Thermal management system, control method and electric equipment

Abstract

The invention relates to the technical field of batteries, and provides a heat management system, a control method and electric equipment.The heat management system comprises a circulation unit and a branch unit, and the circulation unit comprises a refrigerant circulation flow path, a compressor, a heat exchange device, a first throttling device, a heat exchanger and a reversing device; the compressor, the heat exchange device, the first throttling device and the heat exchanger are sequentially arranged on the refrigerant circulation flow path in series. The reversing device is arranged on the refrigerant circulation flow path to change the flowing direction of a refrigerant in the refrigerant circulation flow path, and the refrigerant circulation flow path is provided with a first node and a second node. The branch unit comprises a refrigerant branch, a heating device and a second throttling device, the refrigerant branch communicates with the first node and the second node, and the heating device and the second throttling device are both arranged on the refrigerant branch. At least one of the heat exchanger and the heating device can be selected to heat the refrigerant according to the environment temperature, so that the heating requirement of the single battery under the large-range environment temperature can be met through double-source heating of the air source and the heating device.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a thermal management system, control method and electrical equipment. Background Technology

[0002] Battery cells can be used to store or provide electrical energy, and they can be used in electrical devices, such as vehicles and energy storage devices.

[0003] In related technologies, thermal management systems regulate the temperature of battery cells by exchanging heat between the refrigerant and the individual cells. When it's necessary to raise the temperature of the battery cells, the refrigerant absorbs heat from the air source and then releases it to the battery cells, thus increasing their temperature. However, in low ambient temperatures, the refrigerant's heating effect on the battery cells is poor. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide a thermal management system, control method, and electrical equipment that can meet the heating needs of battery cells under a wide range of ambient temperatures through dual-source heating of air source and heating device.

[0005] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows:

[0006] This application provides a thermal management system, including:

[0007] A circulating unit includes a refrigerant circulation path, a compressor, a heat exchange device, a first throttling device, a heat exchanger, and a reversing device. The compressor, the heat exchange device, the first throttling device, and the heat exchanger are connected in series in the refrigerant circulation path. The reversing device is located in the refrigerant circulation path to change the flow direction of the refrigerant in the refrigerant circulation path. The heat exchanger is used for heat exchange with an air source, and the heat exchange device is used for heat exchange with individual battery cells. The refrigerant circulation path has a first node and a second node. The first node is located between the heat exchange device and the first throttling device, and the second node is located between the heat exchanger and the reversing device.

[0008] The branch unit includes a refrigerant branch, a heating device, and a second throttling device. The refrigerant branch connects the first node and the second node. The heating device and the second throttling device are both located in the refrigerant branch, and the second throttling device is located between the heating device and the first node.

[0009] The thermal management system provided in this application uses refrigerant as an intermediate medium to regulate the temperature of individual battery cells. When a battery cell needs to be heated, an air source can be selected as the heat source, and a heat exchanger can be used to exchange heat between the refrigerant and the air source, transferring the heat from the air source to the battery cell using the refrigerant as the intermediate medium. Alternatively, a heating device can be selected as the heat source, and a heating device can be used to exchange heat between the refrigerant and other energy sources, transferring the heat from the other energy sources to the battery cell using the refrigerant as the intermediate medium. For the heating needs of the battery cells, the heat exchanger can facilitate heat exchange between the air source and the refrigerant, and the heating device can heat the refrigerant. Depending on the ambient temperature, at least one of the heat exchanger and the heating device can be selected to heat the refrigerant. This dual-source heating of air source and heating device can meet the heating needs of the battery cells over a wide range of ambient temperatures.

[0010] In some embodiments, the thermal management system includes a superheater having a first channel and a second channel, the first channel being connected in series between the reversing device and the heat exchange device, and the second channel being connected in series between the second node and the heating device.

[0011] In this embodiment, the refrigerant in the first channel and the refrigerant in the second channel have different pressures and temperatures. The refrigerant in the first channel and the refrigerant in the second channel can exchange heat, thereby regulating the temperature of the refrigerant in the first channel and the refrigerant in the second channel.

[0012] In some embodiments, the thermal management system includes a first detection device disposed in the refrigerant path between the first channel and the heat exchange device to detect a first temperature and a first pressure of the refrigerant.

[0013] In this embodiment, the first temperature and the first pressure can be obtained through the first detection device, thereby obtaining the superheat of the refrigerant in the refrigerant path between the first channel and the heat exchange device.

[0014] In some embodiments, the thermal management system includes a second detection device disposed in the refrigerant path between the heat exchange device and the first throttling device to detect a second temperature and a second pressure of the refrigerant.

[0015] In this embodiment, the second temperature and the second pressure can be obtained through the second detection device, thereby obtaining the subcooling of the refrigerant in the refrigerant path between the heat exchange device and the first throttling device.

[0016] In some embodiments, the thermal management system includes a third detection device, the compressor has an inlet, and the third detection device is disposed in the refrigerant path between the inlet and the reversing device to detect a third temperature and a third pressure of the refrigerant.

[0017] In this embodiment, a third temperature and a third pressure can be obtained through a third detection device, thereby obtaining the state of the refrigerant in the refrigerant path between the inlet and the reversing device.

[0018] In some embodiments, the thermal management system includes a first heating mode in which the first throttling device is in a closed state, the second throttling device is in a closed state, and both the compressor and the heating device are in an operating state.

[0019] In this embodiment, the thermal management system can operate in a first heating mode to heat the battery cells and increase their temperature.

[0020] In some embodiments, the thermal management system operates in the first heating mode when the ambient temperature is not greater than the set temperature.

[0021] In this embodiment, when the ambient temperature is less than or equal to the set temperature, the thermal management system operates in the first heating mode, which provides a heat source through the heating device. This can minimize the impact of low air source heat exchange efficiency caused by low ambient temperature and improve the heating effect.

[0022] In some embodiments, the thermal management system includes a second heating mode in which the first throttling device is in an open state, the second throttling device is in a closed state, the heating device is in a stopped state, the compressor is in an operating state, and the heat exchanger is an evaporator.

[0023] In this embodiment, the thermal management system can operate a second heating mode to heat the battery cells and increase their temperature.

[0024] In some embodiments, the thermal management system operates in the second heating mode when the ambient temperature is higher than the set temperature.

[0025] In this embodiment, when the ambient temperature is higher than the set temperature, the thermal management system operates in a second heating mode, providing heat through an air source, thus achieving the effect of environmental protection and energy saving.

[0026] In some embodiments, the thermal management system includes a third heating mode in which both the first throttling device and the second throttling device are in the open state, both the heating device and the compressor are in the running state, and the heat exchanger is an evaporator.

[0027] In this embodiment, the thermal management system operates in a third heating mode, providing dual heat sources through a heating device and an air source, which can take into account both energy-saving requirements and heating performance requirements.

[0028] In some embodiments, the thermal management system includes a cooling mode in which the first throttling device is in an open state, the second throttling device is in a closed state, the heating device is in a stopped state, the compressor is in an operating state, and the heat exchanger is a condenser.

[0029] In this embodiment, the thermal management system can operate in a cooling mode to cool down the individual battery cells and reduce their temperature.

[0030] In some embodiments, the thermal management system includes a defrosting unit, the defrosting unit includes a defrosting branch and a switching valve, the switching valve is disposed in the defrosting branch, the refrigerant circulation path has a third node and a fourth node, the third node is located between the reversing device and the heat exchange device, the fourth node is located between the first throttling device and the heat exchanger, and the defrosting branch connects the third node and the fourth node.

[0031] In this embodiment, since the heat exchanger is used for heat exchange with the air source, it acts as an evaporator during the heating process. The heat exchanger absorbs heat from the air source, which can easily lead to excessively low air temperatures around the heat exchanger. Water in the air condenses on the heat exchanger, causing frost formation and affecting its heat exchange efficiency. Therefore, when frost forms on the heat exchanger, the on / off valve can be opened. Some of the high-temperature gaseous refrigerant enters the heat exchanger through the defrosting branch and the fourth node. The high-temperature gaseous refrigerant releases heat, melting the frost on the heat exchanger.

[0032] In some embodiments, the thermal management system includes a defrost mode in which the first throttling device is closed, the second throttling device and the switching valve are both open, and the heating device and the compressor are both running.

[0033] In this embodiment, in defrosting mode, not only can the heat exchanger be defrosted, but the individual battery cells can also be heated. Thus, if frost forms on the heat exchanger during heating, the heating of the individual battery cells can continue, and the defrosting unit can defrost the heat exchanger.

[0034] In some embodiments, the heat exchange device includes a manifold, at least two branch lines, and at least two heat exchange components, each heat exchange component being used to exchange heat with at least one of the battery cells, each heat exchange component being connected to one of the branch lines, and all the heat exchange components being connected to the refrigerant circulation path; all the branch lines are connected to the manifold, and all the branch lines are connected to the refrigerant circulation path through the manifold.

[0035] In this embodiment, the refrigerant is combined and divided through a manifold, at least two branch pipes, and at least two heat exchangers. Each heat exchanger is used to exchange heat with at least one battery cell. By exchanging heat with at least two battery cells through at least two heat exchangers, the refrigerant can be heated and cooled.

[0036] This application provides a control method for the aforementioned thermal management system, the control method comprising:

[0037] Obtain the ambient temperature;

[0038] When the ambient temperature is not greater than the set temperature, the first throttling device is closed, the second throttling device is opened, and the compressor and the heating device are operated.

[0039] The control method provided in this application embodiment can utilize a heating device as a heat source when the ambient temperature is not higher than the set temperature. This can minimize the impact of low air source heat exchange efficiency caused by low ambient temperature and improve the heating effect.

[0040] In some embodiments, the control method includes:

[0041] When the ambient temperature is higher than the set temperature, open the first throttling device, close the second throttling device, stop the heating device, and run the compressor.

[0042] In this embodiment, when the ambient temperature is higher than the set temperature, an air source can be used as a heat source, achieving the effect of environmental protection and energy saving.

[0043] In some embodiments, the thermal management system includes a superheater having a first channel and a second channel, the first channel being connected in series between the reversing device and the heat exchange device, and the second channel being connected in series between the second node and the heating device; the control method includes:

[0044] Obtain the first temperature and first pressure of the refrigerant in the refrigerant path between the first channel and the heat exchange device;

[0045] The superheat is obtained based on the first temperature and the first pressure;

[0046] If the superheat exceeds the first threshold, increase the opening of the second throttling device and / or reduce the speed of the compressor.

[0047] In this embodiment, when the superheat exceeds the first threshold, the superheat can be reduced by increasing the opening of the second throttling device and reducing the speed of the compressor. This can, to some extent, avoid the problem of uneven heating caused by excessive superheat during the heating process of individual battery cells and reduce the temperature difference between individual battery cells.

[0048] In some embodiments, the control method includes:

[0049] If the superheat is less than the second threshold, the opening of the second throttling device is reduced and / or the speed of the compressor is increased, where the second threshold is less than the first threshold.

[0050] In this embodiment, when the superheat is less than the second threshold, the superheat can be increased by reducing the opening of the second throttling device and increasing the speed of the compressor, which can avoid uneven heating caused by excessively low superheat during the heating process of the battery cells to a certain extent, and reduce the temperature difference between the individual battery cells.

[0051] In some embodiments, the control method includes:

[0052] Obtain the second temperature and second pressure of the refrigerant in the refrigerant path between the heat exchange device and the first throttling device;

[0053] The degree of subcooling is obtained based on the second temperature and the second pressure;

[0054] If the subcooling degree is greater than the third threshold, increase the opening of the first throttling device and / or increase the speed of the compressor.

[0055] In this embodiment, when the supercooling is greater than the third threshold, the supercooling can be reduced by increasing the opening of the first throttling device and increasing the speed of the compressor, which can avoid the problem of uneven heating caused by excessive supercooling during the heating process of the battery cells to a certain extent, and reduce the temperature difference between the individual battery cells.

[0056] In some embodiments, the control method includes:

[0057] If the subcooling degree is less than the fourth threshold, reduce the opening of the first throttling device and / or reduce the speed of the compressor, where the fourth threshold is less than the third threshold.

[0058] In this embodiment, when the supercooling is less than the fourth threshold, the supercooling can be increased by reducing the opening of the first throttling device and reducing the speed of the compressor, which can avoid uneven heating caused by excessively low supercooling during the heating process of the battery cells to a certain extent, and reduce the temperature difference between the individual battery cells.

[0059] In some embodiments, the thermal management system includes a defrosting unit, the defrosting unit including a defrosting branch and a switching valve, the switching valve being disposed in the defrosting branch, the refrigerant circulation path having a third node and a fourth node, the third node being located between the reversing device and the heat exchange device, the fourth node being located between the first throttling device and the heat exchanger, the defrosting branch connecting the third node and the fourth node, the compressor having a suction inlet, and the control method including:

[0060] Obtain the third pressure of the refrigerant in the refrigerant path between the inlet and the reversing device;

[0061] When the third pressure is less than the preset pressure, the first throttling device is closed, the second throttling device and the switching valve are opened, and the compressor and the heating device are operated.

[0062] In this embodiment, when the third pressure is less than the preset pressure, frost forms on the surface of the heat exchanger. The first throttling device is closed, and the second throttling device and the switching valve are opened. Without affecting the heating of the battery unit, some of the high-temperature gaseous refrigerant enters the heat exchanger through the defrosting branch and the fourth node. The high-temperature gaseous refrigerant can release heat, causing the frost on the heat exchanger to melt.

[0063] In some embodiments, the control method includes:

[0064] Obtain the third temperature of the refrigerant in the refrigerant path between the inlet and the reversing device;

[0065] If the third temperature is not lower than the preset temperature, the switching valve is closed.

[0066] In this embodiment, when the third temperature is not less than the preset temperature, it can be used to indicate that the frost on the surface of the heat exchanger has basically melted, and the switching valve can be closed so that the high-pressure gaseous refrigerant no longer enters the heat exchanger through the defrosting branch.

[0067] This application also provides an electrical device, including a battery cell and a thermal management system as described in any one of the above embodiments, wherein the battery cell is used to store or provide electrical energy.

[0068] The electrical equipment provided in this application includes the thermal management system provided in this application, and has the same or corresponding beneficial effects as the thermal management system. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the vehicle structure in one embodiment of this application;

[0070] Figure 2This is a schematic diagram of the thermal management system in cooling mode according to an embodiment of this application, wherein the arrows indicate the flow direction of the refrigerant;

[0071] Figure 3 This is a schematic diagram of the thermal management system in a first heating mode according to an embodiment of this application, wherein the arrows indicate the flow direction of the refrigerant;

[0072] Figure 4 This is a schematic diagram of the thermal management system in a second heating mode according to an embodiment of this application, wherein the arrows indicate the flow direction of the refrigerant;

[0073] Figure 5 This is a schematic diagram of the thermal management system in a third heating mode according to an embodiment of this application, wherein the arrows indicate the flow direction of the refrigerant;

[0074] Figure 6 This is a schematic diagram of the thermal management system in defrost mode according to an embodiment of this application, wherein the arrows indicate the flow direction of the refrigerant;

[0075] Figure 7 This is a flowchart illustrating the control method in one embodiment of this application.

[0076] Explanation of reference numerals in the attached figures

[0077] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 1, Circulation Unit; 11, Refrigerant Circulation Flow Path; 111, First Node; 112, Second Node; 113, Third Node; 114, Fourth Node; 12, Compressor; 121, Inlet; 13, Heat Exchanger; 131, Combinator / Diverter; 132, Diverter Pipeline; 133, Heat Exchanger Component; 14, First Throttling Device; 15, Heat Exchanger; 16, Reversing Device; 2, Branch Unit; 21, Refrigerant Branch; 22, Heating Device; 23, Second Throttling Device; 3, Superheater Cooler; 31, First Channel; 32, Second Channel; 4, First Detection Device; 5, Second Detection Device; 6, Third Detection Device; 7, Defrosting Unit; 71, Defrosting Branch; 72, Switch Valve; 10, Battery Cell. Detailed Implementation

[0078] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0079] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0080] In the description of the embodiments of this application, the technical terms "first", "second", "third", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0081] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0082] It should be noted that in this application, "at least two" refers to a quantity of two or more. "Multiple" refers to a quantity of two or more. The unit "℃" is degrees Celsius. The unit "W / (m³)" is... 2 "·K)" means watts per square meter (kPa). The unit "kPa" means kilopascal.

[0083] Please see Figure 1 and Figure 2 To facilitate understanding of the battery cell 10, battery device 100, and electrical equipment provided in the embodiments of this application, some basic structures of the battery cell 10, battery device 100, and electrical equipment provided in the embodiments of this application will be introduced first.

[0084] The battery device 100 provided in the embodiments of this application includes the battery cell 10 in any embodiment of this application.

[0085] The number of battery cells 10 can be one or more, and the battery cells 10 are used to provide voltage and capacity. Multiple battery cells 10 can be connected in series, parallel, or mixed via a busbar. The busbar is used to achieve electrical connection between at least two battery cells 10.

[0086] For example, "hybrid connection" refers to at least two battery cells 10 that are connected in both series and parallel. At least two battery cells 10 can be directly connected in series, parallel, or hybrid connections; of course, at least two battery cells 10 can first be connected in series, parallel, or hybrid connections to form a module, and then the module can be connected in series, parallel, or hybrid connections to form a whole.

[0087] In this embodiment of the application, the battery cell 10 can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0088] The battery cell 10 can be a lithium-ion battery cell, sodium-ion battery cell, sodium-lithium-ion battery cell, lithium metal battery cell, sodium metal battery cell, lithium-sulfur battery cell, magnesium-ion battery cell, nickel-metal hydride battery cell, nickel-cadmium battery cell, or lead-acid battery cell, etc., and the embodiments of this application are not limited to this.

[0089] A battery cell 10 generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator located between the negative and positive electrodes. During the charging and discharging process of the battery cell 10, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, located between the positive and negative electrodes, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0090] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0091] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0092] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0093] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0094] In some embodiments, the negative electrode can be a negative electrode sheet, which may include a negative electrode current collector.

[0095] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0096] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0097] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0098] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 10. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 10 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0099] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0100] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0101] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0102] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0103] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0104] In some embodiments, the battery cell 10 further includes an electrolyte, which is disposed within the casing of the battery cell 10. The electrolyte serves to conduct active ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte, which can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0105] Liquid electrolytes include electrolyte salts and solvents.

[0106] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0107] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0108] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain performance of the battery cell 10, such as additives that improve the overcharge / fast charge performance of the battery cell 10, additives that improve the high-temperature performance of the battery cell 10, additives that improve the low-temperature performance of the battery cell 10, etc.

[0109] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0110] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0111] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0112] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0113] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0114] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0115] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0116] In some implementations, the electrode assembly is a stacked structure.

[0117] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0118] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0119] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0120] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0121] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0122] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0123] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0124] In some embodiments, the battery cell 10 may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0125] As an example, the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0126] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0127] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0128] In some embodiments, a pressure relief mechanism is provided on the housing. The pressure relief mechanism is used to release the internal gas of the battery cell 10.

[0129] As an example, the internal pressure or temperature of the battery cell 10 is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 10 reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 10.

[0130] In some embodiments, the battery cell assembly is typically formed by arranging multiple battery cells 10.

[0131] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity.

[0132] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 10 together to form an independent module. As an example, a battery module can be formed by bundling multiple battery cells 10 together with cable ties.

[0133] In some embodiments, the battery device 100 may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0134] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0135] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0136] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0137] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0138] Please see Figures 2 to 6 This application provides an electrical device, including a battery cell 10 and a thermal management system in any embodiment of this application, wherein the battery cell 10 is used to store or provide electrical energy.

[0139] Electrical equipment includes, but is not limited to, energy storage devices, mobile phones, tablets, laptops, electric toys, power tools, vehicles, ships, or spacecraft. Vehicles can include electric bicycles and electric cars, electric toys can include electric bicycles and electric cars, and so on, including stationary or mobile electric toys such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft.

[0140] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices.

[0141] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0142] Please see Figure 1 The following description will take a vehicle 1000 as an example of an embodiment of the electrical equipment used in this application. The description will be made in conjunction with the accompanying drawings.

[0143] Figure 1 The diagram illustrates the structure of a vehicle 1000 as provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Figure 1 As shown, a battery device 100 is installed inside the vehicle 1000. The battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0144] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0145] In related technologies, battery cells undergo intense internal chemical reactions under high-temperature environments or during high-current charging and discharging, generating significant heat and necessitating cooling. Conversely, in low-temperature environments, battery cells are prone to capacity decay, reduced charging and discharging performance, and shortened lifespan, requiring heating to maintain a suitable operating temperature and improve efficiency and safety. Thermal management systems achieve heating or cooling of battery cells through heat exchange between the refrigerant and the cells. During the heating process, the refrigerant absorbs heat from the air source and releases it to the battery cells. If the ambient temperature is low, for example below -10°C, the heat exchange efficiency between the refrigerant and the air source is low, resulting in poor heating of the battery cells or even an inability to heat them.

[0146] In view of this, embodiments of this application provide a thermal management system, which includes a circulating unit and branch units. The circulating unit includes a refrigerant circulation path, a compressor, a heat exchange device, a first throttling device, a heat exchanger, and a reversing device. The compressor, heat exchange device, first throttling device, and heat exchanger are sequentially connected in series in the refrigerant circulation path. The reversing device is disposed in the refrigerant circulation path to change the flow direction of the refrigerant in the refrigerant circulation path. The heat exchanger is used for heat exchange with an air source, and the heat exchange device is used for heat exchange with individual battery cells. The refrigerant circulation path has a first node and a second node. The first node is located between the heat exchange device and the first throttling device, and the second node is located between the heat exchanger and the reversing device. The branch units include a refrigerant branch, a heating device, and a second throttling device. The refrigerant branch connects the first node and the second node. Both the heating device and the second throttling device are disposed in the refrigerant branch, and the second throttling device is located between the heating device and the first node.

[0147] The thermal management system provided in this application uses refrigerant as an intermediate medium to regulate the temperature of individual battery cells. When a battery cell needs to be heated, an air source can be selected as the heat source, and a heat exchanger can be used to exchange heat between the refrigerant and the air source, transferring the heat from the air source to the battery cell using the refrigerant as the intermediate medium. Alternatively, a heating device can be selected as the heat source, and a heating device can be used to exchange heat between the refrigerant and other energy sources, transferring the heat from the other energy sources to the battery cell using the refrigerant as the intermediate medium. For the heating needs of the battery cells, the heat exchanger can facilitate heat exchange between the air source and the refrigerant, and the heating device can heat the refrigerant. Depending on the ambient temperature, at least one of the heat exchanger and the heating device can be selected to heat the refrigerant. This dual-source heating of air source and heating device can meet the heating needs of the battery cells over a wide range of ambient temperatures.

[0148] The thermal management system provided in this application embodiment is further described below with reference to the accompanying drawings. The thermal management system provided in this application embodiment is used to regulate the temperature of the battery cell 10. The thermal management system exchanges heat with the battery cell 10 through a refrigerant to cool or heat the battery cell 10.

[0149] Please see Figures 2 to 6 The thermal management system includes circulating unit 1 and branch unit 2.

[0150] The circulating unit 1 includes a refrigerant circulation path 11, a compressor 12, a heat exchange device 13, a first throttling device 14, a heat exchanger 15, and a reversing device 16. The compressor 12, the heat exchange device 13, the first throttling device 14, and the heat exchanger 15 are connected in series in the refrigerant circulation path 11. The reversing device 16 is disposed in the refrigerant circulation path 11 to change the flow direction of the refrigerant in the refrigerant circulation path 11. The heat exchanger 15 is used for heat exchange with the air source, and the heat exchange device 13 is used for heat exchange with the battery cell 10. The refrigerant circulation path 11 has a first node 111 and a second node 112. The first node 111 is located between the heat exchange device 13 and the first throttling device 14, and the second node 112 is located between the heat exchanger 15 and the reversing device 16.

[0151] The branch unit 2 includes a refrigerant branch 21, a heating device 22, and a second throttling device 23. The refrigerant branch 21 connects the first node 111 and the second node 112. The heating device 22 and the second throttling device 23 are both located in the refrigerant branch 21. The second throttling device 23 is located between the heating device 22 and the first node 111.

[0152] Refrigerant circulation path 11 refers to the path through which the refrigerant circulates. The refrigerant can circulate within refrigerant circulation path 11.

[0153] Refrigerant is a flowable fluid. It can be a fluid that easily absorbs heat and turns into a gaseous state, and easily releases heat and turns into a liquid state. Refrigerant can undergo phase change after absorbing or releasing heat. For example, refrigerant includes, but is not limited to, fluorinated refrigerants (such as HFC refrigerants) or hydrocarbon refrigerants, etc.

[0154] The compressor 12 is used to compress and circulate the refrigerant, and can convert the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant.

[0155] The heat exchange device 13 is a device that allows refrigerant to flow through and enables heat exchange between the refrigerant and the battery cell 10.

[0156] The first throttling device 14 is a device that allows refrigerant to flow and throttles and reduces the pressure of the refrigerant.

[0157] The heat exchanger 15 is a device that allows refrigerant to circulate and enables heat exchange between the refrigerant and the air source.

[0158] The reversing device 16 is used to change the flow direction of the refrigerant in the refrigerant circulation path 11. For example, when the refrigerant flows in the forward direction in the refrigerant circulation path 11, the refrigerant can flow out from the outlet of the compressor 12 and flow sequentially through the heat exchange device 13, the first throttling device 14 and the heat exchanger 15, and then flow back into the compressor 12 through the suction port 121 of the compressor 12; when the reversing device 16 switches the refrigerant flow direction to the reverse direction, the refrigerant flows in the reverse direction in the refrigerant circulation path 11, the refrigerant can flow out from the outlet of the compressor 12 and flow sequentially through the heat exchanger 15, the first throttling device 14 and the heat exchange device 13, and then flow back into the compressor 12 through the suction port 121 of the compressor 12.

[0159] It is understandable that forward and reverse are two opposite flow directions of the refrigerant in the refrigerant circulation path 11. For example, if the forward direction can be clockwise, then the reverse direction is counterclockwise. Or, for another example, if the forward direction can be counterclockwise, then the reverse direction is clockwise.

[0160] Refrigerant branch 21 is the flow path of the refrigerant. Refrigerant branch 21 connects the first node 111 and the second node 112, so that the refrigerant in the refrigerant circulation path 11 can enter the refrigerant branch 21. For example, the refrigerant flowing out of the heat exchange device 13 can enter the refrigerant branch 21 at the first node 111 and then flow back to the refrigerant circulation path 11 at the second node 112.

[0161] The heating device 22 can generate heat to heat the refrigerant flowing through the refrigerant branch 21.

[0162] The energy source of the heating device 22 is not limited, and the energy source of the heating device 22 includes, but is not limited to, electrical energy.

[0163] The second throttling device 23 is a device that allows refrigerant to flow and throttles and reduces the pressure of the refrigerant.

[0164] When the battery cell 10 needs to be heated, the high-pressure gaseous refrigerant discharged from the compressor 12 enters the heat exchange device 13 and releases heat to the battery cell 10. The battery cell 10 absorbs the heat to raise its temperature. The refrigerant in the heat exchange device 13 releases heat and condenses into high-pressure liquid refrigerant. If the ambient temperature is relatively high, the refrigerant can continue to flow along the refrigerant circulation path 11. The high-pressure liquid refrigerant from the heat exchange device 13 enters the first throttling device 14. The high-pressure liquid refrigerant is throttled and depressurized by the first throttling device 14 and transformed into a low-pressure, low-temperature gas-liquid two-phase mixture. The low-pressure, low-temperature gas-liquid two-phase mixture can enter the heat exchanger 15 to exchange heat with the air source to absorb the heat from the air source and transform into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant flows back into the compressor 12. If the ambient temperature is relatively low, at least a portion of the high-pressure liquid refrigerant from the heat exchange device 13 can enter the refrigerant branch 21. The high-pressure liquid refrigerant is throttled and depressurized by the second throttling device 23 and transformed into a low-pressure, low-temperature gas-liquid two-phase mixture. The low-pressure, low-temperature gas-liquid two-phase mixture can enter the heating device 22. The heating device 22 heats the low-pressure, low-temperature gas-liquid two-phase mixture into a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant flows back into the compressor 12.

[0165] The thermal management system provided in this application embodiment uses refrigerant as an intermediate medium to regulate the temperature of the battery cell 10. When the battery cell 10 needs to be heated, an air source can be selected as the heat source, and heat exchange between the refrigerant and the air source can be achieved through heat exchanger 15, transferring the heat from the air source to the battery cell 10 through the refrigerant as the intermediate medium; alternatively, a heating device 22 can be selected as the heat source, and heat exchange between the refrigerant and other energy sources can be achieved through heating device 22, transferring the heat from other energy sources to the battery cell 10 through the refrigerant as the intermediate medium. For the heating requirements of the battery cell 10, heat exchanger 15 can achieve heat exchange between the air source and the refrigerant, and heating device 22 can heat the refrigerant. Depending on the ambient temperature, at least one of heat exchanger 15 and heating device 22 can be selected to heat the refrigerant. Thus, through dual-source heating of air source and heating device 22, the heating requirements of the battery cell 10 can be met over a wide range of ambient temperatures.

[0166] In some embodiments, the heating device 22 may include a heating element that can convert electrical energy into heat energy. The heating element includes, but is not limited to, a resistance heating element and / or a PTC heating element. A PTC (Positive Temperature Coefficient) heating element refers to a heating element with a positive temperature coefficient.

[0167] In some embodiments, the heating device 22 may include a flow channel connected in series with the refrigerant branch 21. The refrigerant can flow through the flow channel, and the heating element can heat the refrigerant flowing through the flow channel.

[0168] In some embodiments, the heating element may be located outside the flow channel and in contact with the wall of the flow channel. In this way, the heating element may not interfere with the flow of refrigerant within the flow channel.

[0169] In some embodiments, the heating element's heat-generating portion can be located within the flow channel. This facilitates direct heat exchange between the refrigerant and the heat-generating portion, reducing heat loss.

[0170] In some embodiments, the heating element's heat-generating portion can form at least a portion of the wall surface of the flow channel. For example, the hot end of the PTC heating element can form at least a portion of the wall surface of the flow channel. This facilitates both refrigerant flow and direct contact between the heating element and the refrigerant.

[0171] In some embodiments, the first throttling device 14 includes, but is not limited to, an electronic expansion valve.

[0172] In some embodiments, the second throttling device 23 includes, but is not limited to, an electronic expansion valve.

[0173] In some embodiments, the reversing device 16 includes, but is not limited to, a four-way valve. A four-way valve is a control valve with four ports. The four-way valve can change the flow direction of the refrigerant by opening or closing the different ports.

[0174] In some embodiments, please refer to Figures 2 to 6 The thermal management system includes a superheater 3, which has a first channel 31 and a second channel 32. The first channel 31 is connected in series between the reversing device 16 and the heat exchange device 13, and the second channel 32 is connected in series between the second node 112 and the heating device 22.

[0175] As an example, when heating of the battery cell 10 is required, the refrigerant discharged from the compressor 12 flows through the first channel 31 and then into the heat exchange device 13. The refrigerant in the first channel 31 can be in a high-pressure gaseous state. The refrigerant flowing out of the heating device 22 enters the second channel 32, where the refrigerant can be in a low-pressure gaseous state. The high-pressure gaseous refrigerant and the low-pressure gaseous refrigerant can exchange heat through the superheater 3. The temperature of the refrigerant in the first channel 31 can be reduced, thus preventing the refrigerant entering the heat exchange device 13 from becoming excessively overheated.

[0176] In this embodiment, the refrigerant in the first channel 31 and the refrigerant in the second channel 32 have different pressures and temperatures. The refrigerant in the first channel 31 and the refrigerant in the second channel 32 can exchange heat, thereby adjusting the temperature of the refrigerant in the first channel 31 and the refrigerant in the second channel 32.

[0177] The specific structural shape of the superheater 3 is not limited. As an example, the first channel 31 and the second channel 32 can share a partition wall. In other words, the partition wall can serve as the wall of the first channel 31 or the wall of the second channel 32, and the refrigerant in the first channel 31 and the refrigerant in the second channel 32 can conduct heat through the partition wall.

[0178] In some embodiments, please refer to Figures 2 to 6 The thermal management system includes a first detection device 4, which is disposed in the refrigerant path between the first channel 31 and the heat exchange device 13 to detect the first temperature and first pressure of the refrigerant.

[0179] The refrigerant path between the first channel 31 and the heat exchange device 13 refers to the flow trajectory of the refrigerant between the first channel 31 and the heat exchange device 13.

[0180] The first detection device 4 can be installed at any location in the refrigerant path between the first channel 31 and the heat exchange device 13. For example, the first detection device 4 can be installed on the pipe between the first channel 31 and the heat exchange device 13. Another example is that the first detection device 4 can be installed at the port of the first channel 31 near the heat exchange device 13. Yet another example is that the first detection device 4 can be installed at the port of the heat exchange device 13 near the first channel 31.

[0181] For ease of description, the refrigerant path between the first channel 31 and the heat exchange device 13 can be defined as the first path, and the first detection device 4 is used to detect the first temperature and first pressure of the refrigerant in the first path.

[0182] The first pressure can be used to obtain the saturation temperature of the refrigerant in the first path, and the superheat of the refrigerant in the first path can be calculated by using the first temperature and the saturation temperature.

[0183] In this embodiment, the first temperature and the first pressure can be obtained through the first detection device 4, thereby obtaining the superheat of the refrigerant in the refrigerant path between the first channel 31 and the heat exchange device 13.

[0184] In embodiments where the thermal management system includes a superheater 3, the first detection device 4 may be located in the refrigerant path between the superheater 3 and the heat exchange device 13.

[0185] The specific type of the first detection device 4 is not limited. The first detection device 4 may include a first temperature sensor and a first pressure sensor. The first temperature sensor is used to detect a first temperature, and the first pressure sensor is used to detect a first pressure.

[0186] In some embodiments, the first temperature sensor and the first pressure sensor can be an integrated structure. An integrated structure refers to a structure that is integrated into one unit.

[0187] In other embodiments, the first temperature sensor and the first pressure sensor can be discrete structures. A discrete structure is two separate structures.

[0188] In some embodiments, please refer to Figures 2 to 6 The thermal management system includes a second detection device 5, which is disposed in the refrigerant path between the heat exchange device 13 and the first throttling device 14 to detect the second temperature and the second pressure of the refrigerant.

[0189] The refrigerant path between the heat exchange device 13 and the first throttling device 14 refers to the flow trajectory of the refrigerant between the heat exchange device 13 and the first throttling device 14.

[0190] The second detection device 5 can be installed at any location in the refrigerant path between the heat exchange device 13 and the first throttling device 14. For example, the second detection device 5 can be installed on the pipe between the heat exchange device 13 and the first throttling device 14. Another example is that the second detection device 5 can be installed at the port of the heat exchange device 13 near the first throttling device 14. As an example, the second detection device 5 can be installed at the junction port of the manifold 131, which is the port where the manifold 131 connects to the refrigerant circulation path 11. Yet another example is that the second detection device 5 can be installed at the port of the first throttling device 14 near the heat exchange device 13.

[0191] For ease of description, the refrigerant path between the heat exchange device 13 and the first throttling device 14 can be defined as the second path, and the second detection device 5 is used to detect the second temperature and the second pressure of the refrigerant in the second path.

[0192] The second pressure can be used to obtain the saturation temperature of the refrigerant in the second path, and the subcooling of the refrigerant in the second path can be calculated using the second temperature and the saturation temperature.

[0193] In this embodiment, the second temperature and the second pressure can be obtained through the second detection device 5, thereby obtaining the subcooling of the refrigerant in the refrigerant path between the heat exchange device 13 and the first throttling device 14.

[0194] The specific type of the second detection device 5 is not limited. The second detection device 5 may include a second temperature sensor and a second pressure sensor. The second temperature sensor is used to detect a second temperature, and the second pressure sensor is used to detect a second pressure.

[0195] In some embodiments, the second temperature sensor and the second pressure sensor can be an integrated structure.

[0196] In other embodiments, the second temperature sensor and the second pressure sensor may be discrete structures.

[0197] In some embodiments, please refer to Figures 2 to 6 The thermal management system includes a third detection device 6. The compressor 12 has a suction port 121. The third detection device 6 is disposed in the refrigerant path between the suction port 121 and the reversing device 16 to detect the third temperature and third pressure of the refrigerant.

[0198] The suction port 121 is the port through which refrigerant enters the compressor 12.

[0199] The refrigerant path between the inlet 121 and the reversing device 16 refers to the flow trajectory of the refrigerant between the inlet 121 and the reversing device 16.

[0200] The third detection device 6 can be installed at any location in the refrigerant path between the suction port 121 and the reversing device 16. For example, the third detection device 6 can be installed on the pipe between the suction port 121 and the reversing device 16. Alternatively, the third detection device 6 can be installed at the suction port 121. Yet another example is that the third detection device 6 can be installed at the port of the reversing device 16 near the suction port 121.

[0201] For ease of description, the refrigerant path between the inlet 121 and the reversing device 16 can be defined as the third path, and the third detection device 6 is used to detect the third temperature and third pressure of the refrigerant in the third path.

[0202] In this embodiment, the third temperature and the third pressure can be obtained by the third detection device 6, thereby obtaining the state of the refrigerant in the refrigerant path between the inlet 121 and the reversing device 16.

[0203] The specific type of the third detection device 6 is not limited. The third detection device 6 may include a third temperature sensor and a third pressure sensor. The third temperature sensor is used to detect a third temperature, and the third pressure sensor is used to detect a third pressure.

[0204] In some embodiments, the third temperature sensor and the third pressure sensor may be an integrated structure.

[0205] In other embodiments, the third temperature sensor and the third pressure sensor may be discrete structures.

[0206] In some embodiments, please refer to Figure 3 The thermal management system includes a first heating mode. In the first heating mode, the first throttling device 14 is in the closed state, the second throttling device 23 is in the open state, and the compressor 12 and the heating device 22 are both in the running state.

[0207] The first heating mode is the mode for heating the battery cells 10.

[0208] The first throttling device 14 being in the closed state means that the first throttling device 14 is not in the state of allowing refrigerant to flow.

[0209] The second throttling device 23 being in the open state means that the second throttling device 23 allows refrigerant to flow and is able to throttle and reduce the pressure of the refrigerant.

[0210] The compressor 12 being in operation means that the compressor 12 is powered on and in operation.

[0211] The heating device 22 being in operation means that the heating device 22 is capable of generating heat. For example, the heating device 22 is energized and converts electrical energy into heat energy.

[0212] In the first heating mode, the first throttling device 14 is closed and the second throttling device 23 is open. The refrigerant enters the refrigerant branch 21 at the first node 111 without flowing through the heat exchanger 15. Both the compressor 12 and the heating device 22 are running. The high-pressure gaseous refrigerant discharged from the compressor 12 enters the heat exchange device 13 through the reversing device 16. The refrigerant in the heat exchange device 13 releases heat to the battery cell 10, and the high-pressure gaseous refrigerant is converted into high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the first node 111 into the refrigerant branch 21. The second throttling device 23 throttles and reduces the pressure of the high-pressure liquid refrigerant, and the high-pressure liquid refrigerant is converted into a low-pressure, low-temperature gas-liquid two-phase mixture. The heating device 22 heats the low-pressure, low-temperature gas-liquid two-phase mixture into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant re-enters the refrigerant circulation path 11 through the second node 112 and flows back to the compressor 12. The compressor 12's suction port 121 draws in the low-pressure gaseous refrigerant. This process is repeated to heat the battery cell 10.

[0213] In this embodiment, the thermal management system can operate a first heating mode to heat the battery cell 10 to increase the temperature of the battery cell 10.

[0214] In some embodiments, the thermal management system operates in a first heating mode when the ambient temperature is not higher than the set temperature.

[0215] In this embodiment, when the ambient temperature is less than or equal to the set temperature, the thermal management system operates in the first heating mode, providing a heat source through the heating device 22. This can minimize the impact of low air source heat exchange efficiency caused by low ambient temperature and improve the heating effect.

[0216] The method of obtaining ambient temperature is not limited; for example, ambient temperature can be detected by a temperature sensing device.

[0217] The specific temperature setting can be configured according to requirements. For example, the set temperature can be from -15℃ to -5℃. As an example, the set temperature can be -15℃, -12℃, -10℃, -7℃, or -5℃, etc.

[0218] In some embodiments, please refer to Figure 4 The thermal management system includes a second heating mode. In the second heating mode, the first throttling device 14 is in the open state, the second throttling device 23 is in the closed state, the heating device 22 is in the off state, the compressor 12 is in the running state, and the heat exchanger 15 is an evaporator.

[0219] The second heating mode is for heating the battery cells 10.

[0220] The first throttling device 14 being in the open state means that the first throttling device 14 allows refrigerant to flow through and is able to throttle and reduce the pressure of the refrigerant.

[0221] The second throttling device 23 being in the closed state means that the second throttling device 23 is not in the state of allowing refrigerant to flow.

[0222] The heating device 22 being in a shutdown state means that the heating device 22 is not generating heat. For example, the heating device 22 is in a power-off state.

[0223] An evaporator is a device that absorbs heat to transform the refrigerant from a gas-liquid two-phase mixture into a gaseous state.

[0224] In the second heating mode, the first throttling device 14 is open, and the second throttling device 23 is closed. The refrigerant does not enter the refrigerant branch 21 but continues to flow along the refrigerant circulation path 11. The compressor 12 is running, and the high-pressure gaseous refrigerant discharged from the compressor 12 enters the heat exchange device 13 through the reversing device 16. The refrigerant in the heat exchange device 13 releases heat to the battery cell 10, transforming the high-pressure gaseous refrigerant into high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the first throttling device 14, which throttles and reduces the pressure, transforming the high-pressure liquid refrigerant into a low-pressure, low-temperature gas-liquid two-phase mixture. The heat exchanger 15 exchanges heat between the low-pressure, low-temperature gas-liquid two-phase mixture and the air source, transforming the low-pressure, low-temperature gas-liquid two-phase mixture into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant flows back to the compressor 12, and the compressor 12's suction port 121 draws in the low-pressure gaseous refrigerant. This cycle repeats continuously, achieving heating of the battery cell 10.

[0225] In this embodiment, the thermal management system can operate a second heating mode to heat the battery cell 10 to increase the temperature of the battery cell 10.

[0226] In some embodiments, the thermal management system operates a second heating mode when the ambient temperature is higher than the set temperature.

[0227] In this embodiment, when the ambient temperature is higher than the set temperature, the thermal management system operates in a second heating mode, providing heat through an air source, thus achieving the effect of environmental protection and energy saving.

[0228] In some embodiments, please refer to Figure 5 The thermal management system includes a third heating mode. In the third heating mode, the first throttling device 14 and the second throttling device 23 are both in the open state, the heating device 22 and the compressor 12 are both in the running state, and the heat exchanger 15 is an evaporator.

[0229] The third heating mode is a mode for heating the battery cells 10.

[0230] In the third heating mode, both the first throttling device 14 and the second throttling device 23 are open. The refrigerant from the heat exchange device 13 is divided into two streams. One stream continues to flow along the refrigerant circulation path 11 to enter the first throttling device 14, while the other stream enters the refrigerant branch 21 and then the second throttling device 23. Through the throttling and pressure reduction of the first throttling device 14 and the second throttling device 23, the heating device 22 can heat the refrigerant from the second throttling device 23, and the evaporator can heat the refrigerant from the first throttling device 14. Thus, both the heating device 22 and the evaporator can heat the refrigerant, and the heat from the refrigerant is then released to the battery cell 10 via the heat exchange device 13.

[0231] In this embodiment, the thermal management system operates in a third heating mode, providing dual heat sources through the heating device 22 and the air source, which can take into account both energy-saving requirements and heating effect requirements.

[0232] It is understood that in embodiments where the thermal management system includes a superheater 3, in the first heating mode and the third heating mode, the refrigerant in the first channel 31 and the refrigerant in the second channel 32 can exchange heat in the superheater 3. Those skilled in the art can understand the flow pattern of the refrigerant based on the disclosure of this application, and will not elaborate further here.

[0233] In some embodiments, please refer to Figure 2 The thermal management system includes a cooling mode. In the cooling mode, the first throttling device 14 is in the open state, the second throttling device 23 is in the closed state, the heating device 22 is in the off state, the compressor 12 is in the running state, and the heat exchanger 15 is a condenser.

[0234] The cooling mode is a mode that cools down individual battery cells 10.

[0235] A condenser is a heat exchanger that releases heat to change the refrigerant from a gaseous state to a liquid state.

[0236] In cooling mode, the first throttling device 14 is open, and the second throttling device 23 is closed. The refrigerant does not enter the refrigerant branch 21 but continues to flow along the refrigerant circulation path 11. The compressor 12 is running, and the high-pressure gaseous refrigerant discharged from the compressor 12 enters the heat exchanger 15 through the reversing device 16. The refrigerant in the heat exchanger 15 releases heat to the air source, transforming the high-pressure gaseous refrigerant into high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the first throttling device 14, which throttles and reduces the pressure, transforming the high-pressure liquid refrigerant into a low-pressure, low-temperature gas-liquid two-phase mixture. The heat exchange device 13 exchanges heat between the low-pressure, low-temperature gas-liquid two-phase mixture and the battery cell 10, allowing the low-pressure, low-temperature gas-liquid two-phase mixture to absorb heat from the battery cell 10 and transform into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant flows back to the compressor 12, and the compressor 12's suction port 121 draws in the low-pressure gaseous refrigerant. This cycle repeats continuously, achieving cooling of the battery cell 10.

[0237] In this embodiment, the thermal management system can operate in a cooling mode to cool down the battery cell 10, thereby reducing the temperature of the battery cell 10.

[0238] In some embodiments, the heat exchanger 15 may include a refrigerant flow pipe and fins. The fins are disposed on the refrigerant flow pipe, which is used to flow refrigerant, and the fins are used to increase the heat exchange area of ​​the refrigerant flow pipe. That is, the heat exchanger 15 can be a finned tube heat exchanger 15.

[0239] In some embodiments, please refer to Figure 6 The thermal management system includes a defrosting unit 7, which includes a defrosting branch 71 and a switching valve 72. The switching valve 72 is located in the defrosting branch 71. The refrigerant circulation path 11 has a third node 113 and a fourth node 114. The third node 113 is located between the reversing device 16 and the heat exchange device 13, and the fourth node 114 is located between the first throttling device 14 and the heat exchanger 15. The defrosting branch 71 connects the third node 113 and the fourth node 114.

[0240] The defrosting branch 71 is the refrigerant flow path. The defrosting branch 71 connects the third node 113 and the fourth node 114, allowing refrigerant in the refrigerant circulation path 11 to enter the defrosting branch 71. For example, refrigerant flowing out of the reversing device 16 can enter the defrosting branch 71 at the third node 113 and then flow back to the refrigerant circulation path 11 at the fourth node 114.

[0241] The switching valve 72 is located in the defrosting branch 71 and is used to open or close the defrosting branch 71.

[0242] In this embodiment, since the heat exchanger 15 is used for heat exchange with the air source, it acts as an evaporator during the heating process. The heat exchanger 15 absorbs heat from the air source, which can easily lead to excessively low air temperature around the heat exchanger 15. Water in the air condenses on the heat exchanger 15, causing frost to form and affecting its heat exchange efficiency. Therefore, when frost forms on the heat exchanger 15, the switch valve 72 can be opened. Some of the high-temperature gaseous refrigerant enters the heat exchanger 15 through the defrosting branch 71 and the fourth node 114. The high-temperature gaseous refrigerant releases heat, melting the frost on the heat exchanger 15.

[0243] In some embodiments, please refer to Figure 6 The thermal management system includes a defrosting mode. In the defrosting mode, the first throttling device 14 is closed, the second throttling device 23 and the switching valve 72 are both open, and the heating device 22 and the compressor 12 are both running.

[0244] The defrosting mode is the mode for melting the frost on the surface of the heat exchanger 15.

[0245] In defrost mode, the first throttling device 14 is closed, while the second throttling device 23 and the switching valve 72 are both open. The refrigerant enters the refrigerant branch 21 at the first node 111, bypassing the first throttling device 14. At the third node 113, the refrigerant splits into two streams. Specifically, both the compressor 12 and the heating device 22 are running. The high-pressure, high-temperature gaseous refrigerant discharged from the compressor 12 splits into two streams at the third node 113. One stream of high-pressure, high-temperature gaseous refrigerant enters the heat exchanger 15 through the defrost branch 71 and the fourth node 114. The high-temperature gaseous refrigerant releases heat, melting the frost on the heat exchanger 15. The other stream of high-pressure, high-temperature gaseous refrigerant enters the heat exchange device 13 to heat the battery cells 10. The two streams converge at the second node 112 and return to the compressor 12. This cycle repeats continuously, achieving both heating of the battery cells 10 and defrosting of the heat exchanger 15.

[0246] In this embodiment, in defrosting mode, not only can the heat exchanger 15 be defrosted, but the battery cells 10 can also be heated. Thus, if frost forms on the heat exchanger 15 during heating, the heating of the battery cells 10 can continue without stopping; the defrosting unit 7 can be used to defrost the heat exchanger 15.

[0247] In some embodiments, please refer to Figures 2 to 6The heat exchange device 13 includes a manifold 131, at least two branch pipes 132, and at least two heat exchange components 133. Each heat exchange component 133 is used to exchange heat with at least one battery cell 10. Each heat exchange component 133 is connected to one branch pipe 132. All heat exchange components 133 are connected to the refrigerant circulation path 11. All branch pipes 132 are connected to the manifold 131, and all branch pipes 132 are connected to the refrigerant circulation path 11 through the manifold 131.

[0248] The manifold 131 serves both to combine and distribute refrigerant. For example, refrigerant in the refrigerant circulation path 11 can enter all heat exchange components 133. The refrigerant in each heat exchange component 133 enters its corresponding branch pipe 132. The refrigerant in all branch pipes 132 can be combined to the return branch, and then through the manifold 131 back to the refrigerant circulation path 11. This is the combining function of the manifold 131. Alternatively, the refrigerant in the refrigerant circulation path 11 can be divided into multiple streams by the manifold 131, which then enter each branch pipe 132. The streams then enter the corresponding heat exchange components 133, and finally through the heat exchange components 133 back to the refrigerant circulation path 11. This is the distributing function of the manifold 131.

[0249] In this embodiment, the refrigerant is combined and divided through a manifold 131, at least two branch pipes 132 and at least two heat exchangers 133. Each heat exchanger 133 is used to exchange heat with at least one battery cell 10. By exchanging heat with at least two battery cells 10 through at least two heat exchangers 133, the function of heating and cooling at least two battery cells 10 is provided.

[0250] In some embodiments, the heat exchanger 133 has internal channels for refrigerant flow, and the heat exchanger 133 can make thermally conductive contact with the battery cell 10. Thus, the refrigerant in the heat exchanger 133 and the battery cell 10 can exchange heat through thermal conduction.

[0251] In some embodiments, the battery cell 10 can be bonded to the heat exchanger 133 using thermally conductive adhesive. The refrigerant within the heat exchanger 133 exchanges heat with the battery cell 10 through the heat exchanger 133 and the thermally conductive adhesive.

[0252] In some embodiments, the heat exchanger 133 may be generally plate-shaped. The interior of the plate-shaped structure forms channels for the flow of refrigerant.

[0253] As an example, each battery device 100 may be equipped with a heat exchanger 133.

[0254] In some embodiments, the heat exchanger 133 may be part of the housing of the battery device. For example, the heat exchanger 133 may be the bottom plate of the housing.

[0255] Please see Figure 7 This application also provides a control method, which is used in the thermal management system of any embodiment of this application. The control method includes:

[0256] S10. Obtain the ambient temperature;

[0257] Ambient temperature refers to the temperature of the environment in which the thermal management system or battery cell 10 is located.

[0258] S20. When the ambient temperature is not greater than the set temperature, close the first throttling device, open the second throttling device, and run the compressor and the heating device.

[0259] In other words, please see Figure 3 When the ambient temperature is not higher than the set temperature, the first heating mode can be run. The heating device 22 acts as a heat source to supply heat to the refrigerant. The heat from the heating device 22 is transferred to the battery cell 10 through the refrigerant as an intermediate medium, thereby heating the battery cell 10.

[0260] The control method provided in this application embodiment can utilize the heating device 22 as a heat source when the ambient temperature is not higher than the set temperature, thereby minimizing the impact of low air source heat exchange efficiency caused by low ambient temperature and improving the heating effect.

[0261] It is understood that any details of the devices and components involved in the control method provided in the embodiments of this application that are not described in detail can be understood by referring to the description of the thermal management system in the embodiments of this application.

[0262] As an example, the set temperature can be from -15℃ to -5℃. The thermal management system provided in this application embodiment can solve the problem that air source heating cannot operate within the ambient temperature range of -40℃ to -10℃, and realize the full temperature range heating function of -40℃ to 55℃.

[0263] In some embodiments, the control method includes:

[0264] S30. When the ambient temperature is greater than the set temperature, open the first throttling device, close the second throttling device, stop the heating device, and run the compressor.

[0265] In other words, please see Figure 4 When the ambient temperature is higher than the set temperature, the second heating mode can be operated. The heat exchanger 15 is an evaporator that uses an air source as a heat source and uses a refrigerant as an intermediate medium to transfer the heat from the air source to the battery cell 10, thereby heating the battery cell 10.

[0266] In this embodiment, when the ambient temperature is higher than the set temperature, an air source can be used as a heat source, achieving the effect of environmental protection and energy saving.

[0267] It is understood that in the embodiments of this application, steps S20 and S30 are not in any particular order, and one of steps S20 and S30 can be implemented after step S10.

[0268] In some embodiments, the control method includes:

[0269] When the ambient temperature is higher than the set temperature, the first throttling device and the second throttling device are opened, and the compressor and the heating device are operated.

[0270] In this embodiment, please refer to Figure 5 When the ambient temperature is higher than the set temperature, the third heating mode can also be run to balance heating effect and energy saving needs.

[0271] In some embodiments, please refer to Figure 3 The thermal management system includes a superheater 3, which has a first channel 31 and a second channel 32. The first channel 31 is connected in series between the reversing device 16 and the heat exchange device 13, and the second channel 32 is connected in series between the second node 112 and the heating device 22. The control method includes:

[0272] S40. Obtain the first temperature and first pressure of the refrigerant in the refrigerant path between the first channel and the heat exchange device;

[0273] The refrigerant path between the first channel 31 and the heat exchange device 13 can be defined as the first path, and the first temperature and first pressure of the refrigerant in the first path can be obtained.

[0274] S50. Obtain the superheat based on the first temperature and the first pressure;

[0275] The first pressure can be used to obtain the saturation temperature of the refrigerant in the first path, and the superheat of the refrigerant in the first path can be calculated by using the first temperature and the saturation temperature.

[0276] Superheat refers to the difference between the saturation temperature at the first temperature and the first pressure in the first path.

[0277] S60. If the superheat is greater than the first threshold, increase the opening of the second throttling device and / or reduce the speed of the compressor.

[0278] If the temperature difference between individual battery cells 10 in the battery device is too large, it can easily affect the overall charging and discharging performance of the battery device. Therefore, the superheat can be adjusted so that the heat exchange device 13 can heat each individual battery cell 10 relatively evenly, thereby improving the charging and discharging performance of the battery device.

[0279] When the superheat exceeds the first threshold, the first temperature of the refrigerant in the first path is too high, and the temperature of the gaseous refrigerant entering the heat exchange device 13 is too high, which can easily affect the uniform heating of the battery cells 10. Therefore, the opening of the second throttling device 23 can be increased to increase the flow rate of the refrigerant branch 21. The refrigerant with a larger flow rate in the second channel 32 exchanges heat with the refrigerant in the first channel 31 to reduce the temperature of the refrigerant in the first channel 31, thereby reducing the superheat. The speed of the compressor 12 can be reduced to reduce the temperature of the refrigerant at the outlet of the compressor 12, thereby reducing the first temperature of the refrigerant in the first path, thereby reducing the superheat. Therefore, the superheat can be reduced by increasing the opening of the second throttling device 23 and reducing the speed of the compressor 12.

[0280] In this embodiment, when the superheat is greater than the first threshold, the superheat can be reduced by increasing the opening of the second throttling device 23 and reducing the speed of the compressor 12, which to some extent avoids the problem of uneven heating caused by excessive superheat during the heating process of the battery cell 10, and reduces the temperature difference between the individual battery cells 10.

[0281] In some embodiments, the first temperature and the first pressure can be obtained by the first detection device 4. The specific details of the first detection device 4 have been described above and will not be repeated here.

[0282] The first threshold can be set according to requirements. For example, the first threshold can be 1°C to 2°C. For instance, the first threshold can be 1°C, 1.5°C, or 2°C, etc.

[0283] It is understood that the order of the various steps in the embodiments of this application can be adjusted according to requirements, and those skilled in the art can make reasonable combinations based on the control methods disclosed in this application. The embodiments of this application will not be listed one by one.

[0284] In some embodiments, the control method includes:

[0285] S70. If the superheat is less than the second threshold, reduce the opening of the second throttling device and / or increase the speed of the compressor, where the second threshold is less than the first threshold.

[0286] When the superheat is less than the second threshold, the first temperature of the refrigerant in the first path is too low, and the temperature of the gaseous refrigerant entering the heat exchange device 13 is too low, which can easily affect the uniform heating of the battery cell 10. Therefore, the opening of the second throttling device 23 can be reduced to reduce the flow rate of the refrigerant branch 21. The refrigerant with a smaller flow rate in the second channel 32 exchanges heat with the refrigerant in the first channel 31 to increase the temperature of the refrigerant in the first channel 31, thereby increasing the superheat. The speed of the compressor 12 can be increased to increase the temperature of the refrigerant at the outlet of the compressor 12, thereby increasing the first temperature of the refrigerant in the first path, thereby increasing the superheat. Therefore, the superheat can be increased by reducing the opening of the second throttling device 23 and increasing the speed of the compressor 12.

[0287] In this embodiment, when the superheat is less than the second threshold, the superheat can be increased by reducing the opening of the second throttling device 23 and increasing the speed of the compressor 12, which to some extent avoids the problem of uneven heating caused by excessively low superheat during the heating process of the battery cell 10, and reduces the temperature difference between the individual battery cells 10.

[0288] The second threshold is less than the first threshold. The second threshold can be set according to requirements. For example, the second threshold can be between 0℃ and 0.5℃. For instance, the second threshold can be 0℃, 0.2℃, or 0.5℃, etc.

[0289] Taking a lithium-ion battery cell 10 as an example, the operating temperature range of a lithium-ion battery cell is 10℃~35℃, and the temperature difference between lithium-ion battery cells in the battery device is no greater than 6℃. Using the thermal management system provided in this embodiment, during the cooling process of the lithium-ion battery cell, the heat exchange device 13 exchanges heat between the refrigerant and the lithium-ion battery cell, achieving a convective heat transfer coefficient as high as 2500W / (m²). 2 ·K)~25000W / (m 2 ·K), which can meet the heat dissipation requirements of lithium-ion battery cells under fast charging conditions, and also has a high performance coefficient; during the heating process of lithium-ion battery cells, the refrigerant unit and the circulation unit 1 can provide heating to the battery cells 10, meeting the working temperature requirements and temperature difference requirements of lithium-ion battery cells.

[0290] The temperature difference of a single cell 10 in a battery device refers to the difference between the highest and lowest temperatures of two single cells 10 in the battery device.

[0291] In some embodiments, the control method includes:

[0292] S80. Obtain the second temperature and second pressure of the refrigerant in the refrigerant path between the heat exchange device and the first throttling device;

[0293] The refrigerant path between the heat exchange device 13 and the first throttling device 14 can be defined as a second path, and the second temperature and second pressure of the refrigerant in the second path are obtained.

[0294] S90. Obtain the subcooling degree based on the second temperature and the second pressure;

[0295] The second pressure can be used to obtain the saturation temperature of the refrigerant in the second path, and the subcooling of the refrigerant in the second path can be calculated from the second temperature and the saturation temperature.

[0296] Subcooling refers to the difference between the saturation temperature at the second temperature and the second pressure in the second path.

[0297] S100, if the subcooling degree is greater than the third threshold, increase the opening degree of the first throttling device and / or increase the speed of the compressor.

[0298] When the subcooling exceeds the third threshold, the second temperature of the refrigerant in the second path is too low. That is, the temperature of the liquid refrigerant discharged from the heat exchange device 13 is too low, and the battery cells 10 may experience uneven heating. Therefore, the opening of the first throttling device 14 can be increased to increase the flow rate of the refrigerant circulation path 11, thereby enhancing the heat absorption capacity of the heat exchanger 15 and increasing the temperature of the refrigerant at the outlet of the compressor 12, thereby increasing the second temperature of the refrigerant in the second path and reducing the subcooling of the refrigerant in the second path. Increasing the speed of the compressor 12 can increase the temperature of the refrigerant at the outlet of the compressor 12, thereby increasing the temperature of the refrigerant entering the heat exchange device 13 and reducing the subcooling of the refrigerant in the second path. Therefore, the subcooling can be reduced by increasing the opening of the first throttling device 14 and increasing the speed of the compressor 12.

[0299] In this embodiment, when the supercooling is greater than the third threshold, the supercooling can be reduced by increasing the opening of the first throttling device 14 and increasing the speed of the compressor 12, which can avoid the problem of uneven heating caused by excessive supercooling during the heating process of the battery cell 10 to a certain extent, and reduce the temperature difference between the individual battery cells 10.

[0300] The third threshold can be set according to requirements. For example, the third threshold can be 4°C to 5°C. For instance, the third threshold can be 4°C, 4.5°C, or 5°C, etc.

[0301] In some embodiments, the control method includes:

[0302] S110. If the subcooling degree is less than the fourth threshold, reduce the opening of the first throttling device and / or reduce the speed of the compressor, wherein the fourth threshold is less than the third threshold.

[0303] When the subcooling is less than the fourth threshold, the second temperature of the refrigerant in the second path is too high. That is, the temperature of the liquid refrigerant discharged from the heat exchange device 13 is too high, and the battery cell 10 may experience uneven heating. Therefore, the opening of the first throttling device 14 can be reduced to reduce the flow rate of the refrigerant circulation path 11, thereby weakening the heat absorption capacity of the heat exchanger 15, reducing the temperature of the refrigerant at the outlet of the compressor 12, thereby reducing the second temperature of the refrigerant in the second path and increasing the subcooling of the refrigerant in the second path. The speed of the compressor 12 can be reduced to reduce the temperature of the refrigerant at the outlet of the compressor 12, thereby reducing the temperature of the refrigerant entering the heat exchange device 13 and increasing the subcooling of the second path. Therefore, the subcooling can be increased by reducing the opening of the first throttling device 14 and reducing the speed of the compressor 12.

[0304] In this embodiment, when the supercooling is less than the fourth threshold, the supercooling can be increased by reducing the opening of the first throttling device 14 and reducing the speed of the compressor 12, which to some extent avoids the problem of uneven heating caused by excessively low supercooling during the heating process of the battery cell 10, and reduces the temperature difference between the individual battery cells 10.

[0305] The fourth threshold is less than the third threshold. The fourth threshold can be set according to requirements. For example, the fourth threshold can be between 0°C and 1°C. For instance, the fourth threshold can be 0°C, 0.5°C, or 1°C, etc.

[0306] In some embodiments, the second temperature and the second pressure can be obtained by the second detection device 5.

[0307] In some embodiments, the thermal management system includes a defrosting unit 7, which includes a defrosting branch 71 and a switching valve 72. The switching valve 72 is disposed in the defrosting branch 71. The refrigerant circulation path 11 has a third node 113 and a fourth node 114. The third node 113 is located between the reversing device 16 and the heat exchange device 13, and the fourth node 114 is located between the first throttling device 14 and the heat exchanger 15. The defrosting branch 71 connects the third node 113 and the fourth node 114. The compressor 12 has a suction inlet 121. The control method includes:

[0308] S120. Obtain the third pressure of the refrigerant in the refrigerant path between the inlet and the reversing device;

[0309] The refrigerant path between the inlet 121 and the reversing device 16 can be defined as a third path, and the third pressure of the refrigerant in the third path can be obtained.

[0310] S130. When the third pressure is less than the preset pressure, close the first throttling device, open the second throttling device and the switching valve, and run the compressor and the heating device.

[0311] In other words, please see Figure 6 When the third pressure is lower than the preset pressure, the thermal management system enters defrosting mode. When the third pressure is lower than the preset pressure, the refrigerant pressure at the compressor 12's suction inlet 121 is low, causing frost to form on the surface of the heat exchanger 15. The first throttling device 14 can be closed to prevent the gas-liquid two-phase mixture from entering the heat exchanger 15, while the second throttling device 23 can be opened to allow the gas-liquid two-phase mixture from the heat exchanger 13 to enter the refrigerant branch 21, enabling the thermal management system to continuously heat the battery cells 10. Opening the switching valve 72 allows some of the high-pressure gaseous refrigerant discharged from the compressor 12 to enter the heat exchanger 15 through the defrosting branch 71. The high-pressure gaseous refrigerant in the heat exchanger 15 releases heat to melt the frost on its surface.

[0312] In this embodiment, when the third pressure is less than the preset pressure, frost forms on the surface of the heat exchanger 15. The first throttling device 14 is closed, and the second throttling device 23 and the switching valve 72 are opened. Without affecting the heating of the battery cell 10, some of the high-temperature gaseous refrigerant enters the heat exchanger 15 through the defrosting branch 71 and the fourth node 114. The high-temperature gaseous refrigerant can release heat, causing the frost on the heat exchanger 15 to melt.

[0313] The preset pressure can be set according to requirements. For example, the preset pressure can be from 190 kPa to 210 kPa. As an example, the preset pressure can be 190 kPa, 190 kPa, or 210 kPa, etc.

[0314] In some embodiments, the control method includes:

[0315] S140. Obtain the third temperature of the refrigerant in the refrigerant path between the inlet and the reversing device;

[0316] In other words, the third temperature of the refrigerant in the third path is obtained.

[0317] S150. If the third temperature is not lower than the preset temperature, close the switching valve.

[0318] When the third temperature is not lower than the preset temperature, it indicates that the frost on the surface of the heat exchanger 15 has basically melted, and the on / off valve 72 can be closed so that the high-pressure gaseous refrigerant no longer enters the heat exchanger 15 through the defrosting branch 71. In other words, when the third temperature is not lower than the preset temperature, the defrosting mode can be exited.

[0319] In this embodiment, when the third temperature is not less than the preset temperature, it can be used to indicate that the frost on the surface of the heat exchanger 15 has basically melted, and the switch valve 72 can be closed so that the high-pressure gaseous refrigerant no longer enters the heat exchanger 15 through the defrosting branch 71.

[0320] The preset temperature can be set according to needs. For example, the preset temperature can be 14℃ to 16℃. As an example, the preset temperature can be 14℃, 15℃ or 16℃, etc.

[0321] In some embodiments, the third temperature and third pressure of the refrigerant in the third path can be obtained by the third detection device 6.

[0322] In some embodiments, the thermal management system includes a processor and a memory for storing one or more programs that, when executed by the processor, cause the processor to implement the control method in any embodiment of this application.

[0323] In one specific embodiment, please refer to Figures 2 to 7 The thermal management system includes a circulating unit 1, a branch unit 2, a superheater 3, a first detection device 4, a second detection device 5, and a third detection device 6. The circulating unit 1 includes a refrigerant circulation path 11, a compressor 12, a heat exchange device 13, a first throttling device 14, a heat exchanger 15, and a reversing device 16. The compressor 12, the heat exchange device 13, the first throttling device 14, and the heat exchanger 15 are connected in series in the refrigerant circulation path 11. The reversing device 16 is disposed in the refrigerant circulation path 11 to change the flow direction of the refrigerant in the refrigerant circulation path 11. The refrigerant circulation path 11 has a first node 111 and a second node 112. The first node 111 is located between the heat exchange device 13 and the first throttling device 14, and the second node 112 is located between the heat exchanger 15 and the reversing device 16. Branch unit 2 includes a refrigerant branch 21, a heating device 22, and a second throttling device 23. The refrigerant branch 21 connects the first node 111 and the second node 112. The heating device 22 and the second throttling device 23 are both disposed on the refrigerant branch 21, with the second throttling device 23 located between the heating device 22 and the first node 111. Superheater 3 has a first channel 31 and a second channel 32. The first channel 31 is connected in series between the reversing device 16 and the heat exchange device 13, and the second channel 32 is connected in series between the second node 112 and the heating device 22.

[0324] The thermal management system can implement the control method in any of the embodiments of this application. When the ambient temperature is not higher than the set temperature, the thermal management system can operate in a first heating mode. When the ambient temperature is higher than the set temperature, it can operate in either the first heating mode or a third heating mode. When the third pressure is lower than the preset pressure, it can enter a defrosting mode. When the third temperature is not lower than the preset temperature, it can exit the defrosting mode. When it is necessary to cool the battery cell 10, it can operate in a cooling mode.

[0325] In this embodiment, when the battery cell 10 needs to be heated, an air source can be selected as the heat source. The heat exchanger 15 facilitates heat exchange between the refrigerant and the air source, transferring the heat from the air source to the battery cell 10 via the refrigerant. Alternatively, a heating device 22 can be selected as the heat source. The heating device 22 facilitates heat exchange between the refrigerant and other energy sources, transferring the heat from these other energy sources to the battery cell 10 via the refrigerant. For the heating requirements of the battery cell 10, the heat exchanger 15 facilitates heat exchange between the air source and the refrigerant, while the heating device 22 heats the refrigerant. Depending on the ambient temperature, at least one of the heat exchanger 15 and the heating device 22 can be selected to heat the refrigerant. This dual-source heating of the air source and the heating device 22 can meet the heating requirements of the battery cell 10 over a wide range of ambient temperatures. By adjusting the first throttling device 14, the second throttling device 23, and the compressor 12, the superheat of the refrigerant in the first path can be between the second threshold and the first threshold, and the subcooling of the refrigerant in the second path can be between the fourth threshold and the third threshold, thereby reducing the temperature difference between the individual battery cells 10 in the battery device. The defrosting unit 7 can also melt the frost on the surface of the heat exchanger 15.

[0326] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way.

Claims

1. A thermal management system, characterized in that, include: A circulating unit includes a refrigerant circulation path, a compressor, a heat exchange device, a first throttling device, a heat exchanger, and a reversing device. The compressor, the heat exchange device, the first throttling device, and the heat exchanger are connected in series in the refrigerant circulation path. The reversing device is located in the refrigerant circulation path to change the flow direction of the refrigerant in the refrigerant circulation path. The heat exchanger is used for heat exchange with an air source, and the heat exchange device is used for heat exchange with individual battery cells. The refrigerant circulation path has a first node and a second node. The first node is located between the heat exchange device and the first throttling device, and the second node is located between the heat exchanger and the reversing device. The branch unit includes a refrigerant branch, a heating device, and a second throttling device. The refrigerant branch connects the first node and the second node. The heating device and the second throttling device are both located in the refrigerant branch, and the second throttling device is located between the heating device and the first node.

2. The thermal management system according to claim 1, characterized in that, The thermal management system includes a superheater having a first channel and a second channel. The first channel is connected in series between the reversing device and the heat exchange device, and the second channel is connected in series between the second node and the heating device.

3. The thermal management system according to claim 2, characterized in that, The thermal management system includes a first detection device disposed in the refrigerant path between the first channel and the heat exchange device to detect a first temperature and a first pressure of the refrigerant.

4. The thermal management system according to claim 1, characterized in that, The thermal management system includes a second detection device disposed in the refrigerant path between the heat exchange device and the first throttling device to detect a second temperature and a second pressure of the refrigerant.

5. The thermal management system according to claim 1, characterized in that, The thermal management system includes a third detection device. The compressor has a suction port, and the third detection device is disposed in the refrigerant path between the suction port and the reversing device to detect a third temperature and a third pressure of the refrigerant.

6. The thermal management system according to claim 1, characterized in that, The thermal management system includes a first heating mode. In the first heating mode, the first throttling device is in a closed state, the second throttling device is in a closed state, and both the compressor and the heating device are in an operating state.

7. The thermal management system according to claim 6, characterized in that, When the ambient temperature is not higher than the set temperature, the thermal management system operates in the first heating mode.

8. The thermal management system according to claim 1, characterized in that, The thermal management system includes a second heating mode. In the second heating mode, the first throttling device is in the open state, the second throttling device is in the closed state, the heating device is in the off state, the compressor is in the running state, and the heat exchanger is an evaporator.

9. The thermal management system according to claim 8, characterized in that, When the ambient temperature is higher than the set temperature, the thermal management system operates in the second heating mode.

10. The thermal management system according to claim 1, characterized in that, The thermal management system includes a third heating mode, in which the first throttling device and the second throttling device are both in the open state, the heating device and the compressor are both in the running state, and the heat exchanger is an evaporator.

11. The thermal management system according to claim 1, characterized in that, The thermal management system includes a cooling mode, in which the first throttling device is in the open state, the second throttling device is in the closed state, the heating device is in the off state, the compressor is in the running state, and the heat exchanger is a condenser.

12. The thermal management system according to claim 1, characterized in that, The thermal management system includes a defrosting unit, which includes a defrosting branch and a switching valve. The switching valve is located in the defrosting branch. The refrigerant circulation path has a third node and a fourth node. The third node is located between the reversing device and the heat exchange device, and the fourth node is located between the first throttling device and the heat exchanger. The defrosting branch connects the third node and the fourth node.

13. The thermal management system according to claim 12, characterized in that, The thermal management system includes a defrosting mode, in which the first throttling device is in a closed state, the second throttling device and the switching valve are both in an open state, and the heating device and the compressor are both in an operating state.

14. The thermal management system according to any one of claims 1 to 13, characterized in that, The heat exchange device includes a manifold, at least two branch lines, and at least two heat exchange components. Each heat exchange component is used to exchange heat with at least one of the battery cells. Each heat exchange component is connected to one of the branch lines. All the heat exchange components are connected to the refrigerant circulation path. All the branch lines are connected to the manifold, and all the branch lines are connected to the refrigerant circulation path through the manifold.

15. A control method, characterized in that, The control method is used in the thermal management system of claim 1, and the control method includes: Obtain the ambient temperature; When the ambient temperature is not greater than the set temperature, the first throttling device is closed, the second throttling device is opened, and the compressor and the heating device are operated.

16. The control method according to claim 15, characterized in that, The control method includes: When the ambient temperature is higher than the set temperature, open the first throttling device, close the second throttling device, stop the heating device, and run the compressor.

17. The control method according to claim 15, characterized in that, The thermal management system includes a superheater, which has a first channel and a second channel. The first channel is connected in series between the reversing device and the heat exchange device, and the second channel is connected in series between the second node and the heating device. The control method includes: Obtain the first temperature and first pressure of the refrigerant in the refrigerant path between the first channel and the heat exchange device; The superheat is obtained based on the first temperature and the first pressure; If the superheat exceeds the first threshold, increase the opening of the second throttling device and / or reduce the speed of the compressor.

18. The control method according to claim 17, characterized in that, The control method includes: If the superheat is less than the second threshold, the opening of the second throttling device is reduced and / or the speed of the compressor is increased, where the second threshold is less than the first threshold.

19. The control method according to claim 15, characterized in that, The control method includes: Obtain the second temperature and second pressure of the refrigerant in the refrigerant path between the heat exchange device and the first throttling device; The degree of subcooling is obtained based on the second temperature and the second pressure; If the subcooling degree is greater than the third threshold, increase the opening of the first throttling device and / or increase the speed of the compressor.

20. The control method according to claim 19, characterized in that, The control method includes: If the subcooling degree is less than the fourth threshold, reduce the opening of the first throttling device and / or reduce the speed of the compressor, where the fourth threshold is less than the third threshold.

21. The control method according to claim 15, characterized in that, The thermal management system includes a defrosting unit, which includes a defrosting branch and a switching valve. The switching valve is located in the defrosting branch. The refrigerant circulation path has a third node and a fourth node. The third node is located between the reversing device and the heat exchange device, and the fourth node is located between the first throttling device and the heat exchanger. The defrosting branch connects the third node and the fourth node. The compressor has a suction inlet. The control method includes: Obtain the third pressure of the refrigerant in the refrigerant path between the inlet and the reversing device; When the third pressure is less than the preset pressure, the first throttling device is closed, the second throttling device and the switching valve are opened, and the compressor and the heating device are operated.

22. The control method according to claim 21, characterized in that, The control method includes: Obtain the third temperature of the refrigerant in the refrigerant path between the inlet and the reversing device; If the third temperature is not lower than the preset temperature, the switching valve is closed.

23. An electrical appliance, characterized in that, It includes a battery cell and a thermal management system as described in any one of claims 1 to 14, wherein the battery cell is used to store or provide electrical energy.

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