High-voltage battery cooling system and vehicle
Patent Information
- Application Number
- CN202510297969.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2026-09-15
Smart Images
Figure CN122762893A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power batteries, and in particular to high-voltage battery cooling systems and vehicles. Background Technology
[0002] With the rapid development of new energy vehicles, lithium-ion power batteries, which are their power source, have also entered a period of rapid development, among which battery cooling and thermal management are an important part.
[0003] Currently, high-voltage battery cooling systems typically use a water-glycol mixture or refrigerant as the coolant. These systems consist of pipes and heat sinks, and their dimensions ensure safe operation without degradation under normal operating conditions.
[0004] However, current power battery cooling systems still have some defects or problems. For example, existing cooling systems are difficult to adapt to the demand for 5C-level ultra-high-rate charging that lasts for several minutes. To ensure thermal runaway protection, the design specifications of cooling pipes and heat sinks need to far exceed the requirements of daily operating conditions, resulting in increased system weight and significantly higher manufacturing costs. In addition, existing solutions (such as bottom contact cooling) can only exchange heat through a limited contact surface, resulting in a temperature gradient of 8-12°C inside the cell, affecting the overall thermal balance of the battery pack.
[0005] Ethylene glycol coolant leakage may also pose a short-circuit risk, and the electrolyte decomposition reaction will produce a hydrogen-oxygen mixture (H2 / O2 concentration can reach the explosion limit of 4%-75%). Current solutions require the integration of multiple safety protection mechanisms (including pressure relief valves, gas detection modules, etc.), which increases the complexity of the battery pack structure.
[0006] The current multi-stage cooling circuit architecture increases system weight. Furthermore, the serial flow channel design results in a temperature difference of 10-15℃ between the beginning and end of the circuit, with the maximum temperature difference between modules exceeding 8℃. Actual measurement data shows that at an ambient temperature of 45℃, the internal temperature difference of the battery pack further increases to over 20℃, severely impacting charge / discharge consistency and cycle life.
[0007] Therefore, in order to further reduce costs and process complexity, it is desirable to design a cooling system for cooling high-voltage battery packs in vehicles that can achieve efficient cooling and provide uniform thermal management. Summary of the Invention
[0008] This summary is provided to introduce, in a simplified form, some concepts that will be further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.
[0009] To address the above problems, according to a first aspect of the present invention, a cooling system is provided for cooling a high-voltage battery pack of a vehicle, the cooling system comprising: a compressor for compressing a cooling medium; a cooler connected to the compressor for cooling the compressed cooling medium; an expansion device connected to the cooler for controlling the pressure and flow rate of the cooling medium entering the high-voltage battery pack; a cooling medium distribution pipe connected to the expansion device, the cooling medium distribution pipe including a plurality of branch pipes, the end of each branch pipe being assigned to a cooling location of the high-voltage battery pack, wherein each branch pipe has a pressure relief valve at its end for causing the cooling medium to expand at the corresponding cooling location; and a suction pump connected to the high-voltage battery pack for drawing the cooling medium from the high-voltage battery pack and returning the cooling medium to the compressor for further circulation.
[0010] In the technical solution of this invention embodiment, by circulating a non-conductive cooling medium (e.g., CO2) through the cooling system, the cooling medium can directly expand, vaporize, or partially or even transform into a solid (e.g., CO2) at the location to be cooled and absorb a large amount of heat, thereby achieving a highly efficient cooling effect, reducing costs, the size of the cooling system, and providing uniform thermal management.
[0011] According to one embodiment of the present invention, the cooling medium is non-conductive and vaporizes at room temperature.
[0012] According to a further embodiment of the present invention, the cooling medium is carbon dioxide (CO2).
[0013] According to a further embodiment of the present invention, the cooling system further includes: a pressure sensor for measuring the internal pressure of the high-voltage battery pack; and a pressure control device communicatively connected to the pressure sensor for adjusting the compressor, the suction pump, and the expansion device to maintain the internal pressure of the high-voltage battery pack within a predefined range.
[0014] According to a further embodiment of the present invention, a plurality of branch pipes in the cooling medium distribution pipe are located above and / or below the high-voltage battery pack, and are capable of distributing cooling medium in parallel to each cell in each battery module of the high-voltage battery pack and to the switch.
[0015] According to a further embodiment of the present invention, the cooling medium is in direct contact with the components of the high-voltage battery pack to be cooled at the end of each branch pipe in the cooling medium distribution pipe.
[0016] According to a further embodiment of the invention, the pressure relief valve at the end of each branch pipe in the cooling medium distribution pipe has a dedicated opening point or opening pressure for parallel and uniform distribution of the cooling medium to each cell.
[0017] According to a further embodiment of the present invention, the expansion device is configured as an electrically controlled expansion valve, which is used to expand the high-pressure cooling medium via the compressor and the cooler, converting it into a low-temperature, low-pressure cooling medium.
[0018] According to a further embodiment of the invention, the cooling medium escapes from the pressure relief valve at the end of each branch pipe in the cooling medium distribution pipe through expansion.
[0019] According to a further embodiment of the invention, the operating point for expansion can be adjusted so that, when carbon dioxide is used as the cooling medium, it can be partially converted into solid dry ice.
[0020] According to a second aspect of the invention, a method for cooling a high-voltage battery pack of a vehicle is provided, the method comprising: introducing a cooling medium sequentially via a compressor, a cooler, and an expansion device into a cooling medium distribution conduit, wherein the compressor is used to compress the cooling medium, the cooler is used to cool the compressed cooling medium, and the expansion device is used to control the pressure and flow rate of the cooling medium entering the high-voltage battery pack, wherein the cooling medium distribution conduit includes a plurality of branch conduits, the end of each branch conduit being assigned to a cooling location of the high-voltage battery pack, wherein each branch conduit has a pressure relief valve at its end; expanding the cooling medium at the corresponding cooling location at the end of each branch conduit in the cooling medium distribution conduit; and drawing the cooling medium from the high-voltage battery pack using a suction pump and returning the cooling medium to the compressor for further circulation.
[0021] According to one embodiment of the present invention, the cooling medium is non-conductive and vaporizes at room temperature.
[0022] According to a further embodiment of the present invention, the cooling medium is carbon dioxide (CO2).
[0023] According to a further embodiment of the present invention, the method further includes: using a pressure control device to adjust the compressor, the suction pump and the expansion device so that the internal pressure of the high-voltage battery pack is maintained within a predefined range.
[0024] According to a further embodiment of the present invention, a plurality of branch pipes in the cooling medium distribution pipe are located above and / or below the high-voltage battery pack, and are capable of distributing cooling medium in parallel to each cell in each battery module of the high-voltage battery pack and to the switch.
[0025] According to a further embodiment of the present invention, the cooling medium is in direct contact with the components of the high-voltage battery pack to be cooled at the end of each branch pipe in the cooling medium distribution pipe.
[0026] According to a third aspect of the invention, a vehicle is provided comprising a cooling system as described in any of the preceding aspects.
[0027] To address the problems existing in the prior art, this invention designs a cooling system for cooling high-voltage battery packs in vehicles. This system allows the cooling medium to circulate through the cooling medium, expand directly at the location to be cooled, and absorb a large amount of heat, thereby achieving a highly efficient cooling effect, reducing costs, the size of the cooling system, and providing uniform thermal management.
[0028] These and other features and advantages will become apparent from the following detailed description and with reference to the accompanying drawings. It should be understood that the foregoing general description and the following detailed description are illustrative only and do not limit the scope of the claims. Attached Figure Description
[0029] To gain a more detailed understanding of the manner in which the features of this disclosure are described above, reference can be made to the various embodiments for a more specific description of the above-briefly summarized aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and should not be considered as limiting its scope, as this description may allow for other equivalent and effective aspects.
[0030] Figure 1 An example architecture diagram of a cooling system for cooling a high-voltage battery pack of a vehicle, according to an embodiment of the present disclosure, is shown.
[0031] Figure 2 A schematic flowchart illustrating a method for cooling a high-voltage battery pack of a vehicle according to an embodiment of the present disclosure is shown.
[0032] Figure 3 An example vehicle incorporating the cooling system disclosed herein is shown. Detailed Implementation
[0033] The following detailed description is sufficient to enable any person skilled in the art to understand the technical content of one or more embodiments of this specification and to implement them accordingly. Furthermore, based on the specification, claims, and drawings disclosed herein, those skilled in the art can easily understand the objects and advantages associated with one or more embodiments of this specification. Throughout this specification, the term "vehicle" refers to any type of automobile, including but not limited to cars, vans, trucks, buses, etc. For simplicity, the invention is described in relation to "automobile." The terms "A or B" as used in this specification mean "A and B" and "A or B," and do not imply that A and B are exclusive unless otherwise stated.
[0034] As mentioned above, the current cooling systems for vehicle power batteries are generally unable to meet the heat dissipation requirements of 5C-level ultra-high rate charging (lasting for several minutes), thus requiring over-specification design, which leads to a significant increase in system weight and cost. In addition, the effective heat conduction area of the current cooling system is insufficient, and serial cooling results in a temperature difference between the beginning and end.
[0035] To address this problem, embodiments of this specification envision a cooling system for cooling a vehicle's high-voltage battery pack, which allows the cooling medium to circulate through the system, expand directly at the location to be cooled, and absorb a large amount of heat, thereby achieving efficient cooling, reducing costs, the size of the cooling system, and providing uniform thermal management.
[0036] For example, see Figure 1 The diagram illustrates an example architecture of a cooling system 100 for cooling a high-voltage battery pack of a vehicle, according to an embodiment of the present disclosure.
[0037] like Figure 1 As shown, the cooling system 100 may include a compressor 102, which can be used to compress a cooling medium (or refrigerant).
[0038] In one embodiment, the cooling medium is non-conductive and can be vaporized at room temperature.
[0039] Preferably, the cooling medium may include carbon dioxide (CO2).
[0040] Of course, it is understood that any other cooling medium known to those skilled in the art can also be conceived, such as nitrogen, other inert gases, etc.
[0041] For example, CO2 refrigerant is compressed to a pressure of over 100 bar by an AC compressor.
[0042] Furthermore, the cooling system 100 may also include a cooler 104 connected to the compressor 102 described above, which is used to cool the compressed cooling medium.
[0043] Furthermore, the expansion device 106 can be connected to the cooler 104 and can be used to control the pressure and flow rate of the cooling medium entering the high-voltage battery pack.
[0044] In one embodiment, the expansion device 106 may be designed as an electrically controlled expansion valve, which can be used to expand the high-pressure cooling medium via the compressor and cooler to a low-temperature, low-pressure cooling medium, while simultaneously regulating the flow rate and pressure of the cooling medium entering the high-voltage battery pack according to a preset program.
[0045] Furthermore, inside the high-voltage battery pack, there is a cooling medium distribution pipe 108 connected to the expansion device 106, which may include a plurality of branch pipes 110, the end of each branch pipe 110 being assigned to a cooling position of the high-voltage battery pack, wherein each branch pipe 110 has a pressure relief valve 112 at the end, which can be used to cause the cooling medium to expand at the corresponding cooling position.
[0046] In one embodiment, multiple branch pipes 110 in the cooling medium distribution pipe 108 may be located above and / or below the high-voltage battery pack (this only relates to the conventional installation location of the cooling system and battery in the vehicle), and are capable of distributing cooling medium (such as...) in parallel to each cell in each battery module of the high-voltage battery pack and to the switches. Figure 1 (As shown in the embodiments).
[0047] Therefore, since parallel distribution can distribute the cooling medium more evenly, the heat distribution between battery cells is more uniform, thus reducing local overheating or overcooling caused by uneven flow, thereby improving the system's energy efficiency ratio.
[0048] In one implementation, the cooling medium comes into direct contact with the components of the high-voltage battery pack (e.g., cells or battery modules) at the end of each branch of the cooling medium distribution conduit at the point to be cooled. This can be achieved, for example, by using carbon dioxide as a refrigerant, because carbon dioxide is electrically insulating and leaves no residue when it evaporates. There is also no electrical safety issue if carbon dioxide comes into contact with charged parts of the battery. Where cooling is required, the carbon dioxide expands and escapes as a gas. To meet higher cooling requirements, simply increase the size of the cooling conduit.
[0049] In one implementation, since the cooling medium (e.g., CO2) should expand directly at the point of cooling, a pressure relief valve needs to be installed at the end of the cooling medium distribution line. In some cases, the operating point for expansion can be adjusted. For example, in the case of CO2, through the pressure relief valve, CO2 expands and carries away heat from the environment; at the point of pressure release, CO2 can even be converted into dry ice (CO2 snow).
[0050] Preferably, the pressure relief valve at the end of each branch pipe in the cooling medium distribution pipeline may have a dedicated opening point or opening pressure for parallel and uniform distribution of the cooling medium to each cell.
[0051] Furthermore, the cooling system 100 may also include a suction pump 114 connected to the high-voltage battery pack, which can be used to draw cooling medium from the high-voltage battery pack and return the cooling medium to the compressor 102 for further circulation, such as... Figure 1 As shown.
[0052] More preferably, to avoid damage to the degassing device or casing of the high-voltage battery pack, a highly sensitive pressure control device is required. This device must regulate the AC compressor, expansion valve, and suction pump to maintain the internal pressure of the high-voltage battery pack within a certain range to prevent damage.
[0053] Thus, the cooling system 100 may also include a pressure sensor 116 for measuring the internal pressure of the high-voltage battery pack; and a pressure control device 118 communicatively connected to the pressure sensor 116 for adjusting the compressor 102, the suction pump 114, and the expansion device 106 to maintain the internal pressure of the high-voltage battery pack within a predefined range.
[0054] Those skilled in the art will understand that the system and its modules / devices disclosed herein can be implemented in hardware or software, and the modules can be combined or merged in any suitable manner.
[0055] Figure 2 A schematic flowchart of a method 200 for cooling a high-voltage battery pack of a vehicle according to an embodiment of the present disclosure is shown.
[0056] Method 200 begins at step 202, in which a cooling medium is sequentially introduced into a cooling medium distribution pipe 108 via a compressor 102, a cooler 104, and an expansion device 106. The compressor 102 is used to compress the cooling medium, the cooler 104 is used to cool the compressed cooling medium, and the expansion device 106 is used to control the pressure and flow rate of the cooling medium entering the high-voltage battery pack. The cooling medium distribution pipe 108 may include a plurality of branch pipes 110, the end of which is assigned to a cooling location of the high-voltage battery pack. Each branch pipe 110 has a pressure relief valve 112 at its end.
[0057] In one embodiment, the cooling medium is non-conductive and vaporizes at room temperature.
[0058] Preferably, the cooling medium can be carbon dioxide (CO2).
[0059] In one embodiment, the expansion device 106 may be designed and configured as an electrically controlled expansion valve, which can be used to expand the high-pressure cooling medium via the compressor and cooler, transforming it into a low-temperature, low-pressure cooling medium.
[0060] In one embodiment, multiple branch pipes in the cooling medium distribution pipe may be located above and / or below the high-voltage battery pack, and are capable of distributing cooling medium in parallel to each cell in each battery module of the high-voltage battery pack and to the switches.
[0061] Further, in step 204, the cooling medium is expanded at the corresponding cooling location at the end of each branch pipe in the cooling medium distribution pipe.
[0062] In other words, inside the high-voltage battery pack, the cooling medium is distributed to the locations requiring cooling (potentially the bottom and top of the battery cells and switches) via cooling pipes. At each end of the cooling medium distribution pipe, i.e., each location requiring cooling, there is a pressure relief valve to ensure that the cooling medium expands only at the location requiring cooling. Due to the pressure drop, the cooling medium will cool significantly, and may even partially solidify (e.g., carbon dioxide snow). This change in polymer state helps the cooling medium absorb a large amount of heat from the areas requiring cooling.
[0063] Preferably, the cooling medium is in direct contact with the components of the high-voltage battery pack at the end of each branch pipe 110 in the cooling medium distribution pipe 108, at the location to be cooled. This can be achieved by using CO2 as a coolant, as CO2 has electrical insulating properties and leaves no residue upon evaporation. Furthermore, no electrical safety issues will arise if CO2 comes into contact with the charged components of the battery.
[0064] In step 206, the cooling medium is drawn from the high-voltage battery pack using the suction pump 114 and returned to the compressor for further circulation.
[0065] Furthermore, the pressure control device 118 can be used to regulate the compressor 102, the suction pump 114, and the expansion device 106 so that the internal pressure of the high-voltage battery pack is maintained within a predefined range.
[0066] Therefore, by circulating the cooling medium through the cooling system, it expands directly at the location to be cooled and absorbs a large amount of heat, thereby achieving a highly efficient cooling effect, reducing costs, the size of the cooling system, and providing uniform thermal management.
[0067] Figure 3An example vehicle 500 including a cooling system according to this application is shown. The vehicle may include, but is not limited to, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, etc. Currently, passenger vehicle power batteries are mostly single-pack systems (i.e., battery packs), which use assembly technology to integrate individual battery cells into a battery pack, mainly involving structure, thermal management, electrical connection design, and BMS technology. Assembly technology may include, for example, MTP, CTP, CTC, CTB, or MTP. For example, MTP technology refers to first integrating cells into modules, and then integrating modules into a pack. The core of MTP assembly technology lies in module design; a module generally consists of a frame (end plate, side plate, base plate), cells, high and low voltage electrical connection components, CCS components, insulation and buffer components. CTP technology refers to the technology of directly integrating cells into a pack.
[0068] By utilizing the aforementioned cooling system, a non-conductive cooling medium (e.g., CO2) can be circulated through the system, allowing the cooling medium to expand directly at the location to be cooled, vaporize, or even partially or completely transform into a solid state (e.g., CO2 snow) and absorb a large amount of heat, thereby achieving a highly efficient cooling effect, reducing costs, the size of the cooling system, and providing uniform thermal management.
[0069] The foregoing description includes examples of various aspects of the claimed subject matter. It is certainly impossible to describe every conceivable combination of components or methods for the purpose of depicting the claimed subject matter, but those skilled in the art will recognize that many further combinations and arrangements of the claimed subject matter are possible. Thus, the disclosed subject matter is intended to cover all such changes, modifications, and variations that fall within the spirit and scope of the appended claims.
Claims
1. A cooling system (100) for cooling a high-voltage battery pack of a vehicle, the cooling system (100) comprising: Compressor (102) for compressing cooling medium; A cooler (104) connected to the compressor (102) is used to cool the compressed cooling medium; An expansion device (106) connected to the cooler (104) is used to control the pressure and flow rate of the cooling medium entering the high-voltage battery pack; A cooling medium distribution pipe (108) connected to the expansion device (106) includes a plurality of branch pipes (110), the end of each branch pipe (110) being assigned to a cooling location of the high-voltage battery pack, wherein each branch pipe (110) has a pressure relief valve (112) at its end for causing the cooling medium to expand at the corresponding cooling location; and A suction pump (114) connected to the high-voltage battery pack is used to draw the cooling medium from the high-voltage battery pack and return the cooling medium to the compressor (102) for further circulation.
2. The cooling system (100) as claimed in claim 1, characterized in that, The cooling medium is non-conductive and vaporizes at room temperature.
3. The cooling system (100) as claimed in claim 1, characterized in that, The cooling medium is carbon dioxide (CO2).
4. The cooling system (100) as claimed in claim 1, characterized in that, The cooling system (100) further includes: Pressure sensor (116) for measuring the internal pressure of the high-voltage battery pack; and A pressure control device (118) communicatively connected to the pressure sensor (116) is used to adjust the compressor (102), the suction pump (114), and the expansion device (106) so that the internal pressure of the high-voltage battery pack is maintained within a predefined range.
5. The cooling system (100) as claimed in claim 1, characterized in that, The multiple branch pipes (110) in the cooling medium distribution pipe (108) are located above and / or below the high-voltage battery pack, and are capable of distributing cooling medium in parallel to each cell in each battery module of the high-voltage battery pack and to the switch.
6. The cooling system (100) as claimed in claim 1, characterized in that, The cooling medium comes into direct contact with the components of the high-voltage battery pack at the end of each branch pipe (110) in the cooling medium distribution pipe (108) where it is to be cooled.
7. The cooling system (100) as claimed in claim 1, characterized in that, The pressure relief valve at the end of each branch pipe (110) in the cooling medium distribution pipe (108) has a dedicated opening point or opening pressure for parallel and uniform distribution of the cooling medium to each cell.
8. The cooling system (100) as claimed in claim 1, characterized in that, The expansion device (106) is configured as an electrically controlled expansion valve, which is used to expand the high-pressure cooling medium via the compressor (102) and the cooler (104) to a low-temperature, low-pressure cooling medium.
9. The cooling system (100) as claimed in claim 8, characterized in that, The cooling medium escapes from the pressure relief valve at the end of each branch pipe (110) in the cooling medium distribution pipe (108) through expansion.
10. The cooling system (100) as claimed in claim 9, characterized in that, The operating point for expansion can be adjusted so that, when carbon dioxide is used as the cooling medium, it can be partially converted into solid dry ice.
11. A method for cooling a high-voltage battery pack of a vehicle, the method comprising: The cooling medium is sequentially passed through the compressor (102), cooler (104), and expansion device (106) into the cooling medium distribution pipe (108). The compressor (102) is used to compress the cooling medium, the cooler (104) is used to cool the compressed cooling medium, and the expansion device (106) is used to control the pressure and flow rate of the cooling medium entering the high-voltage battery pack. The cooling medium distribution pipe (108) includes a plurality of branch pipes (110), the end of each branch pipe (110) being assigned to the cooling position of the high voltage battery pack, wherein each branch pipe (110) has a pressure relief valve (112) at the end of its end. The cooling medium expands at the corresponding cooling location at the end of each branch pipe (110) in the cooling medium distribution pipe (108); and The cooling medium is drawn from the high-voltage battery pack using a suction pump (114) and returned to the compressor (102) for further circulation.
12. The method as described in claim 11, characterized in that, The cooling medium is non-conductive and vaporizes at room temperature.
13. The method as described in claim 12, characterized in that, The cooling medium is carbon dioxide (CO2).
14. The method as described in claim 11, characterized in that, The method further includes: The compressor (102), the suction pump (114), and the expansion device (106) are adjusted using a pressure control device (118) to maintain the internal pressure of the high-voltage battery pack within a predefined range.
15. The method as described in claim 11, characterized in that, The multiple branch pipes (110) in the cooling medium distribution pipe (108) are located above and / or below the high-voltage battery pack, and are capable of distributing cooling medium in parallel to each cell in each battery module of the high-voltage battery pack and to the switch.
16. The method as described in claim 11, characterized in that, The cooling medium comes into direct contact with the components of the high-voltage battery pack at the end of each branch pipe (110) in the cooling medium distribution pipe (108) where it is to be cooled.
17. A vehicle comprising a cooling system (100) as claimed in any one of claims 1-10.