Immersion evaporation type high-energy-efficiency self-driven battery thermal management system

Abstract

The invention provides an immersion evaporation type high-energy-efficiency self-driven battery thermal management system which comprises an inner layer shell, an outer layer shell and a battery monomer, the outer layer shell is arranged outside the inner layer shell in a sleeving manner, and a certain shell gap is formed between the outer layer shell and the inner layer shell; the inner-layer shell is used for accommodating a plurality of single batteries and liquid cooling liquid, and the single batteries are inversely arranged in the inner-layer shell and immersed in the liquid cooling liquid; inlets and outlets are formed in the side walls of the inner-layer shell and the outer-layer shell, the inlets of the two-layer shell correspond to each other in position, and the outlets of the two-layer shell correspond to each other in position; a tab and an anti-explosion valve are arranged on the battery monomer, and a tab opening and an anti-explosion valve opening which are matched with each other are formed in the bottom of the inner-layer shell. The heat generated by the battery can be absorbed by utilizing the phase change latent heat of the cooling liquid in the evaporation process, and the energy efficiency is higher.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery thermal management, and specifically relates to an immersion evaporation type high-efficiency self-driven battery thermal management system, and more particularly to an immersion evaporation type high-efficiency self-driven battery pack, thermal management system and method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the development of new energy technologies, especially their widespread application in electric vehicles, mobile devices and renewable energy storage, battery technology has gradually become a core component of the modern energy system. Therefore, developing power battery packs with higher energy density and supporting more advanced battery management systems to maximize and demonstrate their excellent performance has become an important issue that needs to be solved urgently.

[0004] The battery thermal management system is a crucial component of the battery management system. Especially today when high energy density batteries and fast charging technology are widely used, the performance, life and safety of the battery are directly affected by temperature. The main function of the thermal management system is to effectively regulate the operating temperature of the battery to ensure that it operates within the optimal temperature range, thereby improving the overall performance of the battery, extending its service life, and ensuring its safety.

[0005] The chemical reaction of the battery is very sensitive to temperature. For example, the optimal operating temperature of lithium-ion batteries is usually 20℃~40℃. Within this temperature range, the battery can provide the best charging and discharging performance and has a long service life. Too high or too low temperature will cause the battery performance to deteriorate and may cause safety risks. When the battery temperature exceeds a certain threshold, the chemical reaction speed in the battery accelerates. Although it may increase the power output of the battery in the short term, long-term high temperature will accelerate the aging of the internal materials of the battery, resulting in accelerated capacity decay and ultimately reducing the performance of the battery. In addition, in high temperature environments, lithium-ion batteries may experience thermal runaway, which may cause fire or explosion in severe cases. At low temperatures, the ion migration rate of the electrolyte inside the battery slows down, the internal resistance of the battery increases, the charging and discharging efficiency decreases, and even the phenomenon of abnormal charging and discharging may occur. Especially in cold environments, the charging and discharging capacity of the battery is greatly reduced, which may cause the battery to be unable to be used normally under low temperature conditions.

[0006] Temperature also has a significant impact on the service life of the battery. Long-term operation at high temperatures will accelerate the chemical reaction and structural damage of the battery's internal materials, leading to rapid capacity decay. Low temperatures will increase the viscosity of the battery electrolyte and the internal resistance of the battery, which will not only accelerate the internal loss of the battery, but also affect the health of the battery.

[0007] In summary, with the continuous improvement of battery energy density and more diverse changes in application scenarios, battery thermal management technology will continue to be a core element in battery technology research and development and product design to ensure that the battery can operate in an efficient and safe state.

[0008] The submerged evaporation battery thermal management system is a new type of battery thermal management solution. Its core principle is to use dielectric phase change fluid to directly contact the battery and absorb heat. The liquid coolant surrounding the battery absorbs heat and its temperature rises, then evaporates into gas, and removes the heat generated by the battery through phase change latent heat. The evaporated gaseous coolant is directed to a heat exchanger or condenser, where it releases the absorbed heat and re-condenses into liquid coolant, and then returns to the liquid bath to complete the thermal cycle.

[0009] The immersion evaporation battery thermal management system has many advantages: (1) It provides superior thermal management performance, ensures uniform temperature distribution through direct contact with the battery, and reduces the formation of hot spots; (2) Compared with traditional air cooling systems, it is more compact in design and does not require large-scale cooling fins or fans; (3) By maintaining the battery operating within the optimal temperature range, it reduces the risk of overheating and effectively extends the battery life; (4) The use of non-flammable dielectric coolant reduces the risk of thermal runaway and fire and enhances the overall safety of the system; (5) Due to the high thermal efficiency of phase change coolant, the system usually requires less energy to maintain operation, thereby achieving energy saving.

[0010] However, although there are many different types of immersion evaporation battery thermal management solutions, they all have certain defects. For example, patent number CN115039271A discloses a battery system and evaporative cooling method, which immerses part of the battery pack in a heat transfer fluid, and cools the battery by absorbing the coolant through a porous core. However, only part of the battery cells in the battery pack are immersed in the liquid, and the part not immersed in the liquid cannot use the flow between the liquids to dissipate heat. Patent number CN207098018U discloses a battery evaporation system, in which the coolant circulates between the condenser and the evaporation chamber during operation to maintain the battery temperature stable. However, the system cannot maintain the constant height of the coolant in the battery pack and control the pressure of the steam in the battery pack, so it cannot ensure the uniformity of heat dissipation and system safety of various parts of the battery. Patent number CN116093484A discloses a solution for dielectric liquid evaporative cooling. The wicking component absorbs the heat dissipated by the battery, and the wicking component includes a steam escape passage for steam escape. However, the system cannot adjust the evaporation amount of the dielectric liquid, so it cannot accurately control the temperature of the battery. Patent No. CN219393512U discloses an evaporative cooling battery module system that can evenly dissipate heat from batteries in different locations. However, the system does not consider the impact that the flame generated by the rupture of the battery explosion-proof valve may have on the coolant and system stability. Summary of the invention

[0011] In order to solve the above problems, the present invention proposes an immersed evaporation high-efficiency self-driven battery pack, thermal management system and method. The present invention can use the phase change latent heat of the coolant during the evaporation process to absorb the heat generated by the battery, which has higher energy efficiency. The present invention also takes into account the possible impact of the flame generated after the battery explosion-proof valve ruptures on the coolant and system stability, and designs an ingenious structure to overcome the above problems.

[0012] According to some embodiments, the present invention adopts the following technical solutions:

[0013] An immersion evaporation high-efficiency self-driven battery pack comprises an inner shell, an outer shell and a battery cell, wherein the outer shell is sleeved on the outside of the inner shell, and there is a certain shell gap between the two; the inner shell is used to accommodate a plurality of battery cells and liquid coolant, and the battery cells are invertedly arranged in the inner shell and immersed in the liquid coolant;

[0014] The side walls of the inner shell and the outer shell are both provided with an inlet and an outlet, and the inlet positions of the two shells correspond to each other, and the outlet positions correspond to each other;

[0015] The battery cell is provided with a pole lug and an explosion-proof valve, and the bottom of the inner shell is provided with a matching pole lug opening and an explosion-proof valve opening.

[0016] As an optional embodiment, an inlet of the inner shell is provided on the side wall of the inner shell at a position below the liquid coolant level, and an inlet of the outer shell is provided at a corresponding position of the side wall of the outer shell, and the outlet of the water pump can pass through the inlet of the outer shell to be connected with the inlet of the inner shell.

[0017] As an optional embodiment, an inner shell outlet is provided on the side wall of the inner shell at a position above the liquid coolant level, and an outer shell outlet is provided at a corresponding position on the side wall of the outer shell, and the fan inlet can pass through the outer shell outlet to be connected to the inner shell outlet.

[0018] As an optional implementation, the liquid level of the liquid coolant is at least flush with the height of the battery.

[0019] As an optional embodiment, a liquid level sensor is installed on the inner wall of the inner shell, a pressure sensor is installed on the inner wall of the inner shell at a position above the liquid coolant level, and a temperature sensor is installed at a position below the liquid coolant level;

[0020] A liquid sensor is installed on the outer wall of the inner shell or the inner wall of the outer shell, located in the shell gap.

[0021] As an optional implementation, the number of the tab openings and the explosion-proof valve openings matches the number of battery cells, and the tabs of each battery cell pass through the corresponding tab openings on the bottom surface of the inner shell and are connected in series and parallel in the shell gap;

[0022] The explosion-proof valve of each battery cell is aligned with the corresponding explosion-proof valve opening on the bottom surface of the inner shell.

[0023] As a further feature, the tab opening and the explosion-proof valve opening are both sealed or have a sealing structure.

[0024] As an optional embodiment, the outer shell is a split structure, including a detachable shell and an upper cover, the upper cover is provided with a plurality of ventilation holes or ventilation grooves, and the positions of the ventilation holes or ventilation grooves correspond to the positions of the shell gaps.

[0025] An immersion evaporation type high energy efficiency self-driven battery thermal management system comprises the above-mentioned battery pack, a cooling circulation subsystem and an electronic control subsystem, wherein the cooling circulation subsystem comprises a fan and a water pump, wherein the inlet of the fan passes through the outlet of the outer shell of the battery pack and is connected to the outlet of the inner shell, and the outlet of the water pump passes through the inlet of the outer shell of the battery pack and is connected to the inlet of the inner shell;

[0026] The electronic control subsystem includes a battery management system control unit, which is connected to a liquid level sensor, a pressure sensor, a temperature sensor and a liquid sensor arranged in the battery pack, and is used to control the operation of the fan and the water pump, as well as the fan speed and the water pump flow rate according to the data of each sensor.

[0027] As an optional embodiment, the cooling circulation subsystem also includes a condenser and a compensating water tank, the outlet of the fan is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the compensating water tank, and the outlet of the compensating water tank is connected to the inlet of the water pump.

[0028] As an optional implementation, the battery management system control unit is configured to adjust the flow rate of the water pump according to the liquid level data obtained by the liquid level sensor to maintain a constant liquid level height of the liquid coolant so that the battery cells are always immersed in the liquid coolant;

[0029] According to the pressure data obtained by the pressure sensor and the temperature data obtained by the temperature sensor, the speed of the fan is adjusted. When the temperature data is greater than the set value, the speed of the fan is controlled to be greater than the first speed. When the temperature data is less than or equal to the set value, the speed of the fan is controlled to be less than or equal to the first speed.

[0030] Based on the data obtained by the liquid sensor, detect whether coolant leakage occurs, and if so, stop the operation of the water pump and fan.

[0031] The working method based on the above system includes the following steps:

[0032] Obtain data from a liquid level sensor, a pressure sensor, a temperature sensor, and a liquid sensor installed in the battery pack, and adjust the flow rate of the water pump according to the liquid level data obtained by the liquid level sensor to maintain a constant liquid coolant level height so that the battery cells are always immersed in the liquid coolant;

[0033] According to the pressure data obtained by the pressure sensor and the temperature data obtained by the temperature sensor, the speed of the fan is adjusted. When the temperature data is greater than the set value, the speed of the fan is controlled to be greater than the first speed. When the temperature data is less than or equal to the set value, the speed of the fan is controlled to be less than or equal to the first speed.

[0034] Based on the data obtained by the liquid sensor, detect whether coolant leakage occurs, and if so, stop the operation of the water pump and fan.

[0035] A power mechanism or energy storage mechanism includes the above-mentioned battery pack or thermal management system.

[0036] The power mechanism includes but is not limited to electric vehicles and mobile devices, and the energy storage mechanism includes but is not limited to renewable energy storage facilities.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. By completely immersing the battery in liquid coolant and using a liquid level sensor and a water pump to maintain a constant liquid coolant level, the liquid coolant can directly absorb and exchange the heat generated by different parts of the battery through convection, thereby improving the temperature uniformity and heat dissipation effect of the battery.

[0039] 2. The heat generated by the battery is absorbed through the evaporation phase change of the liquid coolant, and the pressure of the gaseous coolant is adjusted using a pressure sensor, a temperature sensor and a fan to maintain or change the evaporation rate of the coolant, which can accurately control the battery temperature and improve the heat dissipation effect of the battery.

[0040] 3. When the battery is working, the temperature near the pole ear is higher, and the temperature away from the pole ear is lower. By inverting the battery, the liquid coolant can absorb more heat generated by the battery during the upward flow, thereby increasing the evaporation of the liquid coolant and improving the heat dissipation effect of the battery.

[0041] 4. By arranging the pole ear opening and the explosion-proof valve opening at the bottom of the inner shell, on the one hand, the battery cell can be fixed to achieve an inverted installation method; on the other hand, the pole ear can be led out to the gap of the shell for series and parallel connection without being disturbed by the liquid coolant; on the other hand, the flame can be guided out and separated from the battery and coolant, thereby improving the safety of the battery pack.

[0042] 5. By setting up an inner and outer double-layer shell and installing a liquid sensor in the shell gap, when the inner shell leaks, the liquid coolant can flow into the shell gap, and at the same time stop the operation of the water pump and fan to prevent the coolant from flowing out of the battery pack, thereby improving the reliability of the battery pack.

[0043] 6. By inverting the battery so that the explosion-proof valve opens downward and setting a shell gap between the inner and outer shells, when the battery has thermal runaway and causes the explosion-proof valve to rupture, the flame can spread in the shell gap and the heat of the flame can be absorbed by the coolant inside the inner shell and the air outside the outer shell, thereby reducing the temperature of the flame and extinguishing the flame, thereby improving the safety of the battery pack.

[0044] 7. By setting vents on the battery pack cover, the gap between the inner and outer shells is kept connected to the atmosphere, preventing flames from causing explosions and improving the safety of the battery pack.

[0045] 8. The battery management system control unit only needs to adjust the flow of the water pump and the speed of the fan according to the information collected by the liquid level sensor, pressure sensor and temperature sensor to drive the thermal management system to operate normally, reducing energy consumption and manufacturing costs.

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0048] Figure 1 An exploded schematic diagram of an embodiment;

[0049] Figure 2 is a schematic diagram of the appearance of an embodiment;

[0050] Figure 3 A schematic diagram of the appearance of an embodiment in another direction;

[0051] Figure 4 A schematic diagram of a battery pack cover according to an embodiment;

[0052] Figure 5 A schematic diagram of a battery cell according to an embodiment;

[0053] Figure 6 A schematic diagram of an inner shell of a battery pack according to an embodiment;

[0054] Figure 7 A bottom view of an inner shell of a battery pack according to an embodiment;

[0055] Figure 8 A schematic diagram of an outer shell of a battery pack according to an embodiment;

[0056] Fig. 9 A top view of a battery cell, an inner shell and an outer shell after assembly according to an embodiment;

[0057] Fig.10 A cross-sectional view of a battery cell, an inner shell, an outer shell and a battery pack cover after assembly according to an embodiment;

[0058] Fig.11 A schematic diagram of a cooling cycle subsystem of an embodiment;

[0059] Fig.12 is a schematic diagram of an electronic control subsystem of an embodiment;

[0060] Among them, 1. battery pack, 2. battery pack cover, 2-1. vent, 3. battery cell, 3-1. explosion-proof valve, 3-2. pole ear, 4. inner shell, 4-1. inner shell inlet, 4-2. inner shell outlet, 4-3. pole ear opening, 4-4. explosion-proof valve opening, 5. outer shell, 5-1. outer shell inlet, 5-2. outer shell outlet, 6. shell gap, 7. fan, 8. condenser, 9. compensation water tank, 10. water pump, 11. liquid level sensor, 12. pressure sensor, 13. temperature sensor, 14. liquid sensor, 15. battery management system control unit BCU. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0062] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0063] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0064] In the absence of conflict, the embodiments in this application and the features in the embodiments may be combined with each other.

[0065] Embodiment 1

[0066] An immersion evaporation type high energy efficiency self-driving battery pack, such as Figure 1 , Fig.10 As shown, it includes an inner shell 4, an outer shell 5 and a battery cell 3, wherein the outer shell 5 is sleeved on the outside of the inner shell 4, and there is a certain shell gap 6 between the two; in this embodiment, the inner shell 4 and the outer shell 5 are both rectangular, and in order to ensure a stable connection between the inner shell 4 and the outer shell 5, it can be as follows Figure 1 As shown, a plurality of fixing blocks are arranged on the inner wall of the outer shell 5 to limit the inner shell 4 .

[0067] In this embodiment, square fixing blocks are provided at the corners of the outer shell 5 to ensure a stable connection between the two and to maintain a certain shell gap 6.

[0068] Of course, in other embodiments, the shape and size of the inner shell 4 and the outer shell 5 can be changed or adjusted according to the battery installation object or the battery installation space, and are not limited to the shape and size given in this embodiment.

[0069] Similarly, in some other embodiments, other methods may be used to maintain a stable shell gap 6 between the inner shell 4 and the outer shell 5 .

[0070] For example, in some embodiments, the inner shell 4 and the outer shell 5 can be changed to an I-shape, and a number of elastic gaskets can be arranged between the inner shell 4 and the outer shell 5 to ensure a stable connection between the inner shell 4 and the outer shell 5, and to have a certain shell gap 6, and to reduce the influence of the vibration generated when the battery pack moves on the position and safety of the inner shell 4 and the outer shell 5.

[0071] The inner shell 4 is used to accommodate a plurality of battery cells 3 and liquid coolant. The battery cells 3 are invertedly arranged in the inner shell 4 and immersed in the liquid coolant.

[0072] When the battery is working, the temperature near the tab 3-2 is higher, and the temperature away from the tab is lower. By inverting the battery, the liquid coolant can absorb more heat generated by the battery during the upward flow, thereby increasing the evaporation of the liquid coolant and improving the heat dissipation effect of the battery.

[0073] The side walls of the inner shell 4 and the outer shell 5 are both provided with an inlet and an outlet. Figure 1 The inner shell inlet 4-1, the inner shell outlet 4-2, the outer shell inlet 5-1 and the outer shell outlet 5-2 are shown. The inner shell inlet 4-1 and the outer shell inlet 5-1 are in corresponding positions, that is, when the inner shell 4 and the outer shell 5 are nested and connected, the inner shell inlet 4-1 and the outer shell inlet 5-1 are connected. The inner shell outlet 4-2 and the outer shell outlet 5-2 are in corresponding positions, that is, when the inner shell 4 and the outer shell 5 are nested and connected, the inner shell outlet 4-2 and the outer shell outlet 5-2 are connected;

[0074] As a more preferred embodiment, the inner shell inlet 4-1 and the inner shell outlet 4-2 are arranged opposite to each other, which can extend the flow path length of the liquid coolant and enhance the cooling effect.

[0075] like Figure 5 , Figure 6 , Fig.10 As shown, the battery cell 3 is provided with a tab 3 - 2 and an explosion-proof valve 3 - 1 , and the bottom of the inner shell 4 is provided with a matching tab opening 4 - 3 and an explosion-proof valve opening 4 - 4 .

[0076] The number of the tab openings 4-3 and the explosion-proof valve openings 4-4 matches the number of the battery cells 3, and the tabs of each battery cell 3 pass through the corresponding tab openings 4-3 on the bottom surface of the inner shell 4 and are connected in series and parallel in the shell gap 6;

[0077] The explosion-proof valve 3 - 1 of each battery cell 3 is aligned with the corresponding explosion-proof valve opening 4 - 4 on the bottom surface of the inner case 4 .

[0078] The tab opening 4-3 and the explosion-proof valve opening 4-4 ​​are both sealed or have a sealing structure.

[0079] In this embodiment, if Figure 7 , Fig. 9 , Fig.10 As shown, there are multiple battery cells 3 in the battery pack, which are arranged in a matrix in the inner shell 4, and the tab openings 4-3 and the explosion-proof valve openings 4-4 are also adapted to be distributed in a matrix.

[0080] Of course, in some other embodiments, the number of battery cells 3 in the battery pack can be adjusted according to demand.

[0081] By arranging the pole ear opening 4-3 and the explosion-proof valve opening 4-4 ​​at the bottom of the inner shell, on the one hand, the battery cell 3 can be fixed to realize the inverted installation mode; on the other hand, the pole ear can be led out to the shell gap 6 for series and parallel connection without being disturbed by the liquid coolant; on the other hand, the flame can be led out and separated from the battery and the coolant, thereby improving the safety of the battery pack.

[0082] By inverting the battery so that the explosion-proof valve opening 4-4 ​​is facing downward, and providing a shell gap 6 between the inner and outer shells, when the battery experiences thermal runaway and causes the explosion-proof valve to rupture, the flame can propagate in the shell gap 6, and the heat of the flame can be absorbed by the coolant inside the inner shell 4 and the air outside the outer shell 5, thereby reducing the temperature of the flame and extinguishing the flame, thereby improving the safety of the battery pack.

[0083] In this embodiment, Figure 1 , Figure 3 and Figure 4 As shown, an inner shell inlet 4-1 is provided on the side wall of the inner shell 4 at a position below the liquid coolant level, and an outer shell inlet 5-1 is provided at a corresponding position of the side wall of the outer shell 5. The outlet of the water pump can pass through the outer shell inlet 5-1 to be connected to the inner shell inlet 4-1.

[0084] In this embodiment, an inner shell outlet 4-2 is provided on the side wall of the inner shell 4 at a position above the liquid coolant level, and an outer shell outlet 5-2 is provided at a corresponding position of the side wall of the outer shell 5. The inlet of the fan can pass through the outer shell outlet 5-2 to be connected to the inner shell outlet 4-2.

[0085] The liquid level of the liquid coolant is at least flush with the height of the battery and needs to immerse the battery cell 3. A liquid level sensor 11 is installed on the inner wall of the inner shell 4. A pressure sensor 12 is installed on the inner wall of the inner shell 4 at a position above the liquid coolant level, and a temperature sensor 13 is installed at a position below the liquid coolant level.

[0086] By completely immersing the battery in liquid coolant and using the liquid level sensor 11 and the water pump to maintain the constant liquid coolant level, the liquid coolant can directly absorb and exchange the heat generated by different parts of the battery through convection, thereby improving the temperature uniformity and heat dissipation effect of the battery.

[0087] A liquid sensor 14 is installed on the outer wall of the inner shell 4 or the inner wall of the outer shell 5, located in the shell gap 6. By providing an inner and outer double shell, and installing the liquid sensor 14 in the shell gap 6, when the inner shell leaks, the liquid coolant can flow into the shell gap 6, and the operation of the water pump and the fan is stopped, preventing the coolant from flowing out of the battery pack, thereby improving the reliability of the battery pack.

[0088] like Figure 2 As shown, the battery pack is a split structure, including a detachable battery pack 1 and a battery pack cover 2, and the battery pack cover 2 is provided with a plurality of ventilation holes 2-1 or ventilation grooves, and the positions of the ventilation holes 2-1 or ventilation grooves correspond to the position of the shell gap 6.

[0089] By providing a vent hole 2-1 or a vent groove on the battery pack upper cover 2, the gap between the inner and outer shells is kept connected to the atmosphere, preventing flames from causing explosions and improving the safety of the battery pack.

[0090] In this embodiment, the battery pack cover 2 is also rectangular and is compatible with the inner and outer double-layer shells and can be detachably connected, such as by snapping.

[0091] Embodiment 2

[0092] An immersion evaporation type high energy efficiency self-driven battery thermal management system, which consists of a battery pack, a cooling cycle subsystem and an electronic control subsystem. Its main working principle is: Figure 1 As shown, each battery cell 3 in the battery pack 1 is immersed in the liquid coolant. Fig.11 As shown, when the temperature of the battery rises, the high temperature will cause the liquid coolant to vaporize and evaporate to form a gaseous coolant, which is then drawn out by the fan 7 and sent to the condenser 8. The condenser 8 cools the gaseous coolant into liquid coolant again, which then flows into the compensation water tank 9. The water pump 10 pumps the liquid coolant in the compensation water tank 9 back into the battery pack 1, so that the battery cells 3 are always immersed in the liquid coolant, and the battery temperature is maintained within a reasonable range. "High energy efficiency" means that compared with conventional air-cooled battery thermal management systems and liquid-cooled battery thermal management systems, the present invention uses the latent heat of phase change of the coolant during the evaporation process to absorb the heat generated by the battery, so the energy efficiency is higher.

[0093] like Figure 1 , Figure 2 , Fig. 9 , Fig.10As shown, the core component of the present invention is a battery pack 1. The battery pack 1 has a double-layer shell structure, which includes an inner shell 4 and an outer shell 5, both of which are open shells, and there is a shell gap 6 between the two. Studies have shown that in the immersion evaporation system, the inverted installation of the battery cells 3 helps to increase the evaporation amount of the liquid coolant and improve the heat dissipation effect of the battery. Therefore, each battery cell 3 in the battery pack 1 is installed in an inverted manner at the bottom of the inner shell 4. The liquid coolant fills around each battery cell 3, and the liquid level is flush with the battery height, so that the battery cell 3 is completely immersed in the liquid coolant. The battery pack cover 2 is installed on the top of the inner shell 4 and the outer shell 5.

[0094] like Figure 1 , Figure 2 , Figure 6 , Figure 8 , Fig.11 , Fig.12 As shown, an inner shell inlet 4-1 is provided on the side wall of the inner shell 4 at a position below the liquid coolant level, and an outer shell inlet 5-1 is provided at a corresponding position of the outer shell 5. The outlet of the water pump 10 passes through the outer shell inlet 5-1 and is connected to the inner shell inlet 4-1. A liquid level sensor 11 (not shown in the structural diagram) is installed on the inner wall of the inner shell 4 at the position of the liquid coolant level. The battery management system control unit BCU 15 can adjust the flow of the water pump 10 in real time according to the data collected by the liquid level sensor 11, so that the liquid level of the liquid coolant in the inner shell 4 remains constant.

[0095] like Figure 1 , Figure 3 , Figure 6 , Figure 8 , Fig.11 , Fig.12 As shown, on the other side wall of the inner shell 4, at a position above the liquid coolant level, an inner shell outlet 4-2 is opened, and at a corresponding position of the outer shell 5, an outer shell outlet 5-2 is opened, and the inlet of the fan 7 passes through the outer shell outlet 5-2 and is connected to the inner shell outlet 4-2. On the inner wall of the inner shell 4, at a position above the liquid coolant level, a pressure sensor 12 (not shown in the structure diagram) is installed, and at a position below the liquid coolant level, a temperature sensor 13 (not shown in the structure diagram) is installed. The battery management system control unit BCU 15 can adjust the speed of the fan 7 in real time according to the data collected by the pressure sensor 12 and the temperature sensor 13, and maintain or change the pressure of the gaseous coolant in the inner shell 4.

[0096] like Figure 1 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 , Fig.10As shown, the bottom surface of the inner shell 4 is provided with a tab opening 4-3 and an explosion-proof valve opening 4-4 ​​according to the number of battery cells 3. The tabs 3-2 of each battery cell 3 pass through the tab opening 4-3 on the bottom surface of the inner shell and are connected in series and parallel in the shell gap 6. The explosion-proof valve 3-1 of each battery cell 3 is aligned with the explosion-proof valve opening 4-4 ​​on the bottom surface of the inner shell. Sealing measures are taken between each tab opening 4-3 and the tab 3-2, and between each explosion-proof valve opening 4-4 ​​and the explosion-proof valve 3-1 to prevent leakage of liquid coolant.

[0097] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 , Fig.10 As shown, since there is a shell gap 6 between the inner shell 4 and the outer shell 5, when the battery cell 3 has a thermal runaway and causes the explosion-proof valve 3-1 to rupture, the flame can enter the shell gap 6 between the inner and outer shells from the explosion-proof valve opening 4-4 ​​on the bottom surface of the inner shell. The liquid coolant in the inner shell 4 can quickly absorb the heat of the flame through conduction, convection and evaporation, and the air outside the outer shell 5 can also absorb the heat of the flame through conduction and convection, thereby reducing the temperature of the flame and extinguishing the flame. On the battery pack cover 2, between the inner and outer shells, a vent 2-1 is opened to connect the shell gap 6 to the atmosphere to prevent the flame from causing an explosion.

[0098] like Figure 1 , Fig. 9 , Fig.10 , Fig.12 As shown, since there is a shell gap 6 between the inner shell 4 and the outer shell 5, when the liquid coolant in the inner shell 4 leaks, the liquid coolant can flow into the shell gap 6 and will not flow outside the battery pack 1. A liquid sensor 14 (not shown in the structure diagram) is installed in the shell gap 6. The battery management system control unit BCU15 can detect whether a coolant leak occurs based on the data collected by the liquid sensor 14, thereby stopping the operation of the water pump 10 and the fan 7 and issuing an alarm.

[0099] like Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 8 , Fig.11As shown, in addition to the battery pack 1, the battery thermal management system also includes a cooling circulation subsystem consisting of a fan 7, a condenser 8, a compensation water tank 9 and a water pump 10. The inlet of the fan 7 passes through the outer shell outlet 5-2 of the battery pack 1 and is connected to the inner shell outlet 4-2. The outlet of the fan 7 is connected to the inlet of the condenser 8, and the outlet of the condenser 8 is connected to the inlet of the compensation water tank 9. The outlet of the compensation water tank 9 is connected to the inlet of the water pump 10, and the outlet of the water pump 10 passes through the outer shell inlet 5-1 of the battery pack 1 and is connected to the inner shell inlet 4-1. The function of the fan 7 is to extract the gaseous coolant from the battery pack 1 and send it to the condenser 8. The function of the condenser 8 is to condense the gaseous coolant extracted by the fan 7 into liquid coolant and send it to the compensation water tank 9. The function of the compensation water tank 9 is to store the liquid coolant from the condenser 8. The function of the water pump 10 is to pump the liquid coolant in the compensation water tank 9 into the battery pack 1. Through the mutual cooperation between various parts, the thermal management of the battery is completed.

[0100] like Fig.12 As shown, in addition to the battery pack 1 and the cooling cycle subsystem, the battery thermal management system also includes an electronic control subsystem. The battery management system control unit BCU 15 is respectively connected to the liquid level sensor 11, the pressure sensor 12, the temperature sensor 13, the liquid sensor 14, the fan 7 and the water pump 10. The battery management system control unit BCU 15 is used to control the speed of the fan 7 and the flow rate of the water pump 10 according to the liquid level data collected by the liquid level sensor 11, the pressure data collected by the pressure sensor 12 and the temperature data collected by the temperature sensor 13. At the same time, it is determined whether to stop the operation of the fan 7 and the water pump 10 according to the data collected by the liquid sensor 14, and an alarm is issued.

[0101] The battery management system control unit BCU 15 can adjust the flow rate of the water pump 10 in real time according to the liquid level data collected by the liquid level sensor 11, keep the liquid coolant level constant, and make the battery cell 3 always immersed in the liquid coolant, thereby improving the temperature uniformity and heat dissipation effect of the battery. The battery management system control unit BCU 15 can adjust the speed of the fan 7 in real time according to the pressure data collected by the pressure sensor 12 and the temperature data collected by the temperature sensor 13, thereby accurately controlling the temperature of the battery. When the temperature of the battery is high, on the one hand, the temperature of the liquid coolant is also high, and on the other hand, the speed of the fan 7 is accelerated, which reduces the pressure of the gaseous coolant in the inner shell 4. The two effects jointly increase the evaporation rate of the liquid coolant and increase the evaporation amount of the liquid coolant, thereby effectively reducing the temperature of the battery. Correspondingly, when the temperature of the battery is low, on the one hand, the temperature of the liquid coolant is also low, and on the other hand, the speed of the fan 7 is slowed down, which increases the pressure of the gaseous coolant in the inner shell 4. The two effects jointly reduce the evaporation rate of the liquid coolant and reduce the evaporation amount of the liquid coolant, thereby effectively increasing the temperature of the battery. The battery management system control unit BCU 15 can detect whether a coolant leak occurs based on the data collected by the liquid sensor 14, thereby stopping the operation of the water pump 10 and the fan 7 and issuing an alarm.

[0102] Embodiment 3

[0103] The working method of the system provided in the second embodiment includes the following steps:

[0104] Obtain data from a liquid level sensor, a pressure sensor, a temperature sensor, and a liquid sensor installed in the battery pack, and adjust the flow rate of the water pump according to the liquid level data obtained by the liquid level sensor to maintain a constant liquid coolant level height so that the battery cells are always immersed in the liquid coolant;

[0105] According to the pressure data obtained by the pressure sensor and the temperature data obtained by the temperature sensor, the speed of the fan is adjusted. When the temperature data is greater than the set value, the speed of the fan is controlled to be greater than the first speed. When the temperature data is less than or equal to the set value, the speed of the fan is controlled to be less than or equal to the first speed.

[0106] Based on the data obtained by the liquid sensor, detect whether coolant leakage occurs, and if so, stop the operation of the water pump and fan.

[0107] Embodiment 4

[0108] A power or energy storage mechanism includes the battery pack provided in the first embodiment or the thermal management system provided in the second embodiment.

[0109] The power mechanism is an electric car or other equipment powered by batteries. The energy storage mechanism is a renewable energy storage facility or other equipment powered by batteries. This is not exhaustive.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention without creative labor shall be included in the protection scope of the present invention.

Claims

1. An immersion evaporation high-efficiency self-driven battery pack, characterized in that: The battery comprises an inner shell, an outer shell and a battery cell, wherein the outer shell is sleeved on the outside of the inner shell, and there is a certain shell gap between the two; the inner shell is used to accommodate a plurality of battery cells and liquid coolant, and the battery cell is invertedly arranged in the inner shell and immersed in the liquid coolant; The side walls of the inner shell and the outer shell are both provided with an inlet and an outlet, and the inlet positions of the two shells correspond to each other, and the outlet positions correspond to each other; The battery cell is provided with a pole lug and an explosion-proof valve, and the bottom of the inner shell is provided with a matching pole lug opening and an explosion-proof valve opening.

2. The submerged evaporation high-efficiency self-driven battery pack according to claim 1, characterized in that: An inlet of the inner shell is provided on the side wall of the inner shell at a position below the liquid coolant level, and an inlet of the outer shell is provided at a corresponding position of the side wall of the outer shell. The outlet of the water pump can pass through the inlet of the outer shell to be connected with the inlet of the inner shell; Or / and, an inner shell outlet is provided on the side wall of the inner shell at a position above the liquid coolant level, and an outer shell outlet is provided at a corresponding position on the side wall of the outer shell, and the fan inlet can pass through the outer shell outlet to be connected to the inner shell outlet.

3. The submerged evaporation high-efficiency self-driven battery pack according to claim 1, characterized in that: The liquid level of the liquid coolant is at least flush with the height of the battery; A liquid level sensor is installed on the inner wall of the inner shell, a pressure sensor is installed on the inner wall of the inner shell at a position above the liquid coolant level, and a temperature sensor is installed at a position below the liquid coolant level; A liquid sensor is installed on the outer wall of the inner shell or the inner wall of the outer shell, located in the shell gap.

4. The submerged evaporation high-efficiency self-driven battery pack according to claim 1, characterized in that: The number of the tab openings and the explosion-proof valve openings matches the number of battery cells, and the tabs of each battery cell pass through the corresponding tab openings on the bottom surface of the inner shell and are connected in series and parallel in the shell gap; The explosion-proof valve of each battery cell is aligned with the corresponding explosion-proof valve opening on the bottom surface of the inner shell; The pole ear opening and the explosion-proof valve opening are both sealed or have a sealing structure.

5. The submerged evaporation high-efficiency self-driven battery pack according to claim 1, characterized in that: The outer shell is a split structure, including a detachable shell and an upper cover, the upper cover is provided with a plurality of vent holes or vent grooves, and the positions of the vent holes or vent grooves correspond to the positions of the shell gaps.

6. An immersion evaporation high-efficiency self-driven battery thermal management system, characterized in that: A battery pack, a cooling circulation subsystem and an electronic control subsystem according to any one of claims 1 to 5, wherein the cooling circulation subsystem comprises a fan and a water pump, wherein the inlet of the fan passes through the outlet of the outer shell of the battery pack and is connected to the outlet of the inner shell, and the outlet of the water pump passes through the inlet of the outer shell of the battery pack and is connected to the inlet of the inner shell; The electronic control subsystem includes a battery management system control unit, which is connected to a liquid level sensor, a pressure sensor, a temperature sensor and a liquid sensor arranged in the battery pack, and is used to control the operation of the fan and the water pump, as well as the fan speed and the water pump flow rate according to the data of each sensor.

7. The immersion evaporation high-efficiency self-driven battery thermal management system according to claim 6, characterized in that: The cooling circulation subsystem also includes a condenser and a compensation water tank. The outlet of the fan is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the compensation water tank, and the outlet of the compensation water tank is connected to the inlet of the water pump.

8. The submerged evaporation high-efficiency self-driven battery thermal management system according to claim 6, characterized in that: The battery management system control unit is configured to adjust the flow rate of the water pump according to the liquid level data obtained by the liquid level sensor to keep the liquid coolant level constant so that the battery cells are always immersed in the liquid coolant; According to the pressure data obtained by the pressure sensor and the temperature data obtained by the temperature sensor, the speed of the fan is adjusted. When the temperature data is greater than the set value, the speed of the fan is controlled to be greater than the first speed. When the temperature data is less than or equal to the set value, the speed of the fan is controlled to be less than or equal to the first speed. Based on the data obtained by the liquid sensor, detect whether coolant leakage occurs, and if so, stop the operation of the water pump and fan.

9. An immersion evaporation high-efficiency self-driven battery thermal management method, comprising the system according to any one of claims 6 to 8, characterized in that: The following steps are involved: Obtain data from a liquid level sensor, a pressure sensor, a temperature sensor, and a liquid sensor installed in the battery pack, and adjust the flow rate of the water pump according to the liquid level data obtained by the liquid level sensor to maintain a constant liquid coolant level height so that the battery cells are always immersed in the liquid coolant; According to the pressure data obtained by the pressure sensor and the temperature data obtained by the temperature sensor, the speed of the fan is adjusted. When the temperature data is greater than the set value, the speed of the fan is controlled to be greater than the first speed. When the temperature data is less than or equal to the set value, the speed of the fan is controlled to be less than or equal to the first speed. Based on the data obtained by the liquid sensor, detect whether coolant leakage occurs, and if so, stop the operation of the water pump and fan.

10. A power mechanism or energy storage mechanism, characterized in that: A battery pack comprising any one of claims 1-5 or a thermal management system according to any one of claims 6-8.

Images