Power battery bidirectional thermal management system and method based on electrostatic spraying

Abstract

The invention provides a bidirectional thermal management system and method for a power battery based on electrostatic spraying. The bidirectional thermal management system comprises a cooling subsystem, a heating subsystem, an electrostatic spraying heat exchange plate, a high-voltage electrostatic generator, a power battery module, a battery management system and a controller, a high-temperature liquid return pipeline and a low-temperature liquid return pipeline are arranged below the electrostatic spraying heat exchange plate; the battery management system is connected with a built-in temperature sensor of the power battery module and monitors real-time temperature information of the power battery module; the heating subsystem and the cooling subsystem share an electrostatic spraying heat exchange plate; the controller judges whether the power battery module is heated or cooled according to the real-time temperature information, and then the throttle valve, the high-voltage electrostatic generator and the PTC heater are controlled to be started and stopped. The invention provides an electrostatic spraying integrated solution capable of simultaneously solving the problems of heating and cooling of the power battery, so that the heat exchange efficiency and the space utilization rate of the system are greatly improved, the heat exchange uniformity is remarkably improved, and finally, the high-efficiency low-cost bidirectional heat management of the power battery is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management of new energy vehicles, and in particular relates to a bidirectional thermal management system and method for a power battery based on electrostatic spray technology. Background Art

[0002] With the rapid development of new energy vehicles, the thermal management problem of high-performance power batteries is becoming increasingly severe. As the core component of electric vehicles, power batteries are very sensitive to ambient temperature. Too high or too low temperature will affect their working performance. In low temperature environments, the reduction of battery activity will lead to a significant reduction in battery capacity; in high temperature environments, battery aging will be aggravated, and in severe cases, thermal runaway will occur. Therefore, a reliable thermal management system is crucial to ensure the charging and discharging performance of power batteries and extend their service life.

[0003] The existing low-temperature heating technology for power batteries can be divided into external heating method and internal heating method according to the location of the heat source. Among them, the external heating method has been widely used in the field of power battery thermal management due to its advantages such as simple structure and high reliability. Specifically, it refers to the use of external heat sources such as heating films, heating plates, hot air, and thermal fluids to transfer heat to power batteries by heat conduction, convection, and radiation. However, traditional external heating technology generally has problems such as low heat transfer efficiency, high system energy consumption, and poor temperature uniformity. In terms of power battery cooling technology, with the substantial increase in the demand for power battery charge and discharge rates, liquid cooling will gradually replace traditional air cooling and become the key development direction of future new energy vehicle power battery cooling technology due to its advantages such as higher heat dissipation efficiency and more uniform temperature distribution. At present, the heating and cooling systems of power batteries are usually independent of each other, lacking a highly integrated thermal management solution, which inevitably leads to problems such as high energy consumption, complex structure, and low space utilization of the thermal management system. Summary of the invention

[0004] In response to the above technical problems, the present invention provides a power battery bidirectional thermal management system and method based on electrostatic spraying, so as to simultaneously solve the heating and cooling problems of the power battery of new energy vehicles, greatly improve the system thermal management efficiency, improve the working environment temperature of the power battery, and improve the system space utilization, which is conducive to achieving battery performance and safety assurance of new energy vehicles in various application scenarios.

[0005] Note that the description of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than the above objectives can be extracted from the description of the specification, drawings, and claims.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A power battery bidirectional thermal management system based on electrostatic spraying, comprising a cooling subsystem, a heating subsystem, an electrostatic spraying heat exchange plate, a high-voltage electrostatic generator, a power battery module, a battery management system and a controller;

[0008] The cooling subsystem includes a cryogenic liquid storage tank, a first liquid supply pump, a cooling subsystem liquid supply pipeline, and a first solenoid valve; one end of the cooling subsystem liquid supply pipeline is connected to the cryogenic liquid storage tank through the first liquid supply pump, and the other end is connected to the first liquid inlet of the electrostatic spray heat exchange plate, and the cooling subsystem liquid supply pipeline is provided with a first solenoid valve;

[0009] The heating subsystem includes a high-temperature liquid storage tank, a third liquid supply pump, a heating subsystem liquid supply pipeline, and a third solenoid valve; one end of the heating subsystem liquid supply pipeline is connected to one end of the high-temperature liquid storage tank through the third liquid supply pump, and the other end is connected to the second liquid inlet of the electrostatic spray heat exchange plate, and a third solenoid valve is provided on the heating subsystem liquid supply pipeline;

[0010] A high-temperature liquid return pipeline and a low-temperature liquid return pipeline are arranged below the electrostatic spray heat exchange plate, one end of the high-temperature liquid return pipeline is connected to the second liquid outlet of the electrostatic spray heat exchange plate, and the other end is connected to the high-temperature liquid storage tank through the second liquid supply pump, and a second solenoid valve is arranged on the high-temperature liquid return pipeline; one end of the low-temperature liquid return pipeline is connected to the first liquid outlet of the electrostatic spray heat exchange plate, and the other end is connected to the low-temperature liquid storage tank through the fourth liquid supply pump, and a fourth solenoid valve is arranged on the low-temperature liquid return pipeline;

[0011] The high-voltage electrostatic generator is connected to the electrostatic spray heat exchange plate;

[0012] The power battery module is arranged in the surrounding structure of the electrostatic spray heat exchange plate and is tightly connected by a high thermal conductivity insulating material;

[0013] The battery management system is connected to a temperature sensor built into the power battery module, and the temperature sensor is used to monitor the real-time temperature information of the power battery module and transmit it to the battery management system;

[0014] The controller is respectively connected to the high-voltage electrostatic generator, the battery management system, the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve, and is used to regulate the liquid supply flow of the cooling and heating subsystems and control the high-voltage electrostatic generator to charge the electrostatic spray heat exchange plate, thereby performing electrostatic spray heating or cooling on the power battery module.

[0015] In the above scheme, the electrostatic spray heat exchange plate is provided with a liquid storage cavity, a spray cavity and a power battery module placement cavity from the outside to the inside;

[0016] The upper part of the liquid storage chamber is provided with a first liquid inlet and a second liquid inlet, and the lower part of the spray chamber is provided with a first liquid outlet and a second liquid outlet; the spray chamber is provided with a plurality of array nozzles, the liquid inlet end of the nozzle is connected with the liquid storage chamber, an electrode plate is provided between the liquid storage chamber and the spray chamber, and the electrode plate is connected with a high-voltage electrostatic generator for charging the array nozzles; a high thermal conductivity insulating interlayer is provided between the spray chamber and the cavity where the power battery module is placed; the liquid outlet ends of the plurality of array nozzles face the high thermal conductivity insulating interlayer; the power battery module is grounded.

[0017] Furthermore, the high thermal conductivity insulating layer is made of graphene material.

[0018] Furthermore, the array nozzle is made of metal and has an aperture range of 1-2 mm.

[0019] In the above solution, a PTC heater is provided in the high-temperature liquid storage tank, and the PTC heater is connected to the controller and the battery thermal management system for regulating the temperature of the liquid working fluid.

[0020] In the above scheme, the low temperature liquid storage tank and the high temperature liquid storage tank contain heat exchange liquid; the heat exchange liquid is a dielectric working fluid with a conductivity range of 1×10 -6 -1×10 -4 S / m.

[0021] In the above solution, the spray heat exchange plate is a three-surrounding structure, covering the top surface and two side surfaces of the power battery module.

[0022] A control method for a power battery bidirectional thermal management system based on electrostatic spraying comprises the following steps:

[0023] The temperature sensor built into the power battery module monitors the real-time temperature information of the power battery module and transmits it to the battery management system. When the battery management system detects that the temperature of the power battery module exceeds the preset upper limit of the operating temperature, the controller opens the first solenoid valve to pump the low-temperature liquid in the low-temperature liquid storage tank into the electrostatic spray heat exchange plate through the first liquid supply pump; the controller turns on the high-voltage electrostatic generator to charge the array nozzles of the electrostatic spray heat exchange plate, and electrostatically spray cools the power battery module; the second solenoid valve maintains a synchronous working state with the first solenoid valve, and the liquid after heat exchange in the electrostatic spray heat exchange plate will be recovered to the high-temperature liquid storage tank through the high-temperature return liquid pipeline; when the temperature of the power battery module drops to the preset threshold, the controller closes the first solenoid valve, the second solenoid valve and the high-voltage electrostatic generator, and the cooling subsystem stops working;

[0024] When the battery management system detects that the temperature of the power battery module is lower than the preset lower limit of the operating temperature, the controller opens the third solenoid valve to pump the high-temperature liquid in the high-temperature liquid storage tank into the electrostatic spray heat exchange plate through the third liquid supply pump; the controller controls the PTC heater to work so that the liquid temperature in the high-temperature liquid storage tank remains constant; the controller turns on the high-voltage electrostatic generator to charge the array nozzles of the electrostatic spray heat exchange plate to perform electrostatic spray heating on the power battery module; the fourth solenoid valve and the third solenoid valve maintain a synchronous working state, and the liquid after heat exchange in the electrostatic spray heat exchange plate will be recovered to the low-temperature liquid storage tank through the low-temperature return liquid pipeline; when the temperature of the power battery module rises to the preset threshold, the controller closes the fourth solenoid valve, the third solenoid valve and the high-voltage electrostatic generator, and the heating subsystem stops working.

[0025] In the above scheme, when the cooling subsystem is working, the controller controls the low-temperature liquid supply pipeline and the high-temperature liquid return pipeline to open, and the high-temperature liquid supply pipeline and the low-temperature liquid return pipeline to close.

[0026] In the above scheme, when the heating subsystem is working, the controller controls the high-temperature liquid supply pipeline and the low-temperature liquid return pipeline to open, and the low-temperature liquid supply pipeline and the high-temperature liquid return pipeline to close.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention innovatively proposes an integrated solution for power battery heating and cooling, which can greatly improve the thermal management efficiency of the power battery system; the electrostatic spray used can effectively save the energy required for atomization compared with traditional pressure or mechanical spray, and the existence of electrostatic force can greatly improve the liquid atomization quality and impact heat exchange efficiency; the cooling subsystem and the heating subsystem share the electrostatic spray heat exchange plate, which can greatly reduce the size of the thermal management system and improve the system space utilization rate; the heat exchange plate is a three-surround structure, which can fully ensure the uniformity of temperature distribution of the battery module and effectively improve the working environment temperature of the power battery; in addition, high-temperature liquid and low-temperature liquid are stored independently, and the liquid after heat exchange is cross-recovered, which greatly improves the waste heat recovery rate of the system and effectively reduces the system energy consumption; the present invention realizes integrated and efficient thermal management of heating and cooling of power batteries, and the thermal management system has low energy consumption, simple structure and high space utilization.

[0029] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of a power battery bidirectional thermal management system based on electrostatic spraying according to an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the internal heat exchange scheme of the electrostatic spray heat exchange plate according to one embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of an electrostatic spray heat exchange plate and a liquid supply method thereof according to an embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of a nozzle array scheme on the top surface of an electrostatic spray heat exchange plate according to an embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of a nozzle array scheme on the side of an electrostatic spray heat exchange plate according to an embodiment of the present invention;

[0035] Figure 6 It is a schematic flow chart of a bidirectional thermal management system for a power battery based on electrostatic spraying according to an embodiment of the present invention.

[0036] In the figure: 1. Low-temperature liquid storage tank; 2. First liquid supply pump; 3. Heating subsystem liquid supply pipeline; 4. First solenoid valve; 5. Electrostatic spray heat exchange plate; 5-1. Liquid storage chamber; 5-2. Array nozzle; 5-3. Electrode plate; 5-4. Spray chamber; 5-5. High thermal conductivity insulating barrier; 6. High-voltage electrostatic generator; 7. Power battery module; 8. Battery management system; 9. Controller; 10. Second solenoid valve; 11. High-temperature return liquid pipeline; 12. Second liquid supply pump; 13. High-temperature liquid storage tank; 14. PTC heater; 15. Third liquid supply pump; 16. Heating subsystem liquid supply pipeline; 17. Third solenoid valve; 18. Fourth solenoid valve; 19. Low-temperature return liquid pipeline; 20. Fourth liquid supply pump. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Figure 1 The figure shows a preferred embodiment of the power battery bidirectional thermal management system based on electrostatic spraying of the present invention, which comprises a cooling subsystem, a heating subsystem, an electrostatic spraying heat exchange plate 5, a high-voltage electrostatic generator 6, a power battery module 7, a battery management system 8 and a controller 9;

[0041] The cooling subsystem comprises a cryogenic liquid storage tank 1, a first liquid supply pump 2, a cooling subsystem liquid supply pipeline 3, and a first solenoid valve 4; one end of the cooling subsystem liquid supply pipeline 3 is connected to the cryogenic liquid storage tank 1 through the first liquid supply pump 2, and the other end is connected to the first liquid inlet of the electrostatic spray heat exchange plate 5, and the cooling subsystem liquid supply pipeline 3 is provided with a first solenoid valve 4;

[0042] The heating subsystem includes a high-temperature liquid storage tank 13, a third liquid supply pump 15, a heating subsystem liquid supply pipeline 16, and a third solenoid valve 17; one end of the heating subsystem liquid supply pipeline 16 is connected to one end of the high-temperature liquid storage tank 13 through the third liquid supply pump 15, and the other end is connected to the second liquid inlet of the electrostatic spray heat exchange plate 5, and the heating subsystem liquid supply pipeline 16 is provided with a third solenoid valve 17;

[0043] A high-temperature liquid return pipeline 11 and a low-temperature liquid return pipeline 19 are provided below the electrostatic spray heat exchange plate 5. One end of the high-temperature liquid return pipeline 11 is connected to the second liquid outlet of the electrostatic spray heat exchange plate 5, and the other end is connected to the high-temperature liquid storage tank 13 through the second liquid supply pump 12. A second solenoid valve 10 is provided on the high-temperature liquid return pipeline 11; one end of the low-temperature liquid return pipeline 19 is connected to the first liquid outlet of the electrostatic spray heat exchange plate 5, and the other end is connected to the low-temperature liquid storage tank 1 through the fourth liquid supply pump 20. A fourth solenoid valve 18 is provided on the low-temperature liquid return pipeline 19;

[0044] The high-voltage electrostatic generator 6 is connected to the electrostatic spray heat exchange plate 5 to realize electrostatic atomization of the heat exchange medium;

[0045] The power battery module 7 is arranged in the enclosing structure of the electrostatic spray heat exchange plate 5. The electrostatic spray heat exchange plate 5 is a main heat exchange component and preferably in close contact with the power battery module 7.

[0046] The battery management system 8 is connected to a plurality of temperature sensors built into the power battery module 7. The temperature sensors are used to monitor the real-time temperature information of the power battery module 7 and transmit the real-time temperature information to the battery management system 8 for real-time monitoring of the temperature information.

[0047] The controller 9 is respectively connected to the high-voltage electrostatic generator 6, the battery management system 8, the first solenoid valve 4, the second solenoid valve 10, the third solenoid valve 17 and the fourth solenoid valve 18, and is used to regulate the liquid supply flow of the cooling and heating subsystems and control the high-voltage electrostatic generator 6 to charge the electrostatic spray heat exchange plate 5, thereby performing electrostatic spray heating or cooling on the power battery module 7.

[0048] The electrostatic spray heat exchange plate 5 is a closed thin plate with a cavity structure, which is provided with a liquid storage cavity 5-1, a spray cavity 5-4 and a cavity for placing the power battery module 7 from the outside to the inside; the upper part of the liquid storage cavity 5-1 is provided with a first liquid inlet and a second liquid inlet, and the lower part of the spray cavity 5-4 is provided with a first liquid outlet and a second liquid outlet; the spray cavity 5-4 is provided with a plurality of array nozzles 5-2, the liquid inlet end of the nozzle 5-2 is connected to the liquid storage cavity 5-1, an electrode plate 5-3 is provided between the liquid storage cavity 5-1 and the spray cavity 5-4, and the electrode plate 5-3 is connected to a high-voltage electrostatic generator 6 for charging the array nozzles 5-2; a high thermal conductivity insulating interlayer 5-5 is provided between the spray cavity 5-4 and the cavity for placing the power battery module 7; the liquid outlet ends of the plurality of array nozzles 5-2 face the high thermal conductivity insulating interlayer 5-5; the power battery module 7 is grounded for electrostatic protection.

[0049] The high thermal conductivity insulating layer 5-5 is made of graphene material, which can effectively avoid the influence of a small amount of charge on the power battery system while ensuring the heat exchange efficiency.

[0050] The array nozzle 5 - 2 is made of metal, and the array nozzle 5 - 2 is tightly connected to the metal electrode plate 5 - 3 .

[0051] The array nozzles 5 - 2 are distributed in a rectangular array, and the distance between adjacent array nozzles is preferably such that the spray can better cover the heat exchange surface.

[0052] The first liquid supply pump 2 and the third liquid supply pump 15 are both small-flow non-metallic gear pumps, which can effectively avoid the influence of a small amount of electric charge while ensuring the liquid supply accuracy, and the flow range is 0-0.25L / min.

[0053] The high temperature liquid storage tank 13 is provided with a PTC heater 14, which is connected to the controller 9 and the battery thermal management system 8 and is used to adjust the temperature of the liquid working medium. The controller 9 can preheat the heat exchange liquid through the PTC heater 14 according to the real-time temperature information monitored by the power battery module 7.

[0054] The low-temperature liquid storage tank 1 is used to store low-temperature liquid; the first solenoid valve 4 is connected to the controller 9, and can timely adjust the liquid supply flow from the cooling subsystem to the electrostatic spray heat exchange plate 5 according to the battery temperature information monitored in real time by the battery management system 8; the high-temperature liquid storage tank 13 is used to store high-temperature liquid, and is equipped with a built-in PTC heater 14 and is insulated to achieve temperature control of the heat exchange liquid; similarly, the third solenoid valve 17 is connected to the controller 9, and can timely adjust the liquid supply flow from the heating subsystem to the electrostatic spray heat exchange plate 5 according to the battery temperature information monitored in real time by the battery management system 8.

[0055] The low temperature liquid storage tank 1 and the high temperature liquid storage tank 13 contain heat exchange liquid; the heat exchange liquid is a dielectric medium such as oil and alcohol, and the conductivity range is 1×10 -6 -1×10 -4 S / m, and has a relatively high boiling point, usually not less than 80°C.

[0056] The electrostatic spray heat exchange plate 5 is provided with two liquid inlets and two liquid outlets, wherein the two liquid inlets are arranged at the top and the two liquid outlets are arranged at the bottom; when the cooling subsystem is working, the temperature of the low-temperature liquid in the low-temperature liquid storage tank 1 rises after sufficient heat exchange with the power battery module 7, and then is recovered to the high-temperature liquid storage tank 13 through the low-temperature return liquid pipeline 11 below; when the heating subsystem is working, the temperature of the high-temperature liquid in the high-temperature liquid storage tank 13 drops after sufficient heat exchange with the power battery module 7, and then is recovered to the low-temperature liquid storage tank 1 through the low-temperature return liquid pipeline 19 below; this liquid supply method can effectively improve the heat exchange efficiency of the thermal management system, thereby greatly saving system energy consumption.

[0057] According to this embodiment, preferably, the array nozzle 5-2 is made of metal; the heating subsystem and the cooling subsystem have independent liquid storage and liquid supply devices; the conductivity range of the heat exchange liquid is 1×10 -6 -1×10 -4 S / m; the supply flow range of the heat exchange liquid is 0-0.25L / min; the temperature control range of the PTC heater 14 is 30-60°C; the temperature measurement frequency of the battery management system 8 is to update the temperature information every 1-2 minutes; based on the above parameter range, it is beneficial to achieve efficient heating and cooling performance of the power battery bidirectional thermal management system.

[0058] Figure 2 The figure shows an implementation method of the internal heat exchange scheme of the electrostatic spray heat exchange plate of the present invention. The electrostatic spray heat exchange plate 5 is connected to the liquid supply pipeline, and the heat exchange liquid first enters the liquid storage chamber 5-1; the bottom surface of the liquid storage chamber 5-1 is provided with a plurality of array nozzles 5-2, which are connected through an electrode plate 5-3; the electrode plate 5-3 is connected to a high-voltage electrostatic generator 6, so as to realize uniform charging of the array nozzle; the inner surface of the electrostatic spray heat exchange plate 5 is provided with a graphene high thermal conductivity insulating layer 5-5, which effectively avoids the influence of a small amount of charge on the power battery system while ensuring the heat exchange efficiency. The electrostatic spray mode induced by the array nozzle 5-2 is a stable multi-stream jet mode, which can greatly improve the uniformity of electrostatic spray heat exchange.

[0059] According to this embodiment, preferably, the aperture range of the array nozzle 5-2 is 1-2mm; the height range of the liquid storage chamber 5-1 is 20-40mm; the height range of the spray chamber 5-4 is 30-50mm; the total thickness of the electrostatic spray heat exchange plate 5 does not exceed 100mm; based on the above parameter ranges, it is beneficial to ensure the heat exchange efficiency and system integration of the electrostatic spray heat exchange plate.

[0060] Figure 3 The figure shows an implementation mode of the electrostatic spray heat exchange plate 5 and its liquid supply method of the present invention. The electrostatic spray heat exchange plate 5 is a three-surrounding structure, which covers the top surface and two side surfaces of the power battery module 7 at the same time, and can effectively avoid the occurrence of local hot spots in the power battery module 7; when the cooling subsystem is working, the cooling liquid supply pipeline 3 pumps the low-temperature liquid to the electrostatic spray heat exchange plate 5, and the liquid after heat exchange is recovered to the high-temperature liquid storage tank 13 through the high-temperature return liquid pipeline 11 below; when the heating subsystem is working, the heating liquid supply pipeline 16 pumps the low-temperature liquid to the electrostatic spray heat exchange plate 5, and the liquid after heat exchange is recovered to the high-temperature liquid storage tank 1 through the low-temperature return liquid pipeline 19 below.

[0061] Figure 4 and Figure 5The figures show an implementation scheme of the top and side nozzle arrays of the electrostatic spray heat exchange plate 5 of the present invention, respectively. The array nozzles 5-2 are distributed in a rectangular array; the aperture range of the array nozzles 5-2 is 1-2 mm, which avoids the increase in flow resistance caused by too small apertures on the one hand, and avoids the uneven flow distribution of each array nozzle caused by too large apertures on the other hand.

[0062] According to this embodiment, preferably, the spacing between adjacent array nozzles 5-2 does not exceed 100mm; the aperture range of the array nozzle 5-2 is 1-2mm. Based on the above parameter range, it is beneficial for the electrostatic spray to better cover the bottom heat exchange surface, which can greatly improve the utilization rate of the heat exchange medium.

[0063] The battery management system 8 of the present invention is connected to the built-in temperature sensor of the power battery module 7 to monitor the real-time temperature information of the power battery module 7. The heating subsystem and the cooling subsystem share the electrostatic spray heat exchange plate 5. The controller 9 determines whether to heat or cool the power battery module 7 according to the real-time temperature information, and then controls the start and stop of the solenoid valve, the high-voltage electrostatic generator 6 and the PTC heater 14. The present invention proposes an integrated electrostatic spray solution that can solve the heating and cooling problems of the power battery at the same time, greatly improves the heat exchange efficiency and space utilization of the system, significantly improves the heat exchange uniformity, and finally realizes efficient and low-cost bidirectional thermal management of the power battery.

[0064] Combination Figure 6 As shown, a control method for a power battery bidirectional thermal management system based on electrostatic spraying comprises the following steps:

[0065] First, inject a proper amount of heat exchange liquid into the low-temperature liquid storage tank 1 and the high-temperature liquid storage tank 13 respectively, turn on the first liquid supply pump 2, the second liquid supply pump 12, the third liquid supply pump 15 and the fourth liquid supply pump 20, and keep the first solenoid valve 4, the second solenoid valve 10, the third solenoid valve 17 and the fourth solenoid valve 18 in a closed state;

[0066] Keep the battery management system 8 in working state all the time. The built-in temperature sensor of the power battery module 7 monitors the real-time temperature information of the power battery module 7 and transmits it to the battery management system 8. When the battery management system 8 detects that the temperature of the power battery module 7 exceeds the preset upper limit of the suitable working temperature (about 30°C), the controller 9 opens the first solenoid valve 4, and continuously pumps the low-temperature liquid in the low-temperature liquid storage tank 1 into the electrostatic spray heat exchange plate 5 through the first liquid supply pump 2; the controller 9 turns on the high-voltage electrostatic generator 6 to charge the array nozzle 5-2 of the electrostatic spray heat exchange plate 5, and electrostatically sprays and cools the power battery module 7; the second solenoid valve 10 keeps working synchronously with the first solenoid valve 4, and the liquid after heat exchange in the electrostatic spray heat exchange plate 5 will be recovered to the high-temperature liquid storage tank 13 through the high-temperature return liquid pipeline 11; when the temperature of the power battery module 7 drops to the preset threshold, the controller 9 closes the first solenoid valve 4, the second solenoid valve 10 and the high-voltage electrostatic generator 6, and the cooling subsystem stops working;

[0067] When the battery management system 8 detects that the temperature of the power battery module 7 is lower than the preset lower limit of the suitable working temperature (about 10°C), the controller 9 opens the third solenoid valve 17, and continuously pumps the high-temperature liquid in the high-temperature liquid storage tank 13 into the electrostatic spray heat exchange plate 5 through the third liquid supply pump 15; the controller 9 controls the PTC heater 14 to work, so that the liquid temperature in the high-temperature liquid storage tank 13 remains constant; the controller 9 turns on the high-voltage electrostatic generator 6 to charge the array nozzle 5-2 of the electrostatic spray heat exchange plate 5, and performs electrostatic spray heating on the power battery module 7; the fourth solenoid valve 18 and the third solenoid valve 17 maintain a synchronous working state, and the liquid after heat exchange in the electrostatic spray heat exchange plate 5 will be returned to the low-temperature liquid storage tank 1 through the low-temperature return liquid pipeline 19; when the temperature of the power battery module 7 rises to the preset threshold value, the controller 9 closes the fourth solenoid valve 18 and the third solenoid valve 17 as well as the high-voltage electrostatic generator 6, and the heating subsystem stops working.

[0068] When the cooling subsystem is working, the controller 9 controls the low-temperature liquid supply pipeline 3 and the high-temperature liquid return pipeline 11 to open, and the high-temperature liquid supply pipeline 16 and the low-temperature liquid return pipeline 19 to close.

[0069] When the heating subsystem is working, the controller 9 controls the high-temperature liquid supply pipeline 16 and the low-temperature liquid return pipeline 19 to open, and the low-temperature liquid supply pipeline 3 and the high-temperature liquid return pipeline 11 to close.

[0070] Repeat the above steps. Based on the real-time temperature distribution of the power battery, the system can automatically turn on the cooling subsystem or the heating subsystem to perform electrostatic spray thermal management on the power battery module 7 in a timely manner to ensure that the power battery is always within the appropriate operating temperature range of 10-30°C, ultimately achieving efficient bidirectional thermal management of the power battery module.

[0071] The bidirectional thermal management system for power batteries based on electrostatic spraying described in the present invention is particularly suitable for temperature control of power batteries for high-performance new energy vehicles. Its advantages are that the heating and cooling systems are highly integrated, which greatly improves the system's heat exchange efficiency and space utilization; the heat exchange medium is atomized by electrostatic spraying, which significantly improves the system's heat exchange uniformity; the heating subsystem and the cooling subsystem share the electrostatic spray heat exchange plate, and the liquid medium after heat exchange is recycled and reused in a targeted manner, which greatly saves system energy consumption. Based on the above scheme, efficient and low-cost bidirectional thermal management of power batteries is finally achieved.

[0072] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0073] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A power battery bidirectional thermal management system based on electrostatic spray, characterized in that: It comprises a cooling subsystem, a heating subsystem, an electrostatic spray heat exchange plate (5), a high-voltage electrostatic generator (6), a power battery module (7), a battery management system (8) and a controller (9); The cooling subsystem comprises a cryogenic liquid storage tank (1), a first liquid supply pump (2), a cooling subsystem liquid supply pipeline (3), and a first solenoid valve (4); one end of the cooling subsystem liquid supply pipeline (3) is connected to the cryogenic liquid storage tank (1) via the first liquid supply pump (2), and the other end is connected to a first liquid inlet of an electrostatic spray heat exchange plate (5); and the cooling subsystem liquid supply pipeline (3) is provided with a first solenoid valve (4); The heating subsystem comprises a high-temperature liquid storage tank (13), a third liquid supply pump (15), a heating subsystem liquid supply pipeline (16), and a third solenoid valve (17); one end of the heating subsystem liquid supply pipeline (16) is connected to one end of the high-temperature liquid storage tank (13) through the third liquid supply pump (15), and the other end is connected to the second liquid inlet of the electrostatic spray heat exchange plate (5); and the heating subsystem liquid supply pipeline (16) is provided with a third solenoid valve (17); A high-temperature liquid return pipeline (11) and a low-temperature liquid return pipeline (19) are provided below the electrostatic spray heat exchange plate (5); one end of the high-temperature liquid return pipeline (11) is connected to the second liquid outlet of the electrostatic spray heat exchange plate (5), and the other end is connected to the high-temperature liquid storage tank (13) via a second liquid supply pump (12); a second solenoid valve (10) is provided on the high-temperature liquid return pipeline (11); one end of the low-temperature liquid return pipeline (19) is connected to the first liquid outlet of the electrostatic spray heat exchange plate (5), and the other end is connected to the low-temperature liquid storage tank (1) via a fourth liquid supply pump (20); a fourth solenoid valve (18) is provided on the low-temperature liquid return pipeline (19); The high-voltage electrostatic generator (6) is connected to the electrostatic spray heat exchange plate (5); The power battery module (7) is arranged in the surrounding structure of the electrostatic spray heat exchange plate (5) and is tightly connected via a high thermal conductivity insulating material; The battery management system (8) is connected to a temperature sensor built into the power battery module (7), and the temperature sensor is used to monitor real-time temperature information of the power battery module (7) and transmit the real-time temperature information to the battery management system (8); The controller (9) is respectively connected to the high-voltage electrostatic generator (6), the battery management system (8), the first solenoid valve (4), the second solenoid valve (10), the third solenoid valve (17) and the fourth solenoid valve (18), and is used to adjust the liquid supply flow of the cooling and heating subsystems and control the high-voltage electrostatic generator (6) to charge the electrostatic spray heat exchange plate (5), thereby performing electrostatic spray heating or cooling on the power battery module (7).

2. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The electrostatic spray heat exchange plate (5) is provided with a liquid storage cavity (5-1), a spray cavity (5-4) and a cavity for placing a power battery module (7) in sequence from the outside to the inside; The upper part of the liquid storage chamber (5-1) is provided with a first liquid inlet and a second liquid inlet, and the lower part of the spray chamber (5-4) is provided with a first liquid outlet and a second liquid outlet; the spray chamber (5-4) is provided with a plurality of array nozzles (5-2), the liquid inlet end of the nozzle (5-2) is communicated with the liquid storage chamber (5-1), an electrode plate (5-3) is provided between the liquid storage chamber (5-1) and the spray chamber (5-4), and the electrode plate (5-3) is connected to a high-voltage electrostatic generator (6) for charging the array nozzles (5-2); a high thermal conductivity insulating barrier (5-5) is provided between the spray chamber (5-4) and the cavity for placing the power battery module (7); the liquid outlet ends of the plurality of array nozzles (5-2) face the high thermal conductivity insulating barrier (5-5); and the power battery module (7) is grounded.

3. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 2 is characterized in that: The high thermal conductivity insulating interlayer (5-5) is made of graphene material.

4. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 2 is characterized in that: The array nozzle (5-2) is made of metal and has a hole diameter ranging from 1 to 2 mm.

5. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 1, characterized in that: A PTC heater (14) is provided in the high-temperature liquid storage tank (13); the PTC heater (14) is connected to the controller (9) and the battery thermal management system (8) and is used for regulating the temperature of the liquid working fluid.

6. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 1, characterized in that: The low-temperature liquid storage tank (1) and the high-temperature liquid storage tank (13) contain heat exchange liquid; the heat exchange liquid is a dielectric medium with a conductivity range of 1×10 -6 -1×10 -4 S / m.

7. The power battery bidirectional thermal management system based on electrostatic spraying according to claim 1, characterized in that: The spray heat exchange plate (5) is a three-surrounding structure, covering the top surface and two side surfaces of the power battery module (7).

8. A control method for a power battery bidirectional thermal management system based on electrostatic spraying according to any one of claims 1 to 7, characterized in that: The following steps are involved: The temperature sensor built into the power battery module (7) monitors the real-time temperature information of the power battery module (7) and transmits it to the battery management system (8). When the battery management system (8) detects that the temperature of the power battery module (7) exceeds the preset upper limit of the working temperature, the controller (9) opens the first solenoid valve (4) to pump the low-temperature liquid in the low-temperature liquid storage tank (1) into the electrostatic spray heat exchange plate (5) through the first liquid supply pump (2); the controller (9) turns on the high-voltage electrostatic generator (6) to charge the array nozzles (5-2) of the electrostatic spray heat exchange plate (5) and electrostatically spray cools the power battery module (7); the second solenoid valve (10) and the first solenoid valve (4) maintain a synchronous working state, and the liquid after heat exchange in the electrostatic spray heat exchange plate (5) will be recovered to the high-temperature liquid storage tank (13) through the high-temperature liquid return pipeline (11); when the temperature of the power battery module (7) drops to a preset threshold, the controller (9) closes the first solenoid valve (4), the second solenoid valve (10) and the high-voltage electrostatic generator (6), and the cooling subsystem stops working; When the battery management system (8) detects that the temperature of the power battery module (7) is lower than the preset lower limit of the operating temperature, the controller (9) opens the third solenoid valve (17) to pump the high-temperature liquid in the high-temperature liquid storage tank (13) into the electrostatic spray heat exchange plate (5) through the third liquid supply pump (15); the controller (9) controls the PTC heater (14) to operate so that the temperature of the liquid in the high-temperature liquid storage tank (13) remains constant; the controller (9) turns on the high-voltage electrostatic generator (6) to spray the array of the electrostatic spray heat exchange plate (5) with the high-voltage electrostatic generator (6). The nozzle (5-2) is charged to perform electrostatic spray heating on the power battery module (7); the fourth solenoid valve (18) and the third solenoid valve (17) maintain a synchronous working state, and the liquid after heat exchange in the electrostatic spray heat exchange plate (5) is returned to the low-temperature liquid storage tank (1) through the low-temperature liquid return pipeline (19); when the temperature of the power battery module (7) rises to a preset threshold, the controller (9) closes the fourth solenoid valve (18) and the third solenoid valve (17) and the high-voltage electrostatic generator (6), and the heating subsystem stops working.

9. The control method of the power battery bidirectional thermal management system based on electrostatic spraying according to claim 8, characterized in that: When the cooling subsystem is in operation, the controller (9) controls the low-temperature liquid supply pipeline (3) and the high-temperature liquid return pipeline (11) to open, and the high-temperature liquid supply pipeline (16) and the low-temperature liquid return pipeline (19) to close.

10. The control method of the power battery bidirectional thermal management system based on electrostatic spraying according to claim 8, characterized in that: When the heating subsystem is working, the controller (9) controls the high-temperature liquid supply pipeline (16) and the low-temperature liquid return pipeline (19) to open, and the low-temperature liquid supply pipeline (3) and the high-temperature liquid return pipeline (11) to close.

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