WO2011067490A1

WO2011067490A1 - Motor vehicle comprising an electrical engine supplied with power by means of a battery, and means for cooling said battery

Info

Publication number: WO2011067490A1
Application number: PCT/FR2010/052210
Authority: WO
Inventors: Thierry Fillion; Gilles Mulato; Philippe Dubois; Bruno Berthelot
Original assignee: Renault Sas
Priority date: 2009-12-02
Filing date: 2010-10-18
Publication date: 2011-06-09
Also published as: FR2953166A1; EP2507863A1; FR2953166B1

Abstract

The invention relates to a motor vehicle comprising a battery (1) for supplying power to an electrical engine and moreover relates to a means for cooling said battery, said means comprising a heat exchanger (3). According to the invention, said heat exchanger (3) comprises at least one module functioning according to the Peltier effect, and said cooling means comprises: a first circuit (5) that makes it possible to directly cool the battery, and a second circuit (7) that makes it possible to pass air, coming from outside the vehicle, and through said heat exchanger (3) so as to cool the first circuit fluid exiting said battery.

Description

Motor vehicle comprising an electric motor powered by a battery and means for cooling the battery

The present invention relates to a motor vehicle which comprises an electric motor powered by a battery and cooling means of this battery.

Electric vehicles are driven by an electric motor powered by a large battery, which is usually disposed between the four wheels of the vehicle. This battery heats up during engine operation and must be cooled.

It is known to use the air conditioner of the vehicle to cool the battery.

A battery cooling circuit draws outside air from the front of the vehicle, cools it through the air conditioning heat exchanger and sends it into contact with the battery to cool it down. Air that has warmed up on contact with the battery is expelled to the rear of the vehicle.

The main disadvantage of this type of cooling is that it requires to equip the electric vehicle with an air conditioning system that is expensive and heavy which penalizes the autonomy of the vehicle.

An object of the present invention is to provide a motor vehicle capable of being set in motion by an electric motor powered by a battery and which comprises battery cooling means which are less expensive and less heavy.

This object is achieved by means of a motor vehicle comprising a battery for supplying an electric motor and cooling means for said battery which comprise an exchanger.

According to the invention, said exchanger comprises at least one module operating according to the Peltier effect and said cooling means comprise a first circuit which passes through said exchanger and which makes it possible to circulate a first fluid in said battery so as to cool it directly, the temperature of said first fluid at the outlet of said heat exchanger being lower than the temperature of said fluid at the inlet of said heat exchanger and a second circuit which makes it possible to pass air coming from the outside of said heat exchanger; vehicle through said exchanger, the air temperature at the inlet of said exchanger being lower than the temperature of the air output of said exchanger.

The cooling means therefore comprise a closed circuit and an open circuit. Peltier effect modules are known and are used, for example, for small refrigerators. The Peltier effect modules include a plurality of Peltier cells that are assembled.

According to a particular embodiment, the Peltier effect module comprises two external ducts sandwiching an internal duct and two layers of Peltier effect cells which are arranged between said internal duct and each of the external ducts and said internal duct is part of said first circuit. and said outer conduits are part of said second circuit which splits at said exchanger.

Such an exchanger allows good heat exchange at the Peltier cells and a good flow distribution.

According to one embodiment, said exchanger comprises two Peltier effect modules arranged substantially in V and said first circuit is shaped so that said first fluid coming from said battery arrives between the branches of the V and separates into two streams which each pass through one of said branches.

Such an exchanger allows significant space saving. Indeed it allows to house the entire cooling system according to the invention under the rear floor of a vehicle, with a short overhang.

This provision in V also allows a fast feeding Peltier effect modules in order to meet the thermal performance, compared to a series connection. It also allows a good distribution or homogeneity of the air flows on all the modules. In addition, this form

V constitutes a natural flow guide cone, which avoids having convergents as well as large entry cones.

Advantageously, the tip of the V formed by said Peltier effect modules is oriented towards said battery which allows good efficiency with a minimum space requirement. In particular, this arrangement makes it possible to reduce the return distance of the cooled air flow towards the battery. For reasons of thermal efficiency, advantageously, the air flows in said second countercurrent circuit of said first fluid.

The battery may be disposed between the wheels of said vehicle and said exchanger may then be disposed behind said battery, for example, under the rear trunk of the vehicle.

The disposition of said second circuit is not limited according to the invention. For example, the second circuit may have an inlet disposed at a first wheel well and an outlet disposed at a second wheel well opposite said first passage. All the cooling means are then concentrated at the rear of the vehicle.

Other features and advantages of the invention will emerge on reading the following description of a particular embodiment of the invention, given by way of indication but not limitation, with reference to the accompanying drawings in which:

- Figure 1 shows a schematic sectional view of the underside of the vehicle according to the invention, in a plane parallel to the underside of the battery;

- Figure 2 shows a diagram of the cooling means;

- Figure 3 shows a sectional view along a plane parallel to the lower face of the battery of the exchanger, at the hot loop;

- Figure 4 shows a sectional view along the axis IV-IV of the exchanger cooling means;

- Figure 5 shows a sectional view of the exchanger, in a plane parallel to the underside of the battery, at the cold loop; and - Figure 6 shows a bottom view of the rear of the vehicle and cooling means.

As shown in Figure 1, the vehicle of the invention comprises a battery 1 disposed under the passenger compartment, between the wheels 4. The rear edge 1 1 of the battery 1 is located in front of the rear wheels 4. The battery 1 has longitudinal channels 14 and transverse channels 15 which form a cooling network in which can circulate air to cool the battery 1. At the rear of the vehicle, between the rear wheels 4 is a system battery cooling 1. This cooling system comprises an exchanger 3 which comprises at least one Peltier effect module which will be more fully described later, a first so-called "cold loop" circuit 5 and a second so-called "hot loop" circuit 7.

The cold loop 5 connects the two longitudinal channels 14 located on the opposite sides of the battery 1 and passes through the heat exchanger 3. The cold loop 5 has an inlet 51 and an outlet 52, located at the rear edge 1 1 of the battery 1. The cold loop 5 comprises first means 53 for circulating the air contained therein. These first circulation means 53 may be a fan. They are arranged at the outlet of the exchanger 3. Thus, the hot air that comes from the internal cooling network of the battery 1, formed by the channels 14 and 15, takes a lateral longitudinal channel 14 called "output", enters the cold loop 5 through the inlet 51, passes through the exchanger 3 in which it cools and is sent through the outlet 52, by the circulation means 53 in the longitudinal channel 14 said "input Which is the longitudinal channel 14 farthest along the width of the vehicle, the aforementioned output channel 14. The cold loop 5 and the channel network of the battery 1 form a closed circuit. In the example presented here, the coolant is air but any other fluid can be used because it circulates in a closed circuit.

As shown in FIG. 1, the hot loop 7 has an inlet 71 located at a rear wheel arch and an outlet 72 disposed at the opposite rear wheel arch. The hot loop 7 passes through the exchanger 3 and comprises second moving means 73 which are located upstream of the exchanger 3. The outside air to the vehicle is sucked into the inlet 71 by the second means of implementation. 73, passes through the heat exchanger 3 where it heats, and exits at the outlet 72, outside the vehicle.

Figure 2 schematically shows the cold loop 5, the hot loop 7 and the exchanger 3 and the direction of air flow in each of the circuits. The exchanger 3 comprises two modules Peltier effect 310. These two modules are arranged in V, the tip of the V facing the battery 1, the length of each module extending along the length of a branch of V.

We will first describe the cold loop with reference to Figure 2.

The hot flow leaving the battery 1 through the inlet 51 is sucked by the fan 53 which is disposed at the spaced ends of the branches of the V. In the heat exchanger 3, the hot flow from the battery 1 is divided into two fluxes which each pass through a Peltier effect module 310. The two streams then collect, beyond the tip of the V, into a single cooled stream which is sent into the battery 1 by the outlet 52.

The hot loop will now be described with reference to Figure 2.

The air outside the vehicle is sucked through the inlet 71 by the fan 73 which is disposed close to the spaced branches of the V formed by the two Peltier effect modules 310. The hot loop pipes 7 are arranged in such a way as to that the external air flow arrives at the tip of the V formed by the Peltier effect modules, is divided into two streams which each pass through a module 310. The two streams are then combined into one and the same flow beyond the branches separated from the V. The flow exits through the outlet 72 on the outside of the vehicle. The flows of the cold loop 5 and the hot loop 7 therefore circulate against the current.

3 shows a longitudinal sectional view along a plane parallel to the battery 1 of the hot loop 7. The inlet 71 is provided with an air filter 710 while the outlet 72 is provided with a shutter 720 which prevents the entry of water. The suction pipe 75, which includes the inlet 71, tapers conically and divides into two lines 76, near the tip of the V formed by the modules 310. Each of the lines 76 is open at the of the lateral face of the module 310 (that is to say along the length of the module 310) and comprises a closure wall located at the longitudinal end of the module 310, the side of the spaced apart ends of the modules 310. in other words, each of the ducts 76 is profiled to guide the flow therethrough through the module 310 and to distribute this flow along the length of the module 310 (the length of the module 310 corresponds to the length of a branch of the V) . The pipes 76 shrink near the separated ends of the branches of the V. The two flows then meet between the branches of the V, between the two modules 310, in a cavity 78 of substantially triangular longitudinal section, which comprises a narrowed portion connected to the fan 73. In this cavity 78, the flows are created by the fan 73.

FIG. 4 represents a sectional view of the exchanger 3 along axis IV-

IV. Each module 310 has two layers of Peltier cells 31 1. Each of these layers 31 1 forms an exchanger. The exchanger 3 comprises in fact four lines 76, arranged in pairs in two planes parallel to each other and parallel to the lower face of the battery 1 as shown in FIG. 1. 3 shows a section along a plane parallel to the battery 1 of the upper portion of the hot mouth 7 at the heat exchanger 3. Each pipe 76 is open at a module 310 and arranged so that the flow of air passing through it comes into contact with a Peltier effect cell layer 31 1. Thus, at the level of the upper portion, the flow of air entering the exchanger 3 through the pipe 76 passes on the cell layer 31 1. At the level of the lower portion, the flow passes under a layer of cells 31 1. The flow of the cold loop 5 flows in the space between the two cell layers 31 1, in each of the modules 310.

Thus, the fan 73 draws air from four lines 76 arranged in two groups of two superimposed pipes according to the height of the vehicle (the height of the latter). The two superimposed groups of conduits 76 are arranged in a V-shape. In the hot loop 7 the air circulates in two horizontal planes, parallel to the lower face of the battery shown in FIG. The fan 73 is arranged so as to obtain two horizontal web flows.

Figure 5 shows a sectional view of the cold loop 5, in a plane parallel to the battery as shown in Figure 1. The air flow leaving the battery 1 enters the pipe 54 through the inlet 51, passes through the fan 53 and enters an enlarged cone-shaped portion 55 which flares between the branches of the V of the modules 310. The flow is divided into two streams, each of which passes through a module 310, distributed along the length of the module 310. Each of the streams is channeled at the outlet of the module 310 via a pipe 56, substantially of the same shape as the pipe 76 mentioned above. with reference to FIG. 4. The two lines 56 meet in a cone 57 which narrows towards the outlet 52.

Figure 6 shows a bottom view of the trunk of the vehicle according to the invention. The black arrows represent the flows of the cold loop 5 while the white arrows represent the flows of the upper portion of the hot loop 7. The fan 73 is arranged in a horizontal plane so as to produce a horizontal sheet which passes through the two modules 310 by distributing the air along the modules 310. The two layers of the hot loop 7 are arranged in two superposed horizontal planes and are grouped at the outlet of the exchanger 3 in the horizontal outlet pipe 77 which opens at the level of the exit 72.

As for the cold loop 5, the air circulates in the cold loop 5 between the two layers of the hot loop 7, in the exchanger 3. The fan 53 is arranged in a vertical plane, in the center of the branches formed by the two modules 310.

By way of example, 24 Peltier effect cells are required to ensure optimum cooling of the circulating flow in the cold loop 5. The V-shaped and two-layer arrangement makes it possible to save considerable space in the vehicle and to distribute the flux.

Claims

1. Motor vehicle comprising a battery (1) for supplying an electric motor and means for cooling said battery, said cooling means comprising:

an exchanger (3),

a first circuit (5) which passes through said exchanger (3) and which makes it possible to circulate a first fluid in said battery (1) so as to cool it directly, the temperature of said first fluid leaving said exchanger (3) being lower at the temperature of said fluid at the inlet of said exchanger (3);

and a second circuit (7) which makes it possible to pass air coming from the outside of the vehicle through said exchanger (3), the temperature of the air entering said exchanger (3) being lower than the temperature air at the outlet of said exchanger (3),

characterized in that said exchanger (3) comprises two Peltier effect modules (310) arranged substantially in V and in that said first circuit (5) is shaped so that said first fluid coming from said battery (1) arrives between the branches said V and splits into two streams which each pass through one of said branches.

2. Motor vehicle according to claim 1, characterized in that at least one of said Peltier effect modules comprises two outer ducts (76) sandwiching an inner duct and two layers of Peltier effect cells (31 1) which are arranged between said inner conduit and each of said outer conduits (76) and in that said inner conduit is part of said first circuit (5) and said outer conduits (76) are part of said second circuit (7) which splits at said exchanger ( 3).

3. Vehicle according to claim 1, characterized in that the tip of the V formed by said Peltier effect modules (310) is directed towards said battery

(1) - 4. Vehicle according to any one of the preceding claims, characterized in that the air flows in said second circuit (7) against the current of said first fluid in said first circuit (5).

5. Vehicle according to any one of the preceding claims, characterized in that said battery (1) is disposed between the wheels (4) of said vehicle and in that said exchanger (3) is disposed at the rear of said battery ( 1).

6. Vehicle according to any one of the preceding claims, characterized in that said second circuit (7) has an inlet (71) disposed at a first wheel well and an outlet (72) disposed at a second wheel passage opposite said first passage.