Radiator arrangement with two rear-flow gas coolers, motor vehicle and method for operating a radiator arrangement

Abstract

Radiator arrangement (10) for a motor vehicle (12), comprising a first radiator (24) which is designed to cool a refrigerant, and comprising an air guiding device (26) which has an inlet (28), wherein, in an installed position of the radiator arrangement (10) in the motor vehicle (12), a front side (46) of the first radiator (24) can be subjected to airflow (16) via the inlet (28), and comprising a fan (18), wherein, by operating the fan (18), the first radiator (24) can be subjected to an airflow (22) from a rear side (50) of the first radiator (24) opposite the front side (46), and comprising a control device (52) for controlling the fan (18), characterized in that the radiator arrangement (10) has a second radiator (34) for cooling the refrigerant, wherein an inflow side (48) of the second radiator (34) of the front side (46) of the first cooler (24),wherein the second cooler (34) provides a boundary wall of the air guiding device (26) through which at least a part of the air flow (22) can flow, and wherein in the installed position of the cooler arrangement (10) in the motor vehicle (12), the second cooler (34) can be acted upon by airstream (16) from the inflow side (48) via the inlet (28).

Description

[0001] The invention relates to a radiator assembly for a motor vehicle, comprising a first radiator designed to cool a coolant, and comprising an air guiding device having an inlet. When the radiator assembly is installed in the motor vehicle, a front side of the first radiator can be exposed to airflow via the inlet. By operating a fan of the radiator assembly, the first radiator can be exposed to an airflow from a rear side of the first radiator opposite the front side. A control device of the radiator assembly serves to control the fan. Furthermore, the invention relates to a motor vehicle having such a radiator assembly and a method for operating the radiator assembly.

[0002] DE 10 2013 112 825 A1 describes a front module of a vehicle, comprising a vehicle front element having fresh air openings, an air duct connecting the fresh air openings to the engine compartment of the vehicle, and a heat exchanger of a vehicle air conditioning system arranged in the air duct through which air can flow. A fan arranged in the air duct for supplying air to the heat exchanger is designed to be reversible. Furthermore, a further heat exchanger for engine cooling, battery cooling, or charge air cooling is arranged in the air duct between the heat exchanger of the vehicle air conditioning system and the fan.

[0003] WO 2019 / 058809 A1 describes a similarly constructed heat exchanger system.

[0004] DE 11 2017 004 759 B4 describes a cooling module with a fan arranged downstream of a condenser and a radiator in the front engine compartment of a vehicle. The fan can blow air forward through the condenser when the vehicle is stationary. Furthermore, when the vehicle is moving, the condenser can be exposed to airstream. When the vehicle is stationary, the fan draws in air from a drive engine arranged in the front engine compartment.

[0005] The disadvantage here is that it is difficult to supply the condenser with a sufficiently large mass flow of cooling air when the vehicle is stationary.

[0006] Further radiator arrangements for vehicles are described in US 2012 / 0222833 A1 and WO 2020 / 174191 A1.

[0007] The object of the present invention is to provide a cooler arrangement of the type mentioned at the outset, by means of which a particularly high cooling capacity for cooling the refrigerant can be achieved, as well as to provide a motor vehicle with such a cooler arrangement and a method for operating a cooler arrangement.

[0008] This object is achieved by a radiator arrangement having the features of patent claim 1, a motor vehicle having the features of patent claim 8, and a method having the features of patent claim 9. Advantageous embodiments with expedient further developments of the invention are specified in the dependent patent claims and in the following description.

[0009] The radiator assembly according to the invention for a motor vehicle comprises a first radiator, which is designed to cool a refrigerant, and an air guiding device having an inlet. When the radiator assembly is installed in the motor vehicle, a front side of the first radiator can be exposed to airflow via the inlet.

[0010] By operating a fan of the cooler assembly, the first cooler can be exposed to an airflow from a rear side of the first cooler, opposite the front side. The cooler assembly has a control device designed to control the fan. Furthermore, the cooler assembly has a second cooler for cooling the coolant, with an inflow side of the second cooler facing the front side of the first cooler. A boundary wall of the air guiding device is provided by the second cooler, with at least a portion of the airflow flowing through the boundary wall.

[0011] The second cooler thus provides an outlet path for air conveyed by the fan through the first cooler during fan operation. In other words, at least a portion of the air flow conveyed by the fan during fan operation can pass from the air guiding device, which is closed to the environment except for the inlet and one outlet, through the second cooler into the environment of the air guiding device or cooler arrangement.

[0012] By providing the first cooler and the second cooler, a particularly large cooling surface is provided compared to using only one cooler, over which the air flow conveyed by the fan can flow. This allows for a particularly high cooling performance for cooling the refrigerant. This is advantageous.

[0013] During operation of a refrigerant circuit in which the first cooler and the second cooler are integrated, the refrigerant can be cooled very effectively by means of this air flow. This is particularly advantageous when the refrigerant used is a substance that is not liquefied during operation of the refrigerant circuit, i.e., one in which no phase transition from gaseous to liquid occurs. For example, the two coolers of the cooler arrangement are therefore particularly well suited for cooling the refrigerant carbon dioxide (CO2), also known as R744.

[0014] Operating the fan is particularly advantageous when a radiator assembly is installed in a vehicle when the vehicle is stationary or moving slowly. This is because there is little or no airflow available to flow through the radiators and thus dissipate heat from the refrigerant, which flows through the radiator lines during operation of the refrigerant circuit. Accordingly, in such situations, it is particularly useful to ensure cooling of the refrigerant by subjecting the two radiators to the airflow delivered by the fan.

[0015] Since the fan can discharge at least part of the air flow through the second cooler into the environment of the cooler arrangement, the cooler arrangement enables an increased mass flow and thus an improved cooling performance, in particular when the motor vehicle having the cooler arrangement is stationary.

[0016] Particularly if the motor vehicle is designed as an electric vehicle or a hybrid vehicle, a comparatively large amount of heat must be dissipated when charging an electrical energy storage device of the motor vehicle, which heats up during charging, and thus when the motor vehicle is stationary. Effective cooling of the electrical energy storage device can be achieved by using the two coolers. In particular, a refrigerant circuit, into which the two coolers can be integrated, can be used to cool the electrical energy storage device. Very intensive heat dissipation from the electrical energy storage device is made possible, in particular, by cooling the electrical energy storage device using an evaporator in the refrigerant circuit.

[0017] Since the cooler assembly is capable of providing high cooling performance, particularly when the motor vehicle is stationary, an increase in the charging power during charging, particularly during rapid charging, of the electrical energy storage device can advantageously be achieved in the motor vehicle configured as an electric vehicle or hybrid vehicle. This advantageously results in a reduction in the time required for charging the electrical energy storage device.

[0018] Furthermore, increasing the cooling capacity of the cooler assembly does not require increasing the size of the first cooler. The boundary wall or outer wall of the air guiding device formed by the second cooler can be used to provide an additional cooling surface. Together with the first cooler, a particularly large cooling surface is provided. This results in fewer conflicts with regard to the available installation space. There is no increased space requirement for accommodating an enlarged first cooler in the cooler assembly.

[0019] In the cooler assembly according to the invention, when the cooler assembly is installed in the motor vehicle, the second cooler can be exposed to airflow from the upstream side via the inlet. This allows for high cooling performance for cooling the refrigerant, particularly in a fast-moving motor vehicle that incorporates the cooler assembly.

[0020] Preferably, by operating the fan, the second cooler can be exposed to at least part of the air flow from the upstream side. The fan can thus ensure that the air flow conveyed by the fan firstly passes through the first cooler and secondly that at least a portion of the air flow conveyed by the fan passes through the second cooler into the area surrounding the cooler arrangement. By designing the second cooler as a boundary wall of the air guiding device through which air can flow, the air path is de-throttled during fan operation. This is particularly advantageous for the effective use of both coolers to cool the refrigerant.

[0021] The cooler assembly preferably has a closing device arranged at the inlet, by means of which the inlet can be selectively closed or opened at least in part. The control device is designed to control the closing device depending on the operation of the fan. In this way, the control device can ensure that the inlet, through which airstream can flow into the air guiding device, can be used as an additional outlet for the air flow that can be provided by operating the fan. This allows the air conveyed by the fan to flow particularly unhindered into the surroundings of the cooler assembly. This is advantageous with regard to efficient operation of the fan.

[0022] Preferably, the control device is configured to close the inlet at least partially by means of the closing device when the first radiator is exposed to the air flow from the rear due to the operation of the fan. This effectively ensures, for example, when the vehicle is stationary, that the air flow conveyed by the fan passes through the second radiator into the area surrounding the radiator assembly. This is advantageous with regard to high cooling performance for cooling the refrigerant when the vehicle is stationary.

[0023] Additionally or alternatively, the control device is preferably designed to close the inlet at least partially by means of the closing device depending on the driving speed of the motor vehicle. This allows for the fact that airflow can enter the radiator assembly via the inlet. And if the fan simultaneously promotes the airflow, the fan must essentially work against the airflow. This can be prevented or at least facilitated by closing the inlet at least partially by means of the closing device.

[0024] For example, it can be provided that the control device causes the inlet to be closed at least partially or at least partially by means of the closing device when the driving speed of the motor vehicle exceeds a predetermined threshold. This is because the fan then does not need to work against the airstream, or at least less, when applying the airflow from the rear to the first radiator and when discharging at least part of the airflow into the area surrounding the radiator assembly through the second radiator.

[0025] Furthermore, the control device can ensure that the inlet is increasingly closed by the closing device as the driving speed increases. This can also be achieved by the control device depending on the operation of the fan.

[0026] By means of the control device, the closing device can preferably be used to completely close the inlet. This ensures that the entire airflow conveyed by the fan first passes through the first cooler and then exits the air guiding device through the second cooler into the area surrounding the cooler assembly. This facilitates the most extensive utilization of the cooling capacity provided by the two coolers.

[0027] Preferably, a pressure side of the fan, through which the airflow exits the fan during operation, faces the rear of the first cooler. This ensures, in particular, that the fan does not impair or hinder the airflow from the front of the first cooler.

[0028] The fan is preferably designed to convey the air flow in only one conveying direction. Such a fan is simpler and more cost-effective than a fan in which the air flow can be selectively conveyed in opposite directions, for example, by changing the direction of rotation of a rotor element of the fan. The fan, which is designed to convey the air flow in only one conveying direction, is preferably designed as a pressure fan, which is capable of guiding the air flow through the first cooler from the rear. This is advantageous.

[0029] The radiator assembly preferably comprises a coolant cooler, which is arranged downstream of the inlet with respect to a flow direction of the airstream that can be introduced into the air guiding device via the inlet. With such a coolant cooler, when the radiator assembly is installed in the motor vehicle, the airstream can ensure very effective dissipation of heat from the coolant that flows through lines of the coolant cooler during operation of a coolant circuit. This is advantageous, for example, when the coolant is used to dissipate heat from a drive motor, in particular an electric one, of the motor vehicle, which moves the motor vehicle or at least assists this movement when the motor vehicle is in operation. Furthermore, the coolant can be used, in particular, to dissipate heat from an electrical energy storage device of the motor vehicle.

[0030] Advantageously, when the motor vehicle having the radiator assembly is stationary, another portion of the airflow generated by the fan during operation can flow through the coolant radiator. This allows cooling of the motor vehicle's components that can be cooled by the coolant to be achieved even when the vehicle is stationary. This is advantageous.

[0031] Preferably, the first cooler is arranged substantially parallel to a pressure side of the fan, at which the airflow exits the fan during operation. The inflow side of the second cooler forms an acute angle with the front side of the first cooler. This allows for a very compact design of the cooler assembly. Furthermore, this contributes to efficient airflow and airflow guidance through the air guiding device during operation of the cooler assembly.

[0032] The motor vehicle according to the invention has a radiator assembly according to the invention. In the motor vehicle, the high cooling capacity of the two radiators can be used very efficiently to cool the refrigerant.

[0033] Preferably, the first cooler and the second cooler are integrated into a refrigerant circuit of the motor vehicle, wherein the first cooler and the second cooler can be used as gas coolers during operation of the refrigerant circuit. In particular, a refrigerant can be used in the refrigerant circuit which is not converted into a liquid phase in a condenser of the refrigerant circuit, but which is merely cooled in the gas cooler without a phase transition from gaseous to liquid taking place. In particular, when the radiators or gas coolers contain such a refrigerant, it is advantageous to provide a particularly large cooling surface by providing the first gas cooler and the second gas cooler, via which heat can be dissipated from the refrigerant to be cooled.Especially when using the refrigerant R744 (i.e. carbon dioxide, CO2), it is advantageous to use the two coolers as gas coolers in the operation of the refrigerant circuit.

[0034] In the method according to the invention for operating a radiator assembly for a motor vehicle, the radiator assembly has a first radiator which is designed to cool a refrigerant. An air guiding device of the radiator assembly has an inlet, wherein, in an installed position of the radiator assembly in the motor vehicle, a front side of the first radiator can be exposed to airstream via the inlet. By operating a fan of the radiator assembly, the first radiator is exposed to an airflow from a rear side of the first radiator opposite the front side. A control device of the radiator assembly controls the fan. The radiator assembly has a second radiator for cooling the refrigerant, wherein an inflow side of the second radiator faces the front side of the first radiator.The second cooler provides a boundary wall for the air guiding device, through which at least a portion of the air flow can flow. When the cooler assembly is operated in this way, heat can be dissipated particularly effectively from the coolant by the air flow conveyed by the fan flowing through the first cooler, with at least a portion of the air flow also flowing through the second cooler. When the cooler assembly is installed in the motor vehicle, the second cooler can be exposed to airflow from the upstream side via the inlet.

[0035] The advantages and preferred embodiments described for the radiator arrangement according to the invention also apply to the motor vehicle according to the invention and to the method according to the invention and vice versa.

[0036] The invention therefore also includes further developments of the motor vehicle according to the invention and the method according to the invention that have features already described in connection with the further developments of the radiator assembly according to the invention. For this reason, the corresponding further developments of the motor vehicle according to the invention and the method according to the invention are not described again here.

[0037] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus.

[0038] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0039] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 shows a schematic, partially sectioned perspective view of a radiator arrangement for a motor vehicle; Fig. 2 schematically shows the motor vehicle with the radiator arrangement according to Fig. 1, wherein gas coolers of the cooler arrangement are integrated into a refrigerant circuit of the motor vehicle, and wherein airflow flowing into the cooler arrangement via an inlet can be used to supply the coolers with cooling air; Fig. 3 in a schematic sectional view a variant of the cooler arrangement according to Fig. 1, where the flow conditions are shown for a fast-moving motor vehicle, and Fig. 4 schematically shows the variant of the cooler arrangement according to Fig. 3, where the flow conditions are shown when the vehicle is stationary.

[0040] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0041] In the figures, the same reference symbols designate elements with the same function.

[0042] In Fig. 1 is a schematic and partially sectioned perspective view of a cooler assembly 10 for a Fig. 2 schematically shows a motor vehicle 12. The motor vehicle 12 is preferably designed as an electric vehicle or hybrid vehicle. This entails a high demand for cooling air, particularly when the motor vehicle 12 is stationary. For example, when an electrical energy storage device (not shown) of the motor vehicle 12 is being charged and heats up in the process, heat must be dissipated from the electrical energy storage device.

[0043] Furthermore, it is desirable if, even when the motor vehicle 12 is stationary, a passenger compartment 14 of the motor vehicle 12 (compare Fig. 2) can be cooled. However, when the motor vehicle 12 is stationary, the cooling air cannot be provided by the airstream 16, which, for example, Fig. 2 is schematically illustrated by an arrow.

[0044] The cooler assembly 10 has a fan 18, of which Fig. 1 a fan wheel 20 is shown partially in section. By operating the fan 18, an air flow 22 (cf. Fig. 4). The air flow 22 is in Fig. 4 by two arrows which, during operation of the fan 18, pass through a first cooler 24, which is preferably designed as the first gas cooler of the cooler arrangement 10. By means of the first gas cooler, a refrigerant can be cooled which, during operation of a refrigerant circuit 38 (see Fig. 2) is conveyed through the first cooler 24.

[0045] The radiator assembly 10 comprises an air guiding device 26, within which the first radiator 24 is arranged. The air guiding device 26 has an inlet 28. In the installed position of the radiator assembly 10 in the motor vehicle 12, the airstream 16 can enter the air guiding device 26 via the inlet 28 (see Fig. 3).

[0046] According to Fig. 3, the airflow 16 can pass through the first cooler 24 and then through the fan 18 to reach an environment 32 of the cooler assembly 10 via an outlet 30 of the air guiding device 26. The air guiding device 26 guides the airflow 16 from the inlet 28 through the first cooler 24 and then through the fan 18 to the outlet 30. In the form of the inlet 28 and the outlet 30, the air guiding device 26 has openings to the environment 32.

[0047] However, in the present case, the air guiding device 26 is permeable to air in a wider area than the inlet 28 and the outlet 30. This is because an upper boundary wall of the air guiding device 26, in the installed position of the cooler assembly 10 in the motor vehicle 12, is provided by a second cooler 34, which is preferably designed as a second gas cooler for the coolant. According to Fig. 3, the airstream 16, which enters an interior space 36 of the air guiding device 26 via the inlet 28, can thus also pass through the second cooler 34 into the environment 32 of the cooler arrangement 10.

[0048] Preferably, the first cooler 24 and the second cooler 34 in the motor vehicle 12 are integrated into the refrigerant circuit 38, which is shown in a highly schematic manner in Fig. 2. A compressor 40 of the refrigerant circuit 38 compresses the refrigerant and conveys the compressed refrigerant to the two coolers 24, 32, which are preferably designed as gas coolers. The cooled refrigerant is then expanded by an expansion device 42 of the refrigerant circuit 38 and fed to an evaporator 44 of the refrigerant circuit 38.

[0049] Preferably, carbon dioxide (CO2), which is referred to in refrigeration technology as R744, is used as the refrigerant conveyed through the refrigerant circuit 38. In particular, when cooling the refrigerant carbon dioxide or R744 in the gas coolers, which in this case are provided by the first cooler 24 and the second cooler 34, no condensation of the refrigerant takes place. Therefore, in order to provide a hollow cooling capacity of the refrigerant circuit 38, it is advantageous to integrate both the first cooler 24 and the second cooler 34 into the refrigerant circuit or refrigerant circuit 38. The integration of the two coolers 24, 34 into the refrigerant circuit 38 by connecting refrigerant lines to the two coolers 24, 34 is Fig. 2 not shown in detail for reasons of clarity.

[0050] In the installation position of the radiator assembly 10 in the motor vehicle 12, a front side 46 of the first radiator 24 can be exposed to the airstream 16 (see Fig. 3). The second cooler 34 has an inflow side 48 which faces the front side 46 of the first cooler 24. According to Fig. 3, the second cooler 34 can be exposed to a portion of the airflow 16 from the inflow side 48, whereby this portion of the airflow 16 can pass through the second cooler 34 into the surrounding area 32 of the cooler assembly 10. Another portion of the airflow 16 passes through the first cooler 24 and the fan 18 to the outlet 30 of the air guiding device 26 and from there further into the surrounding area 32 of the cooler assembly 10.

[0051] In particular, when the motor vehicle 12 is stationary, by operating the fan 18, the air flow 22 conveyed by the fan 18 can be used to cool the refrigerant, which flows through the first cooler 24 and through the second cooler 34 during operation of the refrigerant circuit 38 by the refrigerant being conveyed by the compressor 40.

[0052] The permeability of the second cooler 34, designed as a boundary wall of the air guiding device 26, ensures that the air flow 22 can pass very well and very unhindered through the second cooler 34 into the environment 32 of the cooler assembly 10. In other words, the air path is dethrottled when the motor vehicle 12 is stationary, in that one of the boundary walls of the air guiding device 26 is formed or provided by the second cooler 34.

[0053] In addition, the direction of air flow through the first cooler 24 is reversed when the vehicle is stationary. This is because when driving (compare Fig. 3) the airflow 16 flows from the front side 46 through the first radiator 24. When the motor vehicle 12 is stationary, the fan 18 acts on the first radiator 24 from a rear side 50 opposite the front side 46 (compare Fig. 4) with the air flow 22.

[0054] The cooler arrangement 10 comprises a control device 52 (see Fig. 3 and Fig. 4) for controlling the fan 18, wherein the control device 52 is shown for reasons of clarity in Fig. 1 is not shown. Furthermore, the cooler assembly 10 preferably has a closing device 54, through which a controllable cooling air inlet is formed.

[0055] For example, the closure device 54 may have a plurality of slats 56 which can be moved into an open position and a closed position to allow or prevent the passage of air through the closure device 54. When the closure device 54 is open (as in Fig. 3), the airflow 16 can flow unhindered through the inlet 28 into the interior 36 of the air guiding device 26. This allows the airflow 16 to be used effectively for cooling purposes.

[0056] Downstream of the inlet 28, a coolant cooler 58 can be arranged in the air guiding device 26, as shown schematically in Fig. 3 and in Fig. 4. When the motor vehicle 12 is moving, heat can be dissipated from a coolant via this coolant cooler 58. This coolant can be used, for example, to cool at least one (in particular electric) drive motor of the motor vehicle 12 and / or an electrical energy storage device of the motor vehicle 12. After the airstream 16 flows through the coolant cooler 58, the airstream 16 can be further used to dissipate heat from the coolant in the two coolers 24, 34 when the motor vehicle 12 is moving.

[0057] When the motor vehicle 12 is stationary or traveling slowly, the direction of air flow through the first radiator 24 can be reversed. In this case, the coolant cooler 58, if present at all, is then flowed through by a portion of the air flow 22 when the closing device 54 is open. This is because then a portion of the air flow 22 can also reach the environment 32 of the radiator assembly 10 via the inlet 28. When the closing device 54 is open, a certain degree of air flow through the coolant cooler 58 is thus ensured.

[0058] Preferably, when the motor vehicle 12 is stationary or when the motor vehicle 12 is moving slowly, the air which is supplied to the two coolers 24, 34, i.e. the air flow 22, is sucked in via the outlet 30 of the air guiding device 26 (compare Fig. 4). According to Fig. 4 is a pressure side 60 of the fan 18, at which the air flow 22 exits the fan 18 when the fan 18 is operated, facing the rear side 50 of the first cooler 24.

[0059] When the closing device 54 is opened, the Fig. 4, the fan 18 is directed forward against the airstream 16. To at least largely prevent this, the control device 52 can cause the closing device 54 to close the inlet 28 at least partially, depending on the driving speed of the motor vehicle 12. Preferably, the control device 52 controls the closing device 54 depending on the operation of the fan 18.

[0060] The radiator assembly 10 can address the fact that, particularly when the motor vehicle 12 is configured as an electric vehicle or hybrid vehicle, a particularly large amount of air should be available to dissipate heat from the coolant when the motor vehicle 12 is stationary. However, in the front area of ​​the motor vehicle 12, particularly when the motor vehicle 12 is configured as an electric vehicle or hybrid vehicle, there is sometimes not a particularly large amount of space available to provide a large inlet 28.

[0061] This can be due, in particular, to the fact that, in the direction of the vehicle's vertical axis z, above the inlet 28 and the closing device 54, installation space is used to provide components that dissipate impact energy in the event of a collision of the motor vehicle 12 with an obstacle. And, in the downward direction of the vehicle's vertical axis z, the size of the cooling air inlet or inlet 28 is limited by the fact that a certain ground clearance of the motor vehicle 12 must be provided.

[0062] In addition, in a lower area in a front panel 62 of the motor vehicle 12 (see Fig. 2) Sensors may be arranged, for example in the form of a radar device, which may also hinder the entry of the airstream 16 into the inlet 28 of the radiator assembly 10. The vehicle vertical axis z, the vehicle transverse axis y and the vehicle longitudinal axis x are in Fig. 1 and Fig. 2 illustrated by respective coordinate systems.

[0063] When the motor vehicle 12 is traveling forward at high speed, it is easy to apply the airflow 16 to the coolant cooler 58 and the coolers 24, 34 via the inlet 28 of the air guiding device 26 (compare Fig. 3). However, when the fan 18 is designed as a suction fan, it is difficult, when the motor vehicle 12 is stationary, to ensure that the first radiator 24 is sufficiently exposed to cooling air from its front side 46 by operating the fan 18. This is because, when the fan 18 is designed as a suction fan, the cooling air to be supplied to the first radiator 24 must first flow through both the closure device 54 and the inlet 28. Furthermore, the flow resistance of the radiator 24 itself must be overcome.

[0064] To counteract this circumstance, the fan 18 is operated in this case when the motor vehicle 12 is stationary or when the motor vehicle 12 is traveling at a low speed in such a way that the first cooler 24 is cooled as in Fig. 4, is supplied with the air flow 22 from the rear side 50. Therefore, it is sufficient in the present case if the fan 18 is designed as a pressure fan, which is designed to convey the air flow 22 in only one conveying direction, namely from the rear side 50 of the first cooler 24 through the first cooler 24 (cf. Fig. 4). Such a fan 18 is less complex than a fan that can be operated both as a suction fan and as a pressure fan.

[0065] It is also advantageous that in the Fig. 4, the air flow 22 conveyed from the rear side 50 of the first cooler 24 through the first cooler 24 has not been previously preheated by the coolant cooler 58. Rather, the cooling air, which is provided in the form of the air flow 22, is sucked in by the fan 18 via the outlet 30 of the cooler assembly 10 or the air guiding device 26. In particular, by a well-closed or well-sealed air duct, i.e., by a high degree of tightness of the air guiding device 26, unwanted recirculation can be very effectively avoided.

[0066] When the fan 18 is operating at low speed of the motor vehicle 12, the airstream 16 can impede the discharge of the airflow 22 conveyed by the fan 18 into the environment 32 via the inlet 28. Therefore, it is advisable for the opening and closing of the inlet 28 by means of the closing device 54 to be coupled with the control of the fan 18. This can be easily implemented by appropriate programming of the control device 52.

[0067] Out of Fig. 3 and Fig. 4 it is further apparent that the first cooler 24 is preferably arranged substantially parallel to the pressure side 60 of the fan 18. Furthermore, in Fig. 1, in Fig. 3 and in Fig. 4 clearly shows that the inflow side 48 of the second cooler 34 can form an acute angle with the front side 46 of the first cooler 24.

[0068] Here, the coolant cooler 58 is preferably (as in Fig. 3 and Fig. 4) is arranged between end regions 64, 66 of the two coolers 24, 34, which are close to the inlet 28. In particular, the end region 66 of the second cooler 34 can extend as far as the inlet 28. In contrast, the end region 64 of the first cooler 24 can be spaced somewhat from the inlet 28.

[0069] In particular, the coolant cooler 58 can be arranged between these two end regions 64, 66, provided that the cooler arrangement 10 includes the coolant cooler 58. Accordingly, the first cooler 24, the second cooler 34 and the coolant cooler 58 can form a triangle, as shown schematically in Fig. 3 and Fig. 4 is shown.

[0070] Overall, the examples show how an improved cooling concept for cooling the refrigerant R744 can be provided by a reversible air flow in the cooler arrangement 10.

Claims

[1] Radiator arrangement (10) for a motor vehicle (12), comprising a first radiator (24) which is designed to cool a refrigerant, and comprising an air guiding device (26) which has an inlet (28), wherein, in an installed position of the radiator arrangement (10) in the motor vehicle (12), a front side (46) of the first radiator (24) can be subjected to airflow (16) via the inlet (28), and comprising a fan (18), wherein, by operating the fan (18), the first radiator (24) can be subjected to an air flow (22) from a rear side (50) of the first radiator (24) opposite the front side (46), and comprising a control device (52) for controlling the fan (18), characterized byin that the cooler arrangement (10) has a second cooler (34) for cooling the coolant, wherein an inflow side (48) of the second cooler (34) faces the front side (46) of the first cooler (24), wherein a boundary wall of the air guiding device (26) through which at least a part of the air flow (22) can flow is provided by the second cooler (34), and wherein in the installed position of the cooler arrangement (10) in the motor vehicle (12), the second cooler (34) can be acted upon by airstream (16) from the inflow side (48) via the inlet (28). [2] Radiator arrangement (10) according to claim 1, characterized by that by operating the fan (18) the second cooler (34) can be supplied with at least part of the air flow (22) from the inflow side (48). [3] Radiator arrangement (10) according to one of the preceding claims, characterized byin that the cooler arrangement (10) has a closing device (54) arranged on the inlet (28), by means of which the inlet (28) can be selectively closed or opened at least in some areas, wherein the control device (52) is designed to control the closing device (54) depending on the operation of the fan (18). [4] Radiator arrangement (10) according to claim 3, characterized by that the control device (52) is designed to effect the at least partial closure of the inlet (28) by means of the closing device (54) when the first cooler (24) is subjected to the air flow (22) from the rear side (50) by the operation of the fan (18), and / or to effect the at least partial closure of the inlet (28) by means of the closing device (54) as a function of a driving speed of the motor vehicle (12). [5] Radiator arrangement (10) according to one of the preceding claims, characterized by that a pressure side (60) of the fan (18), at which the air flow (22) exits the fan (18) when the fan (18) is operated, faces the rear side (50) of the first cooler (24), wherein the fan (18) is designed to convey the air flow (22) in only one conveying direction. [6] Radiator arrangement (10) according to one of the preceding claims, characterized by in that the cooler arrangement (10) comprises a coolant cooler (58) which is arranged downstream of the inlet (28) with respect to a flow direction of the airstream (16) which can be introduced into the air guiding device (26) via the inlet (28). [7] Radiator arrangement (10) according to one of the preceding claims, characterized bythat the first cooler (24) is arranged substantially parallel to a pressure side (60) of the fan (18), at which the air flow (22) exits the fan (18) when the fan (18) is operated, wherein the inflow side (48) of the second cooler (34) forms an acute angle with the front side (46) of the first cooler (24). [8] Motor vehicle (12) with a cooler arrangement (10) according to one of the preceding claims, wherein the first cooler (24) and the second cooler (34) are integrated into a refrigerant circuit (38) of the motor vehicle (12), wherein the first cooler (24) and the second cooler (34) can be used as a gas cooler during operation of the refrigerant circuit (38). [9] A method for operating a cooler assembly (10) for a motor vehicle (12), comprising a first cooler (24) designed to cool a coolant, and comprising an air guiding device (26) having an inlet (28), wherein, in an installed position of the cooler assembly (10) in the motor vehicle (12), a front side (46) of the first cooler (24) can be subjected to airflow (16) via the inlet (28), wherein, by operating a fan (18) of the cooler assembly (10), the first cooler (24) is subjected to an air flow (22) from a rear side (50) of the first cooler (24) opposite the front side (46), wherein a control device (52) of the cooler assembly (10) controls the fan (18), characterized byin that the cooler arrangement (10) has a second cooler (34) for cooling the coolant, wherein an inflow side (48) of the second cooler (34) faces the front side (46) of the first cooler (24), wherein a boundary wall of the air guiding device (26) is provided by the second cooler (34), wherein at least part of the air flow (22) flows through the boundary wall, and wherein, in the installed position of the cooler arrangement (10) in the motor vehicle (12), the second cooler (34) can be acted upon by airstream (16) from the inflow side (48) via the inlet (28).

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