] The busbar 80 of the battery module 30 is electrically connected to the charging and discharging device via a high-voltage connector. It can perform charging and discharging cycles according to a set current curve and is linked to the external circulating medium flow rate and temperature settings to evaluate the cooling effect and temperature difference index under different heat loads. To improve test safety, overvoltage protection, pressure relief and leakage detection are set in the circuit. The electrical side is equipped with main contactor, pre-charge and fuse protection, and the fault status is interlocked to the medium circulation device and the charging and discharging device.

[0072] Under typical operating conditions, the maximum volumetric flow rate at the inlet 11 can reach approximately 40 L / min, with a maximum cooling capacity of approximately 15 kW. The inlet medium temperature of the battery pack is continuously adjustable within the range of approximately 15°C to 45°C, and the steady-state temperature fluctuation is controlled within approximately ±0.1°C. During testing, the external cooling cycle is connected to the battery pack prototype via a flexible hose. Cell modules 30 with different structures and parameters can be replaced as needed. The device can achieve long-term stable monitoring of inlet and outlet pressure, temperature, and flow rate. The control system centrally controls and records the frequency of the variable frequency pump, the outlet water temperature of the chiller, and the set value of the constant temperature bath, thus providing a repeatable and quantifiable experimental platform for the thermal performance evaluation and temperature equalization strategy verification of single-phase immersion liquid-cooled battery modules.

[0073] In a set of prototype tests, the ambient and inlet temperatures were controlled at 25℃. A single-phase immersion medium was used. The immersion liquid-cooled energy storage battery pack 100 (specifically, 208Ah (1p26s)) operated with the aforementioned structure of centerline liquid inlet, side liquid outlet, gradually narrowing main channel in the gap, and a second heat dissipation channel 304 between the cells 31. The electrode temperature, temperature difference, cell 31 surface temperature, voltage difference, and voltage deviation were recorded under 0.5P and 1P charge / discharge conditions. The results showed that as the circulation flow rate increased, the overall temperature of the cell 31 decreased, and the temperature and voltage differences gradually decreased. After the flow rate increased by 18L / min, further increases in flow rate had little effect on improving the temperature and voltage differences, showing a diminishing returns trend. Taking the representative operating condition of 18L / min as an example, the electrode temperature difference was 1.18℃ and the voltage deviation was 38.24mV during 0.5P discharge. During 1P discharge, the electrode temperature difference is 2.34℃, and the voltage deviation is 27.97mV. These data demonstrate that by using a centrally aligned liquid inlet, two-sided dispersed extraction, and the gradual narrowing and orderly distribution of the first heat dissipation channel 303 along its path, dual-scale flow and temperature uniformity of the cell's heated wall surface and the electrode area can be achieved without significantly increasing the system voltage drop. When the flow rate reaches approximately 18 L / min, the structural flow uniformity and heat transfer capacity are essentially fully activated, and further increasing the flow rate yields limited marginal benefits. Therefore, setting this flow rate as a compromise between energy efficiency and thermal uniformity is more suitable.

[0074] In the numerical simulation, the results include cell temperature contour maps, pressure contour maps, and dielectric temperature contour maps, respectively. By optimizing the cell arrangement, the maximum temperature difference can be reduced, the temperature isosurface is smoother, and the hot spot range is reduced. The pressure field is more uniformly distributed in this invention, indicating that the pressure difference between the first heat dissipation channel 303 and the second heat dissipation channel 304 between each cell 31 is more consistent, and secondary flow and local recirculation are suppressed. The dielectric temperature field exhibits a more regular gradient from the inlet to the outlet, and local undercooling or overheating at the lateral junction cavity is weakened. In summary, this invention enables each branch to obtain closer driving force and flow rate, reduces the overall cell temperature difference and improves stability without significantly increasing the pressure drop. When the flow rate rises to a higher range, the system is close to the uniform temperature limit that the structure can provide, and the improvement of further increasing the flow rate is limited.

[0075] In experimental testing, as the flow rate increased from low to high, the cell temperature difference of both the existing technology and the present invention decreased monotonically, indicating that the temperature distribution was more uniform after enhanced convection. The main benefits were concentrated in the low to medium flow rate range, and the curve flattened as the flow rate continued to increase, with marginal benefits decreasing. The cell temperature difference of the present invention was consistently lower than that of the existing technology, especially in the low to medium flow rate range where the decrease was more significant. This indicates that the optimized flow distribution and geometric convergence of the present invention can suppress flow deviation and hot spots earlier and more effectively. The gap between the two narrowed at high flow rates because the influence of structural differences was weakened after forced convection became dominant.

[0076] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An immersion liquid-cooled energy storage battery pack, characterized in that, include: The housing has a cell cooling cavity formed inside it. The cell cooling cavity has a first sidewall and a second sidewall that are arranged opposite to each other in a first direction. The first sidewall has at least one inlet hole for coolant to enter, and the second sidewall has at least one outlet hole for coolant to exit. Along the second direction, the outlet hole and the inlet hole are staggered. The first direction and the second direction are perpendicular to each other. At least two rows of battery cell modules are arranged at intervals along the second direction. A first heat dissipation channel is formed between two adjacent battery cell modules. The first heat dissipation channel and the liquid outlet are staggered along the second direction. Along the first direction, the projection of the liquid inlet coincides with the projection of the first heat dissipation channel, and the flow cross-section of the first heat dissipation channel gradually decreases along the first direction. Multiple battery cells in each row of battery cell modules are arranged at intervals along the first direction. A second heat dissipation channel is formed between adjacent battery cells. The water inlet end of the second heat dissipation channel is connected to the first heat dissipation channel, and the water outlet end of the second heat dissipation channel is connected to the liquid outlet.

2. The immersion liquid-cooled energy storage battery pack according to claim 1, characterized in that, The battery cell module has multiple second heat dissipation channels formed within it. Along the first direction, the flow cross-section of the second heat dissipation channel located in the middle is larger than the flow cross-section of the second heat dissipation channels located at both ends.

3. The immersion liquid-cooled energy storage battery pack according to claim 1, characterized in that, The first heat dissipation channel includes a plurality of tapered sections arranged sequentially along the first direction, wherein the flow cross section of the tapered section on the side away from the liquid inlet is smaller than the flow cross section of the tapered section on the side closer to the liquid inlet.

4. The immersion liquid-cooled energy storage battery pack according to claim 1, characterized in that, Along the direction from the first sidewall toward the first sidewall, the spacing between two adjacent battery cell modules gradually decreases.

5. The immersion liquid-cooled energy storage battery pack according to claim 1, characterized in that, The housing has an outlet and two inlets arranged opposite each other along the second direction. Along the first direction, an inlet chamber and an outlet chamber are formed on both sides of the cell cooling cavity inside the housing. The inlet chamber is connected to the cell cooling cavity through the inlet hole, the outlet chamber is connected to the cell cooling cavity through the outlet hole, the inlet is connected to the inlet chamber, and the outlet is connected to the outlet chamber.

6. The immersion liquid-cooled energy storage battery pack according to claim 5, characterized in that, The submersible liquid-cooled energy storage battery pack also includes a separator, which is disposed inside the housing and divides the housing into a first part and a second part that are isolated from each other. The first part includes the liquid inlet chamber and the cell cooling chamber, and the second part includes a tab cooling chamber, in which the tabs of the cell module are housed.

7. The immersion liquid-cooled energy storage battery pack according to claim 6, characterized in that, The immersion liquid-cooled energy storage battery pack also includes a liquid level regulator, which is connected to the liquid outlet and is used to regulate the liquid level in the tab cooling chamber.

8. The immersion liquid-cooled energy storage battery pack according to claim 7, characterized in that, The submerged liquid-cooled energy storage battery pack also includes a battery management system, which is electrically connected to the busbar of the cell module.

9. The immersion liquid-cooled energy storage battery pack according to any one of claims 1 to 8, characterized in that, At least one liquid inlet hole includes a plurality of liquid inlets, and at least one liquid outlet hole includes a plurality of liquid outlet holes. The plurality of liquid inlets are arranged at equal intervals along a third direction, and the plurality of liquid outlet holes are arranged at equal intervals along the third direction. The first direction, the second direction, and the third direction are perpendicular to each other.

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