High-energy-efficiency energy storage heat management system and method based on electrostatic spraying

Abstract

The invention provides a high-energy-efficiency energy storage heat management system and method based on an electrostatic spraying technology. The high-energy-efficiency energy storage heat management system comprises a liquid storage tank, a liquid supply pump, an energy storage battery box, a liquid supply pipeline, a liquid flow divider, a high-voltage electrostatic generator, an electrostatic spraying cavity, an array nozzle, a liquid cooling plate, a thermocouple, a temperature data acquisition instrument, a controller, a battery module, a liquid return pipeline and a heat exchanger. The high-voltage electrostatic generator is connected with an array nozzle arranged in the electrostatic spraying cavity; a plurality of array temperature thermocouples are arranged in the liquid cooling plate; the temperature data acquisition instrument is connected with the plurality of array thermocouples; and the controller controls the liquid flow divider, the high-voltage electrostatic generator and the array nozzles to work according to the temperature signal. The electrostatic spray cooling and the liquid cooling plate technology are combined, the cooling and heat dissipation capacity of the energy storage heat management system is greatly improved, the utilization rate of cooling liquid is improved, system energy consumption is effectively reduced, the cooling and heat exchange efficiency is improved, and finally high-energy-efficiency energy storage system heat management is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage thermal management, and in particular relates to a high-efficiency energy storage thermal management system and method based on electrostatic spray technology. Background Art

[0002] New energy storage is developing rapidly, and the temperature control of energy storage batteries is crucial. During the charging and discharging process of energy storage batteries, a large amount of heat will be generated while the electrochemical reaction occurs inside, which will cause the battery temperature to rise. For lithium batteries, the optimal operating temperature range is 10-35°C. Too high or too low temperature will affect the battery's charging and discharging performance and service life, and even cause thermal runaway and safety accidents. Studies have shown that thermal runaway caused by internal battery cell failure is the main cause of safety accidents in energy storage systems. Therefore, efficient thermal management of energy storage batteries is the key to ensuring the safe and stable operation of energy storage systems.

[0003] At present, the mainstream energy storage thermal management technologies mainly include air cooling and liquid cooling. Air cooling uses air as a heat exchange medium, and removes heat by flowing air between battery modules. According to the power source of air flow, it can generally be divided into active air cooling and passive air cooling. However, due to the limitations of air's low specific heat capacity and thermal conductivity, air cooling is difficult to meet the high heat flux density heat dissipation scenario, and the active air cooling process is usually accompanied by large noise, which greatly limits the application of this technology. Liquid cooling technology uses coolants such as water and alcohol as heat exchange medium, and its heat dissipation capacity is greatly improved compared to air cooling, and it has great development potential in the field of energy storage thermal management. According to whether the coolant is in direct contact with the battery, liquid cooling can be further divided into direct liquid cooling and indirect liquid cooling, and the corresponding typical technical solutions are immersion liquid cooling and liquid cooling plate. At this stage, as energy storage systems continue to develop towards high power, large capacity, and high integration, although liquid cooling technology can meet the high heat flux density heat dissipation needs to a certain extent, due to the limitations of complex system structure, high operating costs, and low working fluid utilization, its large-scale promotion and application still have many challenges. Summary of the invention

[0004] In response to the above technical problems, the present invention provides a high-efficiency energy storage thermal management system and method based on electrostatic spraying, which greatly improves the cooling and heat dissipation capacity of the energy storage thermal management system, improves the utilization rate of the coolant, effectively saves system energy consumption, improves the cooling and heat exchange efficiency, and ultimately realizes high-efficiency energy storage system thermal management.

[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 high-efficiency energy storage thermal management system based on electrostatic spraying, comprising a liquid storage tank, a liquid supply pump, an energy storage battery box, a liquid supply pipeline, a liquid diverter, a high-voltage electrostatic generator, an electrostatic spray chamber, an array nozzle, a liquid cooling plate, a thermocouple, a temperature data acquisition instrument, a controller, a battery module, a liquid return pipeline and a heat exchanger;

[0008] The liquid storage tank is placed outside the energy storage battery box and is used for storing and recovering the coolant; a plurality of battery modules are arranged in the energy storage battery box; a liquid cooling plate and an electrostatic spray chamber are arranged on the upper surface of the battery module to form a combined upper cooling structure; a liquid cooling plate and an electrostatic spray chamber are also arranged on the lower surface of the battery module to form a combined lower cooling structure; an array nozzle is arranged in the electrostatic spray chamber, and the spray droplets of the array nozzle can be sprayed onto the surface of the liquid cooling plate for local cooling; the liquid supply pump is connected to the liquid storage tank and the liquid diverter through a liquid supply pipeline; the electrostatic spray chamber of the upper cooling structure and the lower cooling structure and the coolant inlet of the liquid cooling plate are connected to the liquid diverter, and the electrostatic spray chamber and the liquid cooling plate are connected to the liquid diverter. The plate cooling liquid outlet is respectively connected to one end of the liquid return pipeline, the other end of the liquid return pipeline is connected to the liquid storage tank, and a heat exchanger is arranged in the liquid return pipeline; the high-voltage electrostatic generator is connected to the array nozzle arranged in the electrostatic spray chamber; the liquid cooling plate is built with a plurality of array temperature measuring thermocouples and grounded; the temperature data acquisition instrument is connected to a plurality of array thermocouples to detect the temperature of the thermocouples and send the temperature signal to the controller; the controller is respectively connected to the temperature data acquisition instrument, the liquid diverter, the high-voltage electrostatic generator and the array nozzle; the controller controls the operation of the liquid diverter, the high-voltage electrostatic generator and the array nozzle according to the temperature signal.

[0009] In the above solution, the liquid supply pump is a non-metallic gear pump.

[0010] In the above solution, the array nozzle is made of metal conductive material, and the atomization cone angle is less than 90°.

[0011] In the above scheme, the array nozzles are distributed in a rectangular array, and the distance between adjacent array nozzles ranges from 50 to 100 mm.

[0012] In the above solution, the distance between the array nozzle and the relative outer surface of the liquid cooling plate is in the range of 10-15 mm.

[0013] In the above scheme, the array nozzles are respectively provided with solenoid valves, which are connected to the controller; each array nozzle and array thermocouple are numbered, and the position of the array nozzle corresponds to the array thermocouple in terms of spatial position, quantity and number, and the spatial position and number of the array nozzle and the array thermocouple 8-2 are set in the controller.

[0014] In the above scheme, the electrostatic spray chamber is connected to the liquid cooling plate and shares a heat sink. A high thermal conductivity insulating layer is arranged between the heat sink and the battery module. The thickness of the high thermal conductivity insulating layer does not exceed 10 mm to eliminate the influence of a small amount of charge in the coolant on the energy storage system.

[0015] In the above solution, the outer surface of the liquid cooling plate opposite to the array nozzles is provided with micro drainage grooves.

[0016] In the above scheme, the thermal management system dissipates heat from the upper and lower surfaces of the battery module at the same time, and the upper and lower surfaces adopt a countercurrent liquid supply method: the liquid supply pipeline is divided into two paths including a first liquid supply pipeline and a second liquid supply pipeline, and one end of the liquid return pipeline is divided into two paths including a first liquid return pipeline and a second liquid return pipeline; the upper cooling structure and the lower cooling structure are respectively provided with a liquid diverter;

[0017] The first liquid supply pipeline is respectively connected to the liquid diverter of the cooling structure on the battery module, and the first liquid return pipeline is respectively connected to the electrostatic spray chamber of the cooling structure on the battery module and the cooling liquid outlet of the liquid cooling plate;

[0018] The second liquid supply pipeline is respectively connected to the liquid diverter of the cooling structure under the battery module, and the second liquid return pipeline is respectively connected to the electrostatic spray chamber of the cooling structure under the battery module and the cooling liquid outlet of the liquid cooling plate.

[0019] A control method for a high-efficiency energy storage thermal management system based on electrostatic spraying comprises the following steps:

[0020] When the thermocouple detects that the temperature of a local area exceeds the preset threshold, the controller will turn on the high-voltage electrostatic generator to apply voltage to the array nozzle corresponding to the local overheating area, and at the same time turn on the liquid supply pump to supply liquid to the liquid supply pipeline. According to the temperature signal collected by the temperature data acquisition instrument, the liquid diverter is controlled to supply liquid to the specified array nozzle, and the coolant is sprayed to the local hot spot area to achieve targeted cooling of the battery module.

[0021] When the thermocouple detects that the temperature of a large area rises, the controller turns on the liquid supply pump to supply liquid to the liquid supply pipeline, and controls the liquid diverter to supply liquid to the liquid cooling plate. At the same time, the liquid supply flow of the liquid diverter is controlled according to the temperature signal characteristics collected by the temperature data acquisition instrument to achieve overall cooling of the battery module.

[0022] When the thermocouple detects that the battery temperature rises rapidly and the temperature of multiple areas exceeds the preset threshold, the controller turns on the liquid supply pump to supply liquid to the liquid supply pipeline, and controls the liquid diverter to supply liquid to the liquid cold plate and the array nozzles corresponding to the overheating area at the same time, and controls the high-voltage electrostatic generator to perform electrostatic spraying on the overheating area, so as to achieve extremely fast cooling of the battery module;

[0023] The coolant flowing through the electrostatic spray chamber and the liquid cooling plate finally enters the liquid return pipeline, is cooled by the heat exchanger, and is recovered to the liquid storage tank for recycling by the heat management system.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention combines electrostatic spray cooling and liquid cooling plate technology, which can greatly improve the cooling and heat dissipation capacity of the energy storage thermal management system; the real-time temperature distribution of the battery module can be obtained by built-in multiple array thermocouples, and the optimal cooling scheme and liquid supply flow rate are determined according to the specific temperature distribution characteristics, avoiding excessive use of coolant and ineffective coverage, and greatly improving the utilization rate of the coolant; at the same time, compared with the traditional atomization method, electrostatic spraying can effectively save system energy consumption, and the electric field acceleration effect can effectively enhance the impact and disturbance of the spray droplets on the heat sink, thereby improving the cooling and heat exchange efficiency; in addition, the thermal management system and the battery module work independently of each other, and the two are isolated by high thermal conductivity insulating materials, which effectively avoids the risk of leakage and the influence of a small amount of free charge on the stability of the energy storage system; based on the above characteristics, high-efficiency energy storage system thermal management is ultimately achieved.

[0026] 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

[0027] Figure 1 It is a schematic structural diagram of a high-efficiency energy storage thermal management system based on electrostatic spraying according to one embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of a combination scheme of electrostatic spray and liquid cooling plate according to one embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of an electrostatic atomization nozzle and a temperature measuring thermocouple array scheme according to an embodiment of the present invention;

[0030] Figure 4 It is a schematic diagram of the division of electrostatic spray heat dissipation areas of a battery module according to an embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the division of the heat dissipation area of ​​the battery module liquid cooling plate according to an embodiment of the present invention.

[0032] In the figure: 1. Liquid storage tank; 2. Liquid supply pump; 3. Energy storage battery box; 4. Liquid supply pipeline; 5. Liquid diverter; 6. High-voltage electrostatic generator; 7. Electrostatic spray chamber; 7-1. Array nozzle; 8. Liquid cooling plate; 8-1. Heat sink; 8-2. Thermocouple; 8-3. High thermal conductivity insulating layer; 9. Temperature data acquisition instrument; 10. Controller; 11. Battery module; 12. Liquid return pipeline; 13. Heat exchanger. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Figure 1The figure shows a preferred embodiment of the high-efficiency energy storage thermal management system based on electrostatic spraying of the present invention, which comprises a liquid storage tank 1, a liquid supply pump 2, an energy storage battery box 3, a liquid supply pipeline 4, a liquid diverter 5, a high-voltage electrostatic generator 6, an electrostatic spray chamber 7, an array nozzle 7-1, a liquid cooling plate 8, a thermocouple 8-2, a temperature data acquisition instrument 9, a controller 10, a battery module 11, a liquid return pipeline 12 and a heat exchanger 13;

[0037] The liquid storage tank 1 is placed outside the energy storage battery box 3 and is used for storing and recovering the cooling liquid; a plurality of battery modules 11 are arranged in the energy storage battery box 3, and the battery module 11 is the basic battery cell unit in the energy storage battery box; a liquid cooling plate 8 and an electrostatic spray chamber 7 are arranged on the upper surface of the battery module 11 to form a combined upper cooling structure; a liquid cooling plate 8 and an electrostatic spray chamber 7 are also arranged on the lower surface of the battery module 11 to form a combined lower cooling structure; an array nozzle 7-1 is arranged in the electrostatic spray chamber 7, and the spray droplets of the array nozzle 7-1 can be sprayed onto the surface of the liquid cooling plate 8 for local cooling; the liquid supply pump 2 is connected to the liquid storage tank 1 and the liquid diverter 5 through the liquid supply pipeline 4, and the liquid storage tank 1 supplies liquid to the electrostatic spray chamber 7 and the liquid cooling plate 8; the cooling liquid inlet of the electrostatic spray chamber 7 and the liquid cooling plate 8 of the upper cooling structure and the lower cooling structure is connected to the liquid diverter 5, and the liquid diverter 5 is used for controlling and distributing the cooling liquid flow, and the electrostatic spray The cooling liquid outlets of the mist chamber 7 and the liquid cooling plate 8 are respectively connected to one end of the return liquid pipeline 12, the other end of the return liquid pipeline 12 is connected to the liquid storage tank 1, and a heat exchanger 13 is arranged in the return liquid pipeline 12, and the heat exchanger 13 is installed in the return liquid pipeline 4, and is used to cool the working medium; the high-voltage electrostatic generator 6 is connected to the array nozzle 7-1 arranged in the electrostatic spray chamber 7, and the liquid cooling plate 8 has a plurality of array temperature measuring thermocouples 8-2 built in and is grounded for electrostatic atomization of the cooling working medium; the temperature data acquisition instrument 9 is connected to a plurality of array thermocouples 8-2, and is used to detect the temperature of the thermocouples 8-2 and send the temperature signal to the controller 10; the controller 10 is respectively connected to the temperature data acquisition instrument 9, the liquid diverter 5, the high-voltage electrostatic generator 6 and the array nozzle 7-1; the controller 10 controls the operation of the liquid diverter 5, the high-voltage electrostatic generator 6 and the array nozzle 7-1 according to the temperature signal.

[0038] The present invention combines electrostatic spray cooling and traditional liquid cooling plate technology, and adjusts the cooling scheme based on the real-time monitored battery temperature distribution characteristics through the controller 10, wherein the electrostatic spray chamber 7 and the liquid cooling plate 8 share the liquid supply pipeline 4 and the heat sink 8-1, and a plurality of array nozzles 7-1 can work independently. At the same time, a plurality of array thermocouples 8-2 are placed inside the heat sink 8-1 for battery module 11 temperature monitoring.

[0039] The liquid supply flow of the electrostatic spray chamber 7 and the liquid cooling plate 8 is controlled by the front liquid diverter 5, and the liquid diverter 5 is connected to the controller 10, and the controller 10 is connected to the temperature data acquisition instrument 9; the temperature data acquisition instrument 9 is connected to a plurality of array thermocouples 8-2, and the real-time temperature distribution of the battery module 11 can be obtained; during operation, the controller 10 controls the liquid diverter 5 to supply liquid to the electrostatic spray chamber 7 and the liquid cooling plate 8 respectively according to the received temperature signal, which is conducive to formulating the optimal cooling scheme for different working conditions, thereby realizing the efficient utilization of the cooling liquid and the high energy efficiency of the system.

[0040] The liquid storage tank 1 and the energy storage battery box are both grounded.

[0041] The liquid supply pump 2 is a non-metallic gear pump, which can effectively avoid the influence of a small amount of free charge on the energy storage system while ensuring the flow accuracy.

[0042] The array nozzles 7-1 are respectively provided with electromagnetic valves, which are connected to the controller 10; each array nozzle 7-1 and array thermocouple 8-2 are numbered, and the position of the array nozzle 7-1 corresponds to the array thermocouple 8-2 in terms of spatial position, quantity and number, and the spatial position and number of the array nozzle 7-1 and the array thermocouple 8-2 are set in the controller 10. The plurality of array nozzles 7-1 can work independently to achieve targeted spray cooling in a local area.

[0043] The electrostatic spray chamber 7 is connected to the liquid cooling plate 8 and shares a heat sink 8-1. The liquid cooling plate 8 and the electrostatic spray chamber 7 heat sink, that is, the heat sink of the liquid cooling plate 8, also serve as a heat sink for electrostatic spray cooling. A plurality of temperature measuring thermocouples 8-2 are arranged inside the heat sink 8-1. The array nozzles 7-1 and the thermocouples 8-2 are both distributed in a rectangular array, covering the entire heat sink 8-1. A high thermal conductivity insulating layer 8-3, such as alumina ceramics, boron nitride ceramics, etc., is arranged between the heat sink 8-1 and the battery module 11. The thickness of the high thermal conductivity insulating layer 8-3 does not exceed 10mm, so as to eliminate the influence of a small amount of charge in the coolant on the energy storage system. The array nozzles 7-1 are made of metal conductive material, and the atomization cone angle is less than 90°. The array nozzles 7-1 are distributed in a rectangular array, and the spacing between adjacent array nozzles 7-1 ranges from 50 to 100mm. The specific number of nozzles depends on the size of the battery module. Based on the above parameter range, it is beneficial to ensure the heat dissipation effect of the energy storage thermal management system.

[0044] The high-voltage electrostatic generator 6 is connected to the array nozzle 7-1, and the heat sink 8-1 is grounded, thereby forming a strong non-uniform electric field between the two. The shearing effect of the electric field force can fully atomize the coolant flowing through the array nozzle 7-1; during operation, according to the specific temperature distribution, the controller 10 will control the high-voltage electrostatic generator 6 to apply voltage to a specific array nozzle 7-1, thereby achieving targeted and precise spray cooling in the local overheating area.

[0045] The array nozzle 7-1 and the heat sink 8-1 are respectively connected to a high voltage electrostatic generator 6 and grounded. The voltage range of the high voltage electrostatic generator 6 can be 0-30 kV.

[0046] The coolant in the electrostatic spray chamber 7 and the liquid cooling plate 8 is not in direct contact with the battery module, but is connected via a high thermal conductivity insulating layer 8-3, which can effectively avoid the risk of leakage and the influence of a small amount of free charge while ensuring the thermal conductivity efficiency.

[0047] The liquid supply pipeline 4 has good sealing performance and is provided with a safety valve.

[0048] The liquid supply pipeline 4 and the liquid return pipeline 12 have good sealing properties, which can meet the pressure increase caused by the vaporization of a small amount of coolant due to heat. At the same time, a heat exchanger 13 is provided in the liquid return pipeline 12, and a fan can be used to accelerate the heat exchange between the coolant and the environment, thereby ensuring the circulation cooling efficiency of the thermal management system. In the above scheme, the outer surface of the liquid cooling plate 8 opposite to the array nozzle 7-1 is provided with a micro drainage groove. Preferably, the surface of the heat sink 8-1 is provided with a micro drainage groove for strengthening the heat exchange process in the electrostatic spray chamber 7 and recovering the coolant.

[0049] The liquid supply pipeline 4 is arranged on both sides of the battery module 11, wherein the cooling structure installed on the upper surface supplies liquid from left to right, while the cooling structure installed on the lower surface supplies liquid from right to left, so that the liquid supply on the upper and lower surfaces of the battery module 11 is in a countercurrent state, so as to fully improve the cooling and heat dissipation efficiency.

[0050] Preferably, the thermal management system dissipates heat from the upper and lower surfaces of the battery module 11 simultaneously, and a countercurrent liquid supply method is adopted for the upper and lower surfaces: the liquid supply pipeline 4 is divided into two paths including a first liquid supply pipeline and a second liquid supply pipeline, and one end of the liquid return pipeline 12 is divided into two paths including a first liquid return pipeline and a second liquid return pipeline; the upper cooling structure and the lower cooling structure are respectively provided with a liquid diverter 5; the first liquid supply pipeline is respectively connected to the liquid diverter 5 of the upper cooling structure of the battery module 11, and the first liquid return pipeline is respectively connected to the electrostatic spray chamber 7 of the upper cooling structure of the battery module 11 and the cooling liquid outlet of the liquid cooling plate 8; the second liquid supply pipeline is respectively connected to the liquid diverter 5 of the lower cooling structure of the battery module 11, and the second liquid return pipeline is respectively connected to the electrostatic spray chamber 7 of the lower cooling structure of the battery module 11 and the cooling liquid outlet of the liquid cooling plate 8.

[0051] Figure 2 The figure shows an implementation of the electrostatic spray and liquid cooling plate combination scheme of the present invention, wherein the electrostatic spray chamber 7 covers the upper surface of the liquid cooling plate 8, and the lower surface of the liquid cooling plate 8 is closely connected to the battery module 11 through a high thermal conductivity insulating thin layer 8-3. When the electrostatic spray chamber 7 works alone, the liquid cooling plate 8 will serve as a heat sink for the electrostatic spray chamber, transferring heat from the battery module 11 to the upper surface of the liquid cooling plate 8, and then achieve local cooling during the continuous impact of the spray droplets in the electrostatic spray chamber 7. When the liquid cooling plate 8 starts to work, the coolant starts to flow inside the liquid cooling plate 8. At this time, the heat is first transferred from the battery module 11 to the metal heat sink of the liquid cooling plate 8, and then transferred from the metal heat sink to the cooling liquid flowing inside to achieve cooling. When the electrostatic spray chamber 7 and the liquid cooling plate 8 work at the same time, part of the heat will be transferred from the upper surface of the liquid cooling plate 8 through the electrostatic spray droplets, and part of the heat will be transferred through the cooling liquid flowing in the liquid cooling plate. The cooling liquid in the electrostatic spray chamber 7 and the liquid cooling plate 8 on the upper and lower surfaces of the battery module 11 is configured to be supplied in a countercurrent manner, so as to fully improve the temperature uniformity and cooling and heat dissipation efficiency of the battery module 11 .

[0052] According to this embodiment, preferably, the distance from the array nozzle 7 - 1 to the upper surface of the liquid cooling plate 8 should be controlled within a range of 10-15 mm to avoid breakdown while ensuring the charging effect.

[0053] Figure 3 The figure shows an implementation mode of the array nozzle 7-1 and the temperature measuring thermocouple 8-2 array scheme of the present invention, wherein the array nozzle 7-1 is distributed in a rectangular array and can completely cover the upper surface of the liquid cooling plate 8; the liquid cooling plate 8 has a plurality of array thermocouples 8-2 built therein, which are also distributed in a rectangular array; the array nozzle 7-1 and the temperature measuring thermocouple 8-2 are numbered so that the two are in a one-to-one correspondence, thereby realizing global temperature monitoring of the battery module 11 and targeted and precise heat dissipation in local areas.

[0054] According to this embodiment, preferably, the spacing between adjacent array nozzles 7-1 should be within the range of 50-100 mm, which is conducive to ensuring that the spray range can cover the entire upper surface of the liquid cooling plate 8, while avoiding electrostatic interference between adjacent nozzles due to too close distance, thereby affecting the atomization effect.

[0055] A control method for a high-efficiency energy storage thermal management system based on electrostatic spraying comprises the following steps:

[0056] When the thermocouple 8-2 detects that the temperature of a local area exceeds a preset threshold, the controller 10 turns on the high-voltage electrostatic generator 6 to apply voltage to the array nozzle 7-1 corresponding to the local overheating area, and turns on the liquid supply pump 2 to supply liquid to the liquid supply pipeline 4. According to the temperature signal collected by the temperature data acquisition instrument 9, the liquid diverter 5 is controlled to supply liquid to the designated array nozzle 7-1, and the coolant is sprayed to the local hot spot area to achieve targeted cooling of the battery module 11;

[0057] When the thermocouple 8-2 detects that the temperature of a large area rises, the controller 10 turns on the liquid supply pump 2 to supply liquid to the liquid supply pipeline 4, and controls the liquid diverter 5 to supply liquid to the liquid cooling plate 8. At the same time, the liquid supply flow rate of the liquid diverter 5 is controlled according to the temperature signal characteristics collected by the temperature data acquisition instrument 9, so as to achieve overall cooling of the battery module 11;

[0058] When the thermocouple 8-2 detects that the battery temperature rises rapidly and the temperature of multiple areas exceeds the preset threshold, the controller 10 turns on the liquid supply pump 2 to supply liquid to the liquid supply pipeline 4, and controls the liquid diverter 5 to simultaneously supply liquid to the liquid cooling plate 8 and the array nozzle 7-1 corresponding to the overheating area, and at the same time controls the high-voltage electrostatic generator 6 to perform electrostatic spraying on the overheating area, so as to achieve extremely rapid cooling of the battery module 11;

[0059] The cooling liquid flowing through the electrostatic spray chamber 7 and the liquid cooling plate 8 finally enters the liquid return pipeline 12, and is recovered into the liquid storage tank 1 after being cooled by the heat exchanger 13, and is circulated by the heat management system.

[0060] In the present invention, when a local hot spot appears, the electrostatic spray at the corresponding position will automatically turn on; when the battery temperature rises over a large range, the electrostatic spray will automatically turn off and the liquid cooling plate 8 will start working; and when the system is in a high-power operation state for a long time, the battery temperature rises rapidly and the temperature of a large area exceeds the established threshold, the electrostatic spray and the liquid cooling plate 8 will be turned on at the same time to achieve rapid cooling of the battery. During the process, the electrostatic spray uses high-voltage static electricity to atomize the coolant, which can effectively save system energy consumption. In addition, according to the real-time temperature distribution characteristics, the liquid supply pipeline will automatically and reasonably distribute the coolant flow between the electrostatic spray chamber and the liquid cooling plate, thereby greatly improving the utilization rate of the cooling medium.

[0061] Specifically, the control method of the high-efficiency energy storage thermal management system based on electrostatic spraying comprises the following steps:

[0062] First, add a proper amount of coolant to the liquid storage tank 1. The filling amount is preferably controlled at about three-quarters of the capacity of the liquid storage tank 1 to meet the system pressure change after part of the working fluid is vaporized; turn on the liquid supply pump 2 to supply liquid to the liquid supply pipeline 4; and ground the energy storage battery box 3 well;

[0063] When the battery module 11 is working, when the array thermocouple 8-2 detects that the temperature of the local area exceeds 35°C, that is, exceeds the optimal working temperature range, the temperature data acquisition instrument 9 will transmit the corresponding temperature information to the controller 10; the controller 10 then controls the liquid diverter 5 to supply liquid to the array nozzle 7-1 in the specific area at an appropriate flow rate according to the specific temperature distribution, and at the same time controls the high-voltage electrostatic generator 6 to apply voltage to the specific array nozzle 7-1, so that the coolant is quickly sprayed in the form of electrostatic spray to the local overheated area on the upper surface of the liquid cooling plate 8, so as to achieve targeted cooling and heat dissipation; the coolant after heat exchange in the electrostatic spray chamber enters the return liquid pipeline 12 through the micro drainage groove on the upper surface of the liquid cooling plate 8, and is recovered to the liquid storage tank 1 after cooling through the radiator 13, so as to achieve the recycling of the coolant repeatedly;

[0064] When the array thermocouple 8-2 detects that the temperature of the battery module 11 is rising slowly as a whole and no local hot spots appear, specifically when the temperature exceeds 35°C, the number of array temperature measuring thermocouples 8-2 corresponding to the temperature exceeds 60% of the total number, and the maximum temperature value does not exceed 45°C, and the local temperature rise rate is less than 0.5°C / min, the controller 10 will control the liquid diverter 5 to supply liquid only to the liquid cooling plate 8, and use the coolant to flow through the built-in pipeline of the liquid cooling plate 8 to take away the heat. The coolant that has completed the heat exchange then flows from the outlet of the liquid cooling plate 8 through the return liquid pipeline 12 and the heat exchanger 13 in sequence, and finally enters the liquid storage tank 1;

[0065] When the array thermocouple 8-2 detects that the temperature of the battery module 11 is rising rapidly and the temperature in a large area exceeds a predetermined threshold, specifically when the local temperature exceeds 45°C, or the local temperature rise is greater than 0.5°C / min, the controller 10 will control the liquid diverter 5 to simultaneously supply a large amount of liquid to the electrostatic spray chamber 7 and the liquid cooling plate 8, and at the same time control the high-voltage electrostatic generator 6 to apply voltage to the local array nozzle 7-1, and comprehensively regulate the coolant supply flow rate and the nozzle applied voltage value to meet the heat dissipation requirements of different working conditions; as the temperature of the battery module 11 monitored by the array thermocouple 8-2 continues to change, the controller 10 will dynamically adjust the liquid supply flow rate and applied voltage of the electrostatic spray chamber 7, as well as the liquid supply flow rate of the liquid cooling plate 8, thereby achieving temperature control while greatly saving the use of coolant and improving system energy efficiency.

[0066] Repeat the above steps. Based on the monitored surface temperature distribution characteristics of the battery module, the system can automatically control the start and stop of different cooling methods and adjust the operating parameters, formulate an optimal cooling plan, and achieve targeted rapid cooling of the battery module.

[0067] Specifically, the temperature of the battery module 11 and the coolant flow rate satisfy the following basic relationship: Taking a certain model of 625Ah, 3.2V large-capacity battery module as an example, its size is 54mm×470mm×182mm, its mass is about 12.5kg, and its specific heat capacity is about 1000J / (kg·K).

[0068] For the electrostatic spray cooling method, according to the design requirements, the array nozzles corresponding to the heat exchange surface on one side of the battery module 11 need to be set to two rows and five columns, a total of 10. At the same time, considering that the upper and lower surfaces of the battery module are provided with cooling structures at the same time, the battery module 11 can be divided into units, and the heat dissipation area corresponding to each array nozzle 7-1 is approximately one twentieth of the size of the battery module, such as Figure 4 As shown. The heat Q1 generated by each electrostatic spray cooling unit can be calculated by the following formula:

[0069] Q1=m1c1(T2-T0)

[0070] Among them, m1 is the mass of the battery module of the electrostatic spray cooling unit (kg), c1 is the average specific heat capacity of the battery module (J / kg·K), T2 is the local battery temperature (℃), and T0 is the initial temperature of the battery module (℃). The initial temperature of the coolant is constant at T1, the specific heat capacity is c2, and it is assumed that only single-phase heat exchange is performed during the process, the working fluid utilization rate is 90%, and the cooling needs to be completed within 0.5 minutes. Therefore, the mass flow rate of the coolant of a single array nozzle 7-1 is It can be calculated by the following formula:

[0071]

[0072]

[0073] Among them, the initial temperature T0 of the battery module 11, the initial temperature T1 of the coolant and the specific heat capacity c2 of the coolant are all known, so the coolant flow rate of a single array nozzle 7-1 can be easily determined based on the monitored battery module temperature.

[0074] For the liquid cooling plate cooling method, the heat dissipation area corresponding to the single-sided liquid cooling plate is half the size of the battery module 11, such as Figure 5 As shown. The heat Q2 generated by this part of the battery can be calculated by the following formula:

[0075]

[0076] Wherein, m2 is the mass of the liquid cooling plate cooling unit battery module (kg), is the average temperature of the battery module of the liquid cooling plate cooling unit (℃). Assume that the working fluid utilization rate of the liquid cooling plate is 60%, and the cooling also needs to be completed within 0.5min. Therefore, the mass flow rate of the coolant of the liquid cooling plate It can be calculated by the following formula:

[0077]

[0078]

[0079] Among them, the initial temperature T0 of the battery module, the initial temperature T1 of the coolant, and the specific heat capacity c2 of the coolant are all known, so the coolant flow rate of the liquid cooling plate can be easily determined according to the monitored battery module temperature.

[0080] When the electrostatic spray and the liquid cooling plate work simultaneously, in order to fully ensure the safe and stable operation of the energy storage battery and avoid thermal runaway, the array nozzle 7-1 and the liquid cooling plate 8 supply liquid according to the theoretical flow rate under separate working conditions. When the system is running, the temperature data of the battery module 11 is updated every 0.5 minutes, thereby realizing real-time dynamic adjustment of the cooling scheme.

[0081] The high-efficiency energy storage thermal management system based on electrostatic spraying described in the present invention is particularly suitable for cooling and heat dissipation of high-power energy storage systems. Its advantage is that it uses coolant as the heat exchange medium, and by combining the two heat dissipation technologies of electrostatic spraying and liquid cooling plate, according to the real-time temperature distribution characteristics of the battery module, the system can formulate and dynamically adjust the preferred thermal management plan, thereby achieving a significant improvement in the utilization rate of the cooling medium and the energy efficiency of the system. The present invention combines the two heat dissipation technologies of electrostatic spraying and liquid cooling plate, according to the real-time temperature distribution characteristics of the battery module, the system can formulate and dynamically adjust the preferred cooling and heat dissipation plan, which can greatly improve the utilization rate of the cooling medium and the energy efficiency of the system compared to the existing energy storage system heat pipe technology.

[0082] The present invention combines electrostatic spray cooling and liquid cooling plate technology, which can greatly improve the cooling and heat dissipation capacity of the energy storage thermal management system; the real-time temperature distribution of the battery module can be obtained by built-in multiple array thermocouples, and the preferred cooling scheme and liquid supply flow rate are determined according to the specific temperature distribution characteristics, avoiding excessive use of coolant and ineffective coverage, and greatly improving the utilization rate of the coolant; at the same time, compared with the traditional atomization method, electrostatic spraying can effectively save system energy consumption, and the electric field acceleration effect can effectively enhance the impact and disturbance effect of the spray droplets on the heat sink, thereby improving the cooling and heat exchange efficiency; in addition, the thermal management system and the battery module work independently of each other, and the two are isolated by high thermal conductivity insulating materials, which effectively avoids the risk of leakage and the influence of a small amount of free charge on the stability of the energy storage system; based on the above scheme, high-efficiency energy storage system thermal management is finally achieved.

[0083] 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.

[0084] 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 high-efficiency energy storage thermal management system based on electrostatic spray, characterized in that: It comprises a liquid storage tank (1), a liquid supply pump (2), an energy storage battery box (3), a liquid supply pipeline (4), a liquid diverter (5), a high-voltage electrostatic generator (6), an electrostatic spray chamber (7), an array nozzle (7-1), a liquid cooling plate (8), a thermocouple (8-2), a temperature data acquisition instrument (9), a controller (10), a battery module (11), a liquid return pipeline (12) and a heat exchanger (13); The liquid storage tank (1) is placed outside the energy storage battery box (3) and is used for storing and recovering the cooling liquid; a plurality of battery modules (11) are arranged in the energy storage battery box (3); a liquid cooling plate (8) and an electrostatic spray chamber (7) are arranged on the upper surface of the battery module (11) to form a combined upper cooling structure; a liquid cooling plate (8) and an electrostatic spray chamber (7) are also arranged on the lower surface of the battery module (11) to form a combined lower cooling structure; an array nozzle (7-1) is arranged in the electrostatic spray chamber (7), and the spray droplets of the array nozzle (7-1) can be sprayed onto the surface of the liquid cooling plate (8) for local cooling; the liquid supply pump (2) is connected to the liquid storage tank (1) and the liquid diverter (5) through a liquid supply pipeline (4); the cooling liquid inlet of the electrostatic spray chamber (7) and the liquid cooling plate (8) of the upper cooling structure and the lower cooling structure is connected to the liquid The liquid cooling plate (8) is connected to a flow divider (5); the cooling liquid outlets of the electrostatic spray chamber (7) and the liquid cooling plate (8) are respectively connected to one end of a liquid return pipeline (12); the other end of the liquid return pipeline (12) is connected to a liquid storage tank (1); a heat exchanger (13) is arranged in the liquid return pipeline (12); the high-voltage electrostatic generator (6) is connected to an array nozzle (7-1) arranged in the electrostatic spray chamber (7); the liquid cooling plate (8) is built with a plurality of array temperature measuring thermocouples (8-2); the temperature data acquisition instrument (9) is connected to the plurality of array thermocouples (8-2) for detecting the temperature of the thermocouples (8-2) and sending the temperature signal to the controller (10); the controller (10) is respectively connected to the temperature data acquisition instrument (9), the liquid flow divider (5), the high-voltage electrostatic generator (6) and the array nozzle (7-1).

2. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The liquid supply pump (2) is a non-metallic gear pump.

3. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The array nozzle (7-1) is made of a metal conductive material, and the atomization cone angle is less than 90°.

4. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The array nozzles (7-1) are distributed in a rectangular array, and the spacing between adjacent array nozzles (7-1) is in the range of 50-100 mm.

5. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The distance between the array nozzle (7-1) and the relative outer surface of the liquid cooling plate (8) is in the range of 10-15 mm.

6. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The array nozzles (7-1) are respectively provided with a solenoid valve, which is connected to a controller (10); each array nozzle (7-1) and array thermocouple (8-2) are numbered, the position of the array nozzle (7-1) corresponds to the array thermocouple (8-2) in terms of spatial position, quantity and number, and the spatial position and number of the array nozzle (7-1) and the array thermocouple (8-2) are set in the controller (10).

7. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The electrostatic spray chamber (7) is connected to the liquid cooling plate (8) and shares a heat sink (8-1); a high thermal conductivity insulating thin layer (8-3) is provided between the heat sink (8-1) and the battery module (11); and the thickness of the high thermal conductivity insulating thin layer (8-3) does not exceed 10 mm.

8. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The outer surface of the liquid cooling plate (8) opposite to the array nozzle (7-1) is provided with a micro liquid drainage groove.

9. The high-efficiency energy storage thermal management system based on electrostatic spraying according to claim 1 is characterized in that: The liquid supply pipeline (4) is divided into two paths including a first liquid supply pipeline and a second liquid supply pipeline, and one end of the liquid return pipeline (12) is divided into two paths including a first liquid return pipeline and a second liquid return pipeline; the upper cooling structure and the lower cooling structure are respectively provided with a liquid diverter (5); The first liquid supply pipeline is respectively connected to the liquid diverter (5) of the cooling structure on the battery module (11), and the first liquid return pipeline is respectively connected to the electrostatic spray chamber (7) of the cooling structure on the battery module (11) and the cooling liquid outlet of the liquid cooling plate (8); The second liquid supply pipeline is respectively connected to the liquid diverter (5) of the cooling structure under the battery module (11), and the second liquid return pipeline is respectively connected to the electrostatic spray chamber (7) of the cooling structure under the battery module (11) and the cooling liquid outlet of the liquid cooling plate (8).

10. A control method for a high-efficiency energy storage thermal management system based on electrostatic spraying according to any one of claims 1 to 9, characterized in that: The following steps are involved: When the thermocouple (8-2) detects that the temperature of a local area exceeds a preset threshold, the controller (10) turns on the high-voltage electrostatic generator (6) to apply voltage to the array nozzle (7-1) corresponding to the local overheated area, and turns on the liquid supply pump (2) to supply liquid to the liquid supply pipeline (4), and controls the liquid diverter (5) to supply liquid to the designated array nozzle (7-1) according to the temperature signal collected by the temperature data acquisition instrument (9), so as to spray the cooling liquid to the local hot spot area; When the thermocouple (8-2) detects that the temperature of a large area has risen, the controller (10) turns on the liquid supply pump (2) to supply liquid to the liquid supply pipeline (4), and controls the liquid diverter (5) to supply liquid to the liquid cooling plate (8), and at the same time controls the liquid supply flow rate of the liquid diverter (5) according to the temperature signal characteristics collected by the temperature data acquisition instrument (9); When the thermocouple (8-2) detects that the battery temperature rises rapidly and the temperatures of multiple regions exceed a preset threshold, the controller (10) turns on the liquid supply pump (2) to supply liquid to the liquid supply pipeline (4), and controls the liquid diverter (5) to simultaneously supply liquid to the liquid cooling plate (8) and the array nozzles (7-1) corresponding to the overheated region, and controls the high-voltage electrostatic generator (6) to turn on electrostatic spraying to the overheated region; The cooling liquid flowing through the electrostatic spray chamber (7) and the liquid cooling plate (8) eventually enters the liquid return pipeline (12), and is recovered into the liquid storage tank (1) after being cooled by the heat exchanger (13).

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