A bidirectional thermal management system and method for power batteries based on electrostatic spraying

Abstract

The application provides a power battery bidirectional thermal management system and method based on electrostatic spraying, which 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; the electrostatic spraying heat exchange plate is provided below with a high-temperature liquid return pipeline and a low-temperature liquid return pipeline; the battery management system is connected with a built-in temperature sensor of the power battery module to monitor real-time temperature information of the power battery module; the heating and cooling subsystems share the electrostatic spraying heat exchange plate; the controller judges whether to heat or cool the power battery module according to the real-time temperature information, and then controls the start and stop of a throttle valve, the high-voltage electrostatic generator and a PTC heater. The application proposes an electrostatic spraying integrated solution which can simultaneously solve the heating and cooling problems of the power battery, greatly improves the heat exchange efficiency and space utilization of the system, significantly improves the heat exchange uniformity, and finally realizes the efficient and low-cost bidirectional thermal management of the power battery.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new energy vehicle thermal management, and particularly relates to a power battery bidirectional thermal management system and method based on electrostatic spraying technology. BACKGROUND

[0002] With the rapid development of new energy vehicles, the thermal management problem of high-performance power batteries is increasingly serious. As the core component of electric vehicles, power batteries are very sensitive to environmental temperature, and high or low temperature will affect their working performance. Among them, in low temperature environment, the reduction of battery activity will cause the battery capacity to be greatly reduced; and in high temperature environment, the battery aging is intensified, and in severe cases, it will also cause thermal runaway. Therefore, a reliable thermal management system is crucial to ensure the charging and discharging performance of power batteries and prolong the service life.

[0003] The existing low-temperature heating technology of power batteries can be divided into external heating method and internal heating method according to the position of the heat source. The external heating method is widely used in the field of power battery thermal management due to its simple structure, high reliability and other advantages, which specifically refers to using external heat sources such as heating film, heating plate, hot air, and hot fluid to transfer heat to the power battery by conduction, convection, and radiation. However, the traditional external heating technology generally has the problems of 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 charging and discharging rate, liquid cooling will gradually replace traditional air cooling as the key development direction of future new energy vehicle power battery cooling technology due to its higher cooling efficiency and more uniform temperature distribution. At present, the heating and cooling systems of power batteries are usually independent of each other, and there is a lack of highly integrated thermal management solutions, so it is inevitable to cause problems such as high energy consumption of the thermal management system, complex structure, and low space utilization. SUMMARY

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

[0005] Note that the recitation of these objects does not preclude the presence of others. One embodiment of the present application does not necessarily achieve all of the above objects. Other objects can be extracted from the recitations of the specification, drawings, and claims.

[0006] The present application achieves the above technical objects 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 comprises a low-temperature liquid storage tank, a first liquid supply pump, a cooling subsystem liquid supply pipeline and a first electromagnetic valve; one end of the cooling subsystem liquid supply pipeline is connected with the low-temperature liquid storage tank through the first liquid supply pump, the other end is connected with a first liquid inlet of the electrostatic spraying heat exchange plate, and the first electromagnetic valve is arranged on the cooling subsystem liquid supply pipeline;

[0009] The heating subsystem comprises a high-temperature liquid storage tank, a third liquid supply pump, a heating subsystem liquid supply pipeline and a third electromagnetic valve; one end of the heating subsystem liquid supply pipeline is connected with one end of the high-temperature liquid storage tank through the third liquid supply pump, the other end is connected with a second liquid inlet of the electrostatic spraying heat exchange plate, and the third electromagnetic valve is arranged on the heating subsystem liquid supply pipeline;

[0010] The electrostatic spraying heat exchange plate is provided below with a high-temperature liquid return pipeline and a low-temperature liquid return pipeline; one end of the high-temperature liquid return pipeline is connected with a second liquid outlet of the electrostatic spraying heat exchange plate, the other end is connected with the high-temperature liquid storage tank through a second liquid supply pump, and a second electromagnetic valve is arranged on the high-temperature liquid return pipeline; one end of the low-temperature liquid return pipeline is connected with a first liquid outlet of the electrostatic spraying heat exchange plate, the other end is connected with the low-temperature liquid storage tank through a fourth liquid supply pump, and a fourth electromagnetic valve is arranged on the low-temperature liquid return pipeline;

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

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

[0013] The battery management system is connected with a temperature sensor arranged in the power battery module, the temperature sensor is used for monitoring real-time temperature information of the power battery module and transmitting the real-time temperature information to the battery management system;

[0014] The controller is connected with the high-voltage electrostatic generator, the battery management system, the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve respectively, and is used for regulating and controlling liquid supply flow of the cooling and heating subsystems, controlling the high-voltage electrostatic generator to charge the electrostatic spraying heat exchange plate, so as to electrostatically spray heat or cool the power battery module.

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

[0016] The upper part of the liquid storage cavity is provided with a first liquid inlet and a second liquid inlet, and the lower part of the spray cavity is provided with a first liquid outlet and a second liquid outlet; the spray cavity is provided with a plurality of array nozzles, the liquid inlet end of the nozzle is communicated with the liquid storage cavity, an electrode plate is arranged between the liquid storage cavity and the spray cavity, the electrode plate is connected with a high-voltage electrostatic generator for charging the array nozzles; a high-thermal-conductivity insulation layer is arranged between the spray cavity and the power battery module placement cavity; the liquid outlet end of the plurality of array nozzles faces the high-thermal-conductivity insulation layer; and the power battery module is grounded.

[0017] Further, the high-thermal-conductivity insulation layer is a graphene material.

[0018] Further, the array nozzle is made of metal and has a pore size ranging from 1 mm to 2 mm.

[0019] In the above scheme, the high-temperature liquid storage tank is provided with a PTC heater, the PTC heater is connected with a controller and a battery thermal management system, and is used for temperature adjustment of the liquid working medium.

[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 medium, and has an electrical conductivity ranging from 1×10 -6 -1×10 -4 S / m.

[0021] In the above scheme, the spray heat exchange plate has a three-enclosure structure and covers the top surface and two side surfaces of the power battery module.

[0022] A control method of the electrostatic spray-based power battery bidirectional thermal management system, comprising the following steps:

[0023] The temperature sensor built in the power battery module monitors real-time temperature information of the power battery module and transmits the information to a battery management system; when the battery management system monitors that the temperature of the power battery module exceeds a preset upper limit of working temperature, a controller opens a first electromagnetic valve, pumps the low-temperature liquid in the low-temperature liquid storage tank into the electrostatic spray heat exchange plate through a first liquid supply pump, opens a high-voltage electrostatic generator to charge the array nozzles of the electrostatic spray heat exchange plate, and performs electrostatic spray cooling on the power battery module; a second electromagnetic valve works synchronously with the first electromagnetic valve, and the liquid after heat exchange in the electrostatic spray heat exchange plate is recovered to the high-temperature liquid storage tank through a high-temperature liquid recovery pipeline; when the temperature of the power battery module drops to a preset threshold value, the controller closes the first electromagnetic valve, the second electromagnetic valve and the high-voltage electrostatic generator, and the cooling subsystem stops working.

[0024] When the battery management system monitors that the power battery module temperature is lower than the preset lower limit of the working temperature, the controller opens the third electromagnetic valve, pumps the high-temperature liquid in the high-temperature liquid storage tank into the electrostatic spray heat exchange plate through the third liquid supply pump, controls the PTC heater to work, keeps the liquid temperature in the high-temperature liquid storage tank constant, opens the high-voltage electrostatic generator to charge the array nozzles of the electrostatic spray heat exchange plate, and performs electrostatic spray heating on the power battery module; the fourth electromagnetic valve and the third electromagnetic valve are kept in a synchronous working state, the heat-exchanged liquid in the electrostatic spray heat exchange plate is recovered to the low-temperature liquid storage tank through the low-temperature liquid recovery pipeline; when the power battery module temperature rises to the preset threshold, the controller closes the fourth electromagnetic valve, the third electromagnetic valve and the high-voltage electrostatic generator, and the heating subsystem stops working.

[0025] In the above scheme, when the cooling subsystem works, the controller controls the low-temperature liquid supply pipeline and the high-temperature liquid recovery pipeline to be opened, and the high-temperature liquid supply pipeline and the low-temperature liquid recovery pipeline to be closed.

[0026] In the above scheme, when the heating subsystem works, the controller controls the high-temperature liquid supply pipeline and the low-temperature liquid recovery pipeline to be opened, and the low-temperature liquid supply pipeline and the high-temperature liquid recovery pipeline to be closed.

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

[0028] The present application innovatively proposes a power battery heating and cooling integrated solution, which can greatly improve the thermal management efficiency of the power battery system; the electrostatic spray adopted can effectively save the energy consumption required for atomization compared with the traditional pressure type or mechanical type 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 space utilization rate of the system; the heat exchange plate has a three-enclosure structure, which can fully ensure the temperature distribution uniformity of the battery module and effectively improve the working environment temperature of the power battery; in addition, the high-temperature liquid and the low-temperature liquid are independently stored, and the heat-exchanged liquid is cross-recovered, which greatly improves the waste heat recovery utilization rate of the system and effectively reduces the system energy consumption; the present application realizes the heating and cooling integration of the power battery, and the thermal management system has low energy consumption, simple structure and high space utilization rate.

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

[0030] Figure 1 is a structure schematic diagram of a power battery bidirectional thermal management system based on electrostatic spray according to an embodiment of the present application;

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

[0032] Figure 3 is a schematic diagram of an electrostatic spray heat exchange plate and its liquid supply mode according to an embodiment of the present application;

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

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

[0035] Figure 6 is a schematic diagram of a two-way thermal management system for power batteries based on electrostatic spray according to an embodiment of the present application.

[0036] In the figure: 1. Low-temperature liquid storage tank; 2. First liquid supply pump; 3. Heating subsystem liquid supply pipeline; 4. First electromagnetic valve; 5. Electrostatic spray heat exchange plate; 5-1. Liquid storage cavity; 5-2. Array nozzle; 5-3. Electrode plate; 5-4. Spray cavity; 5-5. High-thermal-conductivity insulation layer; 6. High-voltage electrostatic generator; 7. Power battery module; 8. Battery management system; 9. Controller; 10. Second electromagnetic valve; 11. High-temperature liquid return 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 electromagnetic valve; 18. Fourth electromagnetic valve; 19. Low-temperature liquid return pipeline; 20. Fourth liquid supply pump. DETAILED DESCRIPTION

[0037] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and letters in the drawing figures and the following description denote the same or like elements or components. The embodiments described below are exemplary and intended to explain the present application, and are not to be understood as limiting the present application.

[0038] In the description of the present application, it is to be understood by those ordinary skilled in the art that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0039] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the communication inside two elements. For those ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] Figure 1 A preferred embodiment of the electrostatic spray-based bidirectional thermal management system for power battery is shown, which 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.

[0041] The cooling subsystem comprises a low-temperature liquid storage tank 1, a first liquid supply pump 2, a cooling subsystem liquid supply pipeline 3 and a first electromagnetic valve 4. One end of the cooling subsystem liquid supply pipeline 3 is connected with the low-temperature liquid storage tank 1 through the first liquid supply pump 2, and the other end is connected with the first liquid inlet of the electrostatic spray heat exchange plate 5. The first electromagnetic valve 4 is arranged on the cooling subsystem liquid supply pipeline 3.

[0042] 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 electromagnetic valve 17. One end of the heating subsystem liquid supply pipeline 16 is connected with one end of the high-temperature liquid storage tank 13 through the third liquid supply pump 15, and the other end is connected with the second liquid inlet of the electrostatic spray heat exchange plate 5. The third electromagnetic valve 17 is arranged on the heating subsystem liquid supply pipeline 16.

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

[0044] The high-voltage electrostatic generator 6 is connected with the electrostatic spray heat exchange plate 5, and is used for realizing electrostatic atomization of the heat exchange working medium.

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

[0046] The battery management system 8 is connected with a plurality of temperature sensors arranged in the power battery module 7, the temperature sensors are used for monitoring real-time temperature information of the power battery module 7, and the real-time temperature information is transmitted to the battery management system 8, so that the real-time temperature information is monitored.

[0047] The controller 9 is connected with the high-voltage electrostatic generator 6, the battery management system 8, the first electromagnetic valve 4, the second electromagnetic valve 10, the third electromagnetic valve 17 and the fourth electromagnetic valve 18 respectively, and is used for regulating and controlling the liquid supply flow of the cooling and heating subsystem, controlling the high-voltage electrostatic generator 6 to charge the electrostatic spray heat exchange plate 5, so that the power battery module 7 is electrostatically sprayed, heated or cooled.

[0048] The electrostatic spray heat exchange plate 5 is a closed thin plate with a cavity structure, and is sequentially provided with a liquid storage cavity 5-1, a spray cavity 5-4 and a power battery module 7 placement cavity from outside to 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 communicated with the liquid storage cavity 5-1, an electrode plate 5-3 is arranged between the liquid storage cavity 5-1 and the spray cavity 5-4, the electrode plate 5-3 is connected with the high-voltage electrostatic generator 6, and is used for charging the array nozzle 5-2; a high-thermal-conductivity insulation layer 5-5 is arranged between the spray cavity 5-4 and the power battery module 7 placement cavity; the liquid outlet end of the plurality of array nozzles 5-2 faces the high-thermal-conductivity insulation layer 5-5; and the power battery module 7 is grounded for electrostatic protection.

[0049] The high-thermal-conductivity insulation layer 5-5 is a graphene material, which can effectively avoid the influence of a small amount of electric 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 with the metal electrode plate 5-3.

[0051] The array nozzle 5-2 is distributed in a rectangular array, and the interval between adjacent array nozzles is preferably suitable for better coverage of the spray on the heat exchange surface.

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

[0053] The high-temperature liquid tank 13 is provided with a PTC heater 14, and the PTC heater 14 is connected with the controller 9 and the battery thermal management system 8, and is used for temperature adjustment 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 tank 1 is used for storing low-temperature liquid; the first electromagnetic valve 4 is connected with the controller 9, and can timely regulate the liquid flow of the cooling subsystem to the electrostatic spray heat exchange plate 5 according to the battery temperature information monitored by the battery management system 8 in real time; the high-temperature liquid tank 13 is used for storing high-temperature liquid, and is provided with a PTC heater 14 and is subjected to heat preservation treatment, so as to realize temperature regulation of the heat exchange liquid; similarly, the third electromagnetic valve 17 is connected with the controller 9, and can timely regulate the liquid flow of the heating subsystem to the electrostatic spray heat exchange plate 5 according to the battery temperature information monitored by the battery management system 8 in real time.

[0055] The low-temperature liquid tank 1 and the high-temperature liquid tank 13 store heat exchange liquid; the heat exchange liquid is dielectric working medium such as oil and alcohol, and the electric conductivity range is 1x10 -6 -1x10 -4 S / m, and has a high boiling point, which is usually not less than 80 DEG 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 above, and the two liquid outlets are arranged below; when the cooling subsystem works, the low-temperature liquid in the low-temperature liquid tank 1 is fully heat exchanged with the power battery module 7, and the temperature of the low-temperature liquid is increased, and then the low-temperature liquid is recovered to the high-temperature liquid tank 13 through the lower high-temperature liquid return pipeline 11; when the heating subsystem works, the high-temperature liquid in the high-temperature liquid tank 13 is fully heat exchanged with the power battery module 7, and the temperature of the high-temperature liquid is decreased, and then the high-temperature liquid is recovered to the low-temperature liquid tank 1 through the lower low-temperature liquid return pipeline 19; this liquid supply mode can effectively improve the heat exchange efficiency of the thermal management system, thereby greatly saving the system energy consumption.

[0057] According to the embodiment, preferably, the array nozzle 5-2 is made of metal; the heating subsystem and the cooling subsystem have independent liquid storage and supply devices; the heat exchange liquid has an electrical conductivity ranging from 1x10 -6 -1x10 -4 S / m; the supply flow rate of the heat exchange liquid ranges from 0 to 0.25 L / min; the temperature control range of the PTC heater 14 is 30-60℃; the temperature measurement frequency of the battery management system 8 is 1-2 minutes; and the above parameter ranges are beneficial to realize the efficient heating and cooling performance of the bidirectional thermal management system of the power battery.

[0058] Figure 2 An embodiment of the internal heat exchange scheme of the electrostatic spraying heat exchange plate is shown. The electrostatic spraying heat exchange plate 5 is connected to a liquid supply pipeline, and the heat exchange liquid first enters a liquid storage cavity 5-1. A plurality of array nozzles 5-2 are arranged on the bottom surface of the liquid storage cavity 5-1 and are connected by an electrode plate 5-3. The electrode plate 5-3 is connected to a high-voltage electrostatic generator 6, thereby realizing uniform charging of the array nozzle. A graphene high-thermal-conductivity insulation layer 5-5 is arranged on the inner surface of the electrostatic spraying heat exchange plate 5, which can effectively avoid the influence of a small amount of electric charge on the power battery system while ensuring the heat exchange efficiency. The electrostatic spraying mode induced by the array nozzle 5-2 is a stable multi-jet mode, which can greatly improve the uniformity of the electrostatic spraying heat exchange.

[0059] According to the embodiment, preferably, the array nozzle 5-2 has a hole diameter ranging from 1 to 2 mm; the height of the liquid storage cavity 5-1 ranges from 20 to 40 mm; the height of the spraying cavity 5-4 ranges from 30 to 50 mm; and the total thickness of the electrostatic spraying heat exchange plate 5 is not more than 100 mm; and the above parameter ranges are beneficial to ensure the heat exchange efficiency and system integration of the electrostatic spraying heat exchange plate.

[0060] Figure 3 An embodiment of the electrostatic spraying heat exchange plate 5 and its liquid supply mode is shown. The electrostatic spraying heat exchange plate 5 has a three-enclosure structure, which covers the top surface and two side surfaces of the power battery module 7, thereby effectively avoiding the occurrence of local hot spots of the power battery module 7. When the cooling subsystem is working, the cooling liquid supply pipeline 3 pumps low-temperature liquid to the electrostatic spraying heat exchange plate 5, and the heat-exchanged liquid is recovered to a high-temperature liquid storage tank 13 through a low-temperature liquid recovery pipeline 11 below. When the heating subsystem is working, the heating liquid supply pipeline 16 pumps low-temperature liquid to the electrostatic spraying heat exchange plate 5, and the heat-exchanged liquid is recovered to the high-temperature liquid storage tank 1 through a low-temperature liquid recovery pipeline 19 below.

[0061] Figure 4 and Figure 5As shown, it is an embodiment of the top surface and side nozzle array scheme of the electrostatic spray heat exchange plate 5, the array nozzles 5-2 are distributed in a rectangular array; the aperture range of the array nozzles 5-2 is 1-2mm, on the one hand, to avoid the increase of flow resistance caused by too small aperture, on the other hand, to avoid the uneven flow distribution of each array nozzle caused by too large aperture.

[0062] According to the embodiment, preferably, the distance between the adjacent array nozzles 5-2 is not more than 100mm; the aperture range of the array nozzles 5-2 is 1-2mm, which is beneficial to the electrostatic spray to cover the bottom heat exchange surface well and greatly improve the utilization rate of the heat exchange working medium based on the above parameter range.

[0063] The battery management system 8 of the application is connected with the temperature sensor in the power battery module 7, monitors the real-time temperature information of the power battery module 7, and the heating subsystem and the cooling subsystem share the electrostatic spray heat exchange plate 5; the controller 9 judges 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 electromagnetic valve, the high-voltage electrostatic generator 6 and the PTC heater 14. The application proposes an electrostatic spray integrated solution that can solve the heating and cooling problems of the power battery at the same time, greatly improves the system heat exchange efficiency and space utilization, significantly improves the heat exchange uniformity, and finally realizes the efficient and low-cost bidirectional thermal management of the power battery.

[0064] In combination with Figure 6 As shown, a control method of the bidirectional thermal management system of the power battery based on the electrostatic spray, comprising the following steps:

[0065] First, inject appropriate amount of heat exchange liquid into the low-temperature liquid tank 1 and the high-temperature liquid tank 13 respectively, open 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 electromagnetic valve 4, the second electromagnetic valve 10, the third electromagnetic valve 17 and the fourth electromagnetic valve 18 in the closed state;

[0066] The battery management system 8 is always in working state. The temperature sensor built-in the power battery module 7 monitors the real-time temperature information of the power battery module 7 and transmits to the battery management system 8. When the battery management system 8 monitors that the temperature of the power battery module 7 exceeds the preset upper limit of the suitable working temperature (about 30℃), the controller 9 opens the first electromagnetic 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 opens 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 cooling on the power battery module 7; the second electromagnetic valve 10 works synchronously with the first electromagnetic valve 4, and the liquid after heat exchange in the electrostatic spray heat exchange plate 5 is recovered to the high-temperature liquid storage tank 13 through the high-temperature liquid recovery pipeline 11; when the temperature of the power battery module 7 decreases to the preset threshold value, the controller 9 closes the first electromagnetic valve 4, the second electromagnetic valve 10 and the high-voltage electrostatic generator 6, and the cooling subsystem stops working.

[0067] When the battery management system 8 monitors that the temperature of the power battery module 7 is lower than the preset lower limit of the suitable working temperature (about 10℃), the controller 9 opens the third electromagnetic 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 temperature of the liquid in the high-temperature liquid storage tank 13 remains constant; the controller 9 opens 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 electromagnetic valve 18 works synchronously with the third electromagnetic valve 17, and the liquid after heat exchange in the electrostatic spray heat exchange plate 5 is recovered to the low-temperature liquid storage tank 1 through the low-temperature liquid recovery pipeline 19; when the temperature of the power battery module 7 rises to the preset threshold value, the controller 9 closes the fourth electromagnetic valve 18 and the third electromagnetic valve 17 and the high-voltage electrostatic generator 6, and the heating subsystem stops working.

[0068] When the cooling subsystem works, the controller 9 controls the low-temperature liquid supply pipeline 3 and the high-temperature liquid recovery pipeline 11 to be opened, and the high-temperature liquid supply pipeline 16 and the low-temperature liquid recovery pipeline 19 to be closed.

[0069] When the heating subsystem works, the controller 9 controls the high-temperature liquid supply pipeline 16 and the low-temperature liquid recovery pipeline 19 to be opened, and the low-temperature liquid supply pipeline 3 and the high-temperature liquid recovery pipeline 11 to be closed.

[0070] The above steps are repeated. Based on the real-time temperature distribution of the power battery, the system can automatically open the cooling subsystem or the heating subsystem to timely perform electrostatic spray thermal management on the power battery module 7, so as to ensure that the power battery is always in the suitable working temperature range of 10-30℃, and finally realize efficient bidirectional thermal management of the power battery module.

[0071] The electrostatic spray-based bidirectional thermal management system of the power battery is particularly suitable for temperature control of high-performance new energy vehicle power batteries. Advantages of the electrostatic spray-based bidirectional thermal management system of the power battery lie in that the heating and cooling systems are highly integrated, the heat exchange efficiency and space utilization of the system are greatly improved, the heat exchange uniformity of the system is significantly improved through electrostatic spray atomization of the heat exchange working medium, the heating subsystem and the cooling subsystem share the electrostatic spray heat exchange plate, the liquid working medium after heat exchange is recycled in a directional manner, and the energy consumption of the system is greatly saved. Based on the above scheme, efficient and low-cost bidirectional thermal management of the power battery is finally achieved.

[0072] It should be understood that, although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0073] The above series of detailed descriptions are only specific descriptions of feasible embodiments of the present application, and are not intended to limit the protection scope of the present application. Any equivalent embodiments or changes made without departing from the spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A bidirectional thermal management system for electrostatic spray based power battery, characterized in that, The cooling subsystem, the heating subsystem, the electrostatic spray heat exchange plate (5), the high-voltage electrostatic generator (6), the power battery module (7), the battery management system (8) and the controller (9); The cooling subsystem comprises a low-temperature liquid storage tank (1), a first liquid supply pump (2), a cooling subsystem liquid supply pipeline (3) and a first electromagnetic valve (4); one end of the cooling subsystem liquid supply pipeline (3) is connected with the low-temperature liquid storage tank (1) through the first liquid supply pump (2), and the other end is connected with a first liquid inlet of the electrostatic spray heat exchange plate (5); and the first electromagnetic valve (4) is arranged on the cooling subsystem liquid supply pipeline (3). 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 electromagnetic valve (17); one end of the heating subsystem liquid supply pipeline (16) is connected with one end of the high-temperature liquid storage tank (13) through the third liquid supply pump (15), and the other end is connected with a second liquid inlet of the electrostatic spray heat exchange plate (5); and the third electromagnetic valve (17) is arranged on the heating subsystem liquid supply pipeline (16). The electrostatic spray heat exchange plate (5) is provided below with a high-temperature liquid return pipeline (11) and a low-temperature liquid return pipeline (19); one end of the high-temperature liquid return pipeline (11) is connected with a second liquid outlet of the electrostatic spray heat exchange plate (5), and the other end is connected with the high-temperature liquid storage tank (13) through a second liquid supply pump (12); the second electromagnetic valve (10) is arranged on the high-temperature liquid return pipeline (11); one end of the low-temperature liquid return pipeline (19) is connected with a first liquid outlet of the electrostatic spray heat exchange plate (5), and the other end is connected with the low-temperature liquid storage tank (1) through a fourth liquid supply pump (20); and the fourth electromagnetic valve (18) is arranged on the low-temperature liquid return pipeline (19). The high-voltage electrostatic generator (6) is connected with the electrostatic spray heat exchange plate (5). The power battery module (7) is arranged in a structure surrounded by the electrostatic spray heat exchange plate (5) and is tightly connected through a high-thermal-conductivity insulating material. The battery management system (8) is connected with a temperature sensor arranged in the power battery module (7); the temperature sensor is used for monitoring real-time temperature information of the power battery module (7) and transmitting the real-time temperature information to the battery management system (8). The controller (9) is connected with the high-voltage electrostatic generator (6), the battery management system (8), the first electromagnetic valve (4), the second electromagnetic valve (10), the third electromagnetic valve (17) and the fourth electromagnetic valve (18) respectively, and is used for regulating and controlling liquid supply flow of the cooling and heating subsystems, controlling the high-voltage electrostatic generator (6) to charge the electrostatic spray heat exchange plate (5), so that the power battery module (7) is electrostatically sprayed, heated or cooled.

2. The electrostatic spray based bidirectional thermal management system of power batteries according to claim 1, characterized in that, The electrostatic spray heat exchange plate (5) is sequentially provided, from outside to inside, with a liquid storage cavity (5-1), a spraying cavity (5-4) and a cavity for placing the power battery module (7). 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) communicates with the liquid storage cavity (5-1), and an electrode plate (5-3) is arranged between the liquid storage cavity (5-1) and the spray cavity (5-4), the electrode plate (5-3) is connected with a high-voltage electrostatic generator (6) and used for charging the array nozzle (5-2); a high-thermal-conductivity insulation layer (5-5) is arranged between the spray cavity (5-4) and the power battery module (7) placement cavity; the liquid outlet end of the plurality of array nozzles (5-2) faces the high-thermal-conductivity insulation layer (5-5); and the power battery module (7) is grounded.

3. The electrostatic spray based bidirectional thermal management system of power batteries according to claim 2, characterized in that, The high-thermal-conductivity insulation layer (5-5) is made of graphene material.

4. The electrostatic spray based bidirectional thermal management system of power battery of claim 2, wherein, The array nozzle (5-2) is made of metal material and has a pore size ranging from 1 mm to 2 mm.

5. The electrostatic spray based bidirectional thermal management system for power batteries of claim 1, wherein, The high-temperature liquid storage tank (13) is provided with a PTC heater (14), the PTC heater (14) is connected with a controller (9) and a battery management system (8) and used for temperature adjustment of the liquid working medium.

6. The electrostatic spray-based bidirectional thermal management system of power batteries according to claim 1, characterized in that, The low-temperature liquid tank (1) and the high-temperature liquid tank (13) contain heat exchange liquid; the heat exchange liquid is dielectric working medium, and the electric conductivity ranges from 1×10 -6 -1×10 -4 S / m.

7. The electrostatic spray-based bidirectional thermal management system of power batteries according to claim 1, characterized in that, The spray heat exchange plate (5) has a three-enclosure structure and covers the top surface and two side surfaces of the power battery module (7).

8. A control method of the electrostatic spray-based bidirectional thermal management system of power batteries according to any one of claims 1-7, characterized in that, The method comprises the following steps: The temperature sensor built in the power battery module (7) monitors real-time temperature information of the power battery module (7) and transmits the information to the battery management system (8), when the battery management system (8) monitors that the temperature of the power battery module (7) exceeds a preset upper limit of working temperature, the controller (9) opens the first electromagnetic 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) opens the high-voltage electrostatic generator (6) to charge the array nozzle (5-2) of the electrostatic spray heat exchange plate (5) and to perform electrostatic spray cooling on the power battery module (7); the second electromagnetic valve (10) and the first electromagnetic valve (4) keep a synchronous working state, the liquid after heat exchange in the electrostatic spray heat exchange plate (5) is recovered to the high-temperature liquid storage tank (13) through the high-temperature liquid recovery pipeline (11); when the temperature of the power battery module (7) drops to a preset threshold value, the controller (9) closes the first electromagnetic valve (4), the second electromagnetic valve (10) and the high-voltage electrostatic generator (6), and the cooling subsystem stops working. When the battery management system (8) monitors that the temperature of the power battery module (7) is lower than the lower limit of the preset working temperature, the controller (9) opens the third electromagnetic valve (17), 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 temperature of the liquid in the high-temperature liquid storage tank (13) remains constant; the controller (9) opens the high-voltage electrostatic generator (6) to charge the array nozzles (5-2) of the electrostatic spray heat exchange plate (5), and electrostatically sprays and heats the power battery module (7); the fourth electromagnetic valve (18) and the third electromagnetic valve (17) are kept in a synchronous working state, and the heat-exchanged liquid in the electrostatic spray heat exchange plate (5) is recovered 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 the preset threshold value, the controller (9) closes the fourth electromagnetic valve (18) and the third electromagnetic valve (17) and the high-voltage electrostatic generator (6), and the heating subsystem stops working.

9. The control method of the electrostatic spray-based bidirectional thermal management system of power batteries according to claim 8, characterized in that, When the cooling subsystem works, the controller (9) controls the low-temperature liquid supply pipeline (3) and the high-temperature liquid return pipeline (11) to be opened, and the high-temperature liquid supply pipeline (16) and the low-temperature liquid return pipeline (19) to be closed.

10. The control method of the electrostatic spray-based bidirectional thermal management system of power batteries according to claim 8, characterized in that, When the heating subsystem works, the controller (9) controls the high-temperature liquid supply pipeline (16) and the low-temperature liquid return pipeline (19) to be opened, and the low-temperature liquid supply pipeline (3) and the high-temperature liquid return pipeline (11) to be closed.

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