[0001] The present disclosure described herein, in general, is directed to
temperature optimization of a coolant to be supplied to a battery pack of a vehicle.
5 In particular, the present disclosure relates to a thermal management system of a
battery pack of an electric vehicle.
BACKGROUND
[0002] The background description includes information that may be useful in
understanding the present disclosure. It is not an admission that any of the
10 information provided herein is prior art or relevant to the presently claimed
subject matter, or that any publication specifically or implicitly referenced is prior
art.
[0003] In an externally cooled electric vehicle, the temperature of a thermal
management system of the vehicle such as a refrigeration system or heating
15 ventilating and air-conditioning (HVAC) system decreases or increases faster as
compared to a battery pack located in proximity with the thermal management
system because the battery pack is generally well insulated from the external
environment of the vehicle. The temperature of the coolant present inside the feed
lines and heat exchanger of the thermal management system therefore also
20 increases or decreases faster than the temperature inside the battery pack. Due to
cooling or heating requirement of the battery pack, the coolant with increased or
decreased temperature is supplied to the battery pack when the vehicle is just
started or powered on without taking into account the temperature conditions of
the coolant, i.e. in hot weather condition if the battery pack is at a higher
25 temperature than the standard temperature, the coolant may be supplied at a
further higher temperature for some time when the requirement is of a coolant
having a lower temperature. Similarly, in cold weather conditions, if the battery
pack is at a lower temperature than the standard temperature, the coolant may be
3
supplied for some time at a further lower temperature when the requirement is of a
coolant having a higher temperature. Although such phenomena prevail for a short
time after the start of the vehicle, however, the performance of the battery pack is
hindered and harmed in the long run.
5 [0004] In view of the above-mentioned issues, there is a need to provide a
solution wherein the supply of the coolant to the battery pack just after the start of
the vehicle is based on the temperature conditions of the coolant and the
temperature conditions of the battery pack so that no harm is caused to the battery
pack and its performance.
10 OBJECTS OF THE DISCLOSURE
[0005] Some of the objects of the present disclosure, which at least one
embodiment herein satisfy, are listed hereinbelow.
[0006] It is a general or primary object of the present disclosure to provide a
thermal management or heating and cooling system of a battery pack of an electric
15 vehicle that supplies coolant to the battery pack with an optimized temperature for
a small period of time just after starting or powering on the vehicle based on the
temperature conditions of the coolant and the temperature conditions of the
battery pack so that no harm is caused to the battery pack and its performance in
long run.
20 [0007] It is another object of the present disclosure to provide a thermal
management or heating and cooling system of a battery pack of an electric vehicle
such that coolant can be used as an energy reservoir i.e. when cooling or heating is
not required in the battery pack but excess energy (heating or cooling energy) is
available at the heat exchanger, the energy can be used to cool or heat the coolant
25 at a lower or higher temperature and later on this energy of coolant can be used to
cool or heat the battery pack without supplying energy to heater or compressor.
4
[0008] These and other objects and advantages will become more apparent
when reference is made to the following description and accompanying drawings.
SUMMARY
[0009] This summary is provided to introduce concepts primarily related to a
5 thermal management system of a battery pack of an electric vehicle. The concepts
are further described below in the detailed description. This summary is not
intended to identify key features or essential features of the claimed subject
matter, nor is it intended to be used to limit the scope of the claimed subject
matter.
10 [0010] The subject matter disclosed herein relates to a thermal management
system of a battery pack of an electric vehicle. The system comprises a third valve
implemented adjacent to the battery pack’s inlet wherein the third valve is
operable to stop a coolant flow inside the battery pack and to bypass the coolant
from an input feed line to an output feed line based on a temperature comparison
15 of the coolant present in the input feed line and a plurality of modules of the
battery pack.
[0011] In an aspect, a vehicle control unit (VCU) is provided in the thermal
management system. The VCU is to receive a first input from a plurality of
temperature sensors implemented in the modules of the battery pack, receive a
20 second input from a temperature sensor provided in the third valve implemented
adjacent to the battery pack’s inlet, compare the first input and the second input,
and operate the third valve based on the comparison. The first input includes
information regarding the temperature of the coolant and the second input
includes information regarding the temperature of the modules of the battery pack.
25 The coolant is diverted into the output feed line from the third valve when the
temperature of the coolant is more than the temperature of the modules of the
battery pack otherwise the coolant is fed into the battery pack from the third valve
when the temperature of the coolant is less than the temperature of the modules of
the battery pack. This helps in preventing the coolant with an undesired
5
temperature from entering inside the battery pack to the modules and affecting
their performance. The feature also supplies the coolant having a required
temperature only to enter inside the battery pack at the instant of starting or
powering on the vehicle.
5 [0012] In another aspect, based on the comparison of the first input and the
second input, the VCU is to further operate a first valve and a second valve,
wherein the first valve being implemented to establish a connection between an
output feed line of the chiller, an output feed line of a cooler, an output feed line
of a heater, and the input feed line of the battery pack. The second valve being
10 implemented to establish a connection between an input feed line of the chiller, an
input feed line of the cooler, an input feed line of the heater, and the output feed
line of the battery pack.
[0013] In yet another aspect, the first valve and the second valve are provided
with temperature sensors that measure the temperature of the coolant and based on
15 the comparison between the measured temperature of the coolant and the modules
of the battery pack, the first and second valves are operated by the VCU.
[0014] In an aspect, the VCU is to operate the first, second, and third valves
only for a predetermined or small period of time after the vehicle is powered on
till cooling or heating of the battery pack gets optimized.
20 [0015] To further understand the characteristics and technical contents of the
present subject matter, a description relating thereto will be made with reference
to the accompanying drawings. However, the drawings are illustrative only but
not used to limit the scope of the present subject matter.
[0016] Various objects, features, aspects, and advantages of the inventive
25 subject matter will become more apparent from the following detailed description
of preferred embodiments, along with the accompanying drawing figures in which
like numerals represent like components.
6
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] It is to be noted, however, that the appended drawings illustrate only
typical embodiments of the present subject matter and are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
5 effective embodiments. The detailed description is described with reference to the
accompanying figures. The illustrated embodiments of the subject matter will be
best understood by reference to the drawings, wherein like parts are designated by
like numerals throughout. The following description is intended only by way of
example, and simply illustrates certain selected embodiments of devices, systems,
10 and methods that are consistent with the subject matter as claimed herein,
wherein:
[0018] FIG. 1 illustrates a block diagram of a thermal management system of
a battery pack of an electric vehicle; and
[0019] FIG. 2 illustrates a modified block diagram of a thermal management
15 system of a battery pack of an electric vehicle in accordance with the present
disclosure.
[0020] The figures depict embodiments of the present subject matter for the
purposes of illustration only. A person skilled in the art will easily recognize from
the following description that alternative embodiments of the structures and
20 methods illustrated herein may be employed without departing from the principles
of the disclosure described herein.
DETAILED DESCRIPTION
[0021] The detailed description of various exemplary embodiments of the
disclosure is described herein with reference to the accompanying drawings. It
25 should be noted that the embodiments are described herein in such details as to
communicate the disclosure. However, the amount of details provided herein is
not intended to limit the anticipated variations of embodiments; on the contrary,
7
the intention is to cover all modifications, equivalents, and alternatives falling
within the spirit and scope of the present disclosure as defined by the appended
claims.
[0022] It is also to be understood that various arrangements may be devised
5 that, although not explicitly described or shown herein, embody the principles of
the present disclosure. Moreover, all statements herein reciting principles, aspects,
and embodiments of the present disclosure, as well as specific examples, are
intended to encompass equivalents thereof.
[0023] The terminology used herein is to describe particular embodiments
10 only and is not intended to be limiting of example embodiments. As used herein,
the singular forms “a”, “an” and “the” are intended to include the plural forms as
well, unless the context indicates otherwise. It will be further understood that the
terms “comprises”, “comprising”, “includes” and/or “including,” when used
herein, specify the presence of stated features, integers, steps, operations, elements
15 and/or components, but do not preclude the presence or addition of one or more
other features, integers, steps, operations, elements, components and/or groups
thereof.
[0024] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For example,
20 two figures shown in succession may be executed concurrently or may sometimes
be executed in the reverse order, depending upon the functionality/acts involved.
[0025] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which example embodiments belong. It will be further
25 understood that terms, e.g., those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their meaning in the
context of the relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
8
[0026] FIG. 1 shows a block diagram 100 of a thermal management system or
a heating and cooling system 102 in connection with a battery pack 104 of an
electric vehicle or a hybrid vehicle. The flow of coolant in the thermal
management system 102 and the battery pack 104 is controlled with the help of a
5 vehicle control unit (VCU) 106 in a known manner. The thermal management
system 102 comprises known components such as a radiator 102a, condenser
102b, chiller 102c, evaporator 102d, compressor 102e, heater 102f, and cooler
102g along with other auxiliary components connected and functioning with each
other and with the VCU 106 in a known manner. The radiator 102a is cooled by
10 the atmospheric air and by the cooler 102g. The battery pack 104 comprises a
plurality of modules that get heated during working and require cooling by the
coolant at a lower temperature for their smooth operation. Also, in some
situations, the plurality of modules is at a very low temperature, and hence require
the coolant at a higher temperature. To achieve the cooling or heating of the
15 battery pack 104, an inlet of the battery pack 104 is connected to the chiller 102c
or heater 102f with an input feed line 108a through which some amount of the
coolant from the chiller 102c or heater 102f is pumped via a pump 110 into the
battery pack 104 to absorb all the heat or cold. An output feed line 108b connects
an outlet of the battery pack 104 back with the chiller 102c or heater 102f where
20 the temperature of the coolant is normalized and is then again supplied back to the
battery pack 104.
[0027] The thermal management system 102 also comprises a first valve 112
and a second valve 114, wherein the first valve 112 is implemented to establish a
connection between an output feed line of the chiller 102c, an output feed line of
25 the cooler 102g, an output feed line of the heater 102f, and the input feed line
108a of the battery pack 104. The second valve 114 is implemented to establish a
connection between an input feed line of the chiller 102c, an input feed line of the
cooler 102g, an input feed line of the heater 102f, and the output feed line 108b of
the battery pack 104.
9
[0028] The first valve 112 and the second valve 114 are provided with
temperature sensors (not shown) that measure the temperature of the coolant and
based on the comparison between the measured temperature of the coolant and the
modules of the battery pack 104, the first valve 112 and the second valve 114 are
5 connected to and operated by the VCU 106. In a preferred embodiment, the first
valve 112 and the second valve 114 is a 4 way, 3 position valve.
[0029] The present thermal management system 102 for optimizing the
temperature of the battery pack 104, however, when exposed to hot or cold
weather conditions, is not able to provide the coolant to the battery pack 104 at a
10 required or optimized temperature for some time just after starting the vehicle
which causes harm to the battery pack 104 and its performance in the long run.
Also, in some cases, the health of some cells of the battery pack 104 is affected
adversely since these cells are nearer to the battery pack’s inlet and don’t receive
optimized hot or cold coolant as compared to other cells of the battery pack 104
15 which are relatively at a farther side. Therefore, there is a need to provide a
solution to the above-mentioned problem.
[0030] Accordingly, the present subject matter discloses a solution to the
above-mentioned problem such that the coolant is supplied to the battery pack 104
of the electric vehicle at a required temperature after starting the vehicle based
20 upon the temperature conditions of the battery pack 104 and the coolant thus
preventing any harm to the battery pack 104 or its performance in long run. FIG. 2
shows a modified block diagram 200 of FIG. 1 incorporating the features or
components of the present disclosure. The whole thermal management system
102' as shown in FIG. 2 further comprises a third valve 202 placed or
25 implemented adjacent to the battery pack’s inlet connecting the input feed line
108a with the output feed line 108b. In a preferred embodiment, the third valve
202 is a 3 way, 2 position valve. The third valve 202 is also provided with a
temperature sensor (not shown) which is to sense the temperature of the coolant
coming through the output feed lines of the chiller 102c, cooler 102g and heater
30 102f via the input feed line 108a. A plurality of temperature sensors is
10
implemented in the plurality of modules of the battery pack 104 as well to sense
the temperature of the modules (not shown). The VCU 106 is connected with the
third valve 202 and the battery pack 104 to receive the sensed temperature inputs
from the third valve 202 and the modules of the battery pack 104 respectively,
5 compare them and then operate the third valve 202 accordingly. The third valve
202 is placed or implemented on the input feed line 108a connected with the first
valve 112 and bypasses the coolant flow to output feed line 108b. This way the
third valve 202 establishes a connection between the input feed line 108a and the
output feed line 108b to bypass the flow away from the battery pack 104.
10 [0031] In a preferred embodiment, the valves 112, 114 and 202 are solenoid
valves. The thermal management system 102' having various temperature sensors
and the third valve 202 helps in supplying the coolant to the battery pack 104 with
a required or optimized temperature just after the vehicle is powered on or started
which is not provided in the thermal management system 102 shown in FIG. 1.
15 The present disclosure provides a double means for cooling the coolant using
either the cooler 102g or the chiller 102c, as the coolant with an undesired or
unallowable temperature is made to pass through them. The distribution of the
coolant, using the first valve 112 and second valve 114, to either the cooler 102g
or the chiller 102c respectively is done based upon the cooling requirement of the
20 battery pack 104. Similarly, the present disclosure also provides the heater 102f
for heating the coolant to an optimum temperature, as the coolant with an
undesired or unallowable temperature is made to pass through it. The operation of
the first, second and third valves 112, 114 and 202 in hot or cold weather
conditions can be understood with the following exemplary conditions. It is to be
25 however to be noted that the below examples are just for explaining the invention
in a better and clear manner and are not to limit the scope of the invention.
Example 1: Operation in hot weather condition
[0032] In a hot weather condition, if the coolant in the input feed line 108a
rises to temperature, say 45°C sensed by the temperature sensor of the third valve
11
202 and the temperature of the plurality of modules of the battery pack 104 is, say
40°C sensed by the temperature sensors of the modules, the VCU 106 doesn’t
allow the coolant with 45°C temperature to enter inside or fed into the battery
pack 104 as the coolant would lead to further heating up the battery pack modules
5 rather than cooling them. Accordingly, a signal is sent to the third valve 202 by
the VCU 106 that stops the coolant supply to the battery pack 104 and bypasses
the coolant to the output feed line 108b by operating the third valve 202. The
VCU 106 operates the second valve 114 in such a way that the coolant is sent to
the chiller 102c for cooling down instead of entering into battery pack 104. After
10 getting cooled in the chiller 102c, the coolant is pumped to the third valve via the
pump 110 where the temperature sensor of the third valve 202 again measures the
temperature of the coolant and compares it with the temperature of the battery
pack 104. If the temperature is below the battery pack temperature (for example
39°C) then the coolant is allowed to pass through the third valve 202 into the
15 battery pack 104. In an aspect, if the temperature of the coolant sensed by the third
valve 202 is still more than battery pack temperature (for example 41°C) then the
VCU 106 will again divert the coolant to output feed line 108b by closing the
third valve 202. In this manner, the coolant is sent to the chiller 102c from the
output feed line 108b to cool or chill down from where the coolant is then passed
20 into the input feed line 108a for supplying to the battery pack 104. It is to be noted
that the radiator 102a of the thermal management system 102' can also be
optionally used to cool down the coolant. This can be done by selectively routing
the coolant flow to the cooler 102g, instead of the chiller 102c by operating the
second valve 114 and the first valve 112. This may help in conserving the overall
25 efficiency of the thermal management system 102'.
[0033] This way it is ensured that a coolant with the optimized temperature is
provided to the battery pack 104 thereby preventing the performance and
condition of the battery pack 104 from getting affected in the long run. It is to be
noted that the VCU 106 is configured to operate the third valve 202, the first valve
30 112 and the second valve 114 only for a predetermined or small period of time
12
after the vehicle is started or powered on, as the temperature of the coolant
supplied to the battery pack 104 becomes less than that of the modules of the
battery pack 104 in a small period of time.
Example 2: Operation in cold weather condition
5 [0034] In a cold-weather condition, if the coolant in the input feed line 108a
falls to temperature, say 5°C sensed by the temperature sensor of the third valve
202 and the temperature of the modules of the battery pack 104 is, say 10°C
sensed by the temperature sensors of the modules, the VCU 106 doesn’t allow the
coolant with 5°C temperature to enter inside or fed into the battery pack 104 as
10 the coolant would lead to further cooling down of the battery pack modules rather
than heating them. Accordingly, a signal is sent to the third valve 202 which stops
the coolant supply to the battery pack 104 and bypasses the coolant to the output
feed line 108b by operating the third valve 202. This time the VCU 106 operates
the second valve 114 in such a way that the coolant flows to the heater 102f via its
15 input feed line. The coolant reaches the heater 102f and absorbs heat from it and
then exits the heater 102f via its output feed line into the input feed line 108a
through the first valve 112 where the coolant is pumped via the pump 110 to reach
the third valve 202. The temperature of the coolant sensed by the temperature
sensor of the third valve 202 is compared with the temperature of the modules of
20 the battery pack 104 by the VCU 106 and if it is found to be more than the
temperature of the battery pack 104, then it is fed into or supplied to the battery
pack 104, otherwise, the coolant recirculates as disclosed above till the
temperature of the coolant is above a specific value.
[0035] This way it is ensured that optimized coolant temperature is provided
25 to the battery pack 104 to prevent its performance and condition from getting
affected in the long run. The VCU 106 is configured to operate the third valve
202, the first valve 112 and the second valve 114 only for a predetermined or
small period of time after the vehicle is started or powered on as the temperature
13
of the coolant supplied to the battery pack 104 becomes more than that of the
modules of the battery pack 104 in a small period of time.
Example 3: Operation during optimum battery temperature and energy
availability condition
5 [0036] In the disclosed thermal management system 102' of the battery pack
104 the coolant can also be used as an energy reservoir temporarily (keeping the
third valve 202 closed to maintain optimum temperature) i.e. when cooling or
heating is not required in the battery pack 104 but excess energy (heating or
cooling energy) is available at the chiller 102c, cooler 102g and heater 102f, the
10 energy can be transferred to the coolant to either cool or heat the coolant at a
lower or higher temperature, and later on this hot or cooled coolant can be used to
cool or heat the battery pack 104 as required without supplying energy. This helps
in power saving.
[0037] It should be understood that the above-described examples are
15 essentially for illustrative purposes only but not in any way for restriction thereto.
TECHNICAL ADVANTAGES
[0038] The present disclosure provides a thermal management system of a
battery pack of an electric vehicle that supplies a coolant with an optimized
temperature to the battery pack just after starting the vehicle based on the
20 temperature conditions of the battery pack and the coolant so that no harm is
caused to the battery pack and its performance in long run.
[0039] The present disclosure provides a thermal management system of a
battery pack of an electric vehicle that provides energy-efficient cooling of the
battery pack by selectively routing the coolant flow to the cooler instead of the
25 chiller again and again. This way the present disclosure provides a double means
for cooling the coolant using either the cooler or the chiller, as the coolant with an
undesired or unallowable temperature is made to pass through them. This helps in
14
cooling the coolant at a faster rate through the cooler. This helps in conserving the
energy, which would have been otherwise used by the compressor.
[0040] While the foregoing describes various embodiments of the present
disclosure, other and further embodiments of the present disclosure may be
5 devised without departing from the basic scope thereof. The scope of the
invention is determined by the claims that follow. The present disclosure is not
limited to the described embodiments, versions or examples, which are included
to enable a person having ordinary skill in the art to make and use the present
disclosure when combined with information and knowledge available to the
10 person having ordinary skill in the art.

We claim:

1. A thermal management system (102') of a battery pack (104), comprising:
a third valve (202) implemented adjacent to the battery pack’s inlet,
wherein said third valve (202) is operable to stop a coolant flow
5 inside the battery pack (104) and to bypass the coolant from an input feed
line (108a) to an output feed line (108b) based on a temperature
comparison of the coolant present in the input feed line (108a), and a
plurality of modules of the battery pack (104).
2. The thermal management system (102') as claimed in claim 1, wherein the
10 coolant is diverted into the output feed line (108b) from the third valve
(202) when the temperature of the coolant is more than the temperature of
the modules of the battery pack (104).
3. The thermal management system (102') as claimed in claim 1, wherein the
coolant is fed into the battery pack (104) from the third valve (202) when
15 the temperature of the coolant is less than the temperature of the modules
of the battery pack (104).
4. The thermal management system (102') as claimed in claim 1, comprising:
a vehicle control unit (VCU) (106) to:
receive a first input from a plurality of temperature sensors
20 implemented in the modules of the battery pack (104);
receive a second input from a temperature sensor provided
in the third valve (202) implemented adjacent to the battery pack’s
inlet;
compare the first input and the second input; and
25 operate the third valve (202) based on the comparison.
16
5. The thermal management system (102') as claimed in claim 4, wherein the
first input includes information regarding the temperature of the coolant
and the second input includes information regarding the temperature of the
modules of the battery pack (104).
5 6. The thermal management system (102') as claimed in claim 4, wherein
based on the comparison, the VCU (106) is to further operate a first valve
(112) and a second valve (114), wherein the first valve (112) being
implemented to establish a connection between an output feed line of a
chiller (102c), an output feed line of a cooler (102g), an output feed line of
10 a heater (102f), and the input feed line (108a) of the battery pack (104),
and wherein the second valve (114) being implemented to establish a
connection between an input feed line of the chiller (102c), an input feed
line of the cooler (102g), an input feed line of the heater (102f), and the
output feed line (108b) of the battery pack (104).
15 7. The thermal management system (102') as claimed in claim 4, wherein the
VCU (106) is to operate the first, second, and third valves (112, 114, 202)
for a predetermined time after the vehicle is powered on.