CN114502403A

CN114502403A - Cooling device for a motor vehicle

Info

Publication number: CN114502403A
Application number: CN202080063463.6A
Authority: CN
Inventors: 托马斯·伯恩申; 维利·帕尔施; 赖因哈德·甘特克; 诺贝特·施蒂尔吉斯; 吉多·科赫
Original assignee: Bozewalsburg Automotive Parts Europe
Current assignee: Bozewalsburg Automotive Parts Europe
Priority date: 2019-09-09
Filing date: 2020-09-08
Publication date: 2022-05-13
Also published as: WO2021048109A1

Abstract

The invention relates to a cooling device (2) for a motor vehicle (4), comprising an external air guide (12, 12') having at least one vehicle-front inlet (70a, 86a) and at least one outlet (70b, 88) oriented transversely thereto, and a first air guide channel (70, 84) formed therebetween, which has a first heat exchanger (30, 92, 94, 96) and a radial fan (76) associated therewith.

Description

Cooling device for a motor vehicle

Technical Field

The invention relates to a cooling device for a motor vehicle, in particular for an electrically driven or drivable motor vehicle. An electrically driven or drivable motor vehicle is understood here to mean in particular an electric vehicle (battery vehicle) having an electric motor which is supplied with power from a rechargeable battery or a hybrid vehicle having an electric motor and an internal combustion engine.

Background

Cooling devices for internal combustion engines, in particular for motor vehicles, primarily dissipate heat released into the combustion chamber or the cylinder wall. Because excessive temperatures can damage the engine, the internal combustion engine must be cooled. With few exceptions, modern internal combustion engines, in particular four-stroke engines in motor vehicles, are liquid-cooled, wherein a mixture of water, antifreeze and corrosion inhibitors is usually used as coolant to maintain the operating temperature of the internal combustion engine and also for the operation of air-conditioning systems.

The coolant in the tubes which are conducted into the cooler network or into the cooling modules of the cooler must be cooled again, in order to sweep the cooling air over the cooler ribs which exchange heat with the coolant. Since the oncoming wind used as cooling air is generally not sufficient for cooling, particularly at low speeds of the motor vehicle, it is known, for example from DE 102013006499U 1, to arrange an axial fan in a radiator frame on a radiator comprising cooling fins. An axial fan, which is preferably driven by an electric motor, generates an additional air flow, wherein the radiator frame has a number of dynamic pressure flap openings, which can be closed with dynamic pressure flaps. When the dynamic pressure flap is open and the vehicle speed is relatively high, a reduced cooling surface coverage and a large free flow area are achieved due to the less blockages, and thus an increased cooling capacity is achieved.

In the direction of travel, the axial fan is usually arranged behind the cooler network or the cooling components of the cooler (heat exchanger). By means of the fan wheel of the fan, air is drawn through the cooler network and deflected to the combustion engine. If, in addition to the chiller network, there is a condenser network of the liquefier of the air conditioning system, the condenser network is usually arranged upstream of the chiller network in the windward direction (air flow direction).

Electrically driven or drivable vehicles or motor vehicles, for example electric vehicles or hybrid vehicles, which are driven or drivable by electric motors, usually comprise an electric motor as an electric drive system, with which the electric motor can drive one or both axles. For supplying electrical energy, the electric motor is usually coupled to a (high-voltage) battery inside the vehicle as an electrical energy store. A battery is to be understood here and hereinafter as meaning in particular a rechargeable electrochemical secondary battery, for example an accumulator.

Such electric motors as electric drives generate relatively little waste heat during operation and therefore require only a low cooling capacity of the cooling device compared to the internal combustion engine. However, in the case of electrically driven or electrically drivable motor vehicles, there is the additional problem that the battery begins to deteriorate at high battery temperatures, for example above 45 ℃. This means that at such elevated temperatures, electrochemical reactions within the cell can occur that damage or completely destroy the cell.

In order to improve electric travel, what is known as a rapid charging operation is generally required in electric vehicles or hybrid vehicles, in which a battery inside the vehicle is charged in the shortest possible time. During this rapid charging process, relatively high currents occur, which lead to an increase in the battery temperature during the charging process.

The battery is typically charged when the vehicle is stationary so that there is no head-on wind to cool. Thus, to improve the cooling performance of the battery in the (fast) charging mode, a cooling air flow through the heat exchanger may be generated, for example, by an axial fan. However, a disadvantage is that such an axial fan causes relatively high noise pollution.

Furthermore, conventional cooling devices have a relatively low cooling capacity during charging operation due to lack of frontal wind, which means that it is generally necessary to reduce the charging current after a certain time of charging in order to avoid overheating and deterioration of the battery. Thereby disadvantageously increasing the charging time of the motor vehicle.

Disclosure of Invention

The object on which the invention is based is to specify a particularly suitable cooling device for a motor vehicle.

This object is achieved according to the invention by the features of claim 1. Advantageous configurations and refinements are the subject of the dependent claims.

The cooling device according to the invention is provided for a motor vehicle and is suitable for this and is provided for this purpose. The cooling apparatus has an outside air guide for vehicle temperature control. The external air guide guides the external air or ambient air of the motor vehicle into the structural space, in particular into the front engine space. The motor vehicle is in particular an electrically driven motor vehicle or an electrically drivable motor vehicle, for example an electric vehicle or a hybrid vehicle. The motor vehicle has an electric motor which is supplied with power by a rechargeable battery, wherein a cooling device, which is also referred to below as a cooling module, is provided in particular for cooling the battery and/or the electric motor.

The conjunction "and/or" is understood here and in the following to mean that the features connected by this conjunction can be designed both together and as a replacement for one another.

The external air guide has at least one inlet opening at the front side of the vehicle and at least one outlet opening oriented transversely thereto and a first air guide channel formed therebetween. A first heat exchanger and a radial fan associated with the first heat exchanger are arranged in the first air guide channel. A particularly suitable cooling device is thereby achieved.

Radial flow fans or radial flow fans are to be understood here and hereinafter as cooler fans: it sucks in cooling air axially and conveys it radially after deflection (90 ° deflection). This means that the radial fan is conveyed (blown out) outward in the radial direction. Correspondingly, an axial fan refers to a cooler fan that draws cooling air in and delivers it out axially.

Radial flow fans produce less noise than axial flow fans. In particular, radial flow fans can achieve significantly reduced sound pressure levels at the same air output. Thereby a cooling device with reduced noise is achieved. In stationary motor vehicles requiring high heat extraction, such as during a battery rapid charging process, the external air guide has significantly lower air noise at the same air output, such as 10dB (A) lower than 70-80 dB (A), compared to a conventional cooler fan module with an axial fan. Thus, the noise generation of the cooling device (cooling module) is as low as possible, i.e. as noiseless (quiet) as possible, at the time of battery charging.

"axial" is understood here to mean a direction parallel (coaxial) to the axis of rotation (axial direction) of the fan or fan wheel, while "radial" is understood to mean a direction perpendicular to the axis of rotation (radial direction) of the fan. The axis of rotation of the fan in turn runs in the longitudinal direction of the guide channel, i.e. substantially parallel to the direction of travel of the motor vehicle.

The recirculation is also reduced or prevented by the improved spatial separation of the inlet and outlet regions, so that the power requirement required for the air volume flow is reduced. The inlet and outlet of the first air guiding channel are preferably spaced apart from each other as far as possible, so that recirculation, i.e. re-suction of heated air, is largely avoided. Thereby ensuring a high efficiency of the cooling device. For example, the outlet is directed towards the front windshield or wheel cover of the motor vehicle.

Furthermore, the cooling device has a particularly high potential for integrating a larger heat exchanger network due to the retracted position in the region of the upwardly extending "engine hood". Furthermore, new constructional freedom for the front part is achieved as well as better space utilization, higher constructional space requirements, and the like. In particular, a significant design potential for a "new vehicle appearance", i.e. a new vehicle front, is thus achieved.

In an advantageous embodiment, the external air guide has at least three controllable louvers. Thereby, the external air guide is adapted and arranged for achieving a concentrated, preferably fully defined air guide from the inlet to the outlet.

Due to the louvers, the external air guide has three actively controllable openings which, depending on the load situation, effect the guiding of the cooling air from the inlet to the outlet. Thereby improving the energy efficiency of the motor vehicle. In particular, the drive power averaged over the driving cycle is reduced, which is achieved in particular by constantly minimizing the drive resistance. For this purpose, the air proportion flowing around the vehicle is maximized, and only in driving situations the air volume flow required for forced heat dissipation flows into the subsystem external air guide. At a given air output, a higher heat dissipation capacity is achieved due to the higher utilization of the cooler assembly and due to the complete (more complete) flow formation within the fan, compared to an axial fan.

In a preferred refinement, the external air guide has a second air guide channel, which has a second heat exchanger with an axial fan assigned to the second heat exchanger. The heat exchangers are designed as separate or mutually separate heat exchangers. Radial flow fans are preferably designed for higher air output at the same loudness compared to axial flow fans.

The heat exchanger is designed, for example, as a cooler network or as a cooling module, i.e. a cooler, respectively, through which the coolant flows. The heat exchangers are connected, for example, to a common coolant circuit of the cooling system. This means that the heat exchangers are arranged in particular spatially separated from one another, but can be coupled to one another in terms of coolant technology. The heat exchanger is arranged in particular side by side behind the inlet on the front side of the vehicle.

The heat exchanger has a front side and a rear side with respect to a direction of travel (X) of the motor vehicle, i.e. with respect to a main direction of movement of the vehicle. The front side of the first heat exchanger is here, for example, directed toward a cooler grille on the front side of the vehicle, wherein the rear side of the heat exchanger is directed toward the respective air guide channel and thus toward the respective cooler fan.

In a suitable installation situation, the cooler fan is arranged in the lower region of the motor vehicle, i.e. close to the ground, whereby the noise during operation is further reduced.

In one suitable configuration, the second air guiding channel is arranged parallel to the first air guiding channel. In other words, the cooling device has two parallel air guiding channels, which are respectively guided from the heat exchanger to the cooler fan. This means that the air flow is guided or can be guided by means of an air guide channel between the heat exchanger and the respective cooler fan.

In terms of flow technology or flow dynamics, the cooler fans are arranged downstream of the respective heat exchangers. In other words, the respective cooler fan is arranged after the respective cooler or heat exchanger in the air flow direction of the cooling air.

In a suitable embodiment, the respective outlets of the air guiding channels are arranged or oriented exactly opposite, i.e. opposite to each other. In other words, the blowing directions of the two cooler fans are preferably oriented exactly opposite to each other. Thereby reducing recirculation between the air guide channels of the external air guide. In particular, the outlet of the first air guiding channel is directed towards the vehicle front windshield, while the outlet of the second air guiding channel is directed towards the vehicle underside. Thereby ensuring the smallest possible recirculation of the heated exhaust gases.

An additional or further aspect of the invention provides that the axial flow fan and the second heat exchanger have a larger cross section than the radial flow fan and the first heat exchanger. The heat exchanger therefore preferably has a different cross section. The (second) heat exchanger with the larger cross section is guided here to a cooler fan designed as an axial fan or axial fan, wherein the (first) heat exchanger with the smaller cross section is guided to a cooler fan designed as a radial fan or radial fan.

The second air guide channel with the axial fan and the (second) heat exchanger, which have a relatively large cross section, has low pressure losses in this case and serves primarily for cooling by utilizing the oncoming wind during driving. The first air guide channel with the radial fan and the (first) heat exchanger having a relatively small cross section has a relatively high pressure loss (relative to the second air guide channel) and is preferably used for motor vehicle cooling during the (ultra-) fast charging process.

Preferably, at least one actively controllable opening or flap or louver and/or a further air channel is provided for each air guiding channel.

This results in a particularly suitable cooling device for an electrically driven or electric motor driven or electrically drivable or drivable by an electric motor of a motor vehicle. In particular, different flow paths for the guided air flow can be realized by different air guides, so that optimum cooling is achieved depending on the operating conditions of the motor vehicle.

Drawings

The invention is explained in more detail below with reference to the drawings. Wherein:

fig. 1 shows in a schematic representation a cooling device of a motor vehicle with a dual-flow external air guide;

fig. 2 shows the external air guide in a perspective illustration;

fig. 3a to 3c show the arrangement of the cooling device in the motor vehicle from different perspectives;

fig. 4 shows the external air guide in a second embodiment in a plan view;

fig. 5 shows an external air guide with a flow profile of the external air in a schematic top view; and

fig. 6 shows an external air guide with a flow profile of the external air in a schematic front view.

Corresponding parts and quantities have always the same reference numerals throughout the drawings.

Detailed Description

Fig. 1 shows a cooling device 2 of a motor vehicle 4 (fig. 3a to 3c) in a schematic and simplified illustration. The motor vehicle 4 is in particular an electrically driven or drivable motor vehicle, for example an electric vehicle or a hybrid vehicle, and has an electric-motor traction drive 6 and a (high-voltage) battery 8. The cooling device 2 is used here for vehicle temperature control, i.e. for temperature control of at least one passenger compartment or vehicle interior 10 of the motor vehicle 4.

The cooling device 2 has an external air guide 12 and a circulation circuit system 14 coupled thereto. The recirculation loop system 14 includes a primary recirculation loop 16 and a secondary recirculation loop system 18 coupled thereto.

The main circuit 16 is designed as a refrigerant circuit for a refrigerant, in particular for a natural refrigerant such as propane. To this end, the main circuit 16 has an electronic expansion valve 20 and an electric refrigerant compressor 22 as well as two heat exchangers 24, 26. The refrigerant compressor 22 is designed, for example, as a scroll compressor and preferably has a cooling jacket 28, which is coupled to the secondary circulation circuit system 18.

The refrigerant, in particular a gaseous refrigerant, is compressed (pressed) by a refrigerant compressor 22, wherein a subsequent (high temperature) heat exchanger 24 operates as a condenser or liquefier such that the refrigerant releases heat. The refrigerant, particularly liquid refrigerant, is then expanded through the expansion valve 20 due to the pressure change. In the subsequent (low-temperature) heat exchanger 26, which serves as a cooler or evaporator, the refrigerant evaporates at low temperature and absorbs heat.

The heat exchangers 24, 26 form an interface with the secondary circulation circuit system 16, which is designed as a coolant circulation circuit. The coolant of the secondary loop system 16 is, for example, water and/or glycol. The coolant line of the heat exchanger 24 is guided to two

heat exchangers

30, 32 of the external air guide 12, which are designed as external heat exchangers. From the

heat exchangers

30, 32, the coolant is directed to an electronic flow regulating mixing valve 34.

The secondary circulation loop system 18 has two

coolant circulation loops

18a, 18b, one high or medium temperature circulation loop 18a coupled to a heat exchanger 24 and one low temperature circulation loop 18b coupled to a heat exchanger 26. Correspondingly, the secondary circulation circuit system 18 has two

inflow sections

36, 38 and two

return sections

40, 42. The inflow portion 36 is a high-temperature or medium-temperature inflow portion, and the return portion 40 is a high-temperature or medium-temperature return portion related to the coolant circulation circuit 18 a. The inflow portion 38 is correspondingly a low-temperature inflow portion, wherein the return portion 42 forms a relevant low-temperature return portion of the coolant circulation circuit 18 b. Two coolant pumps 44, 46 are provided for this purpose. The coolant pump 44 is configured as an electric high or medium temperature coolant pump that delivers coolant from the return portion 40 to the heat exchanger 24. The coolant pump 46 is correspondingly designed as an electric cryogenic coolant pump, which conveys the coolant from the return line 42 in the direction of the heat exchanger 26.

Devices or components of the motor vehicle 4 to be temperature-controlled are connected to the secondary circuit system 18 or to the inflow and return 36, 38, 40, 42. In addition to the traction drive 6 and the battery 8, in the exemplary embodiment the coolant heat accumulator 48 is connected to the coolant circuit as a thermal battery, a cooling heat exchanger 50 and a heating heat exchanger 52 and a surface temperature control element 54 for temperature control of the vehicle interior 10.

The traction drive 6 has, for example, a brake resistor, an inverter (converter), and a charging device. The coolant heat accumulator 48, the battery 8 and the surface temperature control element 54 as well as the vehicle interior 10 preferably each have high-quality heat insulation. The heat exchangers 50, 52 are preferably part of an air conditioning system, not labeled in detail, of the motor vehicle 4 and are coupled to a heating or air conditioning fan 56.

In order to couple the

components

6, 8, 48, 50, 52 to the inflow and return 36, 38, 40, 42 of the secondary circuit system 18, a switching valve 58, in particular an electric two-position, two-way, three-way switching valve, is provided in each case. The heat exchanger 52 is directly coupled to the inflow and return

sections

36, 40. Electronic flow control valves 60 are provided between the

components

6, 8, 48, 50, 52 and the outlet of the switching valves leading to the

return

40, 42 and at the outlet of the heat exchanger 52. The switching valve 58 and the flow regulating valve 60 are provided with reference numerals in the figures merely as examples.

The coolant line of the battery 8 is coupled to the cooling jacket 28 of the coolant compressor 22 via an electronic flow regulating mixing valve 62. An electric coolant mixer pump 64 is arranged between the coolant lines leading to the heat exchanger 26, by means of which coolant can be delivered in particular to the battery 8 for improving the cooling capacity, for example in charging operation or rapid charging operation. When the coolant mixing pump 64 is in operation, this therefore results in particular in a partial recirculation loop for the battery temperature control. The electronic flow rate control valve 66 is provided between the inflow unit 36 and the return unit 40.

The coolant lines leading into and out of the heat exchanger 24 are coupled or can be coupled via a controllable bypass line 67 arranged between the flow-regulating mixing valve 34 and the outlet of the coolant pump 44.

The external air guide 12 has two parallel

air guide channels

68, 70 which lead from

inlets

68a, 70a to

outlets

68b, 70b, respectively. The

inlets

68a, 70a, respectively, can be released as desired through actively controllable louvers 72. The heat exchanger 32 and the axial flow fan 74 disposed behind it are disposed within the air guide passage 68. The air guide duct 70 has a heat exchanger 30 and a radial flow fan 76 arranged behind it.

As can be seen in particular in fig. 2 and 3a to 3c, the external air guide 12 is arranged in the structural space 78 on the front side of the vehicle, in particular in the region of the engine hood. The secondary circulation circuit system 18 is designed here, for example, as a secondary circulation compact module, wherein the compact module and the coolant heat accumulator 48 are preferably spatially compatible with the installation space 78. Two parallel, completely defined

air guide ducts

68, 70 are formed by the external air guide 12, which have

inlets

68a, 70a in the front end and remotely spaced

outlets

68b, 70b on the vehicle underside and in front of the windshield, which have diametrically

opposite blowing directions

80, 82 for the smallest possible recirculation of the heated exhaust gases.

The air guide duct 68 has an axial fan 74 and a heat exchanger 74, wherein the heat exchanger 74 has a relatively large cross section and a relatively small pressure loss and is provided primarily for cooling by the oncoming wind during driving. In particular, the head-on wind is used here by the axial fan 74 to cool the traction drive 6. For this purpose, a relatively large, flat heat exchanger network with low pressure losses is provided. The axial fan 74 suitably has a relatively large volumetric flow and a low pressure differential.

The air guide duct 70 has a radial fan 76 and a heat exchanger 30, wherein the heat exchanger 30 has a relatively small cross section and a relatively high pressure loss and is provided primarily for cooling a stationary vehicle during ultrafast/rapid charging of the battery 8. For this purpose, a relatively small, deep heat exchanger network with a high pressure loss is provided. The radial flow fan 76 suitably has a large volume flow and a large pressure differential. The radial flow fan 76 is preferably designed for higher air output at the same loudness as the axial flow fan 74.

A spatial separation of the heated cooling air and the fresh air supply for the vehicle interior 10 is achieved by the two-channel or dual-flow external air guide 12. Furthermore, an additional heating of the vehicle interior 10 due to the intake of hot air when the ambient temperature is high is avoided.

A second embodiment of the external air guide 12' is explained in more detail below according to fig. 4 to 6. The external air guide 12 ', in particular the single-channel or uniflow external air guide 12 ' in this embodiment, has a fully defined air guide as the air guide channel 84 between the three

inlets

86a, 86b, 86c and the outlet 88, wherein the external air guide 12 ' preferably has four actively controllable openings or

louvers

90a, 90b, 90c, 90d, an air guide channel and one or

more heat exchangers

92, 94, 96 integrated as an assembly, which are oriented obliquely as required in the installation space 74. The air guide channel 84 has a radial fan 76, wherein the guidance of the cooling air from the

inlet

86a, 86b, 86c to the outlet 88, i.e. the position of the

louvers

90a, 90b, 90c, 90d, is adjusted depending on the load. The flow or blowing direction of the cooling air or the outside air is schematically illustrated by arrows in fig. 5 and 6.

The inlet 86a is arranged in the front side in the region of the cooler grille and can be closed and opened as desired by means of louvers 90 a. The entrance 86b is oriented toward the windshield or front (vehicle) window and can be closed by a shutter 90 b. The inlet 86c is oriented toward the wheel housing and can be closed by a louver 90c, wherein the outlet 88 opens into the opposite wheel housing. For this purpose, a diffuser 98 is provided for discharging the cooling air. The louver 90d is disposed before the

heat exchangers

92, 94, 96, i.e., between the

inlets

86a, 86b, 86c and the

heat exchangers

92, 94, 96. The heat exchanger 92 is designed as a refrigerant cooler, wherein the heat exchanger 94 is designed as a low-temperature coolant cooler and the heat exchanger 96 is designed as a high-temperature heat cooler.

At low vehicle speeds below 100km/h (kilometer per hour), i.e. when there is not enough head-on cooling, shutter 90c of inlet 86c is open, shutter 90b of inlet 86b is closed, shutters 90d before

heat exchangers

92, 94, 96 and 90a before inlet 86a are open, with radial fan 76 in active operation.

At high vehicle speeds above 100km/h, i.e. when there is sufficient head-on cooling,

louvers

90c and 90b are closed,

louvers

90a and 90d are open, and radial fan 76 is in passive operation.

When the battery 8 is charged and the motor vehicle 4 is stationary, there is no frontal wind. Where louver 90a is closed and the remaining

louvers

90b, 90c, 90d are open and radial fan 76 is brought into active operation.

By constantly minimizing the driving resistance, the driving power averaged over the driving cycle is reduced by the external air guide 12'. For this purpose, the proportion of air flowing around the vehicle is maximized, and only in driving situations the air volume flow required for forced heat dissipation flows into the subsystem external air guide 12'. For a given air output, a higher heat dissipation capacity is achieved compared to axial fans by: better utilization of the

chiller assemblies

92, 94, 96 is achieved due to the complete (more complete) flow being established within the radial flow fan 76.

The improved spatial separation of the inlet region and the outlet region also reduces or prevents recirculation of the hot air, so that the power requirement required for the air volume flow is reduced.

In particular, the external air guide 12' has a high potential for integrating the larger

heat exchanger networks

92, 94, 96 due to the retracted position in the region of the upwardly extending "bonnet". This also results in new design freedom for the front part, including better space utilization.

The present invention is not limited to the above-described exemplary embodiments. Rather, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the embodiments can also be combined with one another in other ways without departing from the subject matter of the invention.

List of reference numerals

2 Cooling apparatus

4 Motor vehicle

6 traction drive

8 cell

10 vehicle interior space

12. 12' external air guide

14 circulation loop system

16 main circulation loop

18-time circulation loop system

18a, 18b coolant circulation circuit

20 expansion valve

22 refrigerant compressor

24. 26 heat exchanger

28 Cooling jacket

30. 32 heat exchanger

34 flow regulating mixing valve

36. 38 inflow part

40. 42 return part

44. 46 coolant pump

48 coolant heat accumulator

50 cooling heat transmitter

52 heating heat transfer device

54-plane temperature control element

56 air-conditioning fan

58 switching valve

60 flow control valve

62 flow regulating mixing valve

64 Coolant mixing Pump

66 flow control valve

67 bypass line

68 air guide channel

68a inlet

68b outlet

70 air guide channel

70a inlet

70b outlet

72 shutter

74 axial fan

76 radial fan

78 structural space

80. 82 blowing direction

84 air guide channel

86a, 86b, 86c inlet

88 outlet

90a, 90b, 90c, 90d blind

92. 94, 96 heat exchanger

98 diffuser

Claims

1. A cooling device (2) for a motor vehicle (4) has an external air guide (12, 12') having at least one inlet opening (70a, 86a) on the vehicle front side and at least one outlet opening (70b, 88) oriented transversely to the inlet opening, and a first air guide channel (70, 84) formed between the inlet opening and the outlet opening, which has a first heat exchanger (30, 92, 94, 96) and a radial fan (76) associated with the first heat exchanger.

2. Cooling device (2) according to claim 1,

it is characterized in that the preparation method is characterized in that,

the external air guide (12') has at least three controllable louvers (90a, 90b, 90c, 90 d).

3. Cooling apparatus (2) according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the external air guide (12) has a second air guide channel (68) having a second heat exchanger (32), the second heat exchanger (32) having an axial fan (74) associated therewith.

4. Cooling apparatus (2) according to claim 3,

it is characterized in that the preparation method is characterized in that,

the second air guide channel (68) is arranged parallel to the first air guide channel (70).

5. Cooling device (2) according to claim 3 or 4,

it is characterized in that the preparation method is characterized in that,

the outlet (70b) of the first air guide channel (70) and the outlet (68b) of the second air guide channel (68) are directed diametrically opposite each other.

6. Cooling apparatus (2) according to claim 3 to 5,

it is characterized in that the preparation method is characterized in that,

the outlet (70b) of the first air guiding channel (70) is oriented towards a vehicle front windshield of the motor vehicle (4), and the outlet (68b) of the second air guiding channel (68) is oriented towards the vehicle underside.

7. Cooling apparatus (2) according to claim 3 to 6,

it is characterized in that the preparation method is characterized in that,

the axial flow fan (74) and the second heat exchanger (32) have a larger cross-section than the radial flow fan (76) and the first heat exchanger (30).