U.S. patent application number 09/546763 was filed with the patent office on 2002-04-11 for cooling device for electric vehicle with fuel cell.
This patent application is currently assigned to Valeo Thermique Moteur. Invention is credited to Ap, Ngy Srun.
Application Number | 20020040896 09/546763 |
Document ID | / |
Family ID | 9544450 |
Filed Date | 2002-04-11 |
United States Patent
Application |
20020040896 |
Kind Code |
A1 |
Ap, Ngy Srun |
April 11, 2002 |
Cooling device for electric vehicle with fuel cell
Abstract
A cooling device for a vehicle with an electric motor powered by
a fuel cell has a first cooling loop suitable for cooling the fuel
cell and traversed by a first cooling fluid, a second cooling loop
suitable for cooling at least the electric motor and traversed by a
second cooling fluid, and a heat exchanger interposed between the
first cooling loop and the second cooling loop.
Inventors: |
Ap, Ngy Srun; (Saint Remy
Les Chevreuse, FR) |
Correspondence
Address: |
Morgan & Finnegan LLP
345 Park Avenue
New York
NY
10154
US
|
Assignee: |
Valeo Thermique Moteur
|
Family ID: |
9544450 |
Appl. No.: |
09/546763 |
Filed: |
April 11, 2000 |
Current U.S.
Class: |
219/208 ; 165/41;
180/65.31; 219/202 |
Current CPC
Class: |
B60L 3/0046 20130101;
Y02T 90/34 20130101; B60K 11/02 20130101; B60L 3/0053 20130101;
B60L 58/30 20190201; B60L 58/33 20190201; B60L 58/34 20190201; Y02T
90/40 20130101; B60L 2240/36 20130101; B60K 1/04 20130101 |
Class at
Publication: |
219/208 ;
219/202; 165/41; 180/65.3 |
International
Class: |
B60L 001/02; B60H
001/00; H01M 008/00; B60K 011/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 1999 |
FR |
99 04740 |
Claims
1. A cooling device for a vehicle with an electric motor powered by
a fuel cell, the cooling device comprising a first cooling loop
suitable for cooling the fuel cell and traversed by a first cooling
fluid, a second cooling loop suitable for cooling at least the
electric motor and traversed by a second cooling fluid, and a heat
exchanger interposed between the first cooling loop and the second
cooling loop.
2. The device of claim 1, wherein the first cooling loop comprises
thermal regulation means for keeping it in an ice-free
condition.
3. The device of claim 2, wherein the thermal regulation means
comprise at least one electric heating resistance element
integrated into a receptacle traversed by the first cooling
fluid.
4. The device of claim 3, wherein the receptacle is a filling and
outgassing vessel integrated into the first cooling loop.
5. The device of claim 1, further comprising means for thermal
insulation of the first cooling loop.
6. The device of claim 1, wherein the first cooling loop comprises
an electric pump suitable for putting the first cooling fluid into
circulation.
7. The device of claim 1, wherein the second cooling loop comprises
a cooling radiator traversed by the second cooling fluid and
suitable for being swept by a flow of air.
8. The device of claim 7, wherein the second cooling loop comprises
a main branch incorporating the heat exchanger interposed between
the first loop and the second loop, a secondary branch
incorporating the cooling radiator and a thermostatic valve of the
three-way type mounted at the junction of the main branch and of
the secondary branch.
9. A cooling device for a vehicle with an electric motor powered by
a fuel cell, the cooling device comprising a first cooling loop
suitable for cooling the fuel cell and traversed by a first cooling
fluid, a second cooling loop suitable for cooling at least the
electric motor and traversed by a second cooling fluid, and a heat
exchanger interposed between the first cooling loop and the second
cooling loop wherein the second cooling loop comprises a cooling
radiator traversed by the second cooling fluid and suitable for
being swept by a flow of air wherein the second cooling loop
comprises a main branch incorporating the heat exchanger interposed
between the first loop and the second loop, a secondary branch
incorporating the cooling radiator and a thermostatic valve of the
three-way type mounted at the junction of the main branch and of
the secondary branch, wherein the second cooling loop moreover
comprises a cooling element for cooling the electric motor of the
vehicle.
10. The device of claim 9, in which the electric motor is of the
alternating-current type and is controlled by a power control,
wherein the said cooling element serves for cooling the electric
motor and for cooling the power control.
11. The device of claim 9, in which the said cooling element for
cooling the electric motor is incorporated into the main branch of
the second cooling loop.
12. The device of claim 9, wherein the said heat exchanger for
cooling the electric motor is incorporated into a diversion from
the main branch of the second cooling loop.
13. The device of claim 1, wherein the second cooling loop further
comprises a heat exchanger for cooling at least one auxiliary unit
of the fuel cell.
14. The device of claim 9, wherein the second cooling loop further
comprises a heat exchanger for cooling at least one auxiliary unit
of the fuel cell.
15. The device of claim 14, wherein the said heat exchanger for
cooling the auxiliary unit is incorporated into the secondary
branch of the second cooling loop.
16. The device of claim 14, wherein the said heat exchanger for
cooling the auxiliary unit is incorporated into a diversion from
the main branch of the second cooling loop.
17. The device of claim 1, wherein the second cooling loop
comprises a fan heater for heating the passenger compartment of the
vehicle.
18. The device of claim 9, wherein the second cooling loop
comprises a fan heater for heating the passenger compartment of the
vehicle.
19. The device of claim 1, wherein the second cooling loop
comprises an electric pump suitable for putting the second cooling
fluid into circulation.
20. The device of claim 9, wherein the second cooling loop
comprises an electric pump suitable for putting the second cooling
fluid into circulation.
21. The device of claim 1, wherein the heat exchanger interposed
between the first cooling loop and the second cooling loop is
produced essentially from stainless steel.
22. The device of claim 1, wherein the heat exchanger interposed
between the first cooling loop and the second cooling loop is
produced essentially from stainless steel.
23. The device of claim 9, wherein the heat exchanger interposed
between the first cooling loop and the second cooling loop is
produced essentially from stainless steel.
Description
FIELD OF THE INVENTION
[0001] The invention relates to the cooling of motor vehicles.
[0002] It relates more particularly to a cooling device of an
electric vehicle powered by a fuel cell
BACKGROUND OF THE INVENTION
[0003] Much work is currently being devoted to the development of
fuel cells as sources of electrical energy for powering vehicles
driven by electric motors.
[0004] It is known that a fuel cell transforms into electrical
energy the chemical energy produced by a fuel-oxidant pair.
[0005] In the case of motor vehicles, the fuel cells which are
currently proving to be the most promising are the cells of the
membrane type, operating from a source of hydrogen originating
either from a bottle carried on board the vehicle, or from a unit
producing hydrogen directly in the vehicle. Hence it is possible to
produce the hydrogen directly by using a reformer operating with an
appropriate fuel, such as methanol, petrol, diesel oil, etc.
[0006] In a motor vehicle of the abovementioned type, it is
necessary not only to cool the electric motor providing the
propulsion of the vehicle as well as the power control for the said
motor, but also the fuel cell itself, since the latter is generally
supplied with hydrogen and air under pressure, which are usually at
a temperature higher than ambient temperature.
[0007] The cooling of fuel cells poses certain problems given that
it implies using de-ionised water as a cooling fluid. However, this
cooling fluid exhibits several drawbacks. First of all, it is
incompatible with various materials such as aluminium, copper or
steel, for example. Moreover, this fluid freezes as soon as the
temperature falls below 0.degree. C. And, needless to say, it is
not possible to add antifreeze to this de-ionised water, as in the
conventional circuits for cooling engines of motor vehicles.
[0008] The invention aims especially to provide a solution to the
problems mentioned above.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the present invention there is
provided a cooling device for a vehicle with an electric motor
powered by a fuel cell, the cooling device comprising a first
cooling loop suitable for cooling the fuel cell and traversed by a
first cooling fluid, a second cooling loop suitable for cooling at
least the electric motor and traversed by a second cooling fluid,
and a heat exchanger interposed between the first cooling loop and
the second cooling loop.
[0010] Hence, the fuel cell and at least the electric motor are
cooled by two loops using different cooling fluids and exchanging
heat between them via an appropriate heat exchanger. That being so,
the cooling of the fuel cell is carried out indirectly on the basis
of the cooling fluid serving for cooling the motor.
[0011] Advantageously, the first cooling loop comprises thermal
regulation means for keeping it in an ice-free condition.
[0012] These thermal regulation means advantageously comprise at
least one electric heating resistance element integrated into a
receptacle traversed by the first cooling fluid. This receptacle
can be produced particularly in the form of a filling and
outgassing vessel integrated into the first cooling loop.
[0013] Advantageously, the device further comprises means for
thermal insulation of the first cooling loop.
[0014] The latter advantageously comprises an electric pump for
putting the first cooling fluid into circulation.
[0015] In the invention, the second cooling loop advantageously
comprises a cooling radiator traversed by the second cooling fluid
and suitable for being swept by a flow of air.
[0016] According to another characteristic of the invention, the
second cooling loop comprises a main branch incorporating the heat
exchanger interposed between the first loop and the second loop, a
secondary branch incorporating the cooling radiator and a
thermostatic valve of the three-way type mounted at the junction of
the main branch and of the secondary branch.
[0017] According to a further aspect of the invention there is
provided a cooling device for a vehicle with an electric motor
powered by a fuel cell, the cooling device comprising a first
cooling loop suitable for cooling the fuel cell and traversed by a
first cooling fluid, a second cooling loop suitable for cooling at
least the electric motor and traversed by a second cooling fluid,
and a heat exchanger interposed between the first cooling loop and
the second cooling loop wherein the second cooling loop comprises a
cooling radiator traversed by the second cooling fluid and suitable
for being swept by a flow of air wherein the second cooling loop
comprises a main branch incorporating the heat exchanger interposed
between the first loop and the second loop, a secondary branch
incorporating the cooling radiator and a thermostatic valve of the
three-way type mounted at the junction of the main branch and of
the secondary branch, wherein the second cooling loop moreover
comprises a cooling element for cooling the electric motor of the
vehicle.
[0018] When this electric motor is of the alternating-current type
and is controlled by a power control, this cooling element
advantageously serves for cooling both the electric motor and the
power control.
[0019] The abovementioned cooling element may be incorporated
either into the main branch of the second cooling loop, or into a
diversion from this main branch.
[0020] It is advantageous for the second cooling loop further to
comprise a heat exchanger for cooling at least one auxiliary unit
of the fuel cell.
[0021] This heat exchanger may be incorporated into the secondary
branch of the second cooling loop, or else into a diversion from
the main branch of the second cooling loop.
[0022] The second cooling loop advantageously comprises a fan
heater for heating the passenger compartment of the vehicle.
[0023] Moreover, this second cooling loop advantageously comprises
an electric pump for putting the second cooling fluid into
circulation.
[0024] The heat exchanger interposed between the first cooling loop
and the second cooling loop is preferably produced essentially from
stainless steel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the description, which follows, given solely by way of
example, reference will be made to the attached drawings, in
which:
[0026] FIG. 1 is a theoretical diagram of a motor vehicle driven by
an electric motor powered from a fuel cell;
[0027] FIG. 2 is a diagram of a cooling device according to the
invention suitable for a vehicle of the type represented in FIG.
1;
[0028] FIG. 3 is a three-dimensional view of the cooling device of
FIG. 2; and
[0029] FIG. 4 is a diagram similar to that of
[0030] FIG. 2 in a variant embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] In the various figures, like reference numerals refer to
like parts.
[0032] Referring first of all to FIG. 1, a motor vehicle V is
shown, which is propelled by an electric motor 10 powered from a
fuel cell 12, via a power control 14.
[0033] The fuel cell 12 is fed with hydrogen from a reformer 16,
which produces this hydrogen from a source of a fuel (methanol, in
this example) originating from a tank 18.
[0034] The fuel cell 12, which is advantageously of the membrane
type, produces a direct electric current, which is sent to the
power control 14. The latter comprises an inverter 20 suitable for
converting the direct electric current into alternating electric
current applied to the electric motor 10, which is of the
alternating type. The control 14 further comprises a control module
22 and a converter 24 of the direct current/direct current type.
The vehicle further houses batteries 26, of the buffer type,
serving especially for starting. The electric motor 10 is coupled
to the front wheels of the vehicle by means of a gearbox-axle
assembly 28.
[0035] In a vehicle of this type, it is necessary to cool not only
the electric motor 10 as well as the power control 14, but also the
fuel cell 12, which is supplied with hydrogen and with air at a
temperature higher than ambient temperature.
[0036] To that end, it is possible to use a cooling device as
represented in FIGS. 2 and 3. In accordance with the diagram of
FIG. 2, the device comprises a first cooling loop 30 suitable for
cooling the fuel cell 12 and a second cooling loop 32 suitable for
cooling the electric motor 10 as well as the power control 14 which
is associated with it.
[0037] The loop 30 is traversed by a first cooling fluid which is
de-ionised water, that is to say pure water, given that this
represents the only fluid which can be used for cooling the fuel
cell 12.
[0038] In contrast, the cooling loop 32 is traversed by a mixture
of water and of antifreeze (for example ethylene glycol) as used
conventionally in the cooling circuits of motor-vehicle
engines.
[0039] A heat exchanger 34 of the liquid/liquid type is interposed
between the loops 30 and 32 and thus makes it possible to exchange
heat between the two loops, without mixing of the cooling
fluids.
[0040] The heat exchanger 34 may be constituted as a conventional
heat exchanger, as long as it is produced from an appropriate
material compatible with the two cooling fluids. There is a benefit
here in using a heat exchanger constructed essentially from
stainless steel.
[0041] The first loop 30 comprises a receptacle 36, here produced
in the form of a filling and outgassing vessel, serving also for
the expansion of the first cooling fluid. The loop further
comprises an electric pump 38 suitable for putting the first
cooling fluid into circulation in the direction indicated by the
arrows.
[0042] In order to prevent any risk of the cooling liquid freezing,
the device of the invention comprises thermal regulation means here
comprising at least one electric heating resistance element 40
incorporated into the vessel 36. This resistance element is linked
to an appropriate electrical circuit 42 and is supplied with power
as soon as the temperature detected falls close to 0.degree. C. on
the positive temperature side, so as to keep the circuits ice
free.
[0043] Moreover, the device comprises thermal insulation means 44
associated with the loop 30. These advantageously take the form of
an insulating enclosure or of another thermal insulation means,
which encompasses the whole of the loop 30, including the fuel cell
12 and the heat exchanger 34.
[0044] The second loop 32 is traversed by the mixture of water and
of antifreeze, and is therefore not subject to freezing. Under
these conditions, it is not necessary to surround it with thermal
insulation.
[0045] The loop 32 is divided essentially into two branches: a main
branch 46 and a secondary branch 48. These two branches are linked
together by a thermostatic valve 50 of the three-way type, mounted
at their junction. The main branch 46 incorporates the heat
exchanger 34 interposed between the loops 30 and 32, while the
secondary branch 48 incorporates a radiator 52, of the liquid/air
type, which is traversed by the second cooling fluid and which is
suitable for being swept by a flow of air F originating from
outside the vehicle. This flow of air is advantageously blown by a
motor-driven fan unit 54.
[0046] Face-to-face with the radiator 52 is placed a condenser 56
forming part of a conventional air-conditioning circuit (not
represented). Hence, the flow of air can successively sweep the
condenser 56 and the cooling radiator 52.
[0047] The thermostatic valve 50 is actuated as a function of the
temperature of the cooling liquid flowing round the loop 32. When
the temperature detected is below a given threshold (generally of
the order of 60.degree. C.), the second cooling fluid circulates in
closed circuit in the main branch 46, whereas the secondary branch
48 is isolated. In contrast, as soon as the temperature detected
reaches or exceeds the abovementioned threshold, the valve 50 makes
the second cooling fluid circulate in the main branch 46 and the
secondary branch 48, so that the fluid can be cooled by thermal
exchange with the flow of air F.
[0048] The second loop 32 further comprises a cooling element 58
serving for cooling the electric motor 10 and the power control 14.
In this example, the cooling element 58 is incorporated into the
main branch 46 of the loop 32.
[0049] The loop 32 further comprises a heat exchanger 60 serving
for cooling an auxiliary unit of the fuel cell. In this example,
the exchanger 60 is incorporated into a diversion 62 from the main
branch 46 of the loop 32.
[0050] Furthermore, this cooling loop 32 comprises a heating
radiator 64, also called fan heater, serving for heating the
passenger compartment. This radiator 64 is incorporated into the
main branch 46 of the loop 32. It is suitable for being swept by a
flow of air which is then sent into the passenger compartment of
the vehicle.
[0051] Moreover, the cooling loop 32 comprises an electric pump 66
suitable for putting the second cooling fluid into circulation, and
an expansion vessel 68. This expansion vessel, which is also
incorporated into the main branch 46, serves to compensate for the
variations in volume of the second cooling fluid.
[0052] Hence, the fuel cell 12 is cooled by de-ionised water
flowing round the loop 30 in closed circuit, while the electric
motor 10, the power control 14 and the auxiliary unit are cooled by
a water-antifreeze mixture flowing round the loop 32. The loops 30
and 32 exchange heat between them via the heat exchanger 34. Hence,
the excess heat taken away from the cell is transferred to the loop
32 and this heat is eliminated by thermal exchange with the flow of
air F.
[0053] In the event that the ambient temperature (or outside
temperature) falls below 0.degree. C., the thermal regulation means
automatically come into operation so as to heat the de-ionised
water, in order to prevent any risk of freezing of the first loop
30. These risks are also minimised by the presence of the thermal
insulation 44.
[0054] The device of FIG. 2 can be produced in compact form, as
FIG. 3 shows. In this figure, the same elements as in the case of
FIG. 2 are again found, and are designated by the same numerical
references.
[0055] Referring now to FIG. 4, a diagram of a circuit similar to
that of FIG. 2 is represented, in a variant embodiment. The same
elements are again found, designated under the same numerical
references.
[0056] With respect to the embodiment of FIG. 2, that of FIG. 4
differs essentially in the fact that the cooling device 58, the
heat exchanger 60 and the expansion vessel 68 are incorporated into
a diversion 70 from the main branch 46. Otherwise, the device of
FIG. 4 functions substantially in the same way as that of FIG.
2.
[0057] Needless to say, the invention is not limited to the
embodiments described above by way of example and extends to other
variants.
[0058] Hence, it will be understood that the first loop 30 and the
second loop 32 are susceptible of variants, as long as they
exchange heat between them by means of a heat exchanger.
[0059] The invention applies to the motor vehicles driven by
electric motors supplied by fuel cell. The fuel cell is also
susceptible of numerous variants, being supplied with hydrogen
possibly originating from a hydrogen bottle or from a
hydrogen-production unit.
* * * * *