Flow-optimized heat exchanger

Abstract

Device (100) for cooling components of a rear-engine or mid-engine vehicle (10), comprising a heat exchanger (3), an air intake opening (1) provided on a rear lid of the rear-engine or mid-engine vehicle (10), a supply air duct (2) arranged between the supply air opening (1) and an air inlet of the heat exchanger (3), an exhaust air hood (4) arranged at an air outlet of the heat exchanger (3), at least one exhaust air opening (6, 8) provided in a rear area of ​​the rear-engine or mid-engine vehicle (10), wherein the air supply opening (1) is configured to be arranged at a location on the vehicle (10) at which an overpressure of air prevails during normal driving of the vehicle (10), wherein the at least one exhaust air opening (6, 8) is configured to be arranged at a location on the vehicle (10) at which a negative air pressure prevails during normal driving of the vehicle (10), characterized in that at least one second exhaust air opening (8) is provided to be arranged centrally with respect to a transverse axis of the vehicle (10) and at the bottom with respect to the vertical axis of the vehicle (10), namely in the region of a rear bumper (11).

Description

[0001] The present invention relates to a device for cooling components of a rear- or mid-engine vehicle, comprising a heat exchanger. Furthermore, the present invention relates to a rear- or mid-engine vehicle comprising a device for cooling components of the vehicle.

[0002] Due to the continuous optimization of internal combustion engines in terms of performance, fuel consumption, and especially pollutant emissions, the turbocharged engine now represents the optimal concept in almost all vehicle classes. To increase efficiency, charge air cooling devices are used as standard. These cool the compressed process air in a heat exchanger, thereby increasing its density. This ultimately leads to a higher charge and a reduced tendency for knocking in the internal combustion engine. Both of these factors result in increased specific power, thus more efficient fuel utilization.

[0003] To further increase the efficiency and performance of the engines, the surface area of ​​the heat exchangers, the temperature difference across the heat exchanger or the flow rate of the cooling air across the heat exchanger can be increased.

[0004] This task is particularly important in rear- and mid-engine vehicles. The engine's position in the vehicle allows for a comparatively less favorable arrangement and thus airflow to the heat exchangers than is possible in conventional front-engine vehicles.

[0005] According to the state of the art in mid-engine vehicles, it is common and frequently practiced to arrange the heat exchangers in front of the rear wheels, as is the case with the Bugatti Veyron, for example. These are usually supplied with air through openings in the rear side section of the vehicle and in turn release the heated air through ducts towards the rear wheels or the underbody. The biggest disadvantage of this arrangement is that the cooling ambient air mixes with the heated exhaust air from the front radiators and with the exhaust air from the front wheels heated by the braking system, thereby heating them up. The heat exchangers cannot therefore operate with the maximum possible temperature difference between the ambient air (cooling medium) and the charge air (medium to be cooled), which negatively impacts their efficiency.

[0006] Furthermore, rear-engine vehicles have known arrangements in which the heat exchangers are located to the side of the engine behind the rear wheels. The intake air also enters through openings in the rear side panel, and the exhaust air exits through openings in the rear bumper. The available aerodynamic pressure gradient is comparatively high, resulting in high air flow rates. The fundamental disadvantages of preheated ambient air also apply here.

[0007] Furthermore, large wheel diameters reduce the available space for the air ducts to the heat exchanger, resulting in a throttling point and thus a reduced air throughput.

[0008] Other solutions known from the prior art, with the same radiator arrangement behind the rear wheels, realize the intake airflow in the area of ​​the vehicle's trunk lid, while the exhaust airflow occurs through the rear bumper. The air flowing in through an intake air opening on the trunk lid is guided to the heat exchangers via intake air ducts, passes through these, and flows out through exhaust air openings in the rear bumper. The aerodynamic pressure gradient is high here, as the rear spoiler on the trunk lid creates overpressure in the area of ​​the intake air opening. The advantage of this approach is that the intake air coming from the vehicle roof is not preheated.

[0009] DE 10 2008 045 596 A1 discloses a device for cooling components of a rear-engine vehicle.

[0010] US 2013 / 0 240 284 A1 and DE 10 2012 209 681 A1 each disclose a device for cooling components of a front-engine vehicle.

[0011] US 5 490 572 A discloses a device for cooling components of an electric vehicle.

[0012] It is an object of the present invention to provide a device for cooling components of a vehicle which enables the use of large heat exchangers, throttle-free supply air ducts and throttle-free exhaust air ducts and an increased air throughput.

[0013] This object is achieved by a device for cooling components of a rear-engine or mid-engine vehicle, comprising a heat exchanger, an air supply opening provided on a rear lid of the rear-engine or mid-engine vehicle, an air supply duct arranged between the air supply opening and an air inlet of the heat exchanger, an exhaust air scoop arranged at an air outlet of the heat exchanger, a first exhaust air opening provided in a rear region of the rear-engine or mid-engine vehicle, a first exhaust air duct arranged between the exhaust air scoop and the first exhaust air opening, a second exhaust air opening provided in a rear region of the rear-engine or mid-engine vehicle, and a second exhaust air duct arranged between the exhaust air scoop and the second exhaust air opening, wherein the air supply opening is configured for arrangement at a location on the vehicle at which an overpressure of air prevails during normal driving of the vehicle,wherein the first exhaust air opening is configured to be arranged at a location on the vehicle where a negative air pressure prevails during normal driving of the vehicle, wherein the second exhaust air opening is configured to be arranged at a location on the vehicle where a negative air pressure prevails during normal driving of the vehicle, wherein the second exhaust air opening is intended to be arranged centrally of the vehicle with respect to a transverse axis of the vehicle, namely in the region of a rear bumper.

[0014] The invention also provides the possibility of providing an exhaust air opening in the rear area of ​​the vehicle, which is positioned centrally relative to the transverse axis of the vehicle and at the bottom relative to the vertical axis of the vehicle. This is intended to clarify that only one exhaust air opening is also possible. Those skilled in the art will, of course, also consider the provision of two or more exhaust air openings.

[0015] The device according to the invention makes it possible to utilize existing aerodynamic overpressure and underpressure areas to achieve increased air flow. Furthermore, the first and second exhaust air openings and the arrangements, in particular the arrangement of the second exhaust air opening, allow the heated air to flow out of the heat exchanger with reduced throttling.

[0016] For the purposes of the present invention, a longitudinal axis means an axis passing through the center of the vehicle and pointing straight ahead. For the purposes of the present invention, a transverse axis means an axis intersecting the longitudinal axis at the center of the vehicle and parallel to the rear axle of the vehicle. For the purposes of the present invention, a vertical axis means an axis intersecting the longitudinal axis at the center of the vehicle and arranged orthogonally on a plane spanned by the longitudinal axis and the transverse axis.

[0017] The exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and / or the second exhaust air duct are preferably made of a plastic. However, it is also conceivable that the exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and / or the second exhaust air duct are integrated into further vehicle components. Furthermore, it is conceivable that the exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and the second exhaust air duct are made of aluminum and / or sheet steel. It is conceivable that the first exhaust air opening is intended for arrangement on one side of the vehicle, particularly preferably behind the rear wheel of the vehicle.

[0018] Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0019] According to a preferred embodiment of the invention, the device has a further first exhaust air opening and a further first exhaust air guide arranged between the exhaust air scoop and the further first exhaust air opening, wherein the further first exhaust air opening is configured for arrangement at a location on the vehicle at which a negative air pressure prevails during normal driving of the vehicle, wherein the first exhaust air opening is arranged to the left of the center of the vehicle in the direction of travel with respect to the transverse axis of the vehicle and the further first exhaust air opening is arranged to the right of the center of the vehicle in the direction of travel with respect to the transverse axis of the vehicle. This enables a symmetrical appearance of the device, symmetrical aerodynamics of the vehicle and an enlargement of the cross-section of the exhaust air openings.It is conceivable that the first exhaust air opening and the further first exhaust air opening are configured to be arranged on the left and right sides of the rear bumper of the vehicle, respectively.

[0020] According to a further preferred embodiment of the invention, the second exhaust air opening is configured to discharge gas in a direction parallel to a longitudinal axis of the vehicle. The second exhaust air opening is to be arranged in the region of the rear bumper in the center of the vehicle. In this region, there is a comparatively high negative air pressure, since this second exhaust air opening is located in the aerodynamic wake of the vehicle. Part of the air heated by the heat exchanger leaves the vehicle as a central cooling exhaust air flow. In this way, the not inconsiderable negative air pressure in the vehicle wake is used as described to increase the pressure gradient at the heat exchanger. The result is an increased cooling air mass flow through the heat exchanger and increased cooling performance.

[0021] According to a further preferred embodiment of the invention, the heat exchanger is provided with a fan at its air outlet. This advantageously enables good air flow through the heat exchanger even at low driving speeds or when stationary.

[0022] According to a further preferred embodiment of the invention, a further second exhaust air duct is arranged on the exhaust air scoop, wherein the further second exhaust air duct is configured for the diffused outflow of air. It is conceivable that the further second exhaust air duct is configured to guide air from the exhaust air scoop out of the underbody of the vehicle.

[0023] According to a further preferred embodiment of the invention, the further second exhaust air duct has a further second exhaust air opening, wherein the further second exhaust air opening is configured to direct air flow to vehicle components. This advantageously enables cooling of further components of the vehicle by the air coming from the heat exchanger guided through the further second exhaust air opening.

[0024] A further subject of the invention is a vehicle having a device for cooling components of the vehicle, wherein the device has a heat exchanger, an air supply opening, an air supply duct arranged between the air supply opening and an air inlet of the heat exchanger, an exhaust air scoop arranged at an air outlet of the heat exchanger, a first exhaust air opening, a first exhaust air duct arranged between the exhaust air scoop and the first exhaust air opening, a second exhaust air opening, and a second exhaust air duct arranged between the exhaust air scoop and the second exhaust air opening, wherein the air supply opening is arranged at a location on the vehicle at which an overpressure prevails during normal driving of the vehicle, wherein the first exhaust air opening is arranged at a location on the vehicle at which an underpressure prevails during normal driving of the vehicle, wherein the second exhaust air opening is arranged at a location on the vehicle,at which a negative air pressure prevails during normal driving of the vehicle, characterized in that the second exhaust air opening is arranged centrally of the vehicle with respect to a transverse axis of the vehicle.

[0025] The vehicle according to the invention makes it possible to utilize existing aerodynamic overpressure and underpressure regions in such a way that an increased air throughput occurs. Furthermore, the first and second exhaust air openings and the arrangements, in particular the arrangement of the second exhaust air opening, enable the heated air to flow out of the heat exchanger with reduced throttling. The exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and / or the second exhaust air duct are preferably made of a plastic. However, it is also conceivable that the exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and / or the second exhaust air duct are integrated into other vehicle components.Furthermore, it is conceivable that the exhaust air scoop, the supply air opening, the supply air duct, the first exhaust air opening, the first exhaust air duct, the second exhaust air opening and the second exhaust air duct are made of aluminum and / or sheet steel.

[0026] According to a preferred embodiment of the invention, the device has a further first exhaust air opening and a further first exhaust air guide arranged between the exhaust air scoop and the further first exhaust air opening, wherein the further first exhaust air opening is arranged at a point on the vehicle at which a negative air pressure prevails during normal driving of the vehicle, wherein the first exhaust air opening is arranged to the left of the center of the vehicle in the direction of travel with respect to the transverse axis of the vehicle, and the further first exhaust air opening is arranged to the right of the center of the vehicle in the direction of travel with respect to the transverse axis of the vehicle. This enables a symmetrical appearance of the vehicle, symmetrical aerodynamics of the vehicle, and an enlargement of the cross-section of the exhaust air openings.It is conceivable that the first exhaust air opening and the further first exhaust air opening are arranged on the left and right sides of the rear bumper of the vehicle, respectively.

[0027] According to the invention, the second exhaust air opening is configured to discharge gas in a direction parallel to a longitudinal axis of the vehicle. The second exhaust air opening is arranged in the rear bumper centrally in the vehicle. In this area, a comparatively high negative air pressure prevails, since this second exhaust air opening is located in the aerodynamic wake of the vehicle. Part of the air heated by the heat exchanger leaves the vehicle as a central cooling exhaust air flow. In this way, the considerable negative air pressure in the vehicle wake is used, as described, to increase the pressure gradient at the heat exchanger. The result is an increased cooling air mass flow through the heat exchanger and increased cooling performance.

[0028] According to a further preferred embodiment of the invention, the heat exchanger is provided with a fan at its air outlet. This advantageously enables good air flow through the heat exchanger even at low driving speeds or when stationary.

[0029] According to a further preferred embodiment of the invention, a further second exhaust air duct is arranged on the exhaust air scoop, wherein the further second exhaust air duct is configured for the diffused outflow of air. It is conceivable that the further second exhaust air duct is configured to guide air from the exhaust air scoop out of the underbody of the vehicle.

[0030] According to a further preferred embodiment of the invention, the further second exhaust air duct has a further second exhaust air opening, wherein the further second exhaust air opening is configured to direct air flow to vehicle components. This advantageously enables cooling of further components of the vehicle by the air coming from the heat exchanger, which is guided through the further second exhaust air opening. For example, it is conceivable that the further second exhaust air opening is configured to flow into the engine compartment and / or to direct air flow to the braking system and / or the exhaust system.

[0031] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the scope of the invention. Fig. 1 schematically illustrates a part of the vehicle according to an exemplary embodiment of the present invention with the device according to an exemplary embodiment of the present invention. Fig. 2 schematically illustrates a section through the device according to an exemplary embodiment of the present invention.

[0032] In Fig. 1 schematically illustrates a portion of the vehicle 10 according to an exemplary embodiment of the present invention, including the device according to an exemplary embodiment of the present invention. In the exemplary embodiment shown, the vehicle 10 has two devices according to the invention. For the sake of clarity, only one device, the one arranged on the left side, is described here; the description also applies analogously to the device arranged on the right side.

[0033] The device has the supply air opening 1, which here is the rear lid of the vehicle 10. Furthermore, the device has the supply air duct 2, which extends from the supply air opening 1 to the heat exchanger 3. The exhaust air scoop 4 is connected to the heat exchanger 3 and has one or more openings on the outlet side. The first exhaust air duct 5 and the second exhaust air duct 7 are connected to the exhaust air scoop 4. The first exhaust air duct 5 opens into the first exhaust air opening 6 behind the rear wheel on the bumper 11. The second exhaust air duct 7 opens into the second exhaust air opening 8 in the area of ​​the vehicle center relative to the transverse axis.

[0034] The supply air A flows around the body of the moving vehicle 10. Due to the inflow from the vehicle roof, the supply air A is advantageously not heated by exhaust air, for example from the front radiator or the front wheel brakes (not shown). As a result of the static overpressure in the area of ​​the supply air opening 1, which is essentially caused by a rear spoiler (not shown here for the sake of clarity), a portion of the air flow is directed into the supply air duct 2 and reaches the heat exchanger 3, flows through it and is heated in the process. Several air paths are now open to the heated radiator exhaust air. Through the exhaust air scoop 4 and the subsequent first exhaust air duct 5, a portion of the heated air flows to the first exhaust air opening 6 and leaves the vehicle 10 as the first cooling exhaust air flow B in the area on the side of the rear bumper 11 directly behind the rear wheel (not shown).In this area of ​​the vehicle 10, a significant negative pressure prevails due to the vehicle's rearward-tapering shape (rear intake). Due to the high static pressure gradient between the supply air opening 1 and the first exhaust air opening 6, a high driving pressure gradient is created for the air flow through the heat exchanger 3, which promotes air flow. The second exhaust air opening 8 is located in the rear bumper 11, approximately centrally in the vehicle 10 relative to the transverse axis, and extends from the vehicle center over a certain width to each side of the vehicle. In this area, a comparatively high negative pressure also prevails, since this second exhaust air opening 8 is located in the aerodynamic wake of the vehicle 10. By means of the second exhaust air duct 7, the second exhaust air opening 8 is connected to the exhaust air scoop 4 of the heat exchanger 3. Part of the air heated by the heat exchanger 3 leaves the vehicle as the second cooling exhaust air stream C.This achieves two effects. First, the considerable overpressure in the vehicle wake area is used, as described, to increase the pressure gradient between the heat exchanger inlet and outlet. The result is an increased cooling air mass flow through heat exchanger 3 and increased cooling performance.

[0035] Secondly, the entire exhaust air path is significantly throttled by the additional second exhaust air opening 8.

[0036] The supply air A, which flows through the supply air opening 1 into the heat exchanger 3, now has two paths on the exhaust air side with an overall larger hydraulic cross-section. The result is a reduced flow velocity in both exhaust air paths, i.e. in the first exhaust air duct and in the second exhaust air duct, which leads to the described dethrottling. As a result, the cooling air mass flow through the device is further increased and consequently the cooling performance is further increased. A positive side effect of this solution is that the aerodynamic wake of the vehicle 10 is, so to speak, partially "filled" by the second cooling exhaust air flow C. The result is reduced air resistance of the vehicle 10. With an advantageous design of the second exhaust air duct 7 and the second exhaust air opening 8 with a flow direction approximately along the longitudinal axis of the vehicle 10, the flow is almost buoyancy-neutral.

[0037] Fig.2 schematically illustrates a section through the device according to an exemplary embodiment of the present invention. Shown is a section through the device viewed parallel to the transverse axis of the vehicle. Visible is the heat exchanger 3, into which supply air A flows through the supply air opening 1 and the supply air duct 2. The exhaust air scoop 4 branches off to the first exhaust air duct 5, indicated here by dashed lines, to the second exhaust air duct 7, and to the further second exhaust air duct 9. The further second exhaust air duct 9 is connected to a further second exhaust air opening (not shown here), from which the further second cooling exhaust air flow D flows onto vehicle parts to be cooled, such as the engine compartment, brakes, or the exhaust system (not shown here). The second exhaust air duct 7 is structurally integrated into other vehicle parts in the engine compartment of the vehicle.The second exhaust air duct 7 is made partly of aluminum and partly of sheet steel. The second cooling exhaust air stream C flows parallel to the longitudinal axis of the vehicle from the second exhaust air opening 8, resulting in reduced aerodynamic drag for the vehicle. List of reference symbols 1 air supply opening 2 Supply air duct 3 heat exchangers 4 exhaust air scoop 5 first exhaust air duct 6 first exhaust air opening 7 second exhaust air duct 8 second exhaust air opening 9 additional second exhaust air duct 10 vehicles 11 bumpers 100 device A supply air B first cooling exhaust air stream C second cooling exhaust air stream D further second cooling exhaust air stream

Claims

[1] Device (100) for cooling components of a rear-engine or mid-engine vehicle (10), comprising a heat exchanger (3), an air intake opening (1) provided on a rear lid of the rear-engine or mid-engine vehicle (10), a supply air duct (2) arranged between the supply air opening (1) and an air inlet of the heat exchanger (3), an exhaust air hood (4) arranged at an air outlet of the heat exchanger (3), at least one exhaust air opening (6, 8) provided in a rear area of ​​the rear-engine or mid-engine vehicle (10), wherein the air supply opening (1) is configured to be arranged at a location on the vehicle (10) at which an overpressure of air prevails during normal driving of the vehicle (10), wherein the at least one exhaust air opening (6, 8) is configured to be arranged at a location on the vehicle (10) at which a negative air pressure prevails during normal driving of the vehicle (10), characterized by , that at least one second exhaust air opening (8) is provided to be arranged centrally with respect to a transverse axis of the vehicle (10) and at the bottom with respect to the vertical axis of the vehicle (10), namely in the region of a rear bumper (11). [2] Device (100) according to claim 1, wherein the device (100) has a first exhaust air opening (6) in the region of the rear bumper (11) and a first exhaust air guide (5) arranged between the exhaust air scoop (4) and the first exhaust air opening (6), wherein the first exhaust air opening (6) is configured to be arranged at a location on the vehicle (10) at which a negative air pressure prevails during normal driving of the vehicle (10), wherein the first exhaust air opening (6) is provided to be arranged in the region of the rear bumper (11) relative to that of the vehicle (10) in the direction of travel laterally next to the center of the vehicle (10) behind a rear wheel of the same. [3] Device (100) according to one of the preceding claims, wherein at least one second exhaust opening (8) is configured to discharge gas in a direction parallel to a longitudinal axis of the vehicle (10). [4] Device (100) according to one of the preceding claims, wherein the heat exchanger (3) has a fan at its air outlet. [5] Device (100) according to one of the preceding claims, wherein a further second exhaust air guide (9) is arranged on the exhaust air hood (4), wherein the further second exhaust air guide (9) is configured for the diffuse outflow of air. [6] Device (100) according to claim 5, wherein the further second exhaust air guide (9) has a further second exhaust air opening, wherein the further second exhaust air opening is configured to supply vehicle parts with air. [7] Vehicle (10), namely a rear-engine or mid-engine vehicle, comprising a device (100) for cooling components of the vehicle (10), wherein the device (100) comprises a heat exchanger (3), an air inlet (1) provided on a rear lid of the rear-engine or mid-engine vehicle (10), an air inlet guide (2) arranged between the air inlet (1) and an air inlet of the heat exchanger (3), an exhaust air scoop (4) arranged at an air outlet of the heat exchanger (3), at least one exhaust air inlet (6, 8) provided in a rear region of the rear-engine or mid-engine vehicle (10), wherein the air supply opening (1) is arranged at a location on the vehicle (10) at which an excess air pressure prevails during normal driving of the vehicle (10), wherein the at least one exhaust air opening (6, 8) is arranged at a location on the vehicle (10) at which a negative air pressure prevails during normal driving of the vehicle (10), characterized by , that at least one second exhaust air opening (6) is provided to be arranged centrally with respect to a transverse axis of the vehicle (10) and at the bottom with respect to the vertical axis of the vehicle (10), namely in the region of a rear bumper (11). [8] Vehicle (10) according to claim 7, wherein the device (100) has a first exhaust air opening (6) in the region of the rear bumper (11) and a first exhaust air guide (5) arranged between the exhaust air scoop (4) and the first exhaust air opening (6), wherein the first exhaust air opening (6) is arranged at a point on the vehicle (10) at which a negative air pressure prevails during normal driving of the vehicle (10), wherein the first exhaust air opening (6) is arranged in the region of the rear bumper (11) with respect to the transverse axis of the vehicle (10) in the direction of travel laterally next to the center of the vehicle (10) behind a rear wheel of the same. [9] Vehicle (10) according to one of claims 7 to 8, wherein the second exhaust opening (8) is configured to discharge gas in a direction parallel to a longitudinal axis of the vehicle (10). [10] Vehicle (10) according to one of claims 7 to 9, wherein the heat exchanger (3) has a fan at its air outlet. [11] Vehicle (10) according to one of claims 7 to 10, wherein a further second exhaust air duct (9) is arranged on the exhaust air scoop (4), wherein the further second exhaust air duct is configured for the diffuse outflow of air. [12] Vehicle (10) according to claim 11, wherein the further second exhaust air guide (9) has a further second exhaust air opening, wherein the further second exhaust air opening is configured to supply air to vehicle parts.

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