FR3035764A1 - ELECTRIC RADIATOR FOR HEATING AND AIR CONDITIONING DEVICE - Google Patents

Abstract

The present invention relates to an electric heater (10) for a heating and air conditioning device (1) for a motor vehicle (V). It is characterized in that the electric radiator (10) comprises: - at least one heating element (11); and - at least one heat dissipation plate (12) comprising: - a plurality of air vents (120); and - at least one cavity (121) adapted to receive said at least one heating element (11).

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an electric radiator for a heating and air conditioning device for a motor vehicle. BACKGROUND OF THE INVENTION

It finds a particular but non-limiting application in motor vehicles. TECHNOLOGICAL BACKGROUND OF THE INVENTION Hybrid, electric and thermal motor vehicles comprise a heating and air conditioning device which comprises an electric radiator. In the case of hybrid and thermal vehicles, this radiator is an auxiliary radiator that heats the passenger compartment of the motor vehicle in addition to the main radiator, while in the case of all-electric vehicles, this radiator is the main radiator. This electric radiator is connected to the electrical network of the motor vehicle. An electric heater known to those skilled in the art comprises: a plurality of ceramic stones; a plurality of fins arranged around each ceramic stone and which are in mechanical and electrical contact with the ceramic stone. Each fin is electrically powered via the electrical network of the motor vehicle. In a non-limiting example, when the electric radiator is the main radiator of the motor vehicle, about twenty ceramic stones are used to provide a power of the order of 1200 Watts.

The fins allow to evacuate the heat produced by the ceramic stones and thus heat a flow of air that passes through the assembly formed by the ceramic stones and said fins.

A disadvantage of this state of the art is that this electric heater comprises a very large number of elements (stones and fins). In addition, the assembly of these elements must meet dimensional and geometric constraints because of the limited space that is allocated to the electric heater in the heating and air conditioning device.

The assembly of all the elements is thus complex to achieve. In this context, the present invention aims to solve the aforementioned drawback. GENERAL DESCRIPTION OF THE INVENTION To this end, the invention proposes an electric radiator for a heating and air-conditioning device for a motor vehicle, according to which the electric radiator comprises: at least one heating element; and at least one heat dissipation plate comprising: a plurality of ventilation orifices; and at least one cavity adapted to receive said at least one heating element. Thus, as will be seen in detail below, the number of elements in the electric heater has been reduced and the assembly of the elements has been simplified since it simply includes the introduction of at least one heating element. in a cavity of the heat dissipation plate. The design of the electric radiator can thus be adapted more easily depending on the geometric and dimensional constraints of the heating and air conditioning device.

According to non-limiting embodiments, the electric radiator may further comprise one or more additional characteristics from the following: According to a non-limiting embodiment, said at least one heating element comprises: a resistive wire; and a core around which said at least one resistive wire is wound.

Thus, the heating element is easy to use and inexpensive. According to another non-limiting embodiment, said heating element is of oblong shape. This allows for a larger area for winding the resistive wire around the core. According to a non-limiting embodiment, said heating element is covered with a resin. This protects the heating element against corrosion due to corrosive agents such as water, salt, sulfur dioxide (SO2) and the like. According to a non-limiting embodiment, said core is composed of mica. This allows to electrically and thermally isolate said core.

According to a non-limiting embodiment, said heat dissipation plate is made of aluminum. This makes it possible to obtain a light and inexpensive plate. According to a non-limiting embodiment, the resistive wire is wound around the core in a plurality of turns and the spacing between two consecutive turns is identical all along the core.

This makes it possible to have heating zones of equal power on the heating element. According to a non-limiting embodiment, the resistive wire is wound around the core in a plurality of turns and the spacing between two consecutive turns is variable along the core. This makes it possible to have heating zones of different powers on the heating element.

According to a nonlimiting embodiment, said electric heater comprises a plurality of heating elements, and said at least one heat dissipation plate comprises a plurality of cavities, each adapted to receive a heating element. This provides significant power for an electric heater.

According to a non-limiting embodiment, said heating element comprises two electrical connections adapted to be connected to an electrical network of the motor vehicle. This allows the heating element to be energized so that the heating element can produce thermal energy. According to a non-limiting embodiment, said heating element is adapted to deliver a suitable heating power as a function of: the resistivity of the resistive wire material; and / or the length of the resistive wire; and / or - the section of the resistive wire; and / or - the number of turns of the resistive wire. These different parameters make it possible to easily and precisely adjust the heating power produced by the electric radiator.

It is also proposed a heating and air conditioning device for a motor vehicle comprising an electric heater according to any one of the preceding characteristics.

According to one nonlimiting embodiment, the electric radiator is a main radiator or an auxiliary radiator. Thus, the electric heater can be integrated in a heating and air conditioning device for a thermal automobile vehicle, hybrid or for an all-electric vehicle.

BRIEF DESCRIPTION OF THE FIGURES The invention and its various applications will be better understood on reading the following description and examining the figures that accompany it. FIG. 1 represents a diagram of an electric radiator for a heating and air-conditioning device for a motor vehicle according to a non-limiting embodiment of the invention, said electric radiator comprising a heat dissipation plate and at least one element. Heating; - Figure 2 shows a section along an axis A-A of the heat dissipation plate of the electric heater of Figure 1, excluding the heating element; FIG. 3 represents a diagram of the heating element of the electric radiator of FIG. 1 according to a first nonlimiting embodiment, said heating element comprising a core and a resistive wire; FIG. 4 represents a diagram of the heating element of the electric radiator of FIG. 1 according to a second nonlimiting embodiment, said heating element comprising a core and a resistive wire with a distance between variable turns; - Figure 5 illustrates a first non-limiting embodiment of the core of the heating element of Figure 3 or Figure 4; - Figure 6 illustrates a second non-limiting embodiment of the core of the heating element of Figure 3 or Figure 4; FIG. 7 illustrates a third non-limiting embodiment of the core of the heating element of FIG. 3 or FIG. 4; - Figure 8 illustrates a fourth non-limiting embodiment of the core of the heating element of Figure 3 or Figure 4; and FIG. 9 represents a conceptual diagram of a heating and air-conditioning device 10 comprising the electric radiator of FIG. 1 according to a nonlimiting embodiment. DESCRIPTION OF EMBODIMENTS OF THE INVENTION The identical elements, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references. The electric radiator 10 for the heating and air-conditioning unit 1 for a motor vehicle V is illustrated schematically in FIG. 1. By motor vehicle is meant any type of motorized vehicle. In the nonlimiting example illustrated, the radiator 10 is part of a heating and air conditioning device 1 (described in more detail in the following description).

The electric heater 10 comprises: - at least one heating element 11; at least one heat dissipation plate comprising: a plurality of ventilation orifices 120; and at least one cavity 121 adapted to receive said at least one heating element 11. The various elements of the electric heater 10 are described in more detail below. Heat dissipation plate The heat dissipation plate 12 is described with reference to FIGS. 10 and 2. The ventilation holes 120 of the heat dissipation plate 12 make it possible to let a stream of air 6 pass through said plate 12. The number of ventilation orifices 120 and their diameter is calculated as a function of the desired value of the pressure drop caused by the passage of an air flow 6 through said aeration orifices. 120. In an exemplary non-limiting embodiment, the desired pressure drop is between 3060 Pascal for a mass flow rate of 300kg / h. The heat dissipation plate 12 thus makes it possible to transmit the energy produced by the heating element 11 to the air flow 6 passing through the ventilation orifices 120, which makes it possible to heat said air stream 6. In a non-limiting embodiment, the heat dissipation plate 12 is aluminum. This material is light and allows a very good heat dissipation. It has indeed an exchange coefficient with the air 25 interesting which allows a good heat transfer. Moreover, it is an inexpensive material. In a non-limiting embodiment, the heat dissipation plate 12 comprises a height L1 between 80mm (millimeters) and 160mm and a length L2 between 150mm and 300mm. In a nonlimiting embodiment, the heat dissipation plate 12 comprises a thickness el between 1 mm and 15 mm. These dimensions make it possible to integrate said heat dissipation plate 12 in a restricted place in the heating and air-conditioning device 1 of the motor vehicle V. Of course, other dimensions can be used.

In a non-limiting embodiment, the heat dissipation plate 12 comprises a plurality of cavities 121, each adapted to receive a heating element 11. In the illustrated example, it comprises three cavities 121. There can be seen three heating elements 11 two of which are completely inserted into their associated cavity 121 and the third being inserted. Of course, when the electric heater 10 is completely assembled, and when it is mounted in the heating and air conditioning device 1, the three heating elements 11 are completely inserted in their respective cavity 121. It can also be seen that heat dissipation 12 comprises an alternation of cavities 121 and a set of ventilation holes 120. Thus, the heating elements 11 are regularly distributed in the heat dissipation plate 12 so that the heating power P that they deliver is dissipates well over the entire surface of said heat dissipation plate 12.

A recess 121 illustrated on the section A-A of FIG. 2 is configured so that the heating element 11 can be fully inserted into it. Thus, in a non-limiting embodiment, the cavity 121 is of oblong shape. In non-limiting embodiments, the cavity 121 has a circular, oblong, or rectangular opening. In the non-limiting example of FIG. 2, the cavity 121 has a rectangular opening. In a nonlimiting embodiment, a cavity 121 extends over all or part of the length L2 of the heat dissipation plate 12. In the nonlimiting example illustrated in FIG. 1, the cavity 121 extends over the whole length L2. Of course, in another nonlimiting embodiment, a cavity 121 may extend over all or part of the width L1 of the heat dissipation plate 12. - Heating element 5 The heating element 11 is described with reference 3 to 8. As seen above, in one nonlimiting embodiment, the electric radiator 10 comprises a plurality of heating elements 11. In addition, in a non-limiting embodiment, the heating element 11 is oblong. This allows for a large surface area to produce and dissipate heat. The heating element 11 comprises two electrical connections 113, 114 adapted to be connected to an electrical network 2 of the motor vehicle V.

The electrical network 2 is constituted inter alia by a battery Bat of the motor vehicle V as illustrated in Figure 1. In a non-limiting embodiment, the heating element 11 comprises: - a resistive wire 110; and a core 112 around which is wound at least one resistive wire 110. The resistive wire 110 is connected to the two electrical connections 113 and 114 described above. Thus, a current flows through the resistive wire 110 through the voltage applied to the two electrical connections 113 and 114 and the resistive wire 110 will thus heat and deliver a heating power P of a certain value. The electric power is thus transformed into energy at a certain power (expressed in Watts). The energy which is here heat is transmitted via the resistive wire 110 to the heat dissipation plate 12. In a non-limiting embodiment, the resistive wire 110 is enameled copper alloy. Enameling is an electrical insulating layer which makes it possible to avoid any short circuit between the resistive wire 110 and the thermal dissipation plate 12. Moreover, this makes it possible to avoid any short circuit between the turns themselves. of said resistive wire 110. As can be seen in FIGS. 3 and 4, the resistive wire 110 is wound around the core 112 and the winding of the resistive wire 110 comprises a plurality of turns 111, which makes it possible to form a winding . Two consecutive turns 111 have a spacing d. It is thus possible to vary the heating power P delivered by said heating element 11 as a function of the spacings d between the turns.

In a first nonlimiting variant embodiment illustrated in FIG. 3, the resistive wire 110 is wound around the core 112 in a plurality of turns 111 and the distance d between two consecutive turns 111 is identical all along the core 112. Thus, the regular spacing d between the turns 111 makes it possible to have a heating power in Watts / cm 2 distributed homogeneously over the entire surface of the heating element 11. In a second non-limiting embodiment variant illustrated in FIG. 4, the resistive wire 110 is wound around the core 112 in a plurality of turns 111 and the spacing d between two consecutive turns 111 is variable along the core 12. Thus, the spacing d varies between turns 111 allows to have locally on the heating element 11 different heating zones of power. The heating power in Watts / cm 2 can thus be unevenly distributed over the surface of the heating element 11. In a nonlimiting example illustrated in FIG. 4, it is thus possible to have a first zone z 1 of the heating element. 11 have a heating power equal to 1/3 of the desired total heating power and a second zone z2 of the heating element 11 have a different heating power, equal to 2/3 of the desired total heating power. According to this non-limiting embodiment variant, it is possible to adjust the heating power P of one or more zones of a heating element 11 as a function of the air outlets 5a, 5b, 5c and 5d of the heating device and air conditioner 1 (described later, see Fig. 9). In a non-limiting embodiment, the resistive wire 110 has a positive temperature coefficient (PTC). Thus, when the temperature of the resistive wire 110 increases, its resistance increases. In case of high temperature (in a non-limiting example between 130 ° C (Celsius) and 180 ° C), this limits the heating power P produced. This prevents overheating which could damage the resistive wire 110.

Core 112 is a support for resistive wire 110. The core is non-conductive. In a non-limiting embodiment, the core 112 is composed of mica. This material makes it possible to isolate the core 112 from the resistive wire 110 electrically and thermally. The energy produced by the resistive wire 110 is thus not transmitted to the core. The nucleus 112 does not heat up. There is therefore no overheating of the heating element 11 which could damage the resistive wire 110. In a non-limiting embodiment, said core 112 is oblong. The heating element 11 as a whole is thus oblong and thus forms a heating bar. The oblong shape makes it possible to have a large surface on which the resistive wire 110 can develop. Thus, the length L of the resistive wire 110 can be quite large, which length is one of the parameters for varying the heating power P. In non-limiting embodiments, the core 112 has a section S1 of circular, oblong, oval or rectangular shape as illustrated respectively in Figures 5 to 8. Unlike a circular section, the oblong or oval shaped sections allow to more easily meet the integration requirements of the heating element 11 in the heat dissipation plate 12 whose thickness el is limited. In a non-limiting embodiment, the heating element 11 is covered with a resin (not shown). The resin is thermally conductive and electrically insulating. It thus facilitates the heat transfer between said heating element 11 and the heat dissipation plate 12, and protects the resistive wire 110. In a nonlimiting example, the resin is a silicone which makes it possible to absorb the expansions of the material (here aluminum) of the heat dissipation plate. Thus, the silicone will not have cracks despite the expansion that can undergo the heat dissipation plate 12 under the effect of temperature variations. This resin also makes it possible to protect the heating element 11 against corrosion due to salt spray, salt air, SO2-type pollutants, etc. In a non-limiting embodiment, the resin is injected into the associated cavity 121 to the heating element 11 after the introduction of the latter into said cavity 121. Thus, the resistive wire assembly 110 and core 112 is embedded in 20 resin. With the resin, the resistive wire 110 is not in contact with the heat dissipation plate 12 when the heating element 11 is inserted into the associated cavity 121. Thus, even if the enameling of the resistive wire 110 is damaged, there is no risk of a short circuit between said resistive wire and said heat dissipation plate. In a non-limiting embodiment, the heating element 11 is adapted to deliver a heating power P adapted as a function of: the resistivity p of the resistive wire material 110; and / or the length L of the resistive wire 110; and / or - the section S of the resistive wire 110; and / or 3035764 13 - the number N of turns 111 of the resistive wire 110. Thus, it is easy to modify the heating power P produced by all the heating elements 11 according to one of these parameters without changing the dimensions of the heat dissipation plate 12 which accommodates said heating elements 11. Thus, the heating power P delivered by a heating element 11 may be identical to or different from that delivered by another heating element 11 on the same heat dissipation plate 11.

The heating power P produced by a heating element 11 or by a zone z of a heating element 11 can thus be adapted as a function of the air outlets 5a, 5b, 5c, 5d of the heating and air conditioning device 1 described. further in the description.

In the case of an all-electric vehicle, when the electric radiator forms the main radiator of the motor vehicle, in a non-limiting example, the total heating power P produced by all the heating elements 11 is between 4 and 9kW (kilowatts). Note that in this case, the electric heater 10 is connected to the electrical network 20 2 of the motor vehicle via a battery Bat which provides substantially between 280 and 300 volts in a non-limiting example. To obtain this energy, only one heat dissipation plate 12 is used with a plurality of heating elements 11, or a plurality of thermal dissipation plates 12 are used, a plate including in this case 25 one or more heating elements 11. In a non-limiting example, the heat dissipation plates 12 are arranged one behind the other. Thus, if for example one wants to obtain 4kW, a heat dissipation plate 12 providing 4kW may be used or two heat dissipation plates 12 providing 2kW each may be used.

In the case of a hybrid or thermal vehicle, when the electric radiator forms an auxiliary radiator of the motor vehicle, in a non-limiting example, the total heating power P produced by all the heating elements 11 is between 300W. and 2kW. Note that in this case, the electric heater 10 is connected to the electrical network 2 of the motor vehicle via an alternator and Bat battery that provides substantially between 12 and 24 volts in a non-limiting example. FIG. 9 is a diagram illustrating the electric radiator 10 integrated in a heating and air-conditioning device 1. It will be noted that in a non-limiting example, the heating and air-conditioning device 1 is located at the central console of the V vehicle behind the dashboard.

In the nonlimiting example illustrated, the electric radiator 10 is an auxiliary radiator. As can be seen in FIG. 9, in a nonlimiting embodiment, the heating and air conditioning device 1 comprises in particular an air inlet 4 through which the air stream 6 can enter; a blower 3 arranged facing the air inlet 4 and adapted to circulate the air flow 6 from the air inlet 4 to the air outlets 5a, 5b, 5c and 5d; an evaporator 7 connected to a refrigerant circuit (not shown), said evaporator 7 being adapted to cool the air flow 6; - A cold air chamber 11 disposed downstream of the evaporator 7 and adapted to receive the air stream 6 cooled by the evaporator 7; a heating chamber 12 comprising a main radiator 8 and the auxiliary electric radiator 10 (previously described) and adapted to heat the air flow 6; an air mixing chamber 21 adapted to: - receive the flow of cold air from the cold air chamber 11 and the flow of hot air from the heating chamber 12; delivering a mixed air flow to each of the air outlets 5a to 5d.

Mixed air flow means a flow of air from the mixing chamber 21. This air flow may comprise a mixture of cold air flow and hot air flow or only the flow of air. cold air or hot air flow. Thus, the air mixing chamber 21 comprises an air mixing unit (not shown) which makes it possible to calibrate the proportion of cold air flow and of hot air flow entering said mixing chamber 21. In order to obtain the mixed air flow, the mixing chamber 21 is thus fed with portions of hot air flow and cold air flow or with a totally cold air flow or with a totally air flow. hot.

It will be noted that each of the air outlets 5a, 5b, 5c and 5d is intended to deliver a respective air flow in a specific zone of the passenger compartment of the motor vehicle V and pivoting adjustment flaps (not shown) make it possible to to adjust according to the demands of a user the amount of air flowing through each of these air outlets.

Thus, the air outlet 5a is adapted to distribute air in the upper part of the upper front area of the passenger compartment of the vehicle, namely at the level of the windscreen. The air outlet 5b is adapted to distribute air in the upper part of the central front area of the passenger compartment of the vehicle, namely at the driver and the front passenger. The air outlet 5c is adapted to distribute air in the lower part of the lower front area of the passenger compartment of the vehicle, namely at the feet of the driver and the front passenger. The air outlet 5d is adapted to dispense air into the upper and lower portions of the front center and bottom areas of the vehicle cabin, namely at the front passenger and the front passenger feet 3035764. Of course, in another embodiment, there may be two differentiated air outlets, one for the front passenger and one for the feet of the front passenger.

Of course, the description of the invention is not limited to the embodiments described above. Thus, in another non-limiting embodiment, the heating element 11 may comprise a plurality of resistive wires 110 wound in turns 111 around said core 112. In non-limiting embodiments, the resistive wires 110 are superimposed on each other. the other or are successively wound one next to the other on the core 112. This allows to have a power tier on the same heating element 11. Thus, in a non-limiting embodiment, the electric heater It can be integrated in a device which is a heating device independent of the air conditioning device of the motor vehicle. Thus, in a non-limiting embodiment, a metal for dissipating heat other than aluminum may be used for the heat dissipation plate 12.

Thus, the described invention has the following advantages in particular: it is a simple solution to implement and inexpensive; it makes it possible to propose an electric radiator whose geometry is simple; It makes it possible to propose an adaptable electric radiator according to the demand of the car manufacturers (power, dimensions); it makes it possible to propose an electric heater which is simpler to manufacture and which has few elements and whose design is very flexible. The heat dissipation plate 12 is cut into the desired format according to the manufacturer's application and in particular of the space allocated for the electric radiator 3035764 17; the length of the resistive wire is determined according to the desired heating power, etc. ; it allows to propose an electric radiator with a power adapted to the demand of the car manufacturers; 5 - it allows to provide an electric heater whose heating elements can be isolated very simply (thanks to the resin) and without significant additional cost to manufacture; it makes it possible to manufacture an electric radiator on a fully mechanized chain without human intervention, in particular because the electric radiator comprises simple elements to manufacture, to assemble. It is sufficient to use in particular a stamping tool for cutting the heat dissipation plate, a winding machine for winding a resistive wire around a core and a welding tool for making connections to the electrical connections; it makes it possible to propose an electric radiator in which it is not necessary to make a compromise between the dissipated power and the geometry, the dimensions of the electric radiator unlike the state of the prior art; 20 - it makes it possible to propose an electric radiator whose power is easily adjustable by changing just one or more parameters of the resistive wires (resistivity, length, section, number of turns) and the number of heating elements without changing the geometry of the elements or their size (heat dissipation plate, core); It allows to propose different ranges (in power) of heating elements 11 on the same heat dissipation plate 12.

Claims (13)

REVENDICATIONS1. Electric radiator (10) for a heating and cooling device (1) for a motor vehicle (V), wherein the electric radiator (10) comprises: - at least one heating element (11); and - at least one heat dissipation plate (12) comprising: - a plurality of aeration ports (120); and - at least one cavity (121) adapted to receive said at least one heating element (11). 2. An electric heater (10) according to claim 1, wherein said at least one heating element (11) comprises: - a resistive wire (110); and a core (112) around which said at least one resistive wire (110) is wound. 20 An electric heater (10) according to claim 1 or claim 2, wherein said heating element (11) is oblong in shape. The electric heater (10) according to any one of claims 1 to 3, wherein said heating element (11) is covered with a resin. The electric heater (10) according to any one of claims 2 to 4, wherein said core (112) is composed of mica. 3 0 3 5 7 6 4 19 The electric radiator (10) according to any one of claims 1 to 5, wherein said heat dissipation plate (12) is aluminum. 7. An electric radiator (10) according to any one of claims 2 to 6, wherein the resistive wire (110) is wound around the core (112) in a plurality of turns (111) and the spacing (d) between two consecutive turns (111) is identical all along the core (112). 8. An electric radiator (10) according to any one of claims 2 to 6, wherein the resistive wire (110) is wound around the core (112) in a plurality of turns (111) and the spacing (d) between two consecutive turns (111) is variable along the core (12). The electric heater (10) according to any one of claims 1 to 8, wherein said electric heater (10) has a plurality of heating elements (11), and wherein said at least one heat sink plate (12) ) comprises a plurality of cavities (121), each adapted to receive a heating element (11). Electric radiator (10) according to any one of claims 1 to 9, wherein said heating element (11) comprises two electrical connections (113, 114) adapted to be connected to an electrical network (2) of the motor vehicle ( V). Electric radiator (10) according to any one of claims 2 to 10, wherein said heating element (11) is adapted to deliver a heating power (P) adapted according to: - the resistivity (p) resistive wire material (110); and / or - the length (L) of the resistive wire (110); and / or - the section (S) of the resistive wire (110); and / or - the number (N) of turns (111) of the resistive wire (110). 5 12. Heating and air conditioning device (1) for a motor vehicle (V) comprising an electric radiator (10) according to any one of claims 1 to 11. Heating and air conditioning device (1) according to claim 12, wherein the electric radiator (10) is a main radiator or an auxiliary radiator.