FR3071962A1 - HOUSING FOR THE THERMAL REGULATION OF A MOTOR VEHICLE BATTERY PACK - Google Patents

Abstract

The invention relates to a housing (13) of a battery pack (1) for a motor vehicle, comprising an interior space intended to contain at least one electrical module and an internal circuit for transporting a coolant comprising at least one cooling device. thermal regulation of said at least one electrical module. According to the invention, the housing (13) carries on its external surface a heat exchanger, called "chiller", (2) connected to the internal circuit for transporting a coolant of said housing (13), said heat exchanger, said " chiller ", (2) being intended to be connected on the one hand to an air conditioning circuit of said vehicle in which a refrigerant fluid is intended to circulate and on the other hand to a thermal regulation loop of said at least one electrical module in which the heat transfer fluid is intended to be set in motion so that it circulates in the internal circuit of said housing (13).

Description

Housing for thermal regulation of a motor vehicle battery pack.

1. Field of the invention

The present invention relates to a housing for an electric module of a battery pack for a motor vehicle, and to such a battery pack.

2. Prior art

The electrical energy of vehicles with electric and / or hybrid motorization is supplied by one or more batteries.

In this type of vehicle, the battery is generally formed of a plurality of electrical cells forming one or more modules arranged in a protective housing in order to form what is called a battery pack.

One problem is that during operation, the batteries heat up and risk being damaged.

The thermal regulation of the battery is therefore an important point.

In fact, the temperature of the battery must remain between 20 ° C and 40 ° C in order to ensure the reliability, autonomy, and performance of the vehicle, while optimizing the life of the battery.

This regulation of the temperature of the battery, and in particular its cooling is ensured by means of a heat-transfer fluid, such as water or glycol water, which circulates in the conduits of a circuit placed inside. of the battery pack housing and connecting one or more thermoregulatory plates (or tube exchangers), in contact with the electrical modules, so as to regulate their temperature by thermal conduction.

Such a circuit is part of a thermal regulation loop 6 of the batteries, illustrated diagrammatically in FIG. 1, which further comprises a pump P for forcing the circulation of the heat transfer fluid inside the heat exchange plate. 61 (it could be several plates, however).

The heat transfer fluid can thus absorb the heat emitted by the electric modules in order to cool them and to evacuate this heat at the level of a heat exchanger, called chiller, 8, located outside the case of the battery pack.

The connection between the heat exchanger, called chiller, 8 disposed outside the battery pack housing, and the heat exchange plate 61 is made by means of a flange fixed on the external surface of the protective housing. .

The heat transfer fluid can also, if necessary, provide heat to heat the electrical modules.

To do this, the thermal regulation loop 6 comprises an additional heating device H, using for example electrical resistors or resistors with a positive temperature coefficient.

Such an additional heating device H is essential for regulating the temperature of the electrical modules, in particular by low temperatures in winter, where the temperature of the electrical modules must be increased before starting to charge them.

Furthermore, vehicles are frequently equipped with a heating, ventilation, and / or air conditioning installation to thermally regulate the interior space of the vehicle cabin by delivering an interior air flow at the desired temperature.

The heating, ventilation, and / or air conditioning installation generally comprises an air conditioning loop 7 inside which a refrigerant fluid circulates, and more precisely a main loop 74 comprising a compressor 76 forcing the circulation of refrigerant fluid in this loop. main 74 so that it passes through a condenser 77 before passing through an expansion device, or regulator, TXV1 then an evaporator 78 (making it possible to cool an air intended to circulate towards the passenger compartment of the vehicle, before reaching again the compressor 76.

In this main loop 74, the refrigerant thus performs a thermodynamic cycle in which it dissipates its heat at the level of the condenser 77, and in which it collects the heat at the level of the evaporator 78.

The thermal regulation loop 6 of the electric modules of the battery pack is in relation to the air conditioning loop 7, so as to allow a heat exchange between the refrigerant and the heat-transfer fluid, in particular intended for the cooling of the electric modules.

The heat transfer fluid of the thermal regulation circuit 6 of the electrical modules can thus be cooled by circulation in the so-called chiller heat exchanger 8 of the coolant / coolant type, which is connected to the air conditioning loop 7.

More specifically, the main loop 74 is connected to the so-called chiller heat exchanger 8 by means of another bypass loop 71, which is connected to the outlet of the condenser 77 and to the inlet of the compressor 76.

This bypass loop 71 includes a TXV 2 regulator that the refrigerant passes through before circulating in the so-called chiller 8 heat exchanger and then returns to the main loop by being reinjected at the inlet of the compressor 76.

However, such a solution is bulky and does not meet the current requirements of the automotive field.

Indeed, because of the perpetual increase in the level of electrification of hybrid and electric vehicles, it is necessary to increase the quantity of electric energy storage modules.

However, the space allocated for the integration of such electrical modules is limited, so that it is necessary to optimize the size of the thermal regulation loop of the electrical modules of the battery pack, and more generally of the conditioning system. thermal system of the vehicle comprising a first air conditioning loop and a second thermal regulation loop of a vehicle battery.

3. Summary of the invention

The invention provides for this purpose a housing of a battery pack for a motor vehicle, comprising an interior space intended to contain at least one electrical module and an internal circuit for transporting a heat-transfer fluid comprising at least one device for thermally regulating said at least one electrical module.

According to the invention, the housing carries on its outer surface a heat exchanger, called chiller, connected to the internal circuit for transporting a heat transfer fluid from said housing, said heat exchanger, said chiller, being intended to be connected on the one hand to an air conditioning loop of said vehicle in which a refrigerant is intended to circulate and on the other hand to a thermal regulation loop of said at least one electrical module in which the heat transfer fluid is intended to be set in motion so that it circulates in the internal circuit of said housing.

The invention consists in attaching a heat exchanger, known as a chiller, to the protective housing of the battery pack and in connecting it directly with the transport circuit of a heat transfer fluid, known as the cooling circuit, located in the housing. The connection with the air conditioning loop (refrigerant side) remains external to the housing.

This approach removes:

- the connection flange fixed on the external surface of the protective boxes of the prior art which provides the connection between the chiller, arranged outside the protective box, and the heat exchange plates or tubes arranged within the housing, and

- the connection pipes between the chiller and the connection flange of the housing.

This also makes it possible to reduce the number of fluid connections in the thermal regulation loop, and thus to reduce the risks of leakage of heat transfer fluid.

This solution also reduces the size of the thermal regulation loop (and more generally of the vehicle thermal conditioning system), and proves to be less expensive than the solutions of the prior art.

The heat exchanger, called chiller, placed on the housing, connects the thermal regulation loop of the battery with the air conditioning loop of the vehicle, so as to allow heat exchange between the coolant and the heat transfer fluid, in particular intended cooling the electrical cells forming the battery module (s).

The heat transfer fluid can thus absorb the heat emitted by the electrical cells in order to cool them and evacuate this heat at the level of the heat exchanger, called chiller, in which the heat transfer fluid is in thermal contact with the refrigerant fluid.

Said heat exchanger, known as a chiller, comprises a passage for the circulation of the coolant in the air conditioning circuit of said vehicle and the inlet and outlet pipes for the heat transfer fluid connected to the internal circuit for transporting a heat transfer fluid for the said housing, so as to that the heat transfer fluid circulating in said inlet and outlet conduits heat exchange with the refrigerant fluid circulating in said circulation passage.

In other words, the thermal regulation loop exchanges heat with the air conditioning loop inside the heat exchanger, called chiller.

According to a particular aspect of the invention, the inlet and outlet conduits of the heat transfer fluid of said heat exchanger, known as chiller, are housed in part, in a sealed manner, in holes passing through a wall of the housing and opening into the internal circuit. for transporting a heat transfer fluid from said housing.

In this way, the attachment of the heat exchanger, called chiller, is integrated into the battery pack housing.

According to a particular aspect of the invention, the holes passing through a wall of the housing are closed by a closure plate covering at least partially the internal face of said wall and intended to come into thermal contact with said at least one electrical module.

According to a particular aspect of the invention, the internal circuit for transporting a heat transfer fluid from said housing comprises channels for the passage of heat transfer fluid which are formed in said wall of the housing and which each communicate with one of said holes.

According to a particular aspect of the invention, a tube of the internal circuit for transporting a heat transfer fluid from said housing is arranged in each of said holes, the external surface of said tube coming into contact with the internal peripheral surface of said corresponding hole and the internal surface said tube being in sealed contact with the outer surface of the inlet pipe and the outlet pipe of the heat transfer fluid respectively of said heat exchanger, said chiller.

According to a particular aspect of the invention, each of said tubes is molded into the corresponding hole.

According to a particular aspect of the invention, the housing comprises on its outer surface means for fixing the heat exchanger, called chiller.

The invention also relates to a battery pack, for a motor vehicle, comprising a housing as described above.

The invention further relates to a thermal conditioning system of a vehicle comprising a first air conditioning loop and a second thermal regulation loop of a vehicle battery housed in a housing as described above.

4. List of figures

Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given by way of simple illustrative and nonlimiting examples, and of the appended figures, namely:

Figure 1 is a schematic representation of a thermal conditioning system of a motor vehicle according to the prior art, described above;

Figure 2 is a schematic representation of a protective housing of a battery pack of a motor vehicle according to an embodiment of the invention;

FIG. 3 schematically illustrates a first solution for connecting a heat exchanger, known as a chiller, to the protective housing of a battery pack of FIG. 2;

FIG. 4 schematically illustrates a second solution for connecting a heat exchanger, known as a chiller, to the protective housing of a battery pack of FIG. 2.

5. Detailed description of the invention

In the present description, the term “battery pack” means a box in which are housed:

a battery consisting of at least one electrical module comprising several cells for storing electrical energy, and

means of thermal regulation of this electrical module, in the form of at least one thermoregulatory plate or of a tube heat exchanger in thermal contact with the module.

Furthermore, the term battery designates an electrical energy storage device composed of one or more electrical cells and, also, an assembly composed of one or more electrical energy storage devices comprising, respectively, one or more cells. electric.

The temperature control plate is generally cooled and, therefore, cooling for the module.

However, it is not excluded that it can be used, at least temporarily, to heat a module to bring it to an optimal operating temperature, when the climatic conditions are unfavorable.

FIG. 2 is a schematic representation of a housing 13 for protecting a battery pack 1.

Such a box is intended to be implemented in a thermal conditioning system of an electric or hybrid vehicle comprising as described above, in relation to FIG. 1, a first air conditioning loop and a second thermal regulation loop. a vehicle battery.

The housing 13 is of generally parallelepipedal shape and comprises walls delimiting a closed and sealed enclosure in which is received at least one electrical module (not illustrated) forming the battery.

The enclosure further comprises an internal circuit for transporting a heat transfer fluid (not illustrated), such as glycol water, comprising at least one thermal regulation device, taking the form of a thermoregulatory plate (not illustrated). of the electrical module, in thermal contact with the latter.

Advantageously, a heat exchanger 2 of the chiller type (in English) is carried by an outer surface of the protective housing 13.

It is in the form of a block which can be fixed by screwing on the housing 13 and comprising on a first face a connection flange 21 in which are formed an inlet port 21A of coolant, an outlet port 21B of coolant and a U-shaped passage (not visible) of the coolant connecting the inlet port 21A to the outlet port 21B.

This coolant passage is intended to be part of the air conditioning loop of the vehicle's thermal conditioning system.

The block is traversed by an inlet conduit 22A and an outlet conduit 22B cylindrical with heat transfer fluid projecting from its first and second opposite faces. The end of the conduits 22A, 22B located on the side of the second face (not visible in FIG. 2), forming a male element, is intended to be introduced into a cylindrical hole 132, forming a female element, formed in a wall of the housing 13 .

The two cylindrical holes 132 open out at the level of two bases 131 taking the form of a flattened cylinder 131 projecting from the outside surface of the housing 13.

The two holes 132 also open into the internal circuit for transporting the heat transfer fluid from the housing 13.

Fixing the heat exchanger block 2 of the chiller type directly to the housing 13 is easy and makes it possible to dispense with the implementation of a connection flange on the housing according to the prior art, but also to reduce the number of connections and the risk of heat transfer fluid leakage.

The approach of the invention therefore makes it possible, in general, to reduce the size and the weight of the thermal regulation loop of the electric cells forming the battery.

More generally, this makes it possible to reduce the size of the thermal conditioning system in the motor vehicle, to facilitate its installation and to minimize the risks of non-tightness due to the reduction in the number of fluidic connections.

FIG. 3 illustrates a first solution for connecting the heat exchanger or chiller 2, and in particular of its inlet 22A and outlet conduits

22B of heat transfer fluid, with the internal circuit for transporting the heat transfer fluid from the housing 13.

As illustrated, one end of the inlet duct 22A for heat transfer fluid from the heat exchanger or chiller 2 is housed in a hole 132 passing through a wall of the housing 13.

This hole 132 opens into a channel (not visible) formed in the same wall of the housing 13, the channel being connected to the internal circuit for transporting the heat transfer fluid of the housing 13 and intended to supply heat transfer fluid to the thermoregulatory plate of the battery pack.

It is understood that one end of the outlet pipe 22B of heat transfer fluid from the heat exchanger or chiller 2 is housed in the other hole 132 passing through the same wall of the housing 13.

This hole 132 is configured to direct the heat transfer fluid into a channel (not visible) formed in the same wall of the housing 13, the channel being connected to the internal circuit for transporting the heat transfer fluid from the housing 13 and intended to evacuate the heat transfer fluid from the thermoregulatory plate of the battery pack.

The holes 132 and the corresponding channels are closed by a closure plate 133, made of aluminum for example, which is arranged in a sealed manner against the interior surface of the housing 13.

This closure plate 133 constitutes in this example the thermoregulatory plate intended to come into thermal contact with the battery pack module.

In an exemplary embodiment, this heat exchange plate 133 can form a bottom of the housing 13. Consequently, the battery rests on the heat exchange plate.

However, the heat exchange plate can be arranged on one or more sides of the housing 13, while being in thermal contact with the battery.

It should be noted that the seal between the inlet duct 22A of the heat exchanger or chiller 2 and the cylindrical hole 132 is provided by an O-ring 23 carried by the inlet duct 22A.

Furthermore, the fixing of the block constituting the heat exchanger or chiller 2 on the housing 13 is ensured by screwing or any other suitable means. In Figure 2, the outer surface of the housing 13 has two threads for receiving fixing screws passing through holes in the sides of the block.

FIG. 4 illustrates a second solution for connecting the heat exchanger or chiller 2, and in particular its inlet conduits 22A and outlet 22B of heat transfer fluid, with the internal circuit for transporting the heat transfer fluid from the housing 13.

As illustrated, one end of the inlet duct 22A for heat transfer fluid from the heat exchanger or chiller 2 is housed in a tube 135 extending partly in the hole 132 which passes through a wall of the housing 13.

The tube 135 is here partially overmolded in the hole 132 and is connected to the internal circuit for transporting the heat transfer fluid of the housing 13 so as to supply the heat-regulating plate of the battery pack with heat-transfer fluid.

It is understood that one end of the outlet pipe 22B of heat transfer fluid from the heat exchanger or chiller 2 is housed in another tube 135 and that the latter is connected to the internal circuit for transporting the heat transfer fluid from the housing 13 so as to evacuate the heat transfer fluid from the thermoregulatory plate of the battery pack.

Note that the outer surface of said inlet conduit 22A comes into contact with the inner peripheral surface of said tube 135 and that the seal between the inlet conduit 22A and the tube 135 is ensured by an O-ring 23 carried by the conduit input 22A.

Furthermore, the fixing of the block constituting the heat exchanger or chiller 2 on the housing 13 is ensured by screwing or any other suitable means.

In operation, the heat exchanger or chiller 2 is connected to the air conditioning loop in which a coolant circulates and to the thermal control loop in which a heat transfer fluid circulates, so that the coolant is cooled by the refrigerant at the level of the heat exchanger or chiller 2.

Simultaneously with the circulation of the heat transfer fluid the heat exchanger or chiller 2, the refrigerant passes through the heat exchanger or chiller 2 along a path which can take a U shape or any other form.

Such an arrangement thus allows the refrigerant to regulate the temperature of the heat transfer fluid.

The heat transfer fluid can thus absorb the heat emitted by the electric cells of the battery pack in order to cool them and / or as needed, it can provide them with heat if the temperature of the electric cells is insufficient for their proper functioning.

In FIG. 2, arrows illustrate the direction of circulation of the coolant in the heat exchanger or chiller 2. It thus circulates in the inlet port 21A in a first direction and in the outlet port 21B in a second direction of opposite direction to the first direction.

Arrows also illustrate the direction of circulation of the heat transfer fluid in the heat exchanger or chiller 2 and in the housing 13.

In the operating mode known as “cooling” of the electrical cells, the refrigerant circulating in the heat exchanger or chiller 2 absorbs the heat of the heat transfer fluid circulating in the heat exchanger or chiller 2 by evaporating, which has for effect of cooling the heat transfer fluid and therefore the electrical cells constituting the vehicle battery.

Thus, the heat transfer fluid of the thermal regulation circuit of the vehicle battery is cooled in the so-called chiller heat exchanger 2 by the refrigerant of the air conditioning system which also circulates in this said heat exchanger.

The so-called “heating” function of the heat transfer fluid, and therefore of the electrical cells, is performed in a known manner by the use of a water heater disposed in the thermal regulation loop.

Obviously, the invention is not limited to the embodiments described above and provided only by way of examples.

It encompasses various modifications and variants that a person skilled in the art may envisage within the framework of the present invention.

The refrigerant used in the air conditioning loop is, for example, a gaseous refrigerant, for example a fluorinated compound known under the name R134a, a hydrofluoroalkene known under the name R1234yf or carbon dioxide known under the name R744.

Furthermore, the vehicle's thermal conditioning system can implement a control unit and switching means between the heating mode and the cooling mode of the batteries. In this context, it implements, for example, a probe for measuring the temperature of the heat transfer fluid.

Claims (9)

1. Housing (13) of a battery pack (1) for a motor vehicle, comprising an interior space intended to contain at least one electrical module and an internal circuit for transporting a heat-transfer fluid comprising at least one device for thermally regulating said at least one electrical module, the box (13) being characterized in that it carries on its outer surface a heat exchanger, called a chiller, (2) connected to the internal circuit for transporting a heat transfer fluid from said box (13), said heat exchanger, called chiller, (2) being intended to be connected on the one hand to an air conditioning loop (7) of said vehicle in which a refrigerant is intended to circulate and on the other hand to a thermal regulation loop ( 6) of said at least one electrical module in which the heat transfer fluid is intended to be set in motion so that it circulates in the internal circuit of said housing (13). 2. Housing (13) according to claim 1, characterized in that said heat exchanger, called chiller, (2), comprises a circulation passage (21A, 21B) of the refrigerant of the air conditioning circuit and the inlet conduits and outlet (22A, 22B) of the heat transfer fluid connected to the internal circuit for transporting a heat transfer fluid from said housing (13), so that the heat transfer fluid circulating in said inlet and outlet conduits (22A, 22B) heat exchange with the refrigerant circulating in said circulation passage (21A, 21B). 3. Housing (13) according to claim 2, characterized in that the inlet and outlet conduits (22A, 22B) of the heat transfer fluid of said heat exchanger, called chiller, (2) are housed in part, in a sealed manner, in holes (132) passing through a wall of the housing (13) and opening into the internal circuit for transporting a heat transfer fluid from said housing (13). 4. Housing (13) according to claim 3, characterized in that the holes (132) are closed at one end by a closure plate (133) covering at least partially the internal face of said wall of the housing (13) and intended to come into thermal contact with said at least one electrical module. 5. Housing (13) according to claim 4, characterized in that the internal circuit for transporting a heat transfer fluid from said housing (13) comprises channels for the passage of heat transfer fluid formed in said wall of the housing (13) and each communicating with one of said holes (132). 6. Housing (13) according to claim 3, characterized in that a tube (135) of the internal circuit for transporting a heat transfer fluid from said housing (13) is disposed in each of said holes (132), the outer surface of said tube (135) coming into contact with the interior peripheral surface of said corresponding hole (132) and the interior surface of said tube (135) being in sealed contact with the exterior surface of the inlet conduit (22A) and the outlet conduit (22B ) of the heat transfer fluid respectively of said heat exchanger, called chiller, (2). 7. Housing (13) according to claim 6, characterized in that each of said tubes (135) is molded into the hole (132) corresponding. 8. Housing (13) according to claim 6, characterized in that it comprises on its outer surface means for fixing the heat exchanger, said chiller, (2). 9. Battery pack (1), for a motor vehicle, characterized in that it comprises a housing (13) according to one of claims 1 to 8.