The present disclosure relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to an air cooled thermal management system for battery modules that may be used particularly in vehicular contexts, as well as other applications.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Vehicles using electric power for all or a portion of their motive power may provide numerous advantages as compared to traditional vehicles powered by internal combustion engines. For example, vehicles using electric power may produce fewer pollutants and may exhibit greater fuel efficiency. In some cases, vehicles using electric power may eliminate the use of gasoline entirely and derive the entirety of their motive force from electric power. As technology continues to evolve, there is a need to provide improved power sources, particularly battery modules, for such vehicles. For example, it is desirable to provide effective cooling to the battery modules to prevent premature aging of individual battery cells within the battery module, while simultaneously minimizing the cost of the battery module. It is also desirable to provide a cooling system design that can utilize cabin air as an effective coolant.
Vehicles using electric power for at least a portion of their motive force may derive their electric power from the multiple individual battery cells packaged into the battery modules. The individual cells may utilize lithium-ion chemistry and may be packaged into prismatic casings. The battery modules may contain the multiple individual cells within a generally rectangular housing. As the individual cells are charged and discharged, they may generate heat due to Joule heating caused by current flowing through the internal resistance of the cells. In addition, the individual cells may be subjected to heating via exothermic chemical reactions occurring within the cells. Further, in some cases, elevated ambient temperatures may add heat to the cells via conduction, convection, and/or radiation. These (and other potential) sources of thermo-electrical, thermo-chemical, and environmental heating may cause increased localized temperatures of the cells. The increase in temperature may be aggravated by the tight packaging of multiple cells within the confined space of the battery module housing. Increased temperatures may increase the rate of chemical reactions, cause physical distortion (e.g., swelling, short circuits, open circuits), that may exponentially age the cells and the battery module. Accordingly, it would be desirable to provide an effective cooling system to draw excess heat away from the module, thereby creating an isothermal temperature distribution along the cells in a module or battery pack to preserve the cells.
Further, it may be advantageous to utilize air as the coolant within the cooling system. Typical cooling systems may use a liquid coolant looped from the engine to the battery of the vehicle. However, liquid coolants may be disadvantageous in vehicular systems, which heavily rely on electronic components. For example, a liquid coolant leak may damage any electronic components contacted. Further, liquid coolants are more dense than air, resulting in increased weight and cost associated with liquid coolant based systems. Additionally, use of a liquid coolant requires an additional fluid stream within the vehicle, whereas air may be cycled throughout the cabin and the cooling system, reducing the number of fluids circling through the vehicle. Accordingly, it would be desirable to provide a cooling system that effectively uses air to create the isothermal temperature distribution along the cells.
A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.
The present systems may be adapted to a wide range of settings and may be particularly well suited to vehicles deriving at least a portion of their motive force from electric power. Moreover, the cooling systems may be useful in other applications, such as power storage for alternative energy sources, portable battery modules, and back-up power supplies.
Embodiments of the present disclosure relate to cooling systems for battery modules having multiple individual battery cells. In accordance with disclosed embodiments, the cooling system may include a battery pack contained within a thermally conductive housing. The housing may be placed in physical contact with a plurality of heat sink fins to draw away heat generated by the multiple battery cells. Further, a manifold flow distribution system may direct cooling air through the heat sink fins to augment the heat transfer provided by the fins.
Various refinements of the features noted above may exist in relation to the presently disclosed embodiments. Additional features may also be incorporated in these various embodiments as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more embodiments may be incorporated into other disclosed embodiments, either alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter.
Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:
The term “xEV” is defined herein to include vehicles that use electric power for all or a portion of their vehicular motive force, including, but not limited to, the following vehicles. As will be appreciated by those skilled in the art, hybrid electric vehicles (HEVs) combine an internal combustion engine propulsion system and a battery-powered electric propulsion system. The term HEV may include any variation of a hybrid electric vehicle, such as micro-hybrid and mild hybrid systems, which disable the internal combustion engine when the vehicle is idling and utilize a battery system to continue powering the air conditioning unit, radio, or other electronics, as well as to kick-start the engine when propulsion is desired. The mild hybrid system may apply some level of power assist to the internal combustion engine, whereas the micro-hybrid system may not supply power assist to the internal combustion engine. A plug-in electric vehicle (PEV) is any vehicle that can be charged from an external source of electricity, such as wall sockets, and the energy stored in the rechargeable battery packs drives or contributes to drive the wheels. PEVs are a subcategory of electric vehicles that include all-electric or battery electric vehicles (BEVs), plug-in hybrid vehicles (PHEVs), and electric vehicle conversions of hybrid electric vehicles and conventional internal combustion engine vehicles. An electric vehicle (EV) is an all-electric vehicle that uses one or more motors powered by electric energy for its propulsion.
As described in more detail below, disclosed herein are embodiments of air cooled systems for battery systems and/or modules, which may be well suited to xEV applications. Embodiments of the air cooled system provided herein may include a manifold flow distribution system. The manifold flow distribution system may be physically contacting a housing of the battery system and may include a plurality of fins arranged within manifolds of the air cooled system. Further, the manifold flow distribution system may direct cool air in a specific manner along the battery system. The cooling system described herein may generate an isothermal temperature distribution along the battery system. Further, the cooling system may isolate the cells from the air flow route, such that in the event of an effluent release from the cells, the air is not contaminated by effluent.
The battery systems that include the cooling system may be easily configured for use in xEVs. In certain embodiments, the xEV may include at least one battery system, and each battery system may include the cooling system to remove excess heat and prevent premature aging of the individual cells within the battery systems. Removing heat from the modules, and consequently the individual cells, may enable the cells to facilitate higher currents without exceeding set temperature limits. Further, the removed heat may be recovered and repurposed for other applications throughout the xEV. For example, the waste heat may be used to warm the passenger compartment or defrost the windshield during cold weather.
Turning now to the drawings,
Further, although the battery system 12 is illustrated in
For purposes of discussion, it may be helpful to discuss the battery system 12 with respect to a particular type of xEV, for example, an HEV.
As previously described, each battery system 12 may include a cooling system that removes excess heat generated by the individual cells within a housing of the battery system 12. A basic schematic of a battery system 12 having such a cooling system 30 is illustrated in
As depicted, the cooling system 30 may be disposed beneath the portion of the housing 34 contacting the cells 32. Particularly, when the cells 32 are in prismatic form, it may be advantageous to place the cooling system 30 directly beneath the battery system 12 due to high thermal conductivity of the cells 32 in the z-direction 40, as opposed to the x-direction 42 and the y-direction 44. For example, the coefficient of thermal conductivity may be approximately 3 to 7 times larger in the z-direction 40 as compared to the x-direction 42 and the y-direction 44. However, in alternative embodiments, the cooling system 30 may be disposed against any external surface of the housing 34 of the battery system 12. For example, the cooling system 30 may be disposed against a different external surface of the housing 34 due to space constraints within the vehicle 10.
The cooling system 30 may include a cover plate 46 having multiple channels 48 within it. The channels 48 may each house a fin section 50. In particular embodiments, the fin sections 50 may be folded fins, each section 50 formed from a single piece of material with multiple convolutions. The fin sections 50 may be a separate component from the cover plate 46, simply fitting within the channels 48 of the cover plate 46. In certain embodiments, the fin sections 50 may be attached directly to an external surface of the housing 34 with the cover plate 46 then disposed around the fin sections 50, enclosing them. To enhance the heat transfer achieved by the fin sections 50, the channels 48 of the cover plate 46 may also circulate air as a coolant. The addition of the circulating air may provide high cooling rates via increased convective heat transfer from the fin sections 50. Using air as the coolant may aid in reducing weight of the cooling system 30, minimizing cost of the cooling system 30, and simplifying internal systems of the vehicle 10.
The cooling system 30, having the separate fin sections 50 and the cover plate 46, may provide a flexible, cost-effective design that may be easily adapted for a variety of battery systems 12. The dimensions of the cover plate 46 may be easily scaled to fit the dimensions of the associated battery system 12. Further, for battery modules 12 that generate more heat, the cooling air may be circulated at a higher speed and/or injected into the channels 48 at a lower temperature. Further, the number and spacing of the fins within the sections 50 may be adjusted to provide optimal heat transfer qualities.
A perspective view of the entire battery system 12 and cooling system 30 is presented in
Accordingly, the housing 34 may be formed from a thermally conductive material, which enables heat generated by the cells 32 to be drawn away by the cooling system 30. For example, the housing 34 may be constructed from titanium (and alloys), steel, aluminum (and alloys), brass, carbon composites, or another thermally conductive material. Additionally, the fin sections 50 may be formed from a thermally conductive material, such that they draw heat from the cells 32 via the housing 34. The fin sections 50 may be aluminum (and alloys), copper (and alloys), carbon composites, or another thermally conductive material. Materials may be selected based on implementation-specific considerations, such as cost, weight, availability, thermal conductivity, or a combination thereof.
To provide a better understanding of the internal arrangement of the battery system 12 and the cooling system 30, a cross-sectional view is depicted in
An exploded view of the cooling system 30 is depicted in
As detailed further below, each channel 48 may include a pair of apertures 70, wherein one aperture 70 acts as a cooling air inlet to the channel 48 and one aperture 70 acts as a cooing air outlet to the channel 48. The apertures 70 are depicted as ellipses, but may have a different geometry in alternative embodiments. A gasket 72 may be disposed between the bottom surface of the housing 34 of the battery system 12 and the cover plate 46. The gasket 72 may include portions 74 that align with walls 76 of the channels 48, such that cooling air does not pass between different channels 48. The gasket 72 may aid in ensuring that the cooling air remains contained within the cooling system 30 and distinctly separate from the cells 32.
To supply the channels 48 with cooling air, the cover plate 46 may include an inlet manifold 78 along its length on each side. In this way, flow within the inlet manifolds 78 may be perpendicular to flow within the channels 48. In each channel 48, one of the apertures 70 may provide a fluid connection between one of the inlet manifolds 78 and the respective channel 48. Subsequently, the cooling air may exit the channel 48 via the other aperture 70. The inlet manifolds 78 may be supplied with cooling air by an inlet header 80. The inlet header 80 may have an intake orifice 82, where cooling air enters the cooling system 30. The intake orifice 82 may then split the cooling air into two branches 84. Each branch 84 may feed cooling air to one of the inlet manifolds 78. In certain embodiments, the inlet header 80 may include a fan (not shown) to increase the speed of the cooling air as it travels through the branches 84 and the inlet manifolds 78.
To aid in the explanation of the cooling air flow through the inlet header 80, manifolds 78, and channels 48 of the cooling system 30,
As depicted in
The cooling air may enter adjacent channels 48 from opposite sides of the cooling system 30, as shown in
The flow path for all eight channels 48 is depicted in
The flow path of the cooling air with respect to the positioning of multiple battery modules 60 is provided in
Additionally, the inlet manifolds 78, which contain the cooling air supply, are maintained separately from the outlet manifolds 112, which contain the used, warmer air. In this way, each channel 48 receives the cooling air directly, enabling the cooling air to enter each channel 48 at approximately the same temperature. Since each channel 48 receives cooling air at approximately the same temperature, each channel 48 may be able to achieve an approximately equal amount of heat transfer from the battery modules 60, resulting in generally equal temperatures among the battery modules 60.
Further, the dimensions of the channels 48 with respect to the inlet manifold 78 may also aid in creating the isothermal temperature distribution by ensuring that each channel 48 receives an adequate amount of cooling air. For example, the cross-sectional area of each inlet manifold 78 may be at least four times the cross-sectional area of each channel 48. In this way, each channel 48 may receive approximately the same amount of cooling air, resulting in even cooling of the battery modules 60.
As previously described, the cooling system 30 may create an isothermal temperature distribution among the battery modules 60 of the battery system 12. In this way, the product life and functionality of the cells 32 within the battery modules 60 may be maintained. A method 160 of operation that may be utilized by the cooling system 30 is outlined in
While only certain features and embodiments of the invention have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the claimed invention). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.
This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 61/623,338, entitled “Air Cooled Thermal Management System for HEV Battery Pack,” filed Apr. 12, 2012, which is hereby incorporated by reference for all purposes.
Number | Name | Date | Kind |
---|---|---|---|
4578324 | Koehler | Mar 1986 | A |
5639571 | Waters | Jun 1997 | A |
6544679 | Petillo | Apr 2003 | B1 |
7414843 | Joshi | Aug 2008 | B2 |
7997367 | Nakamura | Aug 2011 | B2 |
8342235 | Kanemaru | Jan 2013 | B2 |
8439104 | de la Cruz | May 2013 | B2 |
8561679 | Richardson | Oct 2013 | B2 |
8584738 | Hurlbert | Nov 2013 | B2 |
8603660 | Houchin-Miller | Dec 2013 | B2 |
8609268 | Fuhr | Dec 2013 | B2 |
8662148 | Wand | Mar 2014 | B2 |
8693198 | Eckberg | Apr 2014 | B2 |
8733427 | So | May 2014 | B2 |
8852778 | Payne | Oct 2014 | B2 |
8869877 | Zaffetti | Oct 2014 | B2 |
8968904 | Han | Mar 2015 | B2 |
9070958 | Obasih | Jun 2015 | B2 |
9350002 | Fuhr | May 2016 | B2 |
9437903 | DeKeuster | Sep 2016 | B2 |
20020195234 | Wu | Dec 2002 | A1 |
20080138670 | Johnston et al. | Jun 2008 | A1 |
20090023056 | Adams | Jan 2009 | A1 |
20090023405 | Forstner | Jan 2009 | A1 |
20090074627 | Fitzgerald | Mar 2009 | A1 |
20100297486 | Fujii | Nov 2010 | A1 |
20110061845 | Wand | Mar 2011 | A1 |
20110262794 | Yoon | Oct 2011 | A1 |
20110269008 | Houchin-Miller | Nov 2011 | A1 |
20120012300 | Dunn | Jan 2012 | A1 |
20120148889 | Fuhr | Jun 2012 | A1 |
20120175100 | Bezama | Jul 2012 | A1 |
20120177971 | Cicero | Jul 2012 | A1 |
20120308860 | Pizzurro | Dec 2012 | A1 |
20130071720 | Zahn | Mar 2013 | A1 |
20130183555 | Boddakayala | Jul 2013 | A1 |
20130192807 | DeKeuster | Aug 2013 | A1 |
Number | Date | Country |
---|---|---|
102008034855 | Jan 2010 | DE |
102008034885 | Jan 2010 | DE |
2017918 | Jan 2009 | EP |
2149771 | Feb 2010 | EP |
2388851 | Nov 2011 | EP |
2010148224 | Dec 2010 | WO |
WO 2010148224 | Dec 2010 | WO |
WO 2010148224 | Apr 2011 | WO |
Entry |
---|
DE 102008034885 (A1)—Jan. 28, 2010; Meintschel, Jens. Espacenet.com, European Patent Office. |
International Search Report & Written Opinion for PCT Application No. PCT/US2013/035157 dated Jun. 28, 2013, 12 pgs. |
Number | Date | Country | |
---|---|---|---|
20130273829 A1 | Oct 2013 | US |
Number | Date | Country | |
---|---|---|---|
61623338 | Apr 2012 | US |