FR3072615A1 - HEATING DEVICE FOR AN AIR CONDITIONING UNIT, IN PARTICULAR A MOTOR VEHICLE, AND AIR CONDITIONING UNIT EQUIPPED WITH SUCH A HEATING DEVICE - Google Patents

Abstract

The invention relates to a heating device (6) for an air conditioning unit (1), said heating device (6) comprising a heating module (10) supplied with current to heat a flow of air passing through said heating module ( 10), the heating module (10) comprising a window (30) configured to allow an air passage providing a pressure drop on the air, reduced or zero compared to the rest of the heating module (10).

Description

The present invention relates to a heating device for an air conditioning unit and an air conditioning unit equipped with such a heating device. It will find its applications, in particular, in the field of motor vehicles.

Electric heating devices are known which are intended to be integrated into vehicle air conditioning units. These are either additional radiators, combined with heating radiators through which a heat transfer fluid flows, in vehicles with an internal combustion engine, or main radiators, in electric or hybrid vehicles.

Such heating devices include a support frame accommodating heating units provided with heating elements. They also include heat sinks such as corrugated fins placed between the heating units to increase the area of heat exchange with the air to be heated.

These heaters are positioned in air conditioning boxes to heat an air flow passing through them. They therefore necessarily create a pressure drop on the air flow. Moreover, at least up to a certain limit, the greater the pressure drop created, the more efficient the heat exchange. To compensate for this pressure drop on the air, the blowers used to generate the air flow must consume even more energy. A compromise is then generally chosen between the energy consumed by the blowers and the efficiency of the heat exchange.

However, such an approach has limits, in particular depending on the type of air conditioning unit used and / or the positioning of the heating device in the air conditioning unit.

The invention aims to at least partially overcome the drawbacks mentioned above and for this purpose provides a heating device for air conditioning unit, said heating device comprising a heating module supplied with current to heat an air flow passing through said heating module, the heating module comprising a window configured to allow an air passage providing a pressure drop on the air, reduced or zero compared to the rest of the heating module.

By providing such an opening in the heating device, an incident air flow or at least a portion of this air flow is allowed to pass through the device without loss of charge, the rest of the flow being warm. by the rest of the heating module. The power to be added to the components used to generate the air flow is therefore reduced without having to compromise between pressure drop and thermal efficiency, at least for the part passing through the window.

According to other characteristics of the invention which can be taken together or separately:

said device comprises a unit for distributing and / or controlling the current flowing in said heating module,

- said device is configured so that said heating module is housed inside a body of the air conditioning unit,

- said device is configured so that said current distribution and / or control unit is located outside the body of the air conditioning unit,

- said device is configured so that said current distribution and / or control unit is located under the body of the air conditioning unit, in the position in which the unit is used,

said window is located in the vicinity of said distribution and / or control unit,

said heating module comprises a frame,

- said frame is provided with reinforcements,

- said window is located between said distribution unit and one of said reinforcements,

said heating module comprises heating elements grouped into heating units selectively supplied with current,

- said heating units are housed in said frame,

- Said device is configured so that at least one of said heating units is positioned so as to heat only a first air flow intended for a first zone, in particular a conductive zone, and at least another of said units heater is positioned so as to heat only a second air flow intended for a second zone, in particular a front passenger zone,

- said device is configured so that each of said heating units is positioned so as to heat only one of the first or second flows,

- at least one of the heating units comprises a bar extending longitudinally,

- the heating elements of the same bar are arranged along the bar,

- the heating elements of the same bar are supplied with current in parallel,

said heating elements are distributed regularly along said heating units, in particular of said bars,

- Said heating module comprises the same number of heating units positioned so as to heat the first flow and the second flow.

The invention also relates to an air conditioning unit comprising a heating device as described above.

According to other characteristics of the invention which can be taken together or separately:

- said housing, in particular said housing body, has an opening for introducing the heating module,

- said orifice is located in the lower part, in the position of use of the housing,

- said housing is configured for the circulation of an air flow, called front, and of an air flow, said rear,

- said housing is configured so that the rear air flow passes through said window and so that the front air flow passes through the rest of the heating module.

The invention is particularly advantageous in the case of an air conditioning unit, part of the air flow, in particular a part intended to supply an area of the vehicle located behind the driver area and / or the passenger area before, passes in the lower part of the housing, said housing being provided with a heating device according to the invention introduced from the bottom of the housing. Indeed, the part of the air flow passing through the lower part of the housing, namely the rear air flow, can then pass through the window of the heating device without undergoing or undergoing very little pressure drop.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

FIG. 1 schematically illustrates in section the interior of an air conditioning unit, a unit heating device being shown in front view,

FIG. 2, schematically illustrates in side view the air conditioning unit of FIG. 1, a heating module of its heating device being illustrated by transparency,

FIG. 3 schematically illustrates a front view of a heating device according to the invention arranged inside an air conditioning unit shown cut,

FIG. 4, schematically illustrates in side view the air conditioning unit of FIG. 3, a heating module of the heating device being illustrated by transparency,

- Figure 5 is a sectional view illustrating more fully than in Figure 4 but in the same orientation an air conditioning unit according to the invention.

As illustrated in FIGS. 3 and 4, the invention relates to an electric heating device 6. It is, for example, a heating device, said to be high voltage, that is to say intended to be supplied by a direct current (DC) or alternating current (AC) having an electrical voltage greater than 60 V, in particular comprised between 60 and 1000 V, more particularly comprised between 180 and 600 V, and / or making it possible to generate a heating power on the air or a consumed electrical power greater than 2 kW, in particular between 2 kW and 10 kW.

The invention also relates to an air conditioning unit 1, in particular for a motor vehicle, comprising said heating device 6. The unit 1 comprises a body 2 which is only partially illustrated here.

Said heating device 6 comprises a heating module 10 supplied with electric current to heat a flow of air passing through said heating module 10.

The heating module 10 comprises a window 30 configured to allow an air passage providing a pressure drop on the air, reduced or zero compared to the rest of the heating module 10.

This reduces the resistance to air flow through the heating module 10, at least for part of the incident air flow, in particular by comparison with the configuration of the air conditioning unit and the heating device. Figures 1 and 2, as will appear better in the following.

However, by other aspects, Figures 1 and 2 illustrate characteristics which are also taken up by the embodiment of the invention illustrated in Figures 3 and 4, in particular in that all of the figures illustrate housings air conditioning and heating devices which modulate the heating of the air passing through the heating device according to zones, in particular zones of the passenger compartment of the vehicle, to which the air is directed, after having been heated . These common characteristics are developed below. When differences exist, they are highlighted.

According to these other aspects, said body 2 of the air conditioning unit is configured to guide a first air flow in the direction of a first zone, in particular a zone intended to be occupied by a driver of the vehicle, and a second air flow towards a second area, in particular an area intended to be occupied by a front passenger of the vehicle, after having been warmed up. For this, the body 2 comprises walls 3 separating the interior of the housing from the exterior as well as various partitions, one of which is illustrated here schematically according to a dashed line marked 4, the partition or partitions making it possible to define each of the flows d air within a single air stream defined by the body of the housing.

Said heating module 10 is configured to heat the first and second air flows. Said heating module 10 here has a substantially parallelepiped configuration, extending on the surface. It is intended to be positioned transversely to the air flow to be heated.

Said air flows are perpendicular to the plane of the figures for Figures 1 and 3. In the example illustrated, upstream of the heating device 6, the body 2 of the housing is configured to guide one or more air flows, illustrated F, F1, F2 in FIGS. 2 and 4, the separation of these flows to form the first and second air flows intended for specific areas of the passenger compartment, using the partition or partitions mentioned above, intervening, for example, just downstream of the heating device 6, according to the direction of air circulation in the housing.

Said heating device 6 comprises heating elements, not shown. The heating elements are, for example, PTC effect resistors (for positive temperature coefficient).

Said heating elements are grouped into heating units 8 (illustrated only in FIG. 1). Said heating units 8 are selectively supplied with current. By this is meant that each heating unit 8 is supplied with current independently of the others and can therefore be traversed by a different current, in particular by its intensity, from the current flowing through the other heating units 8. The value of the current in play here is in particular the value of the average current or the effective current

Said heating units 8 advantageously comprise support bars 12 receiving the heating elements, the latter being located one after the other along each bar. Said heating elements are electrically connected in parallel, in particular by means of electrodes, not shown, situated on said strip 12. Preferably, said heating elements are distributed regularly along said strips 12.

Said heating module 10 contains said heating units 8. It is here housed in the body 2 of the air conditioning unit. The heating module 10 may also include heat sinks, not shown, for example fins, in relation to thermal contact with the heating elements. The heatsinks are positioned, in particular, between said bars 12.

Said heating module comprises a frame 14, in particular made of plastic, accommodating said heating units 8. Said frame comprises two opposite lateral edges 17, 17 ′ as well as a proximal edge 18 and an opposite distal edge 19, said proximal edge 18 and said distal edge 19 joining the lateral edges 17, 17 ′ for example by their ends. Said frame 14 is preferably provided with reinforcements 16 extending transversely between the two lateral edges 17, 17 ′ of the frame 14.

Preferably, the heating device 6 further comprises a unit 20 for distributing and / or controlling the current flowing in said heating module 10. Said heating and / or control unit is advantageously configured to control the current supplying the heating module. heats 10, in particular the various heating units 8, for example using piloted switches, making it possible to respectively control a flow of current in each of the heating units 8. These are, in particular, transistors, for example of the Mosfet or IGBT type, operating in particular by pulse width modulation.

Said distribution and / or control unit 20 comprises a housing 22 located along the proximal edge 18 of the frame 14. Said housing 22 comprises a connection face 24 connected to said frame 12, used for mounting and / or mechanical fixing of the heating module 10. Said distribution and / or control unit 20 further comprises a connector 28 to a current supply circuit and / or to a data transmission network, in particular a circuit and / or a network of the vehicle . Said connector 28 is here located on one face of the housing 22 opposite the connection face 24.

Said current distribution and / or control unit 20 is here located outside the body 2 of the air conditioning unit 1. Said body 2 of the air conditioning unit 1 comprises an orifice 27 for introducing the heating module, in particular produced in one of the walls 3 of said body 2.

In the example illustrated, the heating device 6 and more particularly the heating module 10 comprise a first part A and a second part B. The first part A is intended to be crossed by the first air flow and the second part B is intended to be crossed by the second air flow. The first and second parts A and B are virtually separated by said dashed line 4. The heating device here comprises three heating units 8 in each of said first and second parts A and B.

More generally, at least one of said heating units 8 is positioned so as to heat only the first flow and at least another of said heating units 8 is positioned so as to heat only the second flow. Preferably, each of said heating units 8 is positioned so as to heat only one of the first or second stream. In other words, each of said heating units 8 is located either in the first part A or in the second part B but not straddling one and the other of said parts A and B.

Thanks to such an orientation of the heating device 6 and more particularly thanks to such an arrangement of the heating units 8 in the body 2 of the air conditioning unit, it is possible to achieve selective heating of the areas of the passenger compartment traversed by the flows. air passing through the heating device 6. Indeed, by modulating the current flowing in each of the heating units 8 or at least by modulating the current flowing in the heating units intended to heat the same flow, it is that is to say by modulating the current circulating in the heating units belonging to the same part A or B, it is possible to heat each of the air flows to the desired temperatures. While offering each vehicle passenger the temperature they want, it is thus possible to limit current consumption and consequently increase the range of the electric or hybrid vehicle equipped.

In such a configuration, said insertion orifice 27 of the heating module 10 is advantageously located in the lower part of said body 2. Thus, said current distribution and / or control unit 20 is located under the body 2 of the air conditioning unit , in the position of use of the housing and as is the case in the figures. In other words, the heating device 6 is introduced into the body 2 of the housing from the bottom rather than from the side as is the case with the state-of-the-art housings.

As already indicated, each of the parts A and B comprises three heating units 8. It should be noted that, more generally, said heating device 6 comprises the same number of heating units 8 positioned so as to heat the first flow and the second stream. In other words, each of the zones A and B comprises the same number of heating units 8. In addition, the heating units 8 are identical to each other. Such a configuration promotes the standardization of the heating module 10 and facilitates the configuration of the distribution and / or control unit 20.

As specifically illustrated in Figures 1 and 2, the bar (s) 12 extend longitudinally from the proximal edge 18, where they are connected to the distribution and / or control unit 20, to the distal edge 19. Furthermore, said device heating 6 here comprises one or more heat dissipation plates 26 for removing the heat produced by said current distribution and / or control unit 20. The heat dissipation plate 26 extends along and from the connection face 24 in the direction of the distal edge 19 of the frame 14. Said heat dissipation plate 26 is located at one of the faces of the frame 14, preferably upstream according to the direction of circulation of the air flow. It masks the base of the bars 12 while letting the air flow or flows pass at this level, this with pressure drops on the air promoting heat exchanges.

Conversely and according to the invention, as appears from FIGS. 3 and 4, it can be seen that said window 30, which here forms a zone C, is located, for example, in the vicinity of said distribution unit 20 and / or control, particularly between said distribution unit 20 and one of said reinforcements 16, even more particularly between the connection face 24 and the closest reinforcement 16.

Thus, according to the example illustrated, the heat dissipation plates 26 can be interrupted in line with said window 30. As a variant, the heat dissipation of the heat produced by the distribution and / or control unit 20 is achieved, alternatively or in addition, by any other means known to those skilled in the art.

The dissipators provided between the bars 12 in the embodiment of Figures 1 and 2 may also be interrupted at the right of said window 30 rather than extending as close to the connection face 24. The configuration of the base bars 12 could also be adapted so as not to be in line with said window 30, in particular along the edges of said window 30.

In general, such a configuration with a window of the heating device is more particularly advantageous when it is combined with a location of said window in the lower part of the housing, in particular in the case of so-called multi-zone air conditioning units.

In such a case, as can be seen more clearly from FIG. 5, said housing is configured for the circulation of an air flow F1, called front, and an air flow F2, said rear, for example at using additional partitions 40. The front air flow F1 is intended to heat the part of the passenger compartment welcoming the driver and the front passenger. In other words, in the embodiment of the invention mentioned above, it is composed of the first and second air flows coming respectively from zones A and B of the heating module 10. The rear flow F2 is intended to supply the area behind the driver and front passenger. It is made up of the flux coming from zone C of the heating module.

The housing is then configured so that the rear air flow passes through said window 30 and so that the front air flow passes through the rest of the heating module. In such an operating mode, as already said, the first flow of air guided to a first zone of the passenger compartment and the second flow of air guided to a second zone of the passenger compartment are preferably obtained from the air flow before. As for the rear air flow, it can pass through the heating device 6 without being heated and without undergoing pressure drops or very little. However, if necessary, the rear air flow can also be heated by an independent heating device, in particular placed downstream, according to the direction of circulation of the air flow, said independent heating device being preferably located in The box.

However, in other modes, the window 30 according to the invention may be provided in heating modules which are not necessarily intended to selectively heat several air flows intended for different zones. It can thus be used in heating modules uniformly heating one or more air flows.

In FIG. 5, it can be seen that said box 1 comprises at least one air inlet 50 and several air outlets, in particular a first outlet 52 in the direction of the windshield of the vehicle, a second outlet 54 in the direction of the driver and passengers before, a third outlet 56 towards the feet of the occupants of the passenger compartment of the vehicle and / or a fourth outlet 57 towards the rear zone.

The housing is configured so that the air flow before F1 is selectively sent to the outlet (s) 52, 54, 56, in particular as a function of the position of different distribution flaps 58-60. Said housing is further configured to direct the rear air flow F2 to the fourth outlet 57, located in the lower part of the housing. Said housing further comprises a mixing zone 62 of all or part of the front air flow F1 and the rear air flow F2. Said mixing zone 62 is situated, for example, between said window 30 and said fourth outlet 57.

Said housing may further comprise one or more flaps, not shown, for directing the air towards the window 30 or the rest of the heating body 10, the said flap or flaps being preferably located upstream of the heating device in the direction of the air flow.

Said housing also comprises an evaporator 70, located in the body 2 of the housing. Said evaporator 70 is positioned upstream of the heating device in the direction of air flow, in particular upstream of zones A and B of the heating module.

Claims (10)

1. A heating device (6) for an air conditioning unit (1), said heating device (6) comprising a heating module (10) supplied with current to heat an air flow passing through said heating module (10), the heating module (10) comprising a window (30) configured to allow an air passage providing a pressure drop on the air, reduced or zero compared to the rest of the heating module (10). 2. Device (6) according to claim 1 comprising a unit (20) for distributing and / or controlling the current flowing in said heating module (10). 3. Device (6) according to the preceding claim configured so that said heating module is housed inside a body (2) of the air conditioning unit (1) and so that said unit (20) for distribution and / or current control is located outside said body (2). 4. Device (6) according to any one of claims 2 to 3 wherein said window (30) is located in the vicinity of said unit (20) for distribution and / or control. 5. Device (6) according to any one of claims 2 to 4 wherein said heating module (10) comprises a frame (14) provided with reinforcements (16), said window (30) being located between said distribution unit (20) and one of said reinforcements (16). 6. Device (6) according to any one of the preceding claims, in which said heating module (10) comprises heating elements grouped into heating units (8) selectively supplied with current, said device being configured so that at least one of said heating units (8) is positioned so as to heat only a first air flow intended for a first zone and at least another of said heating units (8) is positioned so as to heat only a second flow air for a second area. 7. Device (6) according to the preceding claim configured so that each of said heating units (8) is positioned so as to heat only one of the first or second flow. 8. Device (6) according to claim 7 wherein at least one of the heating units comprises a strip (12) extending longitudinally, the heating elements being arranged along the strip (12), the heating elements being supplied with current in parallel. 9. Air conditioning unit comprising a heating device (6) according to any one of the preceding claims. 10. Housing according to the preceding claim, said housing having an orifice (27) for introducing the heating module (10), said orifice (27) being located in the lower part, in the position of use of the housing.