FR2757456A1 - DEVICE FOR HEATING THE INTERIOR OF A VEHICLE WITH AN ELECTRIC MOTOR - Google Patents

Abstract

A device for heating the passenger compartment (H) of an electric motor vehicle (M) comprises a heating radiator (12) suitable for being traversed by an air flow (F) and comprising a first layer (14) connected to a first circuit (20) traversed by a first heat transfer fluid and used for cooling the electronic power circuit (CP) of the electric motor (M) of the vehicle, and a second ply (16) connected to a second circuit (32) traversed by a second heat transfer fluid and comprising a capacity (34) in which an electrical resistance (36) is immersed.

Description

I Device for heating the passenger compartment of an electric motor vehicle

  The invention relates to a device for heating the home.

  key of an electric motor vehicle, of the type comprising a heating radiator capable of being traversed by an air flow. To heat the passenger compartment of a vehicle powered by an electric motor, it is known to use an electric type heating radiator powered by the batteries on board the vehicle. This radiator

  electric heating is most often placed in the home-

  key, in place of the traditional heating radiator, traversed by a hot fluid, in the case of an animated vehicle

by a heat engine.

  The use of an electric type heating radiator has various drawbacks. First of all, as this electric radiator is powered from the vehicle's batteries, heating of the passenger compartment takes place at the expense of the vehicle's autonomy, since these are also the

  batteries used to power the electric motor.

  In addition, an electric heater of this type is required-

  limited power, which has the disadvantage that, in cold weather, the heating produced in the passenger compartment

is generally insufficient.

  To overcome this lack of power, it is known to add

  to the electric heating radiator a heating radiator

  conventional fage traversed by a heat transfer fluid used for cooling the power circuit, also called

  "power electronics", of the electric motor of the vehicle

  the. Thus, the heat source is taken from the power circuit of the vehicle engine, through a circuit of heat transfer fluid, usually water added

an antifreeze.

  A major drawback of such a heating device, which can be described as a "mixed device", is that a liquid circuit and an electrical circuit coexist in

  the passenger compartment, close to the occupants, which can represent

ter a great danger.

  The object of the invention is in particular to overcome the drawbacks

mentioned above.

  To this end, it proposes a heating device of the type defined in the introduction, in which the heating radiator comprises a first layer connected to a first circuit traversed by a first heat-transfer fluid and serving for cooling the electronic power circuit of the electric motor. of the vehicle, and a second sheet connected to a second circuit traversed by a second heat transfer fluid and comprising a capacity containing this second heat transfer fluid, in which is immersed at least one

electrical resistance.

  The heating of the passenger compartment is therefore carried out using a single radiator, or heat exchanger, comprising two layers, also called "levels", the first of which is mainly used for cooling the engine power circuit, and the second is used for heating via one or more electrical resistances immersed in the

  capacity traversed by the second fluid.

  To heat the passenger compartment, we recover both the thermal energy generated by the power circuit of the vehicle engine and the thermal energy provided by the electrical resistance (s) immersed in

the capacity.

  Because the radiator has two layers each traversed by a fluid, this avoids making coexist a

  liquid circuit and an electrical circuit.

  In a preferred embodiment of the invention, the first circuit integrates a radiator for cooling the

vehicle electric motor.

  The first circuit is then advantageously provided with a valve capable of taking two positions: a so-called "summer" position in which the first fluid circulates in the cooling radiator, and a so-called "winter" position in which the first fluid circulates in the

  first valve of the heating radiator.

  Thus, the first circuit, which is used to cool the engine power circuit, can take two different positions. In the so-called "summer" position, the first fluid is directed to the vehicle's cooling radiator,

  without crossing the first layer of the heating radiator.

  In the so-called "winter" position, the first fluid flows through the first layer of the heating radiator, which allows

  recover calories to heat the home

key.

  The second layer of the heating radiator is only used

  heating the passenger compartment, during the winter period, through

  of the electrical resistance (s) immersed in the capacity. Obviously, these electrical resistances do not

  are not operated during the summer period.

  According to another characteristic of the invention, the device comprises circulation means for circulating the first heat transfer fluid and the second heat transfer fluid respectively in the first circuit and in the second circuit. Advantageously, these circulation means comprise a two-stage pump comprising a first turbine and a second turbine respectively coupled to the first circuit and to the second circuit, as well as a common electric motor driving the first turbine and the second turbine.

in synchronization.

  Preferably, the first heat transfer fluid and the second heat transfer fluid are each formed by water.

added with antifreeze.

  According to another characteristic of the invention, the first layer and the second layer of the heating radiator are

separated by a slit.

  Preferably, the heating radiator is located on the side of the passenger compartment. On the other hand, the first circuit and the second circuit are advantageously located on the side of the

vehicle engine compartment.

  In the following description, made only as

  for example, reference is made to the appended drawing, in which: FIG. 1 diagrammatically represents a device for heating the passenger compartment of an electric motor vehicle according to the invention; - Figure 2 schematically shows the heating radiator of the device of Figure 1; and - Figure 3 is a perspective view of a pump with two

  stages forming part of the device of FIG. 1.

  First of all, reference is made to FIG. 1 which represents a device 10 according to the invention which is installed in a

  vehicle powered by an electric motor M. This electric motor

  aue M is placed in the engine compartment CM of the vehicle, which is separated from the passenger compartment H by an apron T. The device of the invention comprises a heating radiator 12 situated on the side of the passenger compartment H and comprising a first layer 14 and a second ply 16 suitable for being traversed, in this order, by an air flow F. The air flow F which is either air taken from outside the passenger compartment, or from the recirculated air taken from inside the passenger compartment, or a mixture of the two, is heated by the heating radiator 12 and then sent to

  the passenger compartment H by nozzles (not shown).

  The heating radiator 12 is produced according to a technique

  as known and comprises tubes (not shown) which pass through fins (not shown). As can be seen in Figure 2, the plies 14 and 16 are separated one

on the other by a slot 18.

  The sheet 14 is connected to a first circuit 20 traversed by a first heat transfer fluid, in the example of water added with an antifreeze, such as glycol. Circuit 20

  is connected in series to an exchanger 22 used for cooling

  ment of the power circuit CP (also called "power electronics") of the electric motor M. In fact, the power circuit of an electric motor of a motor vehicle dissipates a considerable thermal energy. Circuit 20

  allows this thermal energy and the vehicle to be recovered

1st in the first layer 14.

  The first circuit 20 further comprises a conventional cooling radiator 24 which is used to cool the engine M. The radiator 24 is connected in bypass to the circuit by lines 26 and 28, access to the radiator 24 being controlled by a valve 30 of the three-way type. This valve 30 can take two positions: a so-called "summer" position in

  which the fluid circulates in the cooling radiator

  ment 24, without crossing the ply 14 of the heating radiator 12, and a so-called "winter" position in which the fluid circulates in the ply 14 of the heating radiator 12, without

  pass through the cooling radiator 24.

  The second layer 16 of the heating radiator 12 is connected to a circuit 32 through which a second heat transfer fluid which, in the example, also consists of water with an antifreeze, such as glycol. This circuit 32 further comprises a capacity 34, that is to say an enclosure through which the second heat transfer fluid passes. Inside the capacity 34 is immersed an electrical resistance 36

  coupled to an electrical source 38, that is to say to the bat-

  of the vehicle, and may or may not be supplied with

  function of the position of a switch 40.

  The circulation of the two heat transfer fluids in the circuits 20 and 32 takes place by means of a pump 42 of the two-stage type. This pump 42 comprises a first stage (turbine 44) integrated in the circuit 20 and a second stage (turbine 46) integrated in the circuit 32 (Figures 1 and 3). The turbines 44 and 46 are driven in synchronism by a

  common electric motor 48 (Figure 3).

  Thus, the pump 42 makes it possible to circulate at the same time the first and the second heat transfer fluids respectively in

  the first circuit 20 and the second circuit 32.

  The device of the invention operates in the following manner. In the so-called "summer" position, the valve 30 circulates the first fluid in the cooling radiator 24, without passing through the first layer 14. Thus, the thermal energy dissipated by the power circuit CP of the engine M is evacuated by the cooling radiator 24. At the same time

  time, the switch 40 is open, so that the resistance

  Electric heater 36 is not actuated and the second fluid is not heated. Consequently, the two layers of the heating radiator 12 are each traversed by a

  cold fluid, and the air flow F is not heated.

  In the so-called "winter" position, the valve 30 circulates the first fluid in the first layer 14 of the heating radiator 12. If the thermal power generated by the first layer 14 is sufficient, the switch 40 is placed in the open position, so that the second fluid contained in the capacity 34 is not heated. On the other hand, if this thermal power is insufficient, the switch 40 is placed in the closed position, which causes the second fluid to heat up in the capacity 34 and a supply of thermal energy in the second layer 16 of the heating radiator 12. Thus, the air flow F is successively heated by the first ply 14 and the second ply 16. As can be seen in FIG. 1, apart from the heating radiator 12 which is located on the side of the passenger compartment H , all the rest of the device 10, in particular the circuits 20 and 32,

  0 is placed inside the engine compartment.

  As a result, only one type of fluid (liquid addi-

  antifreeze) is in the passenger compartment, i.e.

  circulates in the layers 14 and 16 of the heating radiator

age 12.

  There is therefore no high voltage circuit in

  interior, this contributes to safety in the event of an accident.

  tooth. Furthermore, a single electric motor is sufficient to drive the two stages of the circulation pump, which

  minimizes power consumption.

  Another advantage of the invention resides in the fact that the heating radiator is produced according to the technique well

  known from tube radiators passing through fins.

  Of course, the invention is not limited to the embodiment described above by way of example and extends

to other variants.

Claims (9)

Claims   1. A device for heating the passenger compartment of an electric motor vehicle, comprising a heating radiator capable of being traversed by an air flow, characterized in that the heating radiator (12) comprises a first layer (14 ) connected to a first circuit (20) traversed by a first heat transfer fluid and used for cooling the electronic power circuit (CP) of the electric motor (M) of the vehicle, and a second ply (16) connected to a second circuit (32 ) traversed by a second heat transfer fluid and comprising a capacity (34) traversed by the second heat transfer fluid, and in which is   submerged at least one electrical resistance (36).   2. Device according to claim 1, characterized in that the first circuit (20) incorporates a radiator (24) of   cooling of the vehicle's electric motor (M).   3. Device according to claim 2, characterized in that the first circuit (20) comprises a valve (30) capable of taking two positions: a position called "summer" in which the first fluid circulates in the cooling radiator (24) , and a so-called "winter" position in which the first fluid circulates in the first layer   (14) of the heating radiator (12).   4. Device according to one of claims 1 to 3,   characterized in that it comprises circulation means (42) for circulating the first heat transfer fluid and the second heat transfer fluid respectively in the first   circuit (20) and in the second circuit (32).   5. Device according to claim 4, characterized in that the circulation means comprise a two-stage pump (42) comprising a first turbine (44) and a second turbine (46) coupled respectively to the first circuit (20) and to the second circuit (32), as well as a common electric motor (48) driving the first turbine (44) and   the second turbine (46) in synchronism.   6. Device according to one of claims 1 to 5,   characterized in that the first heat transfer fluid and the   second heat transfer fluid are formed by water addi- antifreeze.   7. Device according to one of claims 1 to 6,   characterized in that the first layer (14) and the second layer (16) of the heating radiator (12) are separated by a slot (18).   8. Device according to one of claims 1 to 7,   characterized in that the heating radiator (12) is   located on the side of the passenger compartment (H) of the vehicle.   9. Device according to one of claims 1 to 8,   characterized in that the first circuit (20) and the second circuit (32) are located on the side of the engine compartment (CM) of the vehicle.