FR3099642A1 - Thermal regulation device for at least one electric vehicle battery pack - Google Patents

Abstract

Thermal regulation device (1) of at least one electric battery pack for an electric or hybrid motor vehicle, said thermal regulation device (1) comprising a thermal management circuit of said at least one electric battery pack comprising a management loop thermal (5) in which a first heat transfer fluid is intended to circulate, said thermal management loop (1) comprising at least a first (101) and a second (102) heat exchanger, the latter being configured to exchange heat. heat energy with said at least one electric battery pack, characterized in that said thermal regulation device (1) comprises a magnetocaloric system (M) comprising: a first bypass branch (M1) to which at least a third exchanger is connected heat source (103) configured to exchange heat energy with said electric battery pack, a second bypass branch (M2) on which e is connected a fourth (104) heat exchanger, and a magnetocaloric device (50) arranged jointly on the first and second branch branches (M1 and M2). Figure for the abstract: Fig. 1

Description

Device for thermal regulation of at least one motor vehicle electric battery pack

The invention relates to a device for regulating the temperature of at least one electric battery pack of a motor vehicle and comprising an attached magnetocaloric device.

More specifically, the invention relates to a thermal management device for at least one electric battery pack linked to a circuit of the air conditioning or heat pump type in order to regulate the temperature of an internal air flow intended for the passenger compartment and/or in order to regulate the temperature of the at least one electric battery pack for an electric or hybrid vehicle.

As a general rule, the heat exchangers making up the thermal management devices are sized to exchange sufficient calorific energy to meet the specifications requested by the manufacturers for the most extreme external conditions in terms of thermal power to be evacuated and for ambient conditions . These heat exchangers are therefore generally oversized in most real driving conditions. In the extreme conditions for which they are designed, they are a source of nuisance and overconsumption. In fact, to exchange a lot of heat at the level of the front face, for example during rapid charging of a battery which requires a lot of thermal power to be evacuated, the heat exchangers are oversized and produce a lot of noise and consume a lot of energy. 'energy. In addition, for high powers, the ratio between the thermal power of a heat exchanger and its mass decreases. Larger and heavier exchangers are therefore needed to achieve the thermal power required.

It is also necessary to occasionally provide additional cooling or heating power to the electric battery pack, in particular during rapid recharging. Indeed, during this rapid recharging, the batteries tend to heat up excessively, it is therefore necessary to cool them even more than normal. In winter conditions, it may also be necessary to provide additional heating to the electric battery pack, in particular when switching on an electric or hybrid vehicle. The provision of a one-off thermal "boost" is therefore necessary in order to guarantee a lifespan and optimal autonomy for electric or hybrid vehicles.

The device according to the invention makes it possible to remedy these drawbacks at least partially. To this end, the subject of the invention is a thermal regulation device for at least one electric battery pack for an electric or hybrid motor vehicle, said thermal regulation device comprising a thermal management loop of said at least one electric battery pack in which a first heat transfer fluid is intended to circulate, said thermal management loop comprising at least a first and a second heat exchanger, the second heat exchanger being configured to exchange calorific energy with said at least one battery pack electrical, characterized in that said thermal regulation device comprises a magnetocaloric system comprising:

• a first bypass branch to which is connected at least a third heat exchanger configured to exchange heat energy with said electric battery pack,

• a second bypass branch to which a fourth heat exchanger is connected, and
• a magnetocaloric device arranged jointly on the first and second bypass branches.

The thermal regulation device according to the present invention allows an additional calorific energy supply in the form of a “boost” for cooling or heating the electric battery pack of an electric or hybrid motor vehicle.

According to one or more characteristics of the thermal regulation device, taken alone or in combination:

• the magnetocaloric system is independent of the thermal management loop, in which circulates a second heat transfer fluid distinct from the first heat transfer fluid,
• the first bypass branch is connected to the thermal management loop parallel to the at least one second heat exchanger so that the first heat transfer fluid can circulate therein,
• the at least one second heat exchanger is a heat exchange plate intended to be in contact with the at least one electric battery pack,
• the at least one third heat exchanger is a heat exchange plate intended to be in contact with the at least one electric battery pack,
• the second bypass branch comprises at least two third heat exchangers arranged parallel to each other,
• the at least one electric battery pack comprises a plurality of electric accumulators and the third heat exchangers are each arranged between two of the electric accumulators,
• the at least two third heat exchangers are arranged on the side faces of the electric battery pack,

Other characteristics and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended figures in which:

FIG. 1 shows a schematic representation of a thermal management device according to a first embodiment,

FIG. 2 shows a schematic representation of a thermal management device according to a second embodiment,

FIG. 3 shows a schematic representation of a thermal management device according to a third embodiment,

FIG. 4 shows a representation in perspective of an electric battery pack according to a first embodiment,

FIG. 5 shows a representation in perspective of an electric battery pack according to a second embodiment,

Identical elements in the various figures bear the same reference numerals.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that features of different embodiments may also be combined and/or interchanged to provide other achievements.

In the present description, it is possible to index certain elements or parameters, such as for example first element or second element as well as first and second parameters or even first criterion and second criterion, etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are close, but not identical. This indexing does not imply a priority of one element, parameter or criterion over another and it is easy to interchange such denominations without departing from the scope of the present description. Nor does this indexing imply an order in time, for example, to assess such and such a criterion.

In the present description, “placed upstream” means that one element is placed before another with respect to the direction of circulation of a fluid. Conversely, “placed downstream” means that one element is placed after another in relation to the direction of fluid circulation.

Figures 1 to 3 show a schematic representation of a thermal regulation device 1 of at least one electric battery pack (not shown) according to a simple embodiment. According to the embodiment illustrated in FIG. 1, the thermal regulation device 1 comprises a thermal management loop 5 in which a heat transfer fluid is intended to circulate, the latter preferably comprising glycol water. This thermal management loop 5 comprises a first heat exchanger 101 and a second heat exchanger 102. More specifically, the thermal management loop 5 comprises a pump 3, the first heat exchanger 101 and the second heat exchanger 102.

The first heat exchanger 101 can be a two-fluid heat exchanger arranged jointly on the thermal management loop 5 and for example on a loop of an air conditioning circuit C of a motor vehicle, this so as to allow the exchange of calorific energy between the refrigerant of the loop of an air conditioning circuit C and the first heat transfer fluid of the thermal management loop 5. The first heat exchanger 101 possibly being a two-fluid heat exchanger which is then crossed by the first heat transfer fluid and by a refrigerant fluid.

According to a first variant not shown, the first heat exchanger 101 can be a radiator intended to be crossed by an external air flow 100 in which the heat transfer fluid dissipates heat energy.

The second heat exchanger 102 is arranged directly in contact with an electric battery pack and preferably has the form of a heat exchange plate on which the electric battery pack rests. The second heat exchanger 102 therefore makes it possible to thermally regulate the at least one pack of electric batteries by exchanging heat energy with the first heat transfer fluid. This is so as to allow, for example, the cooling of the electric battery pack when recharging the electric batteries or in particular when the vehicle is running.

The thermal regulation device 1 of at least one electric battery pack further comprises a magnetocaloric system M in which a heat transfer fluid is intended to circulate. The magnetocaloric system M comprises more particularly a magnetocaloric device 50 then arranged jointly on a first and a second branch branch M1 and M2. By magnetocaloric device 50 is meant here a device comprising a material capable of a magnetocaloric effect, that is to say which heats up when it is subjected to a magnetic field, for example by means of an electromagnetic coil, and which cools when this magnetic field is extinguished. A synchronous redirection of one or more fluids with its heating or cooling phases makes it possible to heat or cool an element. For example, when the magnetocaloric device 50 is subjected to a magnetic field, it heats up and transmits calorific energy to the heat transfer fluid which is then heated, conversely when it is no longer subjected to this magnetic field. it cools and absorbs heat energy and cools the heat transfer fluid. The magnetocaloric device 50 comprises a first input M1a and a first output M1b connected to the first bypass branch M1. This magnetocaloric device 50 also comprises a second input M2a and a second output M2b connected to the second bypass branch M2. The first and the second bypass branches M1 and M2 are in fluid communication with each other via the magnetocaloric device 50. Indeed, the first input M1a is connected to the second output M2b and the second input M2a is connected with the first output M1b of the magnetocaloric device 50. In this way the second heat transfer fluid circulates between the first and second branch branches M1 and M2.

The first bypass branch M1 comprises a third heat exchanger 103 intended to exchange heat energy with the pack of electric batteries and preferably having the shape of a heat exchange plate arranged in contact with the pack of electric batteries. This, for example, to allow the cooling of the electric battery pack during rapid recharging or else during operation of the electric battery pack, in particular when the vehicle is running.

The second bypass branch M2 comprises a fourth heat exchanger 104 which can be intended to be crossed by an external air flow in order either to dissipate or to absorb heat energy. Depending on the heat energy dissipated or absorbed by the heat transfer fluid, the latter will then be cooled or heated by the magnetocaloric device 50 in order to improve the cooling or heating effect on the electric battery pack at the level of the third heat exchanger. heat 103.

The arrangement of a magnetocaloric system M within the thermal regulation device 1 allows the provision of an additional cooling or heating "boost" on the pack of electric batteries in order to control the temperature of the latter in particular during charging. fast electric batteries.

According to a first embodiment illustrated in FIG. 1, the thermal management loop 5 and the magnetocaloric system M of the thermal regulation device 1 are independent of each other. In this first embodiment, the thermal management loop 5 includes a first heat transfer fluid while the magnetocaloric system M includes a second heat transfer fluid. By independent, it is meant that the first and second heat transfer fluids are distinct and do not mix. In this first embodiment, the magnetocaloric system M comprises a pump (not shown) allowing the circulation of the second heat transfer fluid within said magnetocaloric system M where the magnetocaloric device 50 is configured to set the second heat transfer fluid in motion.

According to an example of cooling the electric battery pack, the first heat transfer fluid, circulating in the thermal management loop 5, passes through the first heat exchanger 101 in which it is cooled. The cooling of the first heat transfer fluid is obtained for example by an exchange of heat energy with the refrigerant of the air conditioning circuit C. The first heat transfer fluid, once cooled at the level of the first heat exchanger 101, passes through the second heat exchanger 102 and absorbs heat energy from the at least one electric battery pack. The absorption of heat energy at the level of the second heat transfer exchanger 102 allows the cooling of the electric battery pack. At the outlet of the second heat exchanger 102, the first heat transfer fluid is then charged with calorific energy.

Conversely and according to an example of heating the electric battery pack, the first heat exchanger 101 can be in contact with a flow of hot air from a heat pump (not shown) or an electric radiator heating the first heat transfer fluid (not shown). The first heat transfer fluid thus loaded with heat energy then passes through the second heat exchanger 102 then in contact with the battery pack and at the level of which it dissipates heat energy and therefore makes it possible to increase the temperature of said battery pack. The first heat transfer fluid circulating in the thermal management loop 5 then presents a cycle of absorption or dissipation of heat energy allowing the thermal regulation of the electric battery pack at the level of the second heat exchanger 102.

The magnetocaloric system M in this first embodiment also makes it possible to regulate the temperature of the electric battery pack in addition to the thermal regulation resulting from the thermal management loop 5.

According to an example of cooling of the electric battery pack by the magnetocaloric system 50, the second heat transfer fluid circulating in the first bypass branch M1 passes through the magnetocaloric device 50 in which it absorbs calorific energy and is found in the second branch of derivation M2. The second heat transfer fluid passes through the fourth heat exchanger 104 in which it dissipates heat energy and then recrosses the magnetocaloric device 50 in which it is cooled and ends up in the first bypass branch M1. The second heat transfer fluid then cooled passes through the third heat exchanger 103 in contact with the electric battery pack at the level of which it absorbs heat energy and makes it possible to cool said electric battery pack. The reverse is possible, according to an example of heating of the electric battery pack by the magnetocaloric system M, the second heat transfer fluid circulating in the first bypass branch M1 passes through the magnetocaloric device 50 in which it dissipates heat energy. The second heat transfer fluid then circulates in the second bypass branch M2 and passes through the fourth heat exchanger 104 in which it absorbs heat energy. The second heat transfer fluid thus charged with calorific energy recrosses the magnetocaloric device 50 in which it is all the more heated and then finds itself in the first bypass branch M1. Said second heat transfer fluid then heated then passes through the third heat exchanger 103 in contact with the electric battery pack in which it dissipates heat energy in order to heat up said electric battery pack.

According to a second embodiment illustrated in FIG. 2, the thermal management loop 5 and the magnetocaloric system M are connected to each other so that one and the same heat transfer fluid circulates therein. Indeed, the first bypass branch M1 is connected to the thermal management loop 5, parallel to the second heat exchanger 102. More specifically, the first bypass branch M1 comprises an entry point 7 and an exit point 9 of the coolant. The entry point 7 of the heat transfer fluid is placed upstream of the second heat exchanger 102 and the exit point 9 is placed downstream of said second heat exchanger 102 in the direction of the flow of the heat transfer fluid. In order to redirect part of the flow of said heat transfer fluid to the second heat exchanger 102, for example when the magnetocaloric device 50 absorbs or dissipates heat energy in its operating cycle, the thermal management loop 5 comprises a redirection device 52, for example a three-way valve, then arranged at the entry point 7 and connected with the first bypass branch M1.

In this second embodiment, the third heat exchanger 103 is arranged downstream of the magnetocaloric device 50 on the first bypass branch M1. At the entry point 7, part of the flow of heat transfer fluid having passed through the first heat exchanger 101 is redirected by the redirection device 52 towards the second heat exchanger 102 of the thermal management loop in order to heat or cool the electric battery pack, while another part of the heat transfer fluid flow is redirected to the magnetocaloric device 50 via the first bypass branch M1.

According to an example of cooling of the electric battery pack, the part of the heat transfer fluid passing in the first bypass branch M1 passes through the magnetocaloric device 50 where it is heated. The heat transfer fluid then circulates in the second bypass branch M2 and crosses the fourth heat exchanger 104 at the level of which it dissipates heat energy. The heat transfer fluid cools by dissipation of heat energy at the level of the fourth heat exchanger 104 then passes through the magnetocaloric device 50 in which it is all the more cooled. Said heat transfer fluid then circulates in the direction of the third heat exchanger 103 in which it absorbs calorific energy in contact with the electric battery pack, it then returns to the thermal regulation loop 5 via the exit point 9 by a point of connection 53 located downstream of the second heat exchanger 102.

The reverse is also possible, particularly when using the motor vehicle at low temperatures or in winter conditions. Indeed, according to an example of heating of the electric battery pack, the part of the heat transfer fluid having been redirected in the first bypass branch M1 by the redirection device 52 passes through the magnetocaloric device 50 in which it is cooled. The heat transfer fluid then circulates in the second bypass branch M2 and crosses the fourth heat exchanger 104 at the level of which it absorbs calorific energy. The heat transfer fluid recrosses the magnetocaloric device 50 in which it still absorbs calorific energy to then end up in the first bypass branch M1. Said heat transfer fluid then loaded with heat energy then passes through the third heat exchanger 103 in contact with the pack of electric batteries at the level of which it dissipates heat energy in order to heat up said pack of electric batteries. Then, the heat transfer fluid passes through the exit point 9 and circulates in the thermal regulation loop 5.

The magnetocaloric device 50 allows the creation of an additional thermal "boost" of the sole regulation of the thermal management loop 5 then resulting in greater cooling or heating of the electric battery pack.

The third heat exchanger 103 may in particular have a form of heat plate additional to the second heat exchanger 102 also having a form of heat exchange plate. The arrangement of the magnetocaloric system M in addition to the second heat exchanger 102 of the thermal regulation loop makes it possible to provide a thermal "boost" to the electric battery pack, additional to the thermal effect of the second heat exchanger 102 and allowing then to regulate the thermal oscillations of the latter in the event of rapid charging or in extreme thermal conditions.

According to an example illustrated in FIG. 3, the first bypass branch M1 may comprise at least two third heat exchangers 103 and 103'. More precisely, the thermal regulation device 1 illustrated in this same figure 3 comprises four third exchangers 103, 103', 103'' and 103'''. This is only a schematic example and the thermal regulation device 1 could comprise a greater number of third heat exchangers 103. In this example illustrated in FIG. 3, the thermal management loop 5 and the magnetocaloric system M are identical to those previously illustrated in Figures 1 and 2. The third heat exchangers 103, 103 ', 103'' and 103''' as illustrated in Figure 3 are arranged in parallel to each other and each have a shape of heat exchange plate arranged in contact with the electric battery pack in order to allow the exchange of heat energy between the latter and the heat transfer fluid. The third heat exchangers 103, 103', 103'' and 103''' are all connected to the first bypass branch M1 via a common entry point 11 located downstream of the magnetocaloric device 50 and a common exit point 13 located downstream of the third exchanger 103 and connected to the thermal management loop 5. In this example, the heat transfer fluid circulates in the thermal management loop 5 and in the magnetocaloric system M in the same way as in the second illustrated embodiment in FIG. 2. The arrangement of the third heat exchangers 103, 103', 103'' and 103''' in parallel to each other and connected to the first bypass branch M1 according to this example can also be adapted to the first embodiment illustrated in FIG. 1. The heat transfer fluid having been cooled or heated by the magnetocaloric device 50 and entering the first bypass branch M1, this heat transfer fluid will then pass through the third heat exchangers 103, 103', 103'' and 103''' in contact with the electric battery pack with which it will dissipate or absorb heat energy. The arrangement of at least two third heat exchangers 103 and 103' downstream of the magnetocaloric device 50 makes it possible to increase the exchange surface with the electric battery pack and therefore to increase the cooling or heating effect of the " thermal boost obtained by the magnetocaloric device 50, this in comparison with the arrangement of a single third heat exchanger 103.

Figures 4 and 5 illustrate different arrangements of the third heat exchangers 103, 103', 103'' and 103''' in contact with the pack of electric batteries, according to the example illustrated in figure 3. In these figures, the pack of electric batteries comprises a plurality of electric accumulators 17, 17', 17'' and 17'''.

According to a first variant illustrated in FIG. 4, the electric accumulators 17, 17', 17'' and 17''' are spaced apart from each other by spaces into which the third heat exchangers 103, 103', 103' are inserted. ' and 103'''. These third heat exchangers 103, 103', 103'' and 103''' each have the form of a heat exchange plate. This is so that said third heat exchangers 103, 103', 103'' and 103''' are each arranged between two electric accumulators 17, 17', 17'' and 17'''. In this first variant, the second heat exchanger 102 is arranged so as to support the plurality of electric accumulators 17, 17', 17'' and 17''' of said electric battery pack. This configuration makes it possible to increase the heat energy exchange surfaces between the first heat transfer fluid passing through the third heat exchangers 103, 103', 103'' and 103''' and the various electric accumulators 17, 17', 17 '' and 17''. This configuration therefore makes it possible to improve the thermal regulation of said electric battery pack.

According to a second variant illustrated in FIG. 5, two third heat exchangers 103, 103' having the shape of a heat exchange plate are each arranged in contact with the side faces of the electric battery pack and more precisely in contact with the side faces of the accumulators. electric 17, 17', 17'' and 17'''. Just like the first variant represented in FIG. 4, the second heat exchanger 102 is arranged so as to support the plurality of electric accumulators 17, 17', 17'' and 17''' of said electric battery pack. This configuration also makes it possible to increase the exchange surface between the thermal regulation device 1 and the electric battery pack and therefore makes it possible to improve the cooling or heating effect of the thermal “boost” from the magnetocaloric device 50.

The different embodiments of the thermal regulation device 1 illustrated in FIGS. 1 to 5 can be adapted to all forms of existing electric battery packs as well as all geometries of heat exchange plates.

The thermal regulation device 1 of the present invention comprises a thermal management loop 5 and a magnetocaloric system M making it possible to exchange sufficient calorific energy with a heat transfer fluid to respond to the thermal variations of an electric battery pack. Indeed, the magnetocaloric device 50 allows the creation of an additional thermal "boost" of the only thermal regulation then coming from the thermal regulation loop 1 and being punctual so as to regulate the temperature variations of at least one pack of electric batteries and in particular under fast charging conditions or in extreme conditions.

Claims (8)

Thermal regulation device (1) for at least one electric battery pack for an electric or hybrid motor vehicle, said thermal regulation device (1) comprising a circuit for thermal management of said at least one electric battery pack comprising a management loop (5) in which a first heat transfer fluid is intended to circulate, said thermal management loop (5) comprising a first heat exchanger (101) and at least one second heat exchanger (102), said at least one second heat exchanger (102) being configured to exchange calorific energy with said at least one electric battery pack, characterized in that said thermal regulation device (1) comprises a magnetocaloric system (M) comprising:

• a first bypass branch (M1) to which is connected at least a third heat exchanger (103) configured to exchange heat energy with said electric battery pack,
• a second bypass branch (M2) to which a fourth heat exchanger (104) is connected, and
• a magnetocaloric device (50) arranged jointly on the first and second branch branches (M1 and M2).

Thermal regulation device (1) according to the preceding claim, characterized in that the magnetocaloric system (M) is independent of the thermal management loop (5) and in that a second heat transfer fluid distinct from the first heat transfer fluid is intended to circulating in said magnetocaloric system (M). Thermal regulation device (1) according to Claim 1, characterized in that the first bypass branch (M1) is connected to the thermal management loop (5) parallel to the at least one second heat exchanger (102) and in that the first heat transfer fluid circulates within said first bypass branch (M1). Thermal regulation device (1) according to any one of the preceding claims, characterized in that the said at least one second heat exchanger (102) is a heat exchange plate intended to be in contact with the said at least one heat pack. electric batteries. Thermal regulation device (1) according to any one of the preceding claims, characterized in that the said at least one third heat exchanger (103) is a heat exchange plate intended to be in contact with the said at least one battery pack electrical. Thermal regulation device (1) according to any one of the preceding claims, characterized in that the second bypass branch (M2) comprises at least two third heat exchangers (103 and 103') arranged parallel to each other. Thermal regulation device (1) according to the preceding claim, characterized in that the said at least one electric battery pack comprises a plurality of electric accumulators (17, 17', 17'' and 17''') and in that the third heat exchangers (103, 103', 103'' and 103''') are each arranged between two of said electric accumulators (17, 17', 17'' and 17'''). Thermal regulation device (1) according to Claim 6, characterized in that the at least two third heat exchangers (103 and 103') are arranged in contact with the side faces of the electric battery pack.