Power battery pack thermal management system

Abstract

There are several encapsulation housings (6-1) arranged in a matrix within the box. There is heat insulation material (Ⅳ) between the encapsulation housings (6-1). The PCM block (6-4) is placed inside the encapsulation housing (6-1), and the battery cell is arranged in the battery cavity (6-5) of the PCM block (6-4); the evaporation section of the heat pipe (3) is placed in the heat pipe installation grooves (6-2) opened on both side surfaces of the encapsulation housing (6-1) to connect the battery pack (Ⅲ); the cooling surface of the thermoelectric cooler (2) is tightly connected to the condensation section of the heat pipe (3) through thermal conductive silicone, and the heating surface is connected to the heat dissipation fins (1) through thermal conductive silicone; the side wall of the battery box cover (Ⅰ) in the direction perpendicular to the heat dissipation fins (1) is provided with an air duct. In this way, the use efficiency, service life and use safety of the battery pack are improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of power batteries and battery thermal management, and particularly relates to a thermal management system for a power battery pack. Background Art

[0002] In recent years, under the dual pressures of environmental pollution and energy crisis, countries around the world have been vigorously developing new energy vehicles, and electric vehicles have seen an explosive growth. However, in today's electric vehicle industry, there are still a series of thermal safety problems with power batteries. The root cause of the problem is that a large amount of heat is generated during the normal charging and discharging process of power batteries. When the heat dissipation conditions do not meet the standards, the battery heat will quickly accumulate, further leading to thermal runaway of the power battery. Relevant research shows that the optimal working temperature range of power batteries is 20°C - 50°C, and the temperature difference between single cells is less than 5°C. It can be seen that the thermal management level of the battery directly affects the operating state of the battery.

[0003] Chinese Patent CN 110854468 A discloses a thermal management method and working method based on air-coupled phase change materials. The deficiencies of this patent are as follows: it occupies too much battery space, greatly reducing the energy density of the battery pack; it only realizes the heat dissipation function and does not consider the low-temperature working conditions; moreover, it does not consider the shock absorption problem of the battery box.

[0004] Chinese Patent CN 11244571 A discloses a thermal management structure and method based on semiconductor-coupled phase change materials. The deficiencies of this patent are as follows: the phase change material itself has poor heat dissipation, and it is easy to cause the depletion of latent heat of phase change under high-rate working conditions. When the phase change material is completely melted, it will seriously affect the heat dissipation effect; the semiconductor refrigeration chip needs to consume the energy of the battery pack, increasing additional energy consumption and reducing the driving range of the vehicle; and it does not consider the shock absorption problem of the battery pack.

[0005] Chinese Patent CN 107146864 A discloses a hydraulic shock absorption intelligent battery box system for hybrid vehicles. The deficiencies of this patent are as follows: the installation space required for the suspension hydraulic shock absorption device is relatively large; the structure of the suspension hydraulic shock absorption device is relatively complex, and the problem of hydraulic oil leakage needs to be considered. Summary of the Invention

[0006] In view of the problems, defects, and deficiencies in the prior art and existing solutions mentioned in the background art, the present invention proposes a thermal management system for a power battery pack. On the one hand, it further improves the existing heat dissipation structure, improving the heat dissipation efficiency and safety;

[0007] On the other hand, the purpose of this solution for the thermal management of the power battery pack is to use heat dissipation technologies such as air cooling, liquid cooling, heat pipes, and phase change materials to promptly dissipate the heat generated during the operation of the battery pack and control the temperature of the battery pack within the optimal operating temperature range, thereby improving the usage efficiency, service life, and usage safety of the battery pack.

[0008] Currently, the commonly used thermal management methods usually only consider high-temperature heat dissipation, without considering the situation of low-temperature startup, and without considering the additional energy consumption of the heat dissipation device.

[0009] To break through the technical difficulties, the present invention aims to solve the problems of high-temperature heat dissipation, low-temperature startup, and the spread of thermal runaway, and convert the vibration energy during vehicle driving into electrical energy to provide it to the heat dissipation device, reducing energy consumption.

[0010] To achieve the above object, the present invention specifically adopts the following technical solutions:

[0011] A thermal management system for a power battery pack, characterized in that:

[0012] A number of encapsulation shells (6-1) are arranged in a matrix in the battery box of the battery pack (Ⅲ), heat insulation materials (Ⅳ) are provided between the encapsulation shells (6-1), PCM blocks (6-4) are placed in the encapsulation shells (6-1), and battery cells are arranged in the battery cavities (6-5) of the PCM blocks (6-4);

[0013] The evaporation section of the heat pipe (3) is placed in the heat pipe installation grooves (6-2) opened on both side surfaces of the encapsulation shell (6-1) to connect the battery pack (Ⅲ); the refrigerating surface of the semiconductor refrigeration sheet (2) is tightly connected to the condensation section of the heat pipe (3) through thermal conductive silicone, and the heating surface is connected to the heat dissipation fins (1) through thermal conductive silicone; the side wall of the battery box cover (Ⅰ) in the direction perpendicular to the heat dissipation fins (1) is provided with a air duct;

[0014] Under normal working conditions, the heat generated by the battery cells during operation is transferred to the PCM blocks, causing them to heat up. When the temperature reaches the phase change temperature, the PCM blocks control the temperature of the battery within the phase change temperature range through phase change sensible heat and latent heat; at the same time, the heat pipe transfers the heat from the evaporation section to the condensation section and dissipates it into the air through the heat dissipation fins and the air duct to prevent the phase change latent heat of the PCM blocks from being exhausted.

[0015] Furthermore, one end of the single-chip microcomputer (4) is connected to the temperature monitor, and the other end is connected to the semiconductor refrigeration sheet (2); the temperature monitor is arranged inside the PCM block (6-4);

[0016] and an electric energy storage system is provided; wherein, the vehicle-mounted photovoltaic array (12) and the nano piezoelectric array (10) are respectively connected to the supercapacitor bank (14) through a DC / DC buck converter (13) and an AC / DC converter (11), and the supercapacitor bank (14) is connected to the semiconductor refrigerating sheet (2) through a DC / DC boost converter (15);

[0017] Under high-rate working conditions, when the temperature monitor detects that the temperature of the PCM block starts to rise again after reaching the phase change temperature, the supercapacitor bank supplies energy to the semiconductor refrigerating sheet, and the semiconductor refrigerating sheet cools the condensation section of the temperature equalizing plate to accelerate the removal of the heat stored in the PCM block and the heat generated by the battery; when the temperature of the PCM block is lower than the phase change temperature, the semiconductor refrigerating sheet stops refrigerating.

[0018] Furthermore, the single-chip microcomputer (4) controls the forward and reverse connection of the circuit from the supercapacitor bank (14) to the semiconductor refrigerating sheet (2). When semiconductor refrigeration is required, it is connected forward, and when heating is required, the circuit is connected reversely.

[0019] Furthermore, a vibration energy recovery system (Ⅴ) is also provided. The encapsulation housing (6-1) is fixed on the vibration rib (7), and the vibration rib (7) connects the battery pack (Ⅲ) and the vibration energy recovery system (Ⅴ) through a column (7-1);

[0020] The rubber limit block is fixed at the bottom of the vibration rib (7). The fixed sleeve is divided into two parts, a bottom sleeve (8-2) and a top sleeve (8-1). The lower end face of the bottom sleeve (8-2) is fixed to the bottom of the battery box body (VI). The bottom of the flexible piezoelectric nanogenerator (10) contacts the upper end face of the bottom sleeve (8-2), and the top contacts the bottom end face of the top sleeve (8-1). The two sleeves are fixed by threaded connection. The damping spring (8-3) is placed in the fixed sleeve, and the column (7-1) forms a contact connection with the damping spring (8-3);

[0021] When the battery box is in a balanced state, the system compresses the damping spring by its own weight, making the rubber limit block on the vibration rib just contact the flexible piezoelectric nanogenerator; when the battery box vibrates, the damping spring is used to reduce the vibration of the battery box in the vertical direction. The rubber limit block starts to displace downward, forcing the flexible substrate to bend, resulting in the bending strain of the nanoarray of the flexible piezoelectric nanogenerator, causing the generated voltage to advance along the external circuit and generating current during the repeated bending process; the alternating current generated by the piezoelectric nanoarray is converted into direct current by an AC / DC converter and charges the supercapacitor bank together with the vehicle-mounted photovoltaic array, enabling the heat dissipation device to store the generated electric energy without additional energy consumption; at the same time, the rubber limit block is used to prevent the battery pack from directly colliding with the vibration recovery system.

[0022] Further, the middle part of the heat pipe (3) is fixed through two heat pipe mounting grooves (6-2), and the outer part is fixed by the heat pipe mounting groove (6-2) and the vibration guiding groove (Ⅵ-Ⅰ) opened on the inner side of the battery box (Ⅵ);

[0023] The upper rib plate (5) is connected to the battery box (Ⅵ) by bolts, fixed at the upper end of the heat pipe (3), and the single-chip microcomputer (4) is fixed on the top of the upper rib plate (5); the temperature monitor is arranged beside the battery tab of the battery cell and in the PCM block (6-4).

[0024] Further, the material of the encapsulation shell (6-1) is aluminum alloy, and heat-conducting fins (6-3) are arranged inside.

[0025] Further, the vibration energy recovery system (Ⅴ) is connected to the vehicle-mounted photovoltaic array.

[0026] Further, a graphite layer is arranged on the inner wall of the fixed sleeve to prevent the column (7-1) from getting stuck in the fixed sleeve.

[0027] Further, the flexible piezoelectric nanogenerator (10) is composed of a ZnO nanowire array film and a flexible substrate.

[0028] According to the above design, it can be seen that under the preferred general concept of this design, it mainly includes: a battery pack, a coupled thermal management system, a vibration energy recovery system, an electrical energy storage system and other structures, among which:

[0029] The battery pack mainly includes a battery box, several single cells, a PCM block (phase change material), an encapsulation shell, a heat pipe, a vibration rib plate and heat insulation materials. Several encapsulation shells are arranged in the box, the encapsulation shell is fixed to the upper part of the vibration rib plate, the phase change material forms a PCM block to be uniformly filled into the encapsulation shell, and a battery cavity is left, the single cell is placed in the battery cavity, and both sides of the encapsulation shell are in contact with the heat pipe.

[0030] The coupled thermal management system includes a temperature monitor, an upper rib plate, a single-chip microcomputer, a semiconductor refrigeration sheet, heat dissipation fins, and a part of the heat pipe. Its ultimate goal is to realize the switching of three working conditions: normal, high temperature and low temperature. The present invention provides the hardware and structural basis for realizing this function.

[0031] One end of the temperature monitor is placed inside the phase change material and the other end is connected to the single-chip microcomputer. One end of the semiconductor refrigeration sheet is in contact with the heat pipe and the other end is in contact with the heat dissipation fins. The electrical signal is transmitted to the single-chip microcomputer. By controlling the working state of the semiconductor refrigeration sheet, the thermal management requirements under different working conditions can be met.

[0032] The vibration energy recovery system includes a vibration rib plate, a column, a rubber limit block, a damping spring, a fixed sleeve, and a flexible piezoelectric nanogenerator. The vibration rib plate and the column are integrally designed. The rubber limit block is fixed at the bottom of the vibration rib plate. The fixed sleeve is divided into a bottom sleeve and a top sleeve. The lower end face of the bottom sleeve is fixed to the battery box. The bottom of the flexible piezoelectric nanogenerator contacts the upper end face of the bottom sleeve, and the top of the flexible piezoelectric nanogenerator contacts the bottom end face of the top sleeve. The two sleeves are fixed by threaded connection. The spring is placed in the fixed sleeve, and the column contacts the spring.

[0033] The electrical energy storage system mainly consists of an on-vehicle photovoltaic array, a nano piezoelectric array, an AC / DC converter, a DC / DC converter, a supercapacitor bank, a single-chip microcomputer, and a semiconductor refrigeration sheet, etc.

[0034] In addition, the preferred technical design points of the present invention also include the following content:

[0035] The PCM block uses paraffin as the base, and expanded graphite is added to the molten paraffin to enhance the thermal conductivity of the phase change material and its adsorption capacity for liquid paraffin. It can use the encapsulation shell as a mold, pour the molten PCM material into the encapsulation shell, and form the PCM block after cooling and solidification.

[0036] The encapsulation shell is made of high thermal conductivity aluminum alloy material, and heat conduction fins are additionally provided inside the encapsulation shell. The heat conduction fins can quickly transfer the heat generated by the battery to each part of the PCM block to further enhance its thermal conductivity.

[0037] The evaporation section of the heat pipe is in contact with the encapsulation shell, and the condensation section is in contact with the semiconductor refrigeration sheet. The contact surfaces are bonded together by thermal conductive silicone. Utilizing the good viscosity and high thermal conductivity of the thermal conductive silicone to reduce the contact thermal resistance between the two contacts.

[0038] When the vibration energy recovery system is in a balanced state, the bottom of the rubber limit block contacts the top of the flexible piezoelectric nanogenerator. When vibration occurs, the rubber limit block presses down on the flexible piezoelectric nanogenerator to generate electrical energy.

[0039] The flexible piezoelectric nanogenerator consists of a ZnO nanowire array thin film and a flexible substrate, which belongs to the category of existing technologies. The electrical energy generated by the flexible piezoelectric nanogenerator can be used for a temperature monitoring device and a semiconductor refrigeration sheet.

[0040] The vibration energy recovery system can generate electricity complementary to the on-vehicle photovoltaic array. The electrical energy storage system is provided with a supercapacitor bank, which can be used to store electrical energy.

[0041] Phase change materials are functional materials that can absorb heat from the outside world at a constant temperature, effectively control the temperature of the battery pack, and maintain the stability and consistency of the battery pack temperature. Adding expanded graphite to prepare composite phase change materials is to solve the problems of low thermal conductivity of phase change materials themselves and leakage after phase change.

[0042] A heat pipe is a heat diffuser. Its technical principle is similar to that of a heat pipe, but there are differences in the conduction method. The heat pipe conducts heat linearly, while the heat in the heat pipe conducts on a two-dimensional plane, and the heat transfer efficiency is relatively high compared to the heat pipe.

[0043] Adopting the above PCM - heat pipe coupling thermal management solution can combine the advantages of both.

[0044] In this design, a thermoelectric cooler is also added to the condensation section of the heat pipe. When the heat dissipation pressure is high, it can refrigerate to enhance the heat dissipation effect of the heat dissipation system; at low temperatures, it heats through thermoelectric heating and utilizes the characteristic of reversible heat transfer direction of the heat pipe to heat the PCM block, and then heat the battery.

[0045] When arranging the battery pack in this design, each single battery is individually encapsulated, with the same heat dissipation conditions to ensure the consistency of the temperature of each single battery; the battery pack is arranged in the way of encapsulation shell - heat pipe - encapsulation shell, with a small gap left in the middle. Since the heat insulation effect of air is good in a closed space, it can slow down the spread speed in case of thermal runaway and does not affect the heat dissipation effect of the system; moreover, heat insulation materials are placed in the middle of each column of single battery modules, greatly delaying the spread of thermal runaway.

[0046] The working principle of the piezoelectric nanogenerator: When the piezoelectric device is stimulated by an external mechanical stress, the piezoelectric material undergoes deformation, thereby generating polarized charges and an electric field that changes with time, which can drive electrons to flow in the external circuit, and then generate electrical energy. This process realizes the conversion of mechanical energy into electrical energy. And the higher the strain frequency of the piezoelectric material, the more electrical energy is generated. In this invention, a flexible piezoelectric nanomaterial is combined with a vibration damping module. The high-frequency vibration of the car during driving forces the piezoelectric material to undergo strain, and then generates electrical energy, which is provided to the heat dissipation device through a boost voltage regulator. In this way, the energy loss during the vibration of the car can be recovered, the vibration of the battery box can be minimized, and at the same time, the energy consumption of the thermal management system can be reduced.

[0047] Working principle of the electric energy storage system: The alternating current generated by the piezoelectric nanowire array is converted into direct current by an AC / DC converter and used to charge the supercapacitor bank together with the on-vehicle photovoltaic array. When the semiconductor needs to work, the stored electric energy supplies power to the semiconductor refrigeration chip through a DC / DC buck-boost converter. The main function of the single-chip microcomputer is to control the forward and reverse connection of this section of the circuit. When semiconductor refrigeration is required, it is connected forward, and when heating is required, the circuit is connected reversely. This part is only for reference by those skilled in the art to implement the preferred solution of this design and is not the protection object of the invention structure.

[0048] Compared with the prior art, the present invention and its preferred solution have lower costs, a simple structure, energy conservation and environmental protection, good temperature uniformity, temperature control ability, and the ability to slow down the spread of thermal runaway, can convert the mechanical energy of vibration into electric energy, and automatically switch the thermal management mode, and can be widely applied to electric vehicles to increase the cruising range, improve the power performance, and solve safety hazards. Brief Description of the Drawings

[0049] Figure 1 is the exploded view of the overall structure of the device module in the embodiment of the present invention;

[0050] Figure 2 is the half-sectional view of the overall structure in the working state of the embodiment of the present invention;

[0051] Figure 3 is the detailed view of the structure of the encapsulation shell of the device in the embodiment of the present invention;

[0052] Figure 4 is the detailed view of the structure of the phase change material in the embodiment of the present invention;

[0053] Figure 5 is Figure 2 the partial enlarged detailed view of;

[0054] Figure 6 is the detailed view of the structure of the flexible piezoelectric nanogenerator in the embodiment of the present invention;

[0055] Figure 7 is the detailed view of the structure of the upper rib plate in the embodiment of the present invention;

[0056] Figure 8 is the detailed view of the structure of the vibration rib plate in the embodiment of the present invention;

[0057] Figure 9 is the detailed view of the battery box in the embodiment of the present invention;

[0058] Figure 10 is the electrical structure diagram of the electric energy storage system in the embodiment of the present invention.

[0059] In the figure: Ⅰ - Battery box cover, Ⅱ - Coupled thermal management system, Ⅲ - Battery pack, Ⅳ - Thermal insulation material, Ⅴ - Vibration energy recovery system, Ⅵ - Battery box body, Ⅵ-Ⅰ - Vibration guiding groove, 1 - Heat dissipation fin, 2 - Semiconductor refrigeration chip, 3 - Heat spreader, 4 - Single-chip microcomputer, 5 - Upper rib plate, 5-1 - Wiring hole, 6 - Single-cell battery module, 6-1 - Encapsulation shell, 6-2 - Heat spreader mounting groove, 6-3 - Thermal conduction fin, 6-4 - PCM block, 6-5 - Battery cavity, 6-6 - Thermal conduction fin placement groove, 7 - Vibration rib plate, 7-1 - Column, 8 - Vibration damping device, 8-1 - Top sleeve, 8-2 - Bottom sleeve, 8-3 - Vibration damping spring, 9 - Rubber limit block, 10 - Flexible piezoelectric nanogenerator, 10-1 - Flexible substrate, 10-2 - Fixing hole, 10-3 - ZnO nanowire array film, 10-4 - ZnO nanowire, 11 - AC / DC converter, 12 - On-vehicle photovoltaic array, 13 - DC / DC step-down converter, 14 - Supercapacitor bank, 15 - Buck-boost converter. Detailed implementation mode

[0060] To make the features and advantages of this patent more obvious and understandable, three embodiments are specifically given below for detailed description as follows:

[0061] It should be noted that the following detailed descriptions are all illustrative and aim to provide further explanations for this application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0062] As Figure 1 shown, in the device structure corresponding to the battery pack thermal management system based on vibration energy recovery provided in this embodiment, mainly including in terms of functional modules: battery box cover Ⅰ, coupled thermal management system Ⅱ, battery pack Ⅲ, thermal insulation system Ⅳ, vibration energy recovery system Ⅴ, and battery box body Ⅵ. It should be noted that the external structure of the electrical energy storage system is not the focus of its design, so it is not shown in the figure. Its main design lies in the electrical connection structure. For details, see Figure 10 .

[0063] In terms of device structure, as Figure 2 shown, it mainly includes: heat dissipation fin 1, semiconductor refrigeration chip 2, heat spreader 3, single-chip microcomputer 4, upper rib plate 5, single-cell battery module 6, vibration rib plate 7, vibration damping device 8, rubber limit block 9, flexible piezoelectric nanogenerator 10 and other structures.

[0064] As Figure 3 shown, for the single-cell battery module 6, its specific structure is: the battery pack Ⅲ fixes the encapsulation shell 6-1 on the vibration rib plate 7 by welding. The vibration rib plate 7 connects the battery pack Ⅲ and the vibration energy recovery system Ⅴ together through the column 7-1. As Figure 8As shown; the PCM block 6-4 is placed inside the packaging shell 6-1, the heat-conducting fin 6-3 is closely fitted with the heat-conducting fin placement groove 6-6, the battery cell is placed into the battery cavity 6-5 of the PCM block 6-4, thus forming the single-cell battery module 6; the battery pack III is composed of several such single-cell battery modules 6, and heat-insulating material IV is provided in the middle of each column of battery modules, such as Figure 4 As shown.

[0065] Such as Figure 5 , Figure 6 As shown, the vibration energy recovery system V of this embodiment connects the bottom sleeve 8-2 and the battery box VI together by welding, the flexible piezoelectric nanogenerator 10 is placed on the bottom sleeve 8-2, the top sleeve 8-1 is placed on the flexible piezoelectric nanogenerator 10, the flexible piezoelectric nanogenerator 10, the bottom sleeve 8-2 and the top sleeve 8-1 are respectively provided with positioning holes 10-2, external threads and internal threads, and the three are fixed to the bottom of the battery box VI through these; the bottom sleeve 8-2 and the top sleeve 8-1 are respectively provided with blind holes and through holes, and the two form a placement cavity for the damping spring 8-3, and the damping spring 8-3 is placed therein.

[0066] Such as Figure 10 As shown, the vehicle-mounted photovoltaic array 12 and the nano piezoelectric array 10 of the electrical energy storage system are respectively connected to the supercapacitor bank 14 through the DC / DC buck converter 13 and the AC / DC converter 11, and the supercapacitor bank 14 is connected to the semiconductor refrigerating sheet 2 through the DC / DC boost converter 15, and the single-chip microcomputer 4 is connected to this circuit.

[0067] In this embodiment, the coupled heat management system II connects the battery pack III by placing the evaporation section of the heat pipe 3 in the heat pipe installation grooves 6-2 opened on both side surfaces of the packaging shell 6-1, the middle part of the heat pipe 3 is fixed by two heat pipe installation grooves 6-2, and the outer part of the heat pipe 3 is fixed by the heat pipe installation groove 6-2 and the vibration guiding groove VI-I opened on the inner side surface of the battery box VI, such as Figure 3 , Figure 9 As shown;

[0068] The upper rib plate 5 is connected to the battery box VI by bolts and fixed at the upper end of the heat pipe 3, and the single-chip microcomputer 4 is fixed at the top of the upper rib plate 5; the temperature monitor is arranged near the battery tab of the single-cell battery module 6 and in the PCM block 6-4, and the other end is connected to the single-chip microcomputer 4 through the wire hole 5-1 opened on the upper rib plate 5, such as Figure 7As shown; one end of the single-chip microcomputer 4 is connected to the temperature monitor, and the other end is connected to the semiconductor refrigeration sheet 2; the refrigerating surface of the semiconductor refrigeration sheet 2 is tightly connected to the condensation section of the heat pipe plate 3 through heat-conducting silica gel, and the heating surface of the semiconductor refrigeration sheet 2 is tightly connected to the heat dissipation fin 1 through heat-conducting silica gel; the battery box cover I is connected to the battery box body VI by bolts, and a air duct is provided on the side wall of the battery box cover I in the direction perpendicular to the heat dissipation fin 1.

[0069] Based on the above device structure design, the purpose and technical effects of the present invention can be achieved through the following working mechanisms or control methods:

[0070] 1. When the battery box is in a balanced state, the system relies on its own weight to compress the damping spring, so that the rubber limit block on the vibration rib plate just contacts the flexible piezoelectric nanogenerator; when the battery box vibrates, the vibration in the vertical direction of the battery box is reduced through the damping spring, and the rubber limit block starts to move downward, forcing the flexible substrate to bend, resulting in the bending strain of the ZnO nanorod array, causing the generated voltage to advance along the external circuit, and generating current during the repeated bending process; the alternating current generated by the piezoelectric nanorod array is converted into direct current by the AC / DC converter and charges the supercapacitor bank together with the vehicle-mounted photovoltaic array, storing the generated electric energy when the heat dissipation device does not require additional energy consumption; at the same time, the rubber limit block can also prevent the battery pack from directly colliding with the vibration recovery system.

[0071] 2. In the case of low temperature, when the temperature monitor measures that the temperature at the battery tab is lower than 20°C, the supercapacitor bank supplies energy to the semiconductor refrigeration sheet, and the single-chip microcomputer reverses the current flowing into the semiconductor refrigeration sheet. At this time, the surface of the semiconductor refrigeration sheet that fits the heat pipe plate is the heating surface; according to the reversibility of heat transfer of the heat pipe plate: when any end is heated as the evaporation section, the other end dissipates heat as the condensation section. The heat pipe plate quickly transfers the heat generated by the semiconductor refrigeration sheet to the condensation section, and quickly transfers it to the PCM block through the heat dissipation fins of the packaging shell. After the PCM block absorbs heat, it heats up and keeps the battery warm; when the temperature monitor measures that the temperature at the battery tab is greater than 25°C, the semiconductor refrigeration sheet stops heating.

[0072] 3. Under normal working conditions, the heat generated by the single battery during operation is quickly transferred to the PCM block through the heat dissipation fins of the packaging shell, causing it to heat up. When the temperature reaches the phase change temperature, the PCM block controls the temperature of the battery within the phase change temperature range through the sensible heat and latent heat of phase change; at the same time, the heat pipe plate transfers the heat absorbed by the PCM block and part of the heat transferred through the heat dissipation fins from the evaporation section to the condensation section, and only dissipates this heat to the air through the heat dissipation fins and the air duct, so as to avoid the exhaustion of the latent heat of phase change of the PCM block and achieve long-term control of the battery temperature.

[0073] 4. Under high-rate operation, the heat generation rate of the battery will increase significantly. At this time, the heat dissipation requirement for the system is relatively high. When the temperature monitor detects that the temperature of the PCM block starts to rise again after reaching the phase change temperature, the supercapacitor bank supplies energy to the thermoelectric cooler, and the thermoelectric cooler cools the condensation section of the heat spreader to accelerate the removal of the heat stored in the PCM block and the heat generated by the battery. When the temperature of the PCM block is lower than the phase change temperature, the thermoelectric cooler stops cooling.

[0074] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still belong to the protection scope of the technical solution of the present invention.

[0075] This patent is not limited to the above best implementation mode. Anyone can obtain other various forms of the thermal management system for the power battery pack under the inspiration of this patent. All equal changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by this patent.

Claims

1. A power battery pack thermal management system, characterized by: Several packaging shells are arranged in a matrix in the battery box of the battery pack, with heat insulation materials provided between the packaging shells. The PCM blocks are placed in the packaging shells, and the battery cells are placed in the battery cavities of the PCM blocks. The evaporation section of the temperature vapor chamber is placed in the temperature vapor chamber mounting grooves opened on both sides of the packaging shell to connect to the battery pack; the cooling surface of the semiconductor refrigeration plate is tightly connected to the condensing section of the temperature vapor chamber through thermal conductive silicone, and the heating surface of the semiconductor refrigeration plate is connected to the heat dissipation fins through thermal conductive silicone; the battery box cover is provided with an air duct on the side wall perpendicular to the direction of the heat dissipation fins; Under normal operating conditions, the heat generated by the battery cells is transferred to the PCM block, causing it to heat up. When the temperature reaches the phase transition temperature, the PCM block uses the sensible heat and latent heat of the phase transition to control the battery temperature within the phase transition temperature range. At the same time, the vapor chamber transfers heat from the evaporation section to the condensation section, where it is dissipated into the air through the cooling fins and air ducts to prevent the PCM block from being exhausted due to the phase transition latent heat. A vibration energy recovery system is also provided, wherein the package shell is fixed on the vibration rib plate, and the vibration rib plate connects the battery pack and the vibration energy recovery system through a column; The rubber limit block is fixed to the bottom of the vibration rib plate. The fixed sleeve is divided into two parts: the bottom sleeve and the top sleeve. The lower end surface of the bottom sleeve is fixed to the bottom of the battery box. The bottom of the flexible piezoelectric nanogenerator contacts the upper end surface of the bottom sleeve, and the top of the flexible piezoelectric nanogenerator contacts the bottom end surface of the top sleeve. The two sleeves are fixed by threaded connection. The vibration damping spring is placed in the fixed sleeve, and the column forms a contact connection with the vibration damping spring. When the battery box is in a balanced state, the system relies on its own weight to compress the vibration-damping spring, so that the rubber limit block on the vibration rib is exactly in contact with the flexible piezoelectric nanogenerator; when the battery box vibrates, the vibration-damping spring is used to reduce the vertical vibration of the battery box, and the rubber limit block begins to move downward, forcing the flexible substrate to bend, resulting in bending strain of the flexible piezoelectric nanogenerator nanoarray, so that the generated voltage moves along the external circuit, generating current during repeated bending; the alternating current generated by the piezoelectric nanoarray is converted into direct current through an AC / DC converter, and together with the on-board photovoltaic array, it charges the supercapacitor group, allowing the heat dissipation device to store the generated electricity without additional energy consumption; at the same time, the rubber limit block is used to prevent the battery pack from directly colliding with the vibration recovery system.

2. The power battery pack thermal management system according to claim 1, characterized in that: One end of the single chip microcomputer is connected to a temperature monitor, and the other end is connected to a semiconductor refrigeration chip; the temperature monitor is arranged in the PCM block; It is also equipped with an electric energy storage system; wherein the on-board photovoltaic array and nano-piezoelectric array are connected to the supercapacitor group through a DC / DC buck converter and an AC / DC converter respectively, and the supercapacitor group is connected to the semiconductor cooling chip through a DC / DC buck-boost converter; Under high-rate operating conditions, when the temperature monitor detects that the temperature of the PCM block starts to rise again after reaching the phase transition temperature, the supercapacitor group supplies energy to the semiconductor refrigeration chip, which cools the condensation section of the temperature dispersion plate to speed up the removal of heat stored in the PCM block and heat generated by the battery; when the temperature of the PCM block is lower than the phase transition temperature, the semiconductor refrigeration chip stops cooling.

3. The power battery pack thermal management system according to claim 2, characterized in that: The single chip computer controls the positive and negative connection of the super capacitor group to the semiconductor refrigeration circuit. When semiconductor refrigeration is required, the circuit is connected in the positive direction, and when heating is required, the circuit is connected in the reverse direction.

4. The power battery pack thermal management system according to claim 2, characterized in that: The middle part of the temperature plate is fixed by two temperature plate mounting slots, and the outer part is fixed by the temperature plate mounting slots and the vibration guide slots opened on the side surface of the battery box; The upper rib is connected to the battery box by bolts and fixed to the upper end of the temperature equalizing plate. The single chip computer is fixed on the top of the upper rib. The temperature monitor is set beside the battery ear of the battery cell and in the PCM block.

5. The power battery pack thermal management system according to claim 1, characterized in that: The packaging shell is made of aluminum alloy and is internally provided with heat-conducting fins.

6. The power battery pack thermal management system according to claim 1, characterized in that: The vibration energy recovery system is connected to the vehicle-mounted photovoltaic array.

7. The power battery pack thermal management system according to claim 1, characterized in that: The inner wall of the fixed sleeve is provided with a graphite layer to prevent the column from being stuck in the fixed sleeve.

8. The power battery pack thermal management system according to claim 1, characterized in that: The flexible piezoelectric nanogenerator consists of a ZnO nanowire array film and a flexible substrate.

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