A multi-stage temperature-controlled thermal management system and method

Abstract

This disclosure provides a multi-stage temperature-controlled thermal management system and method. The multi-stage temperature-controlled thermal management system includes a battery cell array, a first cold plate, a second cold plate, a flexible heat pipe, a semiconductor cooler, and a heat transfer medium circulation pipeline. Each battery cell has a thermal buffer sleeve on its sidewall, which is in thermal contact with the cold end of the first cold plate and the semiconductor cooler. The hot end of the semiconductor cooler is connected to the second cold plate through the flexible heat pipe, forming a multi-stage heat transfer link. The first and second cold plates share a heat transfer medium circulation pipeline, which includes a variable frequency pump, a liquid storage tank, circulation equipment, and controls such as a three-way valve and a solenoid valve. By constructing a local active heat dissipation path through the thermal buffer sleeve, the semiconductor cooler, and the flexible heat pipe, and in conjunction with the dual liquid cooling channels of the first and second cold plates, the temperature difference between the battery cells in the package is effectively reduced, improving cell consistency and blocking heat diffusion, achieving precise temperature control to meet the requirements of high safety and long lifespan of the battery cells.

Description

Technical Field

[0001] This disclosure relates to the field of battery thermal management technology, and more specifically, to a multi-level temperature control thermal management system and method. Background Technology

[0002] With the rapid development of the new energy vehicle and energy storage industries, cylindrical cells have become the mainstream choice for power battery pack systems due to their advantages such as high energy density, low manufacturing cost, and flexible assembly. However, because cylindrical cells are usually arranged closely in the pack, heat in the central area is difficult to be effectively conducted to the outside, resulting in significant temperature differences between cells, which seriously affects their cycle life and safety performance.

[0003] Specifically, cylindrical cells are typically arranged closely within a module to improve space utilization. However, because heat in the central area is difficult to dissipate, significant temperature gradients occur between different cells, and even within the same cell. According to industry test data, the temperature difference between cells in a battery pack often exceeds 8°C, especially under high loads or in summer environments. This can easily lead to inconsistent cell aging rates, premature capacity decay in certain areas, uneven internal resistance, and an increased risk of thermal runaway, ultimately affecting the lifespan and safety of the entire battery system. Summary of the Invention

[0004] This disclosure provides at least one multi-level temperature control thermal management system and method, which constructs a multi-level heat transfer link and builds a local active heat dissipation path through a thermal buffer sleeve, a semiconductor cooler and a flexible heat pipe. Combined with the first and second cold plates and dual liquid cooling channels, it effectively reduces the temperature difference between cells in the package, improves cell consistency and blocks heat diffusion, and achieves precise temperature control to meet the requirements of high safety and long life of the cells.

[0005] This disclosure provides a multi-level temperature control thermal management system, including: a battery cell array, a first cold plate, a second cold plate, a flexible heat pipe, a semiconductor cooler, and a heat transfer medium circulation pipeline;

[0006] The cell array includes cells with side surfaces enveloping thermal buffer sleeves;

[0007] Each of the heat buffer sleeves is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate;

[0008] The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate.

[0009] The heat transfer medium circulation pipeline has its outlet connected to the inlet of the first cold plate and its inlet connected to the outlet of the first cold plate, forming a primary heat transfer loop.

[0010] The heat transfer medium circulation pipeline has its outlet connected to the inlet of the second cold plate via a solenoid valve, and the inlet connected to the outlet of the second cold plate, forming a two-stage heat transfer loop.

[0011] In one optional embodiment, the first cold plate is provided with through holes corresponding to each of the battery cells;

[0012] Each of the battery cells is vertically inserted into the matching through hole, so that the heat buffer sleeve makes heat transfer contact with the first cold plate.

[0013] In one optional embodiment, the semiconductor cooler is parallel to the first cold plate, and the second cold plate is perpendicular to the semiconductor cooler;

[0014] The semiconductor cooler is disposed in the arrangement gap between the battery cells, and a limiting groove matching the geometry of the battery cells is opened at the cold end;

[0015] Each of the heat buffer sleeves makes heat transfer contact with the cold end of the semiconductor cooler through the limiting groove.

[0016] In one optional embodiment, the cell array further includes a first support and a second support;

[0017] Both the first bracket and the second bracket are provided with limiting holes corresponding to each of the battery cells;

[0018] The positive electrode end of each of the battery cells is vertically fixed to the matching limiting hole in the first bracket, and the negative electrode end is vertically fixed to the matching limiting hole in the second bracket.

[0019] In one optional implementation, a housing is also included;

[0020] The battery cell array, which is fixed by the first bracket and the second bracket, is placed inside the box and forms a battery cell pack with the second cold plate.

[0021] The surface of the housing exposes the liquid inlet and outlet of the first cold plate, and the liquid inlet and outlet of the second cold plate.

[0022] In one optional embodiment, the heat transfer medium circulation pipeline includes: a variable frequency pump, a liquid storage tank, and a heat transfer medium circulation device;

[0023] The outlet of the storage tank is connected to the inlet of the variable frequency pump.

[0024] The outlet of the variable frequency pump serves as the outlet of the heat transfer medium circulation pipeline, connecting to the first cold plate and the second cold plate via the solenoid valve.

[0025] The liquid inlet of the heat transfer medium circulation device serves as the liquid inlet of the heat transfer medium circulation pipeline, and is connected to the liquid outlets of the first cold plate and the second cold plate, respectively.

[0026] The outlet of the heat transfer medium circulation device is connected to the inlet of the storage tank.

[0027] In one optional embodiment, it further includes a first three-way valve and a second three-way valve:

[0028] The first three-way valve has its inlet connected to the outlet of the variable frequency pump, its first outlet connected to the inlet of the second cold plate via the solenoid valve, and its second outlet connected to the inlet of the first cold plate.

[0029] The second three-way valve has an inlet connected to the outlet of the heat transfer medium circulation device, a first outlet connected to the outlet of the first cold plate, and a second outlet connected to the outlet of the second cold plate.

[0030] This disclosure also provides a multi-level temperature control thermal management method, applied to any of the multi-level temperature control thermal management systems described in the above embodiments. The multi-level temperature control thermal management system further includes temperature sensors disposed on both sides of the battery cell and at the center of the side surface. The method includes:

[0031] The temperature sensor monitors the cell temperature in real time. When the cell temperature is lower than a preset first temperature threshold, a heating mode is triggered. When the cell temperature is higher than a preset second temperature threshold, a cooling mode is triggered.

[0032] In the heating mode, if the cell temperature is within a preset first-level heating temperature range, the solenoid valve is closed, and the cell array is heated through the first-level heat transfer loop; if the cell temperature is within a preset second-level heating temperature range, the solenoid valve is opened, and the cell array is heated through the first-level heat transfer loop and the second-level heat transfer loop, wherein the preset second-level heating temperature range is lower than the preset first-level heating temperature range.

[0033] In the cooling mode, if the cell temperature is within a preset first-level cooling temperature range, the solenoid valve is closed, and the cell array is cooled through the first-level heat transfer loop; if the cell temperature is within a preset second-level cooling temperature range, the solenoid valve is opened, and the cell array is cooled through the first-level heat transfer loop and the second cold plate, wherein the preset second-level cooling temperature range is higher than the preset first-level cooling temperature range.

[0034] In one optional implementation, the method further includes:

[0035] Select the first target battery cell whose cell temperature is higher than a preset third temperature threshold or whose temperature rise rate is greater than a preset temperature rise threshold;

[0036] The semiconductor cooler that is in thermal contact with the first target battery cell is controlled to operate at maximum power, and the heat transfer medium circulation pipeline is adjusted to circulate the heat transfer medium at maximum flow rate, wherein the preset third temperature threshold is greater than the preset second temperature threshold.

[0037] In one optional implementation, the method further includes:

[0038] When the cell temperature is within the preset secondary cooling temperature range, a second target cell with a cell temperature difference greater than a preset temperature difference threshold is selected.

[0039] The semiconductor cooler that is in thermal contact with the second target battery cell is controlled to operate in order to reduce the battery cell temperature corresponding to the second target battery cell until the battery cell temperature difference between the second target battery cell and other battery cells is less than the preset temperature difference threshold.

[0040] This disclosure also provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, they perform the steps of the above-described multi-level temperature control thermal management method, or any possible implementation of the above-described multi-level temperature control thermal management method.

[0041] This disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the multi-level temperature control thermal management method described above, or any possible implementation of the multi-level temperature control thermal management method described above.

[0042] This disclosure also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implements the above-described multi-level temperature control thermal management method, or the steps in any possible implementation of the above-described multi-level temperature control thermal management method.

[0043] This disclosure provides a multi-stage temperature-controlled thermal management system and method. The multi-stage temperature-controlled thermal management system includes: a battery cell array, a first cold plate, a second cold plate, a flexible heat pipe, a semiconductor cooler, and a heat transfer medium circulation pipeline. The battery cell array includes battery cells with side surfaces enveloping thermal buffer sleeves. Each thermal buffer sleeve is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate. The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate. The heat transfer medium circulation pipeline has an outlet connected to the inlet of the first cold plate and an inlet connected to the outlet of the first cold plate, forming a primary heat transfer loop. The heat transfer medium circulation pipeline also has an outlet connected to the inlet of the second cold plate via a solenoid valve, and an inlet connected to the outlet of the second cold plate, forming a secondary heat transfer loop. By constructing a localized active heat dissipation path through a thermal buffer sleeve, a semiconductor cooler, and flexible heat pipes, and in conjunction with dual liquid cooling channels of primary and secondary cold plates, the temperature difference between cells in the package is effectively reduced, improving cell consistency and blocking heat diffusion, thereby achieving precise temperature control to meet the requirements of high cell safety and long lifespan.

[0044] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this disclosure and, together with the specification, serve to explain the technical solutions of this disclosure. It should be understood that the following drawings only show some embodiments of this disclosure and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without creative effort.

[0046] Figure 1 A side view of a battery cell array in a multi-level temperature control thermal management system provided in an embodiment of this disclosure is shown;

[0047] Figure 2 A cross-sectional top view of a battery cell array in a multi-level temperature control thermal management system provided in an embodiment of this disclosure is shown;

[0048] Figure 3 This diagram shows an overall schematic of a multi-level temperature control thermal management system provided in an embodiment of the present disclosure;

[0049] Figure 4 A flowchart of a multi-level temperature control thermal management method provided by an embodiment of this disclosure is shown. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0051] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0052] In this document, the term "and / or" merely describes a relationship, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0053] Research has revealed that existing thermal management solutions mostly employ single liquid cooling or air cooling technologies, which cannot meet the requirements for efficient heat dissipation and temperature uniformity under high-speed charging and discharging or extreme environments. Furthermore, traditional PTC heating response is sluggish in low-temperature environments, resulting in low heating efficiency, and uneven heating can easily cause thermal mismatch between the cell tabs and the casing. In addition, traditional temperature control systems mainly achieve control through overall package temperature monitoring, lacking the ability to control temperature at the cell level, making it difficult to respond quickly to extreme situations such as thermal runaway.

[0054] Based on the above research, this disclosure provides a multi-stage temperature-controlled thermal management system and method. The multi-stage temperature-controlled thermal management system includes: a battery cell array, a first cold plate, a second cold plate, a flexible heat pipe, a semiconductor cooler, and a heat transfer medium circulation pipeline. The battery cell array includes battery cells with side surfaces enveloping thermal buffer sleeves. Each thermal buffer sleeve is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate. The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate. The heat transfer medium circulation pipeline has an outlet connected to the inlet of the first cold plate and an inlet connected to the outlet of the first cold plate, forming a primary heat transfer loop. The heat transfer medium circulation pipeline also has an outlet connected to the inlet of the second cold plate via a solenoid valve, and an inlet connected to the outlet of the second cold plate, forming a secondary heat transfer loop. By constructing a localized active heat dissipation path through a thermal buffer sleeve, a semiconductor cooler, and flexible heat pipes, and in conjunction with dual liquid cooling channels of primary and secondary cold plates, the temperature difference between cells in the package is effectively reduced, improving cell consistency and blocking heat diffusion, thereby achieving precise temperature control to meet the requirements of high cell safety and long lifespan.

[0055] To facilitate understanding of this embodiment, a multi-level temperature control and thermal management system disclosed in this disclosure will first be described in detail. See first for reference... Figures 1-2 As shown, Figure 1 A side view of a battery cell array in a multi-level temperature control thermal management system provided in an embodiment of this disclosure is shown. Figure 2 A cross-sectional top view of a cell array in a multi-level temperature control thermal management system provided in an embodiment of this disclosure is shown.

[0056] Specifically, such as Figures 1-2 As shown in the embodiment of this application, the multi-level temperature control thermal management system targets a cell array formed by multiple cells. Each cell has a thermal buffer sleeve covering its outer surface to absorb and buffer instantaneous heat. Preferably, the thermal buffer sleeve 2 is made of a high latent heat phase change material (PCM) and is tightly wrapped around the cell surface with a medium having high elasticity and high thermal conductivity. This allows for rapid heat absorption and delayed heat conduction when the cell's temperature suddenly increases, achieving transient thermal stability.

[0057] Here, to achieve a high-density and controllable thermal path arrangement, each battery cell is fixed between the first and second supports at both ends. The first and second supports each have limiting holes that match the arrangement of the battery cell array. Each limiting hole is used to insert and fix the tab end of one battery cell, ensuring the vertical stability of the battery cell and the accuracy of the electrical connection space.

[0058] The first and second brackets can be fixed within the overall structural framework of the multi-level temperature control thermal management system by means of studs, limit rods or slide rails, forming a rigidly supported cell arrangement sub-module.

[0059] Furthermore, a first cold plate is disposed between the first support and the second support. The first cold plate has multiple through holes for vertical insertion and fixing of the battery cells in the cell array. The size of each through hole is slightly larger than the outer diameter of the heat buffer sleeve to ensure stable thermal conduction contact between the battery cell and the inner wall of the through hole through the heat buffer sleeve. During installation, each battery cell covered with a heat buffer sleeve is inserted from top to bottom into the through hole of the first cold plate, so that the middle part of the heat buffer sleeve forms thermal transfer contact with the first cold plate.

[0060] Here, the first cold plate, as the core component of the primary heat transfer loop in this system, is used to actively perform large-area liquid cooling under normal cell operating conditions, maintaining the overall thermal stability of the cell array. The first cold plate is preferably made of aluminum alloy or composite thermally conductive material in a single piece, and its internal structure employs a microchannel flow channel to accommodate the circulating flow of the heat transfer medium (such as ethylene glycol / water mixture or other coolant) to achieve rapid heat removal. The microchannel design of the first cold plate includes an inlet, an outlet, and a serpentine or parallel distribution of flow channels, which significantly improves heat exchange efficiency and reduces flow resistance.

[0061] The distribution of several through holes on the first cold plate corresponds one-to-one with the arrangement of the cells in the cell array. The cells are in close contact with the inner wall of the through holes through the thermal buffer sleeve, thereby establishing a stable thermal coupling interface. The heat from the cells can be conducted to the first cold plate through the thermal buffer sleeve and then carried away through the liquid cooling channel, realizing the primary heat transfer path.

[0062] Here, the first cold plate has an inlet and an outlet on its side for connecting to the heat transfer medium circulation pipeline. During system operation, the heat transfer medium circulation pipeline injects heat transfer medium at a preset temperature into the inlet of the first cold plate. After absorbing heat and flowing through the internal microchannels, it is discharged from the outlet and enters the subsequent cooling device.

[0063] Optionally, several limiting bosses or positioning posts can be provided at the bottom of the first cold plate to align with the lower support during assembly, ensuring the verticality of the cell array installation and the overall structural robustness of the module. The positions of the liquid inlet and outlet of the first cold plate can be adjusted to be arranged laterally or vertically according to the structural requirements of the cell pack.

[0064] It should be noted that, in order to improve the thermal interface performance between the first cold plate and the battery cell, a highly thermally conductive elastic material, such as a silicone gasket, graphite sheet or flexible phase change material, can be further filled between the through hole of the first cold plate and the thermal buffer sleeve to reduce thermal contact resistance and improve heat dissipation efficiency.

[0065] Furthermore, the semiconductor cooler is parallel to the first cold plate and is positioned in the arrangement gap between the cells in the cell array. The cold end of each semiconductor cooler is in heat transfer contact with the thermal buffer sleeve enveloping the side surface of the cell and is provided with multiple limiting grooves. The shape of the limiting grooves matches the shape of the corresponding cell (such as an arc) to ensure a tight fit between the cold end and the thermal buffer sleeve of the cell.

[0066] Here, the semiconductor cooler, as one of the core active cooling components of the multi-stage temperature control thermal management system, is applied in the secondary heat transfer path of the system to achieve rapid local cooling control of the target battery cell. It is particularly suitable for dealing with sudden temperature rises such as high-rate discharge, local overheating, or thermal runaway of the battery cell. The semiconductor cooler has a cold-end and a hot-end structure. When current is applied, the cold end can actively absorb heat from the contact surface and conduct the heat to the flexible heat pipe through the hot end to achieve directional heat transfer.

[0067] Multiple semiconductor coolers are inserted into the gaps between adjacent cells in the cell array. Preferably, they are elongated structures with their cold ends facing the sidewalls of adjacent cells and are provided with several limiting grooves. The shape of the limiting grooves matches the outer contour of the cell's thermal buffer sleeve (such as an arc groove) to ensure stable and tight thermal conduction contact between the cold end and the thermal buffer sleeve on the cell's sidewall.

[0068] Optionally, to enhance the thermal interface performance between the cold end and the hot buffer sleeve, thermally conductive silicone grease or thermally conductive phase change material can be applied to the limiting groove to reduce contact thermal resistance and improve heat exchange efficiency.

[0069] Here, the hot end of the semiconductor cooler is connected to the evaporation end of the flexible heat pipe via structural clamps or thermally conductive adhesive materials, forming a localized heat extraction path. The condensation end of the flexible heat pipe is further connected to a second cold plate to efficiently dissipate the heat extracted by the cooler back into the system, thus forming a two-stage heat transfer chain: battery cell → thermal buffer sleeve → semiconductor cooler cold end → semiconductor cooler hot end → flexible heat pipe evaporation end → flexible heat pipe condensation end → second cold plate.

[0070] It should be noted that the number of semiconductor coolers can be determined based on the arrangement and number of cells in the cell array. One semiconductor cooler can be used to make thermal contact with the thermal buffer sleeve of each cell, or one semiconductor cooler can be set for each cell, or each semiconductor cooler can make thermal contact with the thermal buffer sleeves of multiple cells depending on the cell arrangement. In other words, the semiconductor cooler only needs to cover and make thermal contact with the thermal buffer sleeve of each cell, and the number is not specifically limited here.

[0071] Furthermore, the second cold plate, as a core component of the secondary heat transfer loop in the multi-stage temperature-controlled thermal management system, works in conjunction with the first cold plate to rapidly extract heat under specific temperature rise or thermal runaway risk conditions, performing local emergency cooling and module temperature equalization. Similar to the first cold plate, the second cold plate is preferably integrally formed from a high thermal conductivity metal material (such as aluminum alloy or copper), with an internal microchannel cooling structure for the circulation of a heat transfer medium (such as water / ethylene glycol solution) to achieve high-efficiency heat exchange. This cold plate has an inlet and an outlet, respectively connected to the heat transfer medium circulation pipeline, and its connection to the circulation system is controlled by a solenoid valve.

[0072] Here, the second cold plate is positioned perpendicular to the first cold plate on the side of the battery cell array and is thermally connected to the condenser ends of several flexible heat pipes. The evaporator end of each flexible heat pipe is connected to the hot end of the underlying semiconductor cooler module via a thermal interface. When the cooler is activated and transfers heat from the battery cells to the flexible heat pipes via the hot end, this heat is ultimately conducted to the second cold plate via the condenser end and carried away by the coolant.

[0073] After introducing the structure of the battery cell array, a detailed explanation of the overall structure of the multi-level temperature control and thermal management system will be provided. For details, please refer to [link to relevant documentation]. Figure 3 As shown, Figure 3 This diagram illustrates an overall schematic of a multi-stage temperature-controlled thermal management system provided in an embodiment of this disclosure. A battery cell array, fixed by a first bracket and a second bracket, and a second cold plate are placed in a housing to form a battery cell pack; the surface of the housing exposes the liquid inlet and outlet of the first cold plate, and the liquid inlet and outlet of the second cold plate.

[0074] Specifically, the multi-stage temperature control thermal management system includes a primary heat transfer loop and a secondary heat transfer loop. The primary heat transfer loop is equipped with a first cold plate and a heat transfer medium circulation pipeline. The secondary heat transfer loop is equipped with a second cold plate, a flexible heat pipe, and at least one semiconductor cooler, and shares the heat transfer medium circulation pipeline with the primary heat transfer loop. Each thermal buffer sleeve is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate, respectively. The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate. A first three-way valve is installed at the liquid outlet of the heat transfer medium circulation pipeline. The first three-way valve is connected to the liquid inlet of the first cold plate and is also connected to the liquid inlet of the second cold plate via a solenoid valve. A second three-way valve is installed at the liquid inlet of the heat transfer medium circulation link. The second three-way valve is connected to the liquid outlets of both the first and second cold plates.

[0075] In its implementation, the multi-level temperature control and thermal management system constructs a two-level heat transfer network, comprising a primary heat transfer loop and a secondary heat transfer loop. These two loops work together to achieve precise heat dissipation and emergency temperature control of the battery pack. The primary heat transfer loop includes a first cold plate located in the center of the battery array and a heat-conducting medium circulation pipeline connected to it, used for basic liquid cooling tasks. The cold plate and each battery cell achieve heat conduction contact through a thermal buffer sleeve on its surface, establishing the first heat transfer path from the battery cell → thermal buffer sleeve → first cold plate → coolant in the heat-conducting medium circulation pipeline. The secondary heat transfer loop is equipped with multiple key heat dissipation components, including a second cold plate that is perpendicular to the first cold plate, and multiple semiconductor coolers distributed in the cell gap area. The cold end of the semiconductor cooler faces the side wall of the cell and makes heat transfer contact with the thermal buffer sleeve, while the hot end is connected to the evaporation end of the flexible heat pipe. The condensation end of the flexible heat pipe is connected to the second cold plate, thus forming a secondary heat transfer link from the cell → thermal buffer sleeve → cold end of the semiconductor cooler → hot end of the semiconductor cooler → evaporation end of the flexible heat pipe → condensation end of the flexible heat pipe → second cold plate.

[0076] Here, regarding the flow control of the heat transfer medium, a first three-way valve is installed at the outlet of the heat transfer medium circulation pipeline. One end of this three-way valve is directly connected to the inlet of the first cold plate, and the other end is connected to the inlet of the second cold plate via a solenoid valve installed on a branch line. By controlling the opening state of the solenoid valve, selective or combined supply of coolant to the first and second cold plates can be achieved.

[0077] Correspondingly, a second three-way valve is installed at the liquid inlet of the heat transfer medium circulation pipeline. This valve is connected to the liquid outlets of the first cold plate and the second cold plate respectively, and is used to collect the circulating heat transfer medium from the two cold plates and then transport it to the downstream refrigerant circulation device for heat exchange and cooling.

[0078] Specifically, the outlet of the storage tank is connected to the inlet of the variable frequency pump via a pipeline; the outlet of the variable frequency pump serves as the outlet of the heat transfer medium circulation pipeline, injecting the heat transfer medium into the first cold plate and the second cold plate respectively; the inlet of the heat transfer medium circulation device serves as the inlet of the heat transfer medium circulation pipeline, receiving the heat transfer medium circulated back from the first cold plate and the second cold plate; the outlet of the heat transfer medium circulation device is connected to the inlet of the storage tank via a pipeline, re-injecting the heat transfer medium circulated back from the first cold plate and the second cold plate into the storage tank.

[0079] In practical implementation, to achieve effective circulation of the heat transfer medium between the first and second cold plates, the system constructs a closed-loop heat transfer medium circulation path, mainly including: a storage tank, a variable frequency pump, cold plate structures (primary and secondary), and heat transfer medium circulation equipment. The outlet of the storage tank is connected to the inlet of the variable frequency pump via a connecting pipeline. The storage tank is used to temporarily store the cooled heat transfer medium and supply it to the circulation system when the pump suction action is triggered. The variable frequency pump, as the power unit of the circulation system, has its outlet set as the main outlet of the entire heat transfer medium circulation pipeline, used to pressurize the heat transfer medium and inject it into the heat dissipation components in the system. Its downstream is connected to the inlet of the first cold plate through a first three-way valve for supplying liquid under normal heat dissipation conditions; the inlet of the second cold plate is opened on demand through a controlled solenoid valve, mainly used to activate the enhanced cooling path in high-temperature or thermal runaway scenarios.

[0080] Here, the heat transfer medium after absorbing heat from the cold plate will flow out from the liquid outlets of the first and second cold plates respectively, and flow into the heat transfer medium circulation device (such as a microchannel cooler or liquid cooling heat dissipation device) set at the end of the circulation through a branch. The liquid inlet of the device constitutes the main return liquid end of the entire system, which is used to receive and cool the heat transfer medium.

[0081] Specifically, for the first three-way valve, the inlet is connected to the outlet of the variable frequency pump via a pipeline, the first outlet is connected to the inlet of the second cold plate via a pipeline through a solenoid valve, and the second outlet is connected to the inlet of the first cold plate via a pipeline; for the second three-way valve, the inlet is connected to the outlet of the heat transfer medium circulation device via a pipeline, the first outlet is connected to the inlet of the first cold plate via a pipeline, and the second outlet is connected to the outlet of the second cold plate via a pipeline.

[0082] Subsequently, the liquid outlet of the heat transfer medium circulation device flows back to the liquid inlet of the front-end storage tank through the connecting pipeline, realizing the re-collection and temporary storage of the heat transfer medium and constructing a complete closed-loop liquid cooling circulation path.

[0083] In this way, through the above structural design, the heat transfer medium completes the entire process of stratified liquid supply, heat absorption, and heat recovery between the two-stage cold plates around the battery cell, possessing excellent flow control capability, path switching capability, and energy efficiency regulation capability. Combined with the flow rate regulation of the variable frequency pump and the on / off control of the solenoid valve, the system can achieve a dynamic temperature control strategy that adapts to operating conditions, thereby meeting the precise thermal management requirements of the battery cell at different operating temperature stages.

[0084] This disclosure provides a multi-stage temperature-controlled thermal management system, comprising a cell array with cell-side surface-enveloping thermal buffer sleeves, a primary heat transfer loop, and a secondary heat transfer loop. The primary heat transfer loop includes a first cold plate and a heat transfer medium circulation pipeline. The secondary heat transfer loop includes a second cold plate, a flexible heat pipe, and at least one semiconductor cooler, sharing the heat transfer medium circulation pipeline with the primary heat transfer loop. Each thermal buffer sleeve is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate, respectively. The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate. A first three-way valve is provided at the outlet of the heat transfer medium circulation pipeline, connecting to the inlet of the first cold plate and via a solenoid valve to the inlet of the second cold plate. A second three-way valve is provided at the inlet of the heat transfer medium circulation pipeline, connecting to the outlets of both the first and second cold plates. By constructing a multi-level heat transfer link, the temperature control accuracy and response speed of the battery pack are significantly improved. The secondary heat dissipation loop is activated only when needed through the graded liquid cooling path, reducing energy consumption and achieving targeted cooling of thermally runaway battery cells. This results in strong thermal safety and effectively delays heat propagation.

[0085] This embodiment also provides an application in... Figures 1-3 The multi-level temperature control and thermal management system shown herein is a multi-level temperature control and thermal management method. This disclosure provides a detailed description of a multi-level temperature control and thermal management method according to an embodiment of the present invention. The multi-level temperature control and thermal management method provided in this disclosure is applied to… Figures 1-3 The multi-level temperature control and thermal management system shown is executed by the MCU chip in the BMS cell control board. In some possible implementations, this multi-level temperature control and thermal management method can be implemented by the processor calling computer-readable instructions stored in memory.

[0086] See Figure 4 The diagram shown is a flowchart of a multi-level temperature control thermal management method provided in an embodiment of this disclosure. The method is applied as described above. Figures 1-3 The multi-stage temperature control thermal management system shown in any of the above includes temperature sensors disposed on both sides of the battery cell and at the center of the side surface. The method includes steps S101 to S103, wherein:

[0087] S101. The temperature of the battery cell is monitored in real time by the temperature sensor. When the temperature of the battery cell is lower than a preset first temperature threshold, a heating mode is triggered. When the temperature of the battery cell is higher than a preset second temperature threshold, a cooling mode is triggered.

[0088] S102. In the heating mode, if the cell temperature is within a preset first-level heating temperature range, the solenoid valve is closed, and the cell array is heated through the first-level heat transfer loop; if the cell temperature is within a preset second-level heating temperature range, the solenoid valve is opened, and the cell array is heated through the first-level heat transfer loop and the second-level heat transfer loop, wherein the second-level heating temperature range is lower than the first-level heating temperature range.

[0089] S103. In the cooling mode, if the cell temperature is within a preset first-level cooling temperature range, the solenoid valve is closed, and the cell array is cooled through the first-level heat transfer loop; if the cell temperature is within a preset second-level cooling temperature range, the solenoid valve is opened, and the cell array is cooled through the first-level heat transfer loop and the second cold plate, wherein the preset second-level cooling temperature range is higher than the preset first-level cooling temperature range.

[0090] In practical implementation, to achieve active full-temperature range control of the battery cell array, the system deploys high-precision temperature sensors at multiple key locations, constructing a distributed temperature monitoring and intelligent response mechanism. Specifically, temperature sensors (such as NTC thermistors) are installed at the positive and negative tabs and the center of the side surface of each battery cell to achieve real-time monitoring of the overall thermal state of the battery cell. The MCU chip in the BMS battery cell control board triggers a heating mode when the battery cell temperature is detected to be below a preset first temperature threshold, and triggers a cooling mode when the battery cell temperature is above a preset second temperature threshold. The preset first and second temperature thresholds can be set according to actual needs and are not specifically limited here.

[0091] Here, regarding the low-temperature heating stage (single-loop heating), when the current cell temperature is detected to be within the primary heating temperature range (e.g., below 5°C, above -5°C), the MCU chip determines that it has entered the low-temperature start-up range. At this time, the heating unit of the heat transfer medium circulation system (such as a PTC reservoir) is activated to preheat the heat transfer medium to the target temperature. Simultaneously, the solenoid valve is kept closed, allowing only the heat transfer medium to circulate through the primary heat transfer loop, utilizing the thermal contact between the first cold plate and the thermal buffer sleeve to heat the entire cell. This process continues until the cell temperature rises to the preset normal operating range (e.g., 25–40°C).

[0092] Here, for the extremely low temperature heating stage (dual-loop heating), when the current cell temperature is detected to be within the preset secondary heating temperature range (e.g., below -5℃), the MCU chip enhances the heating process. Based on the primary heat transfer loop heating, it controls the solenoid valve to open, allowing the heat transfer medium to simultaneously flow into the second cold plate, forming a parallel heating path of primary + secondary dual heat paths, achieving rapid temperature rise across the entire cell. The system automatically exits the dual-loop heating mode once the cell temperature returns to the preset normal operating range.

[0093] Here, for the medium-to-high temperature heat dissipation stage (single-loop cooling), when the current temperature of the battery cell is detected to be within the preset first-level cooling temperature range (e.g., above 45°C, below 55°C), the MCU chip activates the cooling mode. At this time, the control solenoid valve closes, and the heat transfer medium flows only within the first cold plate circulation channel. The heat generated by the battery cell is carried away by the heat exchange of the cold plate, achieving normal heat dissipation regulation until the battery cell temperature returns to the normal range.

[0094] Here, for the high-temperature heat dissipation stage (dual-loop cooling), when the cell temperature is detected to continue to rise and is within the preset secondary cooling temperature range (e.g., above 55°C), the MCU chip initiates the maximum heat dissipation path control process to control the solenoid valve to open, and the heat transfer medium simultaneously enters the first cold plate and the second cold plate.

[0095] It should be noted that when both the primary and secondary heat transfer loops are working simultaneously, the output flow rate of the heat transfer medium controlled by the MCU chip's frequency converter pump is greater than the output flow rate of the heat transfer medium when only the primary heat transfer loop is working.

[0096] As one possible implementation, a first target battery cell is detected whose cell temperature is higher than a preset third temperature threshold or whose corresponding temperature rise rate is greater than a preset temperature rise rate threshold; the semiconductor cooler that is in heat transfer contact with the first target battery cell is controlled to operate at maximum power, and the flow rate of the heat transfer medium in the heat transfer medium circulation pipeline is set to the maximum value.

[0097] In practice, the MCU chip uses multiple temperature sensors distributed across the positive and negative tabs and the center of the side surface of each battery cell to monitor the thermal state of each cell in real time and uploads the acquired temperature data to the BMS control unit for logical judgment. When the current temperature of a battery cell exceeds a preset third temperature threshold (e.g., 65°C), or its temperature rise rate per unit time is greater than a set temperature rise rate threshold (e.g., 2°C / s), the MCU chip in the BMS battery cell control board determines that the battery cell is the first target battery cell, i.e., a potential thermal runaway risk point.

[0098] In this situation, the MCU chip in the BMS cell control board will immediately execute a directional rapid cooling strategy, controlling the semiconductor cooler in heat transfer contact with the first target cell to operate at maximum power. Its cold end, which is in close contact with the heat buffer sleeve on the side wall of the cell, quickly absorbs heat, while the hot end conducts heat to the second cold plate through the connected flexible heat pipe. At the same time, the output frequency of the variable frequency pump in the heat transfer medium circulation system is adjusted to the maximum, so that the flow rate of the coolant in the heat transfer medium circulation pipeline reaches the maximum value designed by the system, thereby improving the overall heat exchange capacity of the first and second cold plates and accelerating the heat extraction efficiency in the system.

[0099] As another possible implementation, when the cell temperature is within the preset secondary cooling temperature range, i.e., when the secondary heat transfer loop is activated, it is determined that the temperature difference between the cells in the cell array is greater than the preset temperature difference threshold for the second target cell; the semiconductor cooler that is in heat transfer contact with the second target cell is controlled to work to reduce the cell temperature corresponding to the second target cell until the temperature difference between the second target cell and other cells in the cell array is less than the preset temperature difference threshold.

[0100] In practical implementation, to further improve the overall thermal uniformity of the cell array and avoid local hot spots affecting system lifespan and consistency, when any cell in the cell array detects that its current temperature is within the preset secondary cooling temperature range (e.g., above 55°C), the MCU chip in the BMS cell control board first determines whether there is an abnormal cell temperature distribution. The MCU chip will traverse the real-time temperature values ​​of all cells in the cell array and calculate the temperature difference between them. When it is detected that there is a cell whose maximum temperature difference with other cells in the array exceeds a preset temperature difference threshold (e.g., 3°C), this cell is determined to be the second target cell, i.e., a local hot spot with a significantly higher temperature than the adjacent cells.

[0101] At this time, the MCU chip in the BMS cell control board controls the semiconductor cooler that is in heat transfer contact with the second target cell to start working. The semiconductor cooler cools the hot cell in a directional manner through the cold end of the semiconductor cooler, and at the same time conducts the heat through the hot end of the semiconductor cooler and the flexible heat pipe to the second cold plate and exhaust it from the system.

[0102] Here, the temperature equalization process will continue until the maximum temperature difference between the second target cell and the other cells falls below the temperature difference threshold, i.e., the temperature tends to be uniform, and then the operation of the corresponding semiconductor cooler will stop.

[0103] This disclosure provides a multi-level temperature control thermal management method. The method uses a temperature sensor to monitor the battery cell temperature in real time. When the battery cell temperature is below a preset first temperature threshold, a heating mode is triggered; when the battery cell temperature is above a preset second temperature threshold, a cooling mode is triggered. In the heating mode, if the battery cell temperature is within a preset first-level heating temperature range, the solenoid valve is closed, and the battery cell array is heated through the first-level heat transfer loop. If the battery cell temperature is within a preset second-level heating temperature range, the solenoid valve is opened, and the battery cell array is heated through both the first-level and second-level heat transfer loops, wherein the preset second-level heating temperature range is lower than the preset first-level heating temperature range. In the cooling mode, if the battery cell temperature is within a preset first-level cooling temperature range, the solenoid valve is closed, and the battery cell array is cooled cyclically through the first-level heat transfer loop. If the battery cell temperature is within a preset second-level cooling temperature range, the solenoid valve is opened, and the battery cell array is cooled through the first-level heat transfer loop and the second cold plate, wherein the preset second-level cooling temperature range is higher than the preset first-level cooling temperature range. It can dynamically identify and intelligently intervene in potential temperature deviation points in the cell array, thereby effectively improving the uniformity of the thermal field distribution of the cells in the module, reducing the difference in cell aging, and enhancing the stability and safety of the entire Pack system.

[0104] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0105] This disclosure also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the multi-level temperature control thermal management method described in the above-described method embodiments. The storage medium can be a volatile or non-volatile computer-readable storage medium.

[0106] This disclosure also provides a computer program product, which includes computer instructions. When the computer instructions are executed by a processor, they can perform the steps of the multi-level temperature control thermal management method described in the above method embodiments. For details, please refer to the above method embodiments, which will not be repeated here.

[0107] The aforementioned computer program product can be implemented through hardware, software, or a combination thereof. In one optional embodiment, the computer program product is specifically embodied in a computer storage medium; in another optional embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0108] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here. In the several embodiments provided in this disclosure, it should be understood that the disclosed device and method can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0109] 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.

[0110] In addition, the functional units in the various embodiments of this disclosure 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.

[0111] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or a portion 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 this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0112] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A multi-level temperature control thermal management system, characterized in that, include: Battery cell array, first cold plate, second cold plate, flexible heat pipe, semiconductor cooler, and heat transfer medium circulation pipeline; The cell array includes cells with side surfaces enveloping thermal buffer sleeves; Each of the heat buffer sleeves is in heat transfer contact with the cold end of the semiconductor cooler and the first cold plate; The hot end of the semiconductor cooler is in heat transfer contact with the evaporation end of the flexible heat pipe, and the condensation end of the flexible heat pipe is in heat transfer contact with the second cold plate. The outlet of the heat transfer medium circulation pipeline is connected to the inlet of the first cold plate, and the inlet of the heat transfer medium circulation pipeline is connected to the outlet of the first cold plate, forming a primary heat transfer loop. The outlet of the heat transfer medium circulation pipeline is connected to the inlet of the second cold plate through a solenoid valve, and the inlet of the heat transfer medium circulation pipeline is connected to the outlet of the second cold plate, forming a two-stage heat transfer loop. The heat transfer medium circulation pipeline includes: a variable frequency pump, a storage tank, and a heat transfer medium circulation device. The outlet of the variable frequency pump serves as the outlet of the heat transfer medium circulation pipeline, connecting to the first cold plate and the second cold plate via the solenoid valve. The inlet of the heat transfer medium circulation device serves as the inlet of the heat transfer medium circulation pipeline, connecting to the outlets of the first cold plate and the second cold plate respectively. The multi-level temperature control and thermal management system also includes temperature sensors disposed on both sides of the battery cell and at the center of the side surface. The multi-level temperature control and thermal management system operates based on the following steps: The temperature sensor monitors the cell temperature in real time. When the cell temperature is lower than a preset first temperature threshold, a heating mode is triggered. When the cell temperature is higher than a preset second temperature threshold, a cooling mode is triggered. In the heating mode, if the cell temperature is within a preset first-level heating temperature range, the solenoid valve is closed, and the cell array is heated through the first-level heat transfer loop; if the cell temperature is within a preset second-level heating temperature range, the solenoid valve is opened, and the cell array is heated through the first-level heat transfer loop and the second-level heat transfer loop, wherein the preset second-level heating temperature range is lower than the preset first-level heating temperature range. In the cooling mode, if the cell temperature is within a preset first-level cooling temperature range, the solenoid valve is closed, and the cell array is cooled through the first-level heat transfer loop; if the cell temperature is within a preset second-level cooling temperature range, the solenoid valve is opened, and the cell array is cooled through the first-level heat transfer loop and the second cold plate, wherein the preset second-level cooling temperature range is higher than the preset first-level cooling temperature range.

2. The multi-level temperature control thermal management system according to claim 1, characterized in that: The first cold plate is provided with through holes corresponding to each of the battery cells; Each of the battery cells is vertically inserted into the matching through hole, so that the heat buffer sleeve makes heat transfer contact with the first cold plate.

3. The multi-level temperature control thermal management system according to claim 2, characterized in that: The semiconductor cooler is parallel to the first cold plate, and the second cold plate is perpendicular to the semiconductor cooler; The semiconductor cooler is disposed in the arrangement gap between the battery cells, and a limiting groove matching the geometry of the battery cells is opened at the cold end; Each of the heat buffer sleeves makes heat transfer contact with the cold end of the semiconductor cooler through the limiting groove.

4. The multi-level temperature control thermal management system according to claim 3, characterized in that, The cell array also includes a first support and a second support; Both the first bracket and the second bracket are provided with limiting holes corresponding to each of the battery cells; The positive electrode end of each of the battery cells is vertically fixed to the matching limiting hole in the first bracket, and the negative electrode end is vertically fixed to the matching limiting hole in the second bracket.

5. The multi-level temperature control thermal management system according to claim 4, characterized in that, It also includes the enclosure; The second cold plate and the cell array fixed to the first bracket and the second bracket are placed inside the box to form a cell pack; The surface of the housing exposes the liquid inlet and outlet of the first cold plate, and the liquid inlet and outlet of the second cold plate.

6. The multi-level temperature control thermal management system according to claim 1, characterized in that: The outlet of the storage tank is connected to the inlet of the variable frequency pump. The outlet of the heat transfer medium circulation device is connected to the inlet of the storage tank.

7. The multi-level temperature control thermal management system according to claim 6, characterized in that, It also includes the first three-way valve and the second three-way valve: The inlet of the first three-way valve is connected to the outlet of the variable frequency pump, the first outlet of the first three-way valve is connected to the inlet of the second cold plate through the solenoid valve, and the second outlet of the first three-way valve is connected to the inlet of the first cold plate. The inlet of the second three-way valve is connected to the outlet of the heat transfer medium circulation device, the first outlet of the first three-way valve is connected to the outlet of the first cold plate, and the second outlet of the first three-way valve is connected to the outlet of the second cold plate.

8. The multi-level temperature control thermal management system according to claim 1, characterized in that, The operation steps of the multi-level temperature control thermal management system also include: Select the first target battery cell whose cell temperature is higher than a preset third temperature threshold or whose temperature rise rate is greater than a preset temperature rise threshold; The semiconductor cooler that is in thermal contact with the first target battery cell is controlled to operate at maximum power, and the heat transfer medium circulation pipeline is adjusted to circulate the heat transfer medium at maximum flow rate, wherein the preset third temperature threshold is greater than the preset second temperature threshold.

9. The multi-level temperature control thermal management system according to claim 1, characterized in that, The operation steps of the multi-level temperature control thermal management system also include: When the cell temperature is within the preset secondary cooling temperature range, a second target cell with a cell temperature difference greater than a preset temperature difference threshold is selected. The semiconductor cooler that is in thermal contact with the second target cell is controlled to operate in order to reduce the cell temperature corresponding to the second target cell until the cell temperature difference between the second target cell and other cells is less than the preset temperature difference threshold.

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