A THERMAL MANAGEMENT SYSTEM FOR A BATTERY PACK AND A METHOD FOR OPERATING THE SAME
BACKGROUND
[0001] Embodiments of a present disclosure relate to a battery pack of an
automobile and more particularly to a thermal management system for a battery pack of an automobile and a method for operating the same.
[0002] Battery based vehicles have risen to prominence due to an inherent clean
characteristic and very low operating costs. A battery pack of the vehicle increases the cost of the vehicle and hence it is important to optimize the life and performance of the battery packs. Optimum life and performance of most of the battery cells may be achieved when the battery cells are operated between 25oC to 35oC. When the battery cells are operated at 45oC or above, the cell life expectancy may decrease by as much as 50 percent (M. Safari and C. Delacourt, Aging of commercial graphite/LiFePO4 cell, J. Electrochem. Soc. 2011 158(10): A1123-A1135). On the other hand, the performance of the cell is poor when the battery cells are operated at temperatures below 5oC (James Marcicki, Marcello Canova, A. Terrence Conlisk, Giorgio Rizzoni, “Design and parametrization analysis of a reduced-order electrochemical model of graphite/LiFePO4 cells for SOC/SOH”, Journal of Power Sources, Vol. 237 pages 310-324, 2013). The electric vehicle on the other hand is expected to operate at a temperature range of -30oC to 50oC. Therefore, various approaches have been implemented for thermal management of the battery packs.
[0003] Air based thermal management is explored by electric-vehicle
manufacturers due to its inherent safety, economy and simplicity of design. Conventionally, it is performed by sending air from side and top of the cell.
[0004] Cooling the battery pack with air, however, is difficult due to low heat
capacity of air and inherent inefficiency of air distribution. Furthermore, development of thermal boundary layer along the flow direction reduces the

effectiveness in the case of surface air cooling. Such improper air distribution leads to sub optimal performance of battery.
[0005] In another approach, liquid based thermal management is implemented
on the battery packs as liquid cooling has superior thermal efficiency. Although, thermally efficient, this method is less economical and is not inherently safe. In some applications, coolant leakage results in electrical short circuit and fire hazard estimation(https://electrek.co/2018/06/16/tesla-model-s-battery-fire investigating/).
[0006] Hence, there is a need for an improved thermal management system for
the battery pack to address the aforementioned issue(s).
BRIEF DESCRIPTION
[0007] In accordance with an embodiment of the present disclosure, a thermal
management system for a battery pack is provided. The system includes an air distribution unit. The air distribution unit includes at least one vertical duct configured to receive air from one or more cooling sources. The air distribution unit also includes at least one manifold mechanically coupled to the at least one vertical duct. The at least one manifold is configured to direct air received from the at least one vertical duct. The air distribution unit further includes a plurality of horizontal ducts mechanically coupled to at least one manifold. Each of the plurality of horizontal ducts includes a plurality of holes. Each of the plurality of holes are aligned with a plurality of cells of the battery pack. Each of the plurality of horizontal ducts are configured to propel a stream of air to the each of the plurality of cells through the plurality of holes for thermal management of the battery pack.
[0008] In accordance with another embodiment of the present disclosure, a
method for thermal management of a battery pack is provided. The method includes injecting air from one or more cooling sources into at least one vertical duct. The method also includes directing the air received from at least one vertical duct using at least one manifold mechanically coupled to at least one vertical duct. The method

further includes propelling a stream of air to each of a plurality of cells through a plurality of holes formed on a plurality of horizontal ducts mechanically coupled to at least one manifold for thermal management of the battery pack. Each of the plurality of holes are aligned with the plurality of cells of the battery pack.
[0009] To further clarify the advantages and features of the present invention, a
more particular description of the invention will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the invention and are therefore not to be considered limiting in scope. The invention will be described and explained with additional specificity and detail with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[0010] FIG. 1 is a schematic representation of a thermal management system for
a battery pack in accordance with an embodiment of the present disclosure;
[0011] FIG. 2 is a schematic representation of top view of the plurality of
horizontal ducts of FIG. 1 in accordance with an embodiment of the present disclosure; and
[0012] FIG. 3 is a flow chart representing the steps involved in a method for
thermal management of a battery pack of FIG. 1 in accordance with an embodiment of the present disclosure.
[0013] Further, those skilled in the art will appreciate that elements in the figures
are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with

details that will be readily apparent to those skilled in the art having the benefit of the description herein.
DETAILED DESCRIPTION
[0014] For the purpose of promoting an understanding of the principles of the
disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[0015] The terms "comprises", "comprising", or any other variations thereof, are
intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[0016] In the following specification and the claims, reference will be made to
a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0017] Embodiments of the present disclosure relate to a thermal management
system of a battery pack. The system includes an air distribution unit. The air

distribution unit includes at least one vertical duct configured to receive air from one or more cooling sources. The air distribution unit also includes at least one manifold mechanically coupled to the at least one vertical duct. The at least one manifold is configured to direct air received from the at least one vertical duct. The air distribution unit further includes a plurality of horizontal ducts mechanically coupled to at least one manifold. Each of the plurality of horizontal ducts includes a plurality of holes. Each of the plurality of holes are aligned with a plurality of cells of the battery pack. Each of the plurality of horizontal ducts are configured to propel a stream of air to the each of the plurality of cells through the plurality of holes for thermal management of the battery pack.
[0018] FIG. 1 is a schematic representation of a thermal management system
(10) for a battery pack in accordance with an embodiment of the present disclosure. The system (10) includes an air distribution unit (20). In one embodiment, the air distribution unit (20) may be housed in a housing unit (30). In such embodiment, the housing unit (30) may include at least one tray (40) characterized in the plurality of cells are in thermal contact on bases. The battery is mounted on top of the at least one tray (40).
[0019] In a specific embodiment, the air distribution unit (20) may be configured
to be operable at an operating temperature around a range of -20 degrees Celsius to 50 degrees Celsius. The air distribution unit (20) includes at least one vertical duct (50) which is configured to receive air from one or more cooling sources. In some embodiments, the cooling source may be configured to reduce or increase the temperature of the battery pack by providing air at a controlled temperature to maintain the temperature of the battery pack within a pre-set temperature range.
[0020] Furthermore, the air distribution unit (20) also includes at least one
manifold (60) which is mechanically coupled to the at least one vertical duct (50). The at least one manifold (60) is configured to direct air received from the at least one vertical duct (50). The air distribution unit (20) further includes a plurality of horizontal ducts (70) which is mechanically coupled to the at least one manifold

(60). Each of the plurality of horizontal ducts (70) include a plurality of holes (80). Each of the plurality of holes (80) are aligned with a plurality of cells of the battery pack as shown in FIG. 2. In one embodiment, the plurality of holes (80) may include a diameter of predefined size.
[0021] Each of the plurality of horizontal ducts (70) are configured to propel a
stream of air to the each of the plurality of cells through the plurality of holes (80) for thermal management of the battery pack. In a preferred embodiment, the air flowing within the plurality of holes (80) of the plurality of horizontal ducts (70) may be perpendicular to the air flowing within the at least one horizontal duct (70).
[0022] Referring to FIG. 1, in operation, cool air is ducted to bottom surface of
the plurality of cells where one or more hot spots are observed in a cell thermal mapping technique (90).
[0023] The cool air is distributed through an air distribution unit (20) which
consists of at least one vertical duct (50), at least one manifold (60) and the plurality of horizontal ducts (70). The at least one manifold (60) is configured to distribute required amount of air to each of the plurality of horizontal ducts (70). The plurality of horizontal ducts (70) includes series of a plurality of holes (80) with optimal size and predefined position for air jet impingement on the cell bottom. The plurality of holes (80) is aligned with the bottom of the plurality of cells of the battery. The air is distributed to the battery through the plurality of holes (80) present on the plurality of horizontal ducts (70) and then escapes over the side of the plurality of cells.
[0024] FIG. 3 is a flow chart representing the steps involved in a method (150)
for thermal management of a battery pack of FIG. 1 in accordance with an embodiment of the present disclosure. The method (150) includes injecting air from one or more cooling sources into at least one vertical duct in step 160. In one embodiment, injecting air from one or more cooling sources into at least one vertical duct may include injecting air from one or more cooling sources into at least one vertical duct to reduce or increase the temperature of the battery pack by providing

air at a controlled temperature to maintain the temperature of the battery pack within a preset temperature range.
[0025] The method (150) also includes directing the air received from at least
one vertical duct using at least one manifold mechanically coupled to at least one vertical duct in step 170.
[0026] Furthermore, the method (150) includes propelling a stream of air to each
of a plurality of cells through a plurality of holes formed on a plurality of horizontal ducts mechanically coupled to at least one manifold for thermal management of the battery pack. Each of the plurality of holes are aligned with the plurality of cells of the battery pack in step 180.
[0027] Various embodiments of the thermal management system described
above enables an effective method for thermal management of lithium ion battery pack by cooling or heating of the plurality of cells in the battery using a ducting system.
[0028] Furthermore, the system enables uniform temperature distribution among
the plurality of cells using air flow distribution through the plurality of horizontal ducts. Lower temperature gradient across the battery resulting in consistent performance and life of the battery.
[0029] The thermal management system may be used in thermal management of
electric vehicle, hybrid vehicle battery pack and thermal management of static power banks.
[0030] It will be understood by those skilled in the art that the foregoing general
description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[0031] While specific language has been used to describe the disclosure, any
limitations arising on account of the same are not intended. As would be apparent

to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0032] The figures and the foregoing description give examples of
embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.

1. A thermal management system (10) for a battery pack comprising:
an air distribution unit (20), wherein the air distribution unit (20) comprises:
at least one vertical duct (50) configured to receive air from one or more cooling sources;
at least one manifold (60) mechanically coupled to the at least one vertical duct (50), wherein the at least one manifold (60) is configured to direct air received from the at least one vertical duct (50); and
a plurality of horizontal ducts (70) mechanically coupled to at least one manifold (60), wherein each of the plurality of horizontal ducts (70) comprises a plurality of holes (80), wherein each of the plurality of holes (80) are aligned with a plurality of cells of the battery pack, wherein each of the plurality of horizontal ducts (70) are configured to propel a stream of air to the each of the plurality of cells through the plurality of holes (80) for thermal management of the battery pack.
2. The thermal management system (10) as claimed in claim 1, wherein an air distribution unit (20) is housed in a housing unit (30).
3. The thermal management system (10) as claimed in claim 1, wherein the air distribution unit (20) is configured to be operable at an operating temperature around a range of -20 degrees Celsius to 50 degrees Celsius.
4. The thermal management system (10) as claimed in claim 1, wherein the cooling source is configured to reduce or increase the temperature of the battery pack by providing air at a controlled temperature to maintain the temperature of the battery pack within a preset temperature range.

5. The thermal management system (10) as claimed in claim 1, wherein the plurality of holes (80) comprises a diameter of predefined size.
6. The thermal management system (10) as claimed in claim 1, wherein the air flowing within the plurality of holes (80) of the plurality of horizontal ducts (70) is perpendicular to the air flowing within the at least one horizontal duct (70).
7. A method (150) for thermal management of a battery pack comprising:
injecting air from one or more cooling sources into at least one vertical duct; (160)
directing the air received from at least one vertical duct using at least one manifold mechanically coupled to at least one vertical duct; (170) and
propelling a stream of air to each of a plurality of cells through a plurality of holes formed on a plurality of horizontal ducts mechanically coupled to at least one manifold for thermal management of the battery pack, wherein each of the plurality of holes are aligned with the plurality of cells of the battery pack. (180)