Thermal management system and method

Abstract

The invention discloses a thermal management system and method, relates to the technical field of battery thermal management, and solves the problem of temperature uniformity of a traditional thermal management system. According to the embodiment of the invention, through integrated cooperation of the bidirectional self-priming pump and the flow direction controller, the flow direction controller controls the cooling liquid to carry out forward and reverse flow circulation based on the temperature information collected at the liquid cooling plate by the temperature sensor, so that the temperature difference between the inlet and the outlet can be counteracted; and in combination with a variable cross-section symmetrical flow channel structure, the flow velocity and flow distribution of the cooling liquid in the flow channel are balanced, and local flow velocity dead angles or overflowing areas are eliminated, so that the homogenization of the surface temperature of the heat source is realized. By adopting the embodiment of the invention, the temperature uniformity of the thermal management system can be improved, and the high-efficiency thermal management requirements under complex working conditions such as high-rate discharge and large battery clusters can be better met.

Description

Technical Field

[0001] This invention relates to the field of battery thermal management technology, and in particular to a thermal management system and method. Background Technology

[0002] With the rapid development of new energy storage, electric vehicles, and other fields, high-energy-density, long-cycle-life, and low-cost battery technologies have become the core of industry research and development. Sodium-ion batteries, with their abundant resources, low cost, and excellent safety, have shown broad application prospects in large-scale energy storage power stations and low-speed electric vehicles, especially in complex operating conditions such as high-rate discharge and large-scale battery cluster integration, where the demand is increasingly urgent. However, sodium-ion battery modules generate a large amount of heat during charging and discharging, and their thermal characteristics differ significantly from traditional lithium-ion batteries. They exhibit rapid heating rates and concentrated heat distribution. Improper thermal management can easily lead to uneven temperature distribution within the module, resulting in a series of performance and safety issues.

[0003] Temperature uniformity is a key factor determining the performance, cycle life, and safety and reliability of battery modules. Studies have shown that when the internal temperature difference of a battery pack exceeds 5°C, the risk of thermal runaway increases significantly. Furthermore, the capacity decay rate of battery cells in high-temperature regions is much faster than that in low-temperature regions. Long-term operation will exacerbate the inconsistency imbalance between battery cells, leading to a decrease in the overall energy efficiency of the battery pack, a shortened cycle life, and even safety accidents such as overcharging, over-discharging, and thermal runaway.

[0004] Currently, liquid cooling systems have become the mainstream solution for thermal management of medium and large battery modules due to their high heat exchange efficiency and strong heat dissipation capacity. However, unreasonable flow channel design in traditional liquid cooling systems leads to uneven pressure drop, unbalanced flow velocity distribution of coolant in each channel, and the formation of "dead water zones" in some areas, making it impossible to achieve uniform heat exchange. Furthermore, the excessive temperature difference between the inlet and outlet results in significant temperature differences between the battery cells at both ends of the module.

[0005] Therefore, there is an urgent need for a thermal management system and method to solve the problem of temperature uniformity in traditional liquid cooling systems, meet the high-efficiency thermal management requirements under complex operating conditions such as high-rate discharge and large battery clusters, and provide technical support for the large-scale application of sodium-ion batteries. Summary of the Invention

[0006] To address the challenge of temperature uniformity in existing thermal management systems, this invention provides a thermal management system and method that improves temperature uniformity in liquid cooling systems, better meeting the high-efficiency thermal management requirements under complex operating conditions such as high-rate discharge and large battery clusters. The specific technical solution is as follows: In a first aspect, embodiments of this application provide a thermal management system, which includes: a flat heat pipe, a liquid cooling plate, a condenser, a bidirectional self-priming pump, a flow direction controller, and a temperature sensor; the condensing section of the flat heat pipe is tightly fitted to the liquid cooling plate and fixedly connected by brazing; a first end of the liquid cooling plate is connected to a second end of the condenser via a pipeline; a first end of the condenser is connected to a second end of the bidirectional self-priming pump via a pipeline; a first end of the bidirectional self-priming pump is connected to a second end of the liquid cooling plate via a pipeline; the flow direction controller is electrically connected to the bidirectional self-priming pump; and the temperature sensor is provided at both the first and second ends of the liquid cooling plate. The evaporation section of the flat heat pipe is used to tightly adhere to the battery module and mechanically bond it to the battery module in order to conduct the heat of the battery module to the liquid cooling plate; the flow controller is used to control the flow direction of the coolant in the system based on the temperature information collected by the temperature sensor through the bidirectional self-priming pump. The flow channel of the liquid cooling plate is a variable cross-section symmetrical flow channel structure. The variable cross-section symmetrical flow channel structure includes a straight section with the same flow channel width, a first gradient section from the inlet of the flow channel to the first end of the straight section where the cross-sectional area of ​​the flow channel gradually increases, and a second gradient section from the second end of the straight section to the outlet of the flow channel where the cross-sectional area of ​​the flow channel gradually decreases. The first gradient section and the second gradient section are symmetrical about the center of the straight section.

[0007] Preferably, the calculation process of the flow channel cross-sectional area change rate of the first transition section is as follows: Based on the fluid dynamics continuity equation and Bernoulli equation, a coupled model of the flow channel cross-sectional area change rate, pressure drop, and flow velocity is established; with the goal of minimizing the flow velocity of the straight section and with the constraint that the total pressure drop of the flow channel is less than a preset pressure drop threshold, the coupled model is solved to obtain the flow channel cross-sectional area change rate of the first transition section.

[0008] Preferably, the inlet and outlet widths of the flow channel are both 5 mm, the width of the straight section is 10 mm, and the cross-sectional area change rate of the first gradient section is 0.01 mm². -1 .

[0009] Preferably, the temperature information includes a first temperature at the first end of the liquid cooling plate and a second temperature at the second end of the liquid cooling plate; the flow direction controller is specifically used to: control the flow direction of the coolant with a preset flow time and a stop time when the temperature difference between the first temperature and the second temperature is less than a first temperature threshold; shorten the stop time to half of a preset stop time when the temperature difference is greater than or equal to the first temperature threshold and less than the second temperature threshold; and shorten the flow time to half of a preset flow time and the stop time to half of a preset stop time when the temperature difference is greater than or equal to the second temperature threshold, and increase the speed of the bidirectional self-priming pump.

[0010] Preferably, the temperature sensor is disposed at the center of the battery module, and the temperature information also includes a third temperature at the center of the battery module; the flow controller is further configured to: when the third temperature is greater than a third temperature threshold, control the coolant to circulate in a fixed direction via the bidirectional self-priming pump until the third temperature is less than a fourth temperature threshold; wherein the fourth temperature threshold is less than the third temperature threshold.

[0011] Preferably, the flat plate heat pipe includes a sodium-water working medium flat plate heat pipe.

[0012] In a second aspect, embodiments of this application provide a thermal management method applied to a flow controller of the system described in the first aspect, the method comprising: The flow controller acquires temperature information collected by the temperature sensor; based on this temperature information, the flow controller controls the flow direction of the coolant in the system through a bidirectional self-priming pump.

[0013] Preferably, the temperature information includes a first temperature at the first end of the liquid cooling plate and a second temperature at the second end of the liquid cooling plate; the flow controller, based on the temperature information and using a bidirectional self-priming pump, controls the flow direction of the coolant in the system, including: when the temperature difference between the first temperature and the second temperature is less than a first temperature threshold, the flow controller controls the flow direction of the coolant with a preset flow time and a stop time; when the temperature difference is greater than or equal to the first temperature threshold and less than the second temperature threshold, the flow controller shortens the stop time to half of the preset stop time; when the temperature difference is greater than or equal to the second temperature threshold, the flow controller shortens the flow time to half of the preset flow time, shortens the stop time to half of the preset stop time, and increases the rotational speed of the bidirectional self-priming pump.

[0014] Preferably, the temperature information includes a third temperature at the center of the battery module; the flow controller controls the flow direction of the coolant in the system based on the temperature information via a bidirectional self-priming pump, including: when the third temperature is greater than a third temperature threshold, controlling the coolant to circulate in a fixed flow direction via the bidirectional self-priming pump until the third temperature is less than a fourth temperature threshold; wherein the fourth temperature threshold is less than the third temperature threshold.

[0015] Thirdly, embodiments of this application provide a computing device, including: a memory for storing a program; and a processor for loading the program to execute the method as described in the second aspect.

[0016] Fourthly, embodiments of this application provide a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the method described in the second aspect.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: Through the integrated operation of a bidirectional self-priming pump and a flow controller, the flow controller, based on temperature information collected by a temperature sensor at the liquid cooling plate, controls the coolant to circulate in both forward and reverse directions, thus offsetting the temperature difference between the inlet and outlet. Furthermore, combined with a variable cross-section symmetrical flow channel structure, the flow velocity and flow rate distribution of the coolant within the flow channel are balanced, eliminating localized dead zones or overflow areas, thereby achieving uniformity of the heat source surface temperature and solving the problems of uneven heat dissipation and pressure drop. Using the embodiments of this application, the temperature uniformity of the thermal management system can be improved, better meeting the high-efficiency thermal management requirements under complex operating conditions such as high-rate discharge and large battery clusters. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale.

[0019] Figure 1 A schematic diagram of a thermal management system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a liquid cooling plate provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a liquid cooling plate flow channel provided in an embodiment of the present invention; Figure 4 A schematic diagram of a coolant flow direction control provided in an embodiment of the present invention; Figure 5 This is a schematic flowchart of a thermal management method provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0022] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] To address the challenge of temperature uniformity in existing thermal management systems, this invention provides a thermal management system and method that can improve temperature uniformity in liquid cooling systems and better meet the high-efficiency thermal management requirements under complex operating conditions such as high-rate discharge and large battery clusters.

[0025] Please see Figure 1 , Figure 1 This is a schematic diagram of a thermal management system provided in an embodiment of this application. Figure 1 As shown, the system includes a flat heat pipe 1, a liquid cooling plate 2, a condenser 3, a bidirectional self-priming pump 4, a flow direction controller 5, and a temperature sensor 6. The condensing section of the flat heat pipe 1 is tightly fitted to the liquid cooling plate 2 and fixedly connected by brazing. The first end of the liquid cooling plate 2 is connected to the second end of the condenser 3 through a pipeline. The first end of the condenser 3 is connected to the second end of the bidirectional self-priming pump 4 through a pipeline. The first end of the bidirectional self-priming pump 4 is connected to the second end of the liquid cooling plate 2 through a pipeline. The flow direction controller 5 is connected to the bidirectional self-priming pump 4 and the temperature sensor 6 respectively. Temperature sensors 6 are provided at both the first and second ends of the liquid cooling plate 2.

[0026] Understandably, in Figure 1 In the specific example, the black lines between components represent pipelines for the flow of coolant, and the gray lines between components represent electrical or communication connections. The first and second ends of the aforementioned components serve as the coolant inlet and outlet during the coolant circulation process, respectively.

[0027] The evaporation section of the flat heat pipe 1 is used to tightly adhere to the battery module 7 and mechanically bond it to the battery module 7 in order to conduct the heat of the battery module 7 to the liquid cooling plate 2.

[0028] Preferably, the flat heat pipes 1 are arranged in a matrix. The flat heat pipe array formed by multiple flat heat pipes 1 is embedded between the liquid cooling plate 2 and the battery module 7. The evaporation section of each flat heat pipe 1 is tightly attached to the surface of the battery unit by high thermal conductivity adhesive, covering areas with high heat flux density such as the tabs. The condensation section is fixedly connected to the flow channel wall of the liquid cooling plate by brazing process, forming a three-level heat transfer path of "battery-heat pipe-liquid cooling plate".

[0029] Understandably, in practical applications, besides Figure 1 In addition to the structural relationship shown, the spatial relationship between the battery module 7, the flat heat pipe 1, and the liquid cooling plate 2 can also be that the battery module 7 is below, the liquid cooling plate 2 is above, and the flat heat pipe 1 is located between the battery module 7 and the liquid cooling plate 2. In this way, the working fluid in the flat heat pipe 1 can absorb heat from the battery module 7, vaporize and rise, transfer the heat to the coolant in the liquid cooling plate 2, and then liquefy and naturally descend, forming a phase change cycle of the working fluid.

[0030] It is understandable that the flat plate heat pipe 1 is a highly integrated single pipe or flat sealed container with a unified internal cavity, which is filled with capillary structure and phase change working fluid; the evaporation section and the condensation section are the upper and lower parts of its internal space, but there is no rigid partition in the physical structure. The flat plate heat pipe 1 is connected to the liquid cooling plate 2 and the battery module 7 through its outer surface.

[0031] For example, in the battery module 7, every two battery cells correspond to three flat heat pipes 1. The evaporation section of the flat heat pipe 1 is tightly attached to the battery surface by high thermal conductivity silicone, the thermal conductivity of which is greater than or equal to 3.5W / (m·K). The condensation section is connected to the liquid cooling plate flow channel wall by brazing process, the weld width is less than or equal to 2mm, ensuring that the heat transfer thermal resistance is less than or equal to 0.01K / W.

[0032] Preferably, the flat plate heat pipe includes a sodium-water working medium flat plate heat pipe.

[0033] The sodium-water working medium flat plate heat pipe has a working temperature range of 50℃ to 200℃, a heat transfer capacity of ≥100W per heat pipe, an effective thermal conductivity of ≥5000W / (m·K), and a thickness of 3mm. It is adapted to the installation gap between the battery module 7 and the liquid cooling plate 2, thus solving the problems of large space occupation and small contact area of ​​the existing U-shaped heat pipe.

[0034] In this embodiment, through the coordinated heat dissipation of the flat plate heat pipe 1 and the liquid cooling plate 2, the flat plate heat pipe 1 handles the heat dissipation of the local high heat flux density area, rapidly transferring concentrated heat to the liquid cooling plate, thereby reducing the local heat load of the liquid cooling system. Simulation experiments show the following effect of this coordinated heat dissipation: After integrating the flat plate heat pipe 1, the heat dissipation required by the liquid cooling plate 2 is reduced by 30%, the pump power of the bidirectional self-priming pump 4 is reduced by 15%, and the overall energy consumption is reduced by 20%. Under the 4-rate discharge condition, the temperature fluctuation of the battery surface is reduced from ±5℃ to ±1.5℃, and the temperature of local hot spots is reduced by more than 10℃, which is better than the existing U-shaped heat pipe solution. Under the high temperature condition of 50℃, the battery life is extended by 15% through the synergistic heat dissipation of the heat pipe and liquid cooling.

[0035] By integrating a flat-plate heat pipe array with a liquid cooling plate to form an integrated heat dissipation structure, local hot spot heat dissipation can be enhanced, reducing the energy consumption of the liquid cooling system. Specifically, this heat dissipation structure solves the problems of limited heat dissipation capacity of liquid cooling systems for local hot spots, loose connection between existing heat pipes and liquid cooling plates, and low heat transfer efficiency; it also solves the problems of unreasonable layout of traditional U-shaped heat pipes, large space occupation, and difficulty in adapting to large battery modules; compared with the traditional U-shaped heat pipe layout, this heat dissipation structure saves 35% of space and can adapt to the installation needs of battery modules of more specifications.

[0036] The liquid cooling plate 2 is used to carry the heat conducted by the flat plate heat pipe 1 to the condenser 3 through the circulation of coolant.

[0037] For details, please refer to [link / reference]. Figure 2 and Figure 3 , Figure 2 and Figure 3 These are schematic diagrams of the liquid cooling plate 2 and the liquid cooling channel within it. The liquid cooling plate 2 has a variable cross-section symmetrical channel structure, comprising a straight section of equal width, a first transition section with gradually increasing cross-sectional area from the inlet to the first end of the straight section, and a second transition section with gradually decreasing cross-sectional area from the second end of the straight section to the outlet. The first and second transition sections are symmetrical about the center of the straight section.

[0038] Among them, the variable cross-section symmetrical flow channel structure can balance the flow velocity and flow rate distribution of the coolant in the flow channel, eliminate local dead velocity or overflow area, and thus achieve uniformity of heat source surface temperature, solving the problems of uneven heat dissipation and uneven pressure drop.

[0039] Preferably, the calculation process of the flow channel cross-sectional area change rate of the first transition section is as follows: Based on the fluid dynamics continuity equation and Bernoulli equation, a coupled model of the flow channel cross-sectional area change rate, pressure drop, and flow velocity is established; with the goal of minimizing the flow velocity of the straight section and with the constraint that the total pressure drop of the flow channel is less than a preset pressure drop threshold, the coupled model is solved to obtain the flow channel cross-sectional area change rate of the first transition section.

[0040] The expression for the fluid dynamics continuity equation is: Where ρ is the coolant density, A is the cross-sectional area of ​​the flow channel, and v is the flow velocity. For incompressible fluids, the density ρ can be considered a constant, and the equation can be simplified to: Q is a constant representing the volumetric flow rate.

[0041] The expression for Bernoulli's equation is: Where p is pressure and h is height. In a horizontal flow channel, Δh≈0, therefore it can be simplified to... .

[0042] Then, based on the above two formulas, a coupled model of the flow channel cross-sectional area change rate with pressure drop and flow velocity can be established, resulting in a differential equation or integral expression with the flow channel cross-sectional area and its change rate as independent variables and the flow velocity and total pressure drop of the flow channel as dependent variables.

[0043] It is understandable that, assuming the height is constant, the cross-sectional area of ​​the flow channel is proportional to the width of the flow channel. Therefore, this coupled model can be further reduced to a differential equation or integral expression with the width of the flow channel and its rate of change as independent variables, and the flow velocity and the total pressure drop of the flow channel as dependent variables.

[0044] Then, the objective function can be constructed: ; ; in, is the time required for the fluid to flow through the straight section, inversely proportional to the flow velocity; x is the vertical distance from the inlet of the flow channel. , These are the vertical distances from the first and second ends of the straight section to the inlet of the flow channel, respectively. Let Q be a width function, Q be a constant representing the volumetric flow rate, and h be the height. The width of the flow channel at the inlet is [value missing]. This is the expansion amplitude coefficient; The center position of the Gaussian distribution function is used to indicate the location of the highest heat generation area or the area that needs enhanced heat exchange in the battery module; is the standard deviation of the Gaussian distribution function, used to control the breadth of the expansion region.

[0045] Then, the constraints are constructed as follows: Voltage drop threshold constraint: .in, The total pressure drop in the flow channel. The voltage drop threshold, This is the maximum usable pressure of the bidirectional self-priming pump under rated voltage.

[0046] It is understandable that the total pressure drop of the flow channel during the optimization process can be obtained by simulation experiments on the flow channel using simulation software, or it can be calculated using relevant formulas in fluid mechanics based on the width function w(x) and the rate of change of the flow channel cross-sectional area, which will not be elaborated here.

[0047] Manufacturing constraints: ,in, This refers to the width of the flow channel in the straight section.

[0048] Rate of change constraint: ,in, This represents the change in cross-sectional area per unit length of the flow channel. This is the maximum local loss coefficient. This rate-of-change constraint is used to forcibly limit the steepness of the flow channel shape change, preventing the flow channel from expanding too rapidly, i.e. When the value is positive and too large, the fluid inertia will prevent it from flowing closely to the wall, causing it to separate from the wall and generate a huge low-pressure vortex region, resulting in problems such as a sharp increase in pressure loss, deterioration of heat transfer, and flow instability.

[0049] For example, the angle between the sidewall of one flow channel and the axis of the flow channel is less than 15°. This is a conversion of the tangent value of the expansion angle.

[0050] For example, the pressure drop threshold is 5 kPa.

[0051] Then, based on the gradient descent algorithm or the genetic algorithm, the coupled model can be solved using simulation software based on the constraints and the objective function to obtain the optimal flow channel cross-sectional area change rate.

[0052] Preferably, the inlet and outlet widths of the flow channel are both 5 mm, the width of the straight section is 10 mm, and the cross-sectional area change rate of the first gradient section is 0.01 mm². -1 .

[0053] When the inlet velocity is 0.2 m / s, the velocity in the central region drops to 0.1 m / s, the residence time is doubled, and the pressure drop is uniform throughout the entire process. The pressure drop from the inlet to the center is 2.1 kPa, and the pressure drop from the center to the outlet is 1.9 kPa, which meets the constraints of Bernoulli's equation and the continuity equation of fluid mechanics.

[0054] In professional fluid simulation software, the performance of traditional serpentine flow channels, existing topology-optimized flow channels, and the variable cross-section symmetrical flow channel of this application embodiment were compared. The results show that the flow channel of this application embodiment has significant advantages in terms of heat dissipation uniformity and pressure drop control. At the same flow rate of 0.2 m / s, the flow channel in this embodiment reduces the temperature of the central region of the battery pack by 8°C, and the temperature difference is reduced from 10°C to 3°C. The cooling effect is better than that of the topology-optimized flow channel. The total pressure drop is reduced by 15% compared with the traditional serpentine flow channel and by 8% compared with the topology-optimized flow channel, and the pump power requirement is significantly reduced.

[0055] After adopting the flow channel structure of the embodiment of this application, the energy efficiency ratio of the liquid cooling system is improved by 25%, the adaptability of the flow channel is improved by 40%, and it can be adapted to 3-10 series-connected battery modules by adjusting the cross-sectional area change rate.

[0056] Condenser 3 is used to cool the coolant in the liquid cooling system that has absorbed heat from the battery, thus achieving the final removal of heat.

[0057] The bidirectional self-priming pump 4 is used to drive the coolant to flow in both directions in the system pipeline, and it also has self-priming capability, allowing it to start without pre-filling. The self-priming capability means that when the system is first started or when a small amount of air resistance occurs in the pipeline, the bidirectional self-priming pump 4 can automatically draw coolant from the pipeline, avoiding circulation interruptions caused by air blockage and improving system reliability.

[0058] The condenser 3, as a cold source component, cools the coolant after absorbing heat to a set temperature range, ensuring that the coolant continuously provides cooling during the circulation process. It is connected in series with the bidirectional self-priming pump 4, so that after the coolant absorbs heat on the liquid cooling plate 2, it is cooled by the condenser 3 and then returns to the liquid cooling plate 2, forming a closed-loop heat dissipation cycle.

[0059] The forward circulation process of the coolant is as follows: the bidirectional self-priming pump 4 drives the coolant in the forward direction → the low-temperature coolant flows into the liquid cooling plate 2 → absorbs the heat of the condensing section of the flat plate heat pipe 1 → the high-temperature coolant flows into the condenser 3 to cool down → the low-temperature coolant flows back to the pump to complete the circulation.

[0060] The reverse circulation process of the coolant is as follows: the pump reverses its direction of flow → the coolant flow direction is switched, and it flows first through the liquid cooling plate corresponding to the high heat area of ​​the battery → to ensure rapid cooling of local hot spots.

[0061] The flow direction controller 5 is used to control the flow direction of the coolant in the system based on the temperature information collected by the temperature sensor 6 via the bidirectional self-priming pump 4. The flow direction controller 5 has a built-in microcontroller unit (MCU) chip, which is used to receive the temperature information collected by the temperature sensor and dynamically adjust the periodic parameters of the flow direction switching based on the temperature information.

[0062] The cycle parameters include flow time and stop time; flow time refers to the duration during which the coolant continuously circulates in the system pipeline when the bidirectional self-priming pump 4 is in the open state; stop time refers to the duration during which the coolant stops circulating in the system pipeline when the bidirectional self-priming pump 4 is in the closed state.

[0063] The flow time and the stop time constitute a flow cycle. When a flow cycle ends, the bidirectional self-priming pump 4 will change the flow direction of the coolant and enter the next flow cycle.

[0064] By integrating a bidirectional self-priming pump with a flow controller, the coolant can circulate in both directions. Combined with a self-developed dynamic cycle adjustment algorithm, the temperature difference between the inlet and outlet is offset, thereby improving the system response speed.

[0065] The system includes at least two temperature sensors 6, which are disposed at the first and second ends of the liquid cooling plate 2. Preferably, the system may also include a temperature sensor 6 disposed at the center or surface of the battery module 7, and a temperature sensor 6 disposed in the condensation section of the flat heat pipe 1. Figure 1 In a specific example, a temperature sensor 6 is provided on the surface of the battery module 7.

[0066] Specifically, the flow controller 5 can determine whether it is necessary to extend the coolant circulation time and reduce the stop time to increase the cooling input based on the temperature information of the battery module 7; it can also determine whether the flat plate heat pipe 1 is in the high-efficiency heat transfer working range based on the temperature change trend of the condensation section of the flat plate heat pipe 1, and make timely feedback adjustments.

[0067] For example, the temperature sensor 6 has a sampling frequency of 10Hz.

[0068] Please see Figure 4 , Figure 4 This is a schematic diagram of a coolant flow direction control process provided in an embodiment of the present invention. Figure 4 As shown, the coolant flow control can be divided into three circulation sections.

[0069] The temperature information includes a first temperature at the first end of the liquid cooling plate, a second temperature at the second end of the liquid cooling plate, and a third temperature at the center of the battery module.

[0070] 1. Basic mode.

[0071] When the temperature difference ΔT between the first temperature and the second temperature is less than the first temperature threshold T_th1, or the third temperature is less than the third temperature threshold T_th3, the flow controller 5 can control the bidirectional self-priming pump 4 to perform periodic bidirectional circulation of coolant according to the preset period parameters, and change the coolant flow direction when the current flow cycle is detected to be over.

[0072] For example, the first temperature threshold T_th1 is 3℃, the third temperature threshold T_th3 is 42℃; the preset flow time in the cycle parameters is 300 seconds, the preset stop time is 60 seconds, and the preset flow cycle is 360 seconds.

[0073] 2. Dynamic mode.

[0074] When the temperature difference ΔT is greater than the first temperature threshold T_th1 and less than the second temperature threshold T_th2, the stopping time is shortened to half of the preset stopping time; when the temperature difference ΔT is greater than the second temperature threshold T_th2, the flow time is shortened to half of the preset flow time, the stopping time is shortened to half of the preset stopping time, and the speed of the bidirectional self-priming pump is increased.

[0075] For example, the second temperature threshold T_th2 is 5°C.

[0076] For example, if the temperature difference ΔT is greater than the second temperature threshold T_th2, the rotational speed of the bidirectional self-priming pump 4 is increased by 10%.

[0077] 3. Protection Mode.

[0078] When the third temperature is greater than the third temperature threshold T_th3, the coolant is controlled to circulate in a fixed direction by the bidirectional self-priming pump until the third temperature is less than the fourth temperature threshold T_th4; wherein the fourth temperature threshold is less than the third temperature threshold.

[0079] When the third temperature is greater than the third temperature threshold T_th3, the flow direction can be locked and changed alternately without stopping time, until the third temperature is less than the fourth temperature threshold T_th4, and then the flow direction of the coolant can be controlled again with preset cycle parameters.

[0080] For example, the third temperature threshold T_th3 is 42℃ and the fourth temperature threshold T_th4 is 40℃.

[0081] Among them, the flow controller 5 controls the forward and reverse winding switching of the bidirectional self-priming pump 4 through the PWM signal, with a response delay of ≤50ms. Compared with the traditional solenoid valve control scheme with a response lag of more than 200ms, the response speed is improved by more than 4 times, which solves the technical bottleneck of response lag in the traditional scheme.

[0082] A control model was built in a simulation platform, and the dynamic periodic strategy of this invention was compared with existing solenoid valve control strategies. The following beneficial effects of the embodiments of this application were obtained: The basic mode in this application embodiment can reduce the temperature difference from 8°C to 3°C, and the dynamic mode is further optimized to 2.5°C; the existing solenoid valve control scheme can only reduce the minimum temperature difference to 4°C, and the response time is 30% longer.

[0083] The embodiments of this application solve the problems of unidirectional flow leading to the accumulation of temperature difference between the inlet and outlet in traditional solutions, the response lag of traditional solenoid valves in controlling the flow direction, and the difficulty in adapting to dynamic heat load changes when switching between fixed flow direction or fixed cycle.

[0084] After adopting the flow control scheme of this application embodiment, the battery pack temperature difference can be reduced by 40%. The minimum temperature difference under dynamic operating conditions can reach 2.5℃; the system response speed is improved by 30%, adapting to transient high-rate discharge conditions, and the pump power loss is reduced by 20%.

[0085] The integrated structure of the above system solves the problems of scattered components and loose connections in traditional solutions. Through the collaborative design of each component, heat transfer efficiency is maximized, while the installation process is simplified and the structural complexity is reduced.

[0086] In this embodiment, the integrated operation of a bidirectional self-priming pump and a flow controller allows the flow controller to control the coolant's forward and reverse flow circulation based on temperature information collected by a temperature sensor at the liquid cooling plate, thus offsetting the temperature difference between the inlet and outlet. Furthermore, the variable cross-section symmetrical flow channel structure balances the flow velocity and flow rate distribution of the coolant within the channel, eliminating localized dead zones or overflow areas, thereby achieving uniform temperature on the heat source surface and resolving issues of uneven heat dissipation and pressure drop. Using this embodiment improves the temperature uniformity of the thermal management system, better meeting the high-efficiency thermal management requirements under complex operating conditions such as high-rate discharge and large battery clusters. In this embodiment, the cross-sectional area change rate of the variable cross-section symmetrical flow channel is accurately derived and optimized based on Bernoulli's equation and continuity equation, achieving dual optimization of cooling and pressure drop balance, which is different from the empirical design of existing topology-optimized flow channels. It adopts a bidirectional self-priming pump and a self-developed dynamic cycle switching algorithm, which improves the response speed by 30%, adapts to dynamic heat load, and is superior to the lag problem of traditional solenoid valve control schemes. Through the integrated brazing connection of the flat plate heat pipe array and the liquid cooling plate, the evaporation section fully covers the high heat flux density area, and the heat dissipation efficiency is improved by 25% compared with the existing U-shaped heat pipe scheme.

[0087] The system provided by the embodiments of this application has been described above. The thermal management method provided by the embodiments of this application will be described below. Please refer to... Figure 5 , Figure 5 This application provides a flowchart illustrating a thermal management method, which is applied to the flow controller of the aforementioned system and specifically includes: Step 501: Flow to the controller to obtain temperature information collected by the temperature sensor.

[0088] Step 502: The flow direction controller controls the flow direction of the coolant in the system based on the temperature information via a bidirectional self-priming pump.

[0089] Preferably, the temperature information includes a first temperature at the first end of the liquid cooling plate and a second temperature at the second end of the liquid cooling plate; the flow controller, based on the temperature information and using a bidirectional self-priming pump, controls the flow direction of the coolant in the system, including: when the temperature difference between the first temperature and the second temperature is less than a first temperature threshold, the flow controller controls the flow direction of the coolant circulation with a preset flow time and stop time using the bidirectional self-priming pump; when the temperature difference is greater than the first temperature threshold and less than the second temperature threshold, the flow controller shortens the stop time to half of a preset value; when the temperature difference is greater than the second temperature threshold, the flow controller shortens both the flow time and the stop time to half of the corresponding preset values. Preferably, the temperature information includes a third temperature at the center of the battery module; the flow controller controls the flow direction of the coolant in the system based on the temperature information via a bidirectional self-priming pump, including: when the third temperature is greater than a third temperature threshold, controlling the coolant to circulate in a fixed flow direction via the bidirectional self-priming pump until the third temperature is less than a fourth temperature threshold; wherein the fourth temperature threshold is less than the third temperature threshold.

[0090] The methods provided in this application can be understood by referring to the relevant content in the foregoing system embodiment section, and will not be repeated here.

[0091] In another embodiment of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the above-described... Figure 5 The method described in the embodiments.

[0092] Those skilled in the art will recognize that the units of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the invention.

[0093] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0094] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0095] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0096] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0097] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A thermal management system, characterized in that, The system includes a flat heat pipe, a liquid cooling plate, a condenser, a bidirectional self-priming pump, a flow direction controller, and a temperature sensor. The condensing section of the flat heat pipe is tightly fitted to the liquid cooling plate and fixedly connected by brazing. The first end of the liquid cooling plate is connected to the second end of the condenser via a pipeline. The first end of the condenser is connected to the second end of the bidirectional self-priming pump via a pipeline. The first end of the bidirectional self-priming pump is connected to the second end of the liquid cooling plate via a pipeline. The flow direction controller is connected to both the bidirectional self-priming pump and the temperature sensor. The temperature sensor is installed at both the first and second ends of the liquid cooling plate. The evaporation section of the flat heat pipe is used to fit tightly against the battery module and mechanically bond it to the battery module in order to conduct the heat of the battery module to the liquid cooling plate. The flow direction controller is used to control the flow direction of the coolant in the system based on the temperature information collected by the temperature sensor via the bidirectional self-priming pump. The flow channel of the liquid cooling plate is a variable cross-section symmetrical flow channel structure. The variable cross-section symmetrical flow channel structure includes a straight section with the same flow channel width, a first gradient section from the inlet of the flow channel to the first end of the straight section where the cross-sectional area of ​​the flow channel gradually increases, and a second gradient section from the second end of the straight section to the outlet of the flow channel where the cross-sectional area of ​​the flow channel gradually decreases. The first gradient section and the second gradient section are symmetrical about the center of the straight section.

2. The system according to claim 1, characterized in that, The calculation process for the rate of change of the cross-sectional area of ​​the flow channel in the first transition section is as follows: Based on the continuity equation and Bernoulli's equation in fluid mechanics, a coupled model of the rate of change of the cross-sectional area of ​​the flow channel with pressure drop and flow velocity is established. With the goal of minimizing the flow velocity in the straight section and the constraint that the total pressure drop of the flow channel is less than a preset pressure drop threshold, the coupled model is solved to obtain the flow channel cross-sectional area change rate of the first gradient section.

3. The system according to claim 2, characterized in that, The inlet and outlet widths of the flow channel are both 5 mm, the width of the straight section is 10 mm, and the cross-sectional area change rate of the first gradient section is 0.01 mm². -1 .

4. The system according to any one of claims 1-3, characterized in that, The temperature information includes a first temperature at the first end of the liquid cooling plate and a second temperature at the second end of the liquid cooling plate. The flow direction controller is specifically used for: When the temperature difference between the first temperature and the second temperature is less than the first temperature threshold, the flow direction of the coolant is controlled by a preset flow time and stop time. If the temperature difference is greater than or equal to the first temperature threshold and less than the second temperature threshold, the stopping time is shortened to half of the preset stopping time. When the temperature difference is greater than or equal to the second temperature threshold, the flow time is shortened to half of the preset flow time, the stop time is shortened to half of the preset stop time, and the rotational speed of the bidirectional self-priming pump is increased.

5. The system according to claim 4, characterized in that, The temperature sensor is located at the center of the battery module, and the temperature information also includes a third temperature at the center of the battery module; the flow controller is further used for: When the third temperature is greater than the third temperature threshold, the coolant is controlled to circulate in a fixed direction by the bidirectional self-priming pump until the third temperature is less than the fourth temperature threshold; wherein the fourth temperature threshold is less than the third temperature threshold.

6. The system according to any one of claims 1-3, characterized in that, The flat plate heat pipe includes a sodium-water working medium flat plate heat pipe.

7. A thermal management method, characterized in that, The method, applied to a flow controller of any one of claims 1 to 6, comprises: The flow controller acquires temperature information collected by the temperature sensor; The flow controller controls the flow direction of the coolant in the system based on the temperature information via a bidirectional self-priming pump.

8. The method according to claim 7, characterized in that, The temperature information includes a first temperature at the first end of the liquid cooling plate and a second temperature at the second end of the liquid cooling plate. The flow controller, via a bidirectional self-priming pump, controls the flow direction of the coolant in the system based on the temperature information, including: When the temperature difference between the first temperature and the second temperature is less than the first temperature threshold, the flow direction controller controls the flow direction of the coolant through the bidirectional self-priming pump with a preset flow time and stop time. If the temperature difference is greater than or equal to the first temperature threshold and less than the second temperature threshold, the flow direction controller will shorten the stop time to half of the preset stop time. When the temperature difference is greater than or equal to the second temperature threshold, the flow direction controller shortens the flow time to half of the preset flow time, shortens the stop time to half of the preset stop time, and increases the speed of the bidirectional self-priming pump.

9. The method according to claim 7, characterized in that, The temperature information includes a third temperature at the center of the battery module; the flow controller, based on the temperature information, controls the flow direction of the coolant in the system via a bidirectional self-priming pump, including: When the third temperature is greater than the third temperature threshold, the coolant is controlled to circulate in a fixed direction by the bidirectional self-priming pump until the third temperature is less than the fourth temperature threshold; wherein the fourth temperature threshold is less than the third temperature threshold.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method as described in any one of claims 7-9.

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