DEVICE FOR EXCHANGING THERMAL ENERGY WITH THE AMBIENT AIR

Description

[0001] The invention relates to a device for exchanging heat energy with the ambient air, comprising at least one heat exchanger through which an airflow can flow, to which an axial fan for conveying the airflow through the heat exchanger and an exhaust housing for receiving the airflow conveyed by the axial fan on the outflow side are assigned, wherein the axial fan has a motor and an impeller with blading which can be driven by the motor to rotate about a rotary axis, and wherein the exhaust housing has an air outlet opening for releasing the airflow to the environment.

[0002] Devices with a heat exchanger through which an airflow passes, an axial fan for conveying the airflow through the heat exchanger, and an exhaust housing that receives the airflow conveyed by the axial fan on the outflow side and has an air outlet opening for releasing the airflow to the environment, are used, for example, in heat pumps and air conditioning systems, where the heat exchanger acts as an evaporator of a refrigerant flowing through the heat exchanger in heating mode and as a condenser in cooling mode.

[0003] Such devices are also used in electronics for cooling electronic components, with the heat exchanger being designed as a heat sink through which the airflow can pass and on which the electronic components are arranged. To ensure that the heat sink is supplied with air by the axial fan, the axial fan is typically chosen to be large enough to almost completely cover the surface of the heat sink.

[0004] Axial fans offer the advantage of a large intake area compared to radial fans, thus enabling a uniform flow through the heat exchanger. However, axial fans have the disadvantage that the delivered volume flow decreases even with a moderate increase in back pressure. For this reason, axial fans often feature unobstructed discharge. In many cases, however, it is necessary to deflect the airflow downstream of the axial fan by 90° for discharge into the environment. To minimize pressure losses during this process, the discharge housing often incorporates a box-like duct whose width is at least equal to the diameter of the axial fan. This results in a considerable increase in the overall size of the device, and pressure losses often cannot be avoided despite the substantial size.

[0005] For heat pumps used to heat buildings or swimming pools, installation in the ground is often preferred to installation in the basement or outdoors due to space constraints. In such cases, returning the airflow to the surrounding environment requires an exhaust housing that, despite significant air deflection, must exhibit minimal flow resistance to prevent a noticeable decrease in the pumped volume flow.

[0006] In the electronics sector, it is also advantageous to increase the cooling performance, especially of high-performance processors, by directing the outflow of the axial fan via an outflow housing with small installation space and minimal pressure loss to an air outlet opening, thus preventing internal backflow, a so-called thermal short circuit.

[0007] From KR 2003 0036581 A, a device for exchanging heat energy with the ambient air is known, comprising the features of the preamble of claim 1. This device uses an exhaust housing which has a rear wall oriented perpendicular to the axis of rotation of the axial fan and a side wall that extends around the circumference in the direction of rotation of the axial fan and expands in a spiral direction. An arc-shaped flow guide element can be arranged inside the exhaust housing.

[0008] From CN 107 525 154 A, a device for exchanging heat energy with the ambient air is known, in which two axially arranged axial fans are used whose direction of rotation is opposite to each other, so that no swirling motion is imposed on the outgoing airflow.

[0009] From KR 101 870 414 B1 a device for exchanging heat energy with the ambient air is known, in which the outflow housing is designed in the form of a conventional pipe bend.

[0010] The object of the present invention is to further develop a device of the type mentioned above in such a way that the outflow of the axial fan can be deflected transversely to the outlet direction of the axial fan with the lowest possible flow losses.

[0011] This problem is solved by a device having the features of claim 1.

[0012] The device according to the invention comprises an exhaust housing that receives the airflow conveyed by the axial fan on the outflow side and directs it to an air outlet opening through which the airflow can be released into the environment. The exhaust housing forms an air intake chamber axially offset from the impeller and motor of the axial fan. This chamber receives the airflow conveyed by the axial fan across the entire cross-section of the impeller and motor and is penetrated by the axis of rotation of the axial fan. In a rear view along the axis of rotation, the exhaust housing covers the impeller and motor like a hood. The airflow conveyed by the axial fan can thus be received by the exhaust housing over a large area and consequently with minimal loss across the entire cross-section of the impeller and motor.

[0013] Under the influence of the axial fan, the conveyed airflow is imparted with a swirling motion around the fan's axis of rotation. According to the invention, the airflow is supplied to the air outlet with a directional component tangential to the swirling motion. Thus, the swirling motion of the airflow is utilized to deflect it by 90°. Due to the imposed swirl, the airflow, which is supplied to the exhaust housing over a large area across the entire cross-section of the impeller and the motor, undergoes a loop-like movement within the hood-like exhaust housing and is supplied to the air outlet essentially in a tangential direction. This results in a parallel flow in the area of ​​the air outlet, which practically fills the entire cross-section of the air outlet uniformly, with the airflow exhibiting virtually no residual swirl.The redirection of the airflow is thus achieved with very low flow losses.

[0014] Compared to a conventional 90° pipe bend with an outlet diameter corresponding to the diameter of the axial fan impeller, the size of the exhaust housing can be significantly smaller. In particular, the axial dimensions of the exhaust housing relative to the axis of rotation can be considerably reduced, resulting in a very compact design for the device according to the invention. Furthermore, a much more uniform airflow velocity distribution can be generated in the area of ​​the air outlet, which further reduces pressure losses.

[0015] The axial extent of the exhaust housing can be adjusted to optimize airflow based on the existing ratio of swirl to axial velocity of the airflow, which depends on the impeller blades used and the selected operating point of the axial fan. The size of the air outlet influencing the exit velocity of the airflow. Increasing the size creates a diffuser effect, thus slowing down the airflow. Reducing the size creates a nozzle effect, thereby accelerating the airflow. The exit velocity can, for example, be selected to be just high enough to reliably prevent backflow to the heat exchanger inlet and thus a thermal short circuit. This enables very high energy efficiency for the device according to the invention.

[0016] The exhaust housing has a rear wall opposite the axial fan, which has at least one rear wall section inclined towards the axis of rotation of the axial fan, thereby increasing the distance between the rear wall and the axial fan. It is advantageous if the at least one rear wall section inclined towards the axis of rotation is located on the side of a central plane coaxial with the axis of rotation, on which the flowing air rotates in a loop-like motion. In the direction of rotation, the mass flow rate increases due to the continuous supply of air from the axial fan. To counteract the associated increase in flow velocity, the cross-sectional area of ​​the airflow can be increased by means of the at least one rear wall section that increases the distance between the rear wall and the axial fan, thus counteracting the increase in flow velocity.This can reduce flow losses.

[0017] According to the invention, the rear wall expands in a spiral direction in the circumferential direction. The spiral expansion enables a particularly low-loss supply of the airflow to the air outlet opening by deflecting the airflow by 90°, thereby counteracting an increase in the velocity of the airflow despite the linearly increasing volume flow from the impeller in the circumferential direction.

[0018] Preferably, the air outlet is arranged downstream of the axial fan in a region of the exhaust housing laterally offset from the axial fan's central plane, wherein the central plane is coaxial with the axial fan's axis of rotation, and wherein the impeller blades rotate in this laterally offset region relative to the air outlet in a rear view of the exhaust housing. In a rear view of the exhaust housing along the axis of rotation, the axial fan's central plane divides the impeller into two halves. The air outlet is arranged downstream of the axial fan on the side of the central plane on which the impeller blades rotate relative to the air outlet when rotating about the axis of rotation in the rear view of the exhaust housing.As a result, the air flowing on this side of the central plane moves essentially tangentially to the air outlet, while the air flowing on the opposite side of the central plane moves in a loop-like motion within the hood-like exhaust housing towards the air outlet. This creates a parallel flow in the air outlet, which practically fills the entire cross-section of the air outlet uniformly and exhibits virtually no residual swirl.

[0019] In a preferred embodiment of the invention, the extent of the air outlet opening transverse to the axis of rotation is a maximum of 1.9 times the outer radius of the impeller. This helps to direct the airflow essentially tangentially to the air outlet opening.

[0020] It is advantageous if the dimension of the air outlet opening transverse to the axis of rotation is at least 0.5 times the outer radius of the impeller. With such an embodiment of the invention, the airflow is accelerated in the area of ​​the air outlet opening and released into the environment at a higher velocity. This reliably prevents backflow towards the inlet of the heat exchanger and thus a thermal short circuit.

[0021] It is advantageous if the exhaust housing has an air outlet nozzle that defines the air outlet opening. The air outlet opening can be oriented tangentially to the swirling motion of the airflow in order to generate a particularly uniform parallel flow and minimize flow losses.

[0022] The air outlet nozzle can be designed to widen or narrow in the direction of airflow. Widening creates a diffuser effect, thus slowing the flow, while narrowing creates a nozzle effect, accelerating the flow. Therefore, choosing a widening or narrowing air outlet nozzle allows you to control the speed at which the airflow is released into the environment.

[0023] It is advantageous if the exhaust housing has a circumferential side wall. This allows for a further reduction in flow losses and prevents dirt deposits inside the exhaust housing.

[0024] It is particularly advantageous if the side wall of the exhaust housing widens with increasing distance from the axial fan. The side wall thus forms a kind of cone that opens in the direction away from the axial fan.

[0025] It is advantageous if the side wall transitions smoothly into the rear wall of the exhaust housing via a rounded edge. The radius of this rounded edge can vary, becoming narrower or wider. This rounded edge facilitates the efficient redirection of the airflow towards the air outlet.

[0026] In an advantageous embodiment of the invention, the axial fan has a housing that defines an inlet channel and an outlet channel, wherein the inlet channel is arranged upstream of the impeller and the outlet channel surrounds the impeller circumferentially. The airflow can be supplied to the impeller via the inlet channel. The inlet channel can connect directly to the heat exchanger. The outlet channel surrounds the impeller and, in combination with the impeller's blades, defines the airflow on the downstream side of the axial fan.

[0027] It is advantageous if the inlet duct extends to a bulkhead with an opening to which the outlet duct connects. The bulkhead allows the inlet side of the axial fan to be separated from its outlet side, thus preventing internal backflow and therefore a thermal short circuit.

[0028] In an advantageous embodiment of the invention, the outlet channel forms a constriction following the opening in the bulkhead, to which an annular wall is attached. This constriction reduces the cross-sectional area of ​​the airflow and thus increases its velocity; in other words, the constriction forms an inlet nozzle. The annular wall, in combination with the impeller's blades, defines the axial movement of the airflow. The annular wall is preferably cylindrical or conical.

[0029] It can be designed so that the exhaust housing connects to the bulkhead of the fan housing and surrounds the exhaust duct of the fan housing circumferentially. In such a design, the fan housing is integrated into the exhaust housing.

[0030] It is advantageous if the heat exchanger has a flat design and the axial fan's axis of rotation is angled relative to the heat exchanger. This angled orientation of the axis of rotation facilitates the efficient redirection of the airflow towards the air outlet.

[0031] In a preferred embodiment of the invention, the axis of rotation of the axial fan is aligned at an angle of a maximum of 30°, in particular 5° to 10°, to the surface normal of the heat exchanger.

[0032] In an advantageous embodiment of the invention, the exhaust housing has a flow guide element directed radially inwards with respect to the axis of rotation of the axial fan, which is arranged in the transition area between an air outlet nozzle and a side wall of the exhaust housing. The flow guide element allows, in a structurally simple manner, the discharged volume flow to be separated from the looped volume flow. This improves the parallel flow in the area of ​​the air outlet opening.

[0033] The flow guide element can, for example, be designed in a tongue-like shape.

[0034] It can be provided that the device according to the invention has a single heat exchanger to which an axial fan and an exhaust housing are associated, wherein an airflow through the heat exchanger can be generated by means of the axial fan, which can be discharged to the environment via the air outlet opening of the exhaust housing.

[0035] Alternatively, the device according to the invention can be provided with several heat exchangers, in particular two heat exchangers, each of which is associated with an axial fan and an exhaust housing, wherein the airflows conveyed by the axial fans can be fed via the air outlet openings of the exhaust housings to a common air outlet duct, through which the airflows can be discharged to the environment, the air outlet openings being oriented obliquely to each other. For example, the device can be provided with two heat exchangers arranged one above the other or side by side, each of which can be supplied with an airflow generated by an axial fan associated with the respective heat exchanger, wherein the airflow can be fed to an exhaust housing, from which the airflow can be supplied to the common air duct via the respective air outlet opening.

[0036] The air outlet openings of the exhaust housings can each be defined by an air outlet nozzle, with the air outlet nozzles of the two exhaust housings being aligned at an angle to each other.

[0037] It is particularly advantageous if the two exhaust housings are identical in design but oriented differently relative to the common air outlet duct. During installation, the two exhaust housings can be rotated into a specific position relative to the respective fan axis of rotation, so that their air outlet nozzles open into the common air outlet duct.

[0038] It is advantageous if the exhaust housing is rotatably mounted on a base plate of the axial fan around its axis of rotation.

[0039] The following description of preferred embodiments, in conjunction with the drawing, serves for further explanation. The drawing shows: Figure 1: an exploded view of a first embodiment of a device for exchanging heat energy with the ambient air; Figure 2: a perspective view of an exhaust housing of the device made of Figure 1 with exemplary streamlines of an airflow; Figure 3: a side view of a second embodiment of a device for exchanging heat energy with the ambient air; Figure 4: a perspective view of the device made of Figure 3 Figure 5: a perspective view of a third embodiment of a device for exchanging heat energy with the ambient air; Figure 6: a side view of the device made of Figure 5 Figure 7: a rear view of the device made of Figure 5 Figure 8: a perspective view of an exhaust housing of the device made of Figure 5with a view of a flow inlet obliquely from below; Figure 9: a side view of a fourth embodiment of a device for exchanging heat energy with the ambient air; Figure 10: a perspective view of a fifth embodiment of a device for exchanging heat energy with the ambient air; Figure 11: a rear view of the device made of Figure 10 Figure 12: a rear view of a sixth embodiment of a device for exchanging heat energy with the ambient air; Figure 13: a perspective view of a seventh embodiment of a device for exchanging heat energy with the ambient air.

[0040] In Figure 1An exploded view schematically depicts a first embodiment of a device for exchanging thermal energy with ambient air, designated by reference numeral 10. The device 10 comprises a conventional planar heat exchanger 12 with a fluid line 14 through which a fluid can flow to heat or cool the fluid, thereby exchanging thermal energy with the ambient air. For this purpose, the heat exchanger 12 can be supplied with an airflow generated by an axial fan 16. The axial fan 16 is connected to the heat exchanger 12 in the direction of airflow and has a fan housing 18 that forms a rectangular inlet channel 20 and a circular outlet channel 22. The axial fan 16 also has an impeller 24 that can be rotated about an axis of rotation 28 by a motor 26.The impeller 24 has a blading 30 formed from several blades for conveying the airflow. The impeller 24 is rotatably mounted in the outlet channel 22, and the inlet channel 20 is arranged upstream of the impeller 24.

[0041] Starting from the heat exchanger 12, the inlet channel 20 extends to a bulkhead 32, which has an opening 33. A constriction 34 of the outlet channel 32 is connected to this opening. The constriction 34 forms an inlet nozzle. An annular wall 36 of the outlet channel 32, which surrounds the impeller 24 circumferentially, connects to the constriction 34. Looking towards the motor 26, the impeller 24 rotates counterclockwise. The direction of rotation of the impeller 24 is in Figure 1 Illustrated by arrow 38.

[0042] The device 10 also has an exhaust housing 40 which connects to the axial fan 16 in the direction of flow of the conveyed airflow and receives the airflow conveyed by the axial fan 16 on the outflow side.

[0043] The exhaust housing 40 is designed like a hood, forming an air intake chamber 41 axially offset from the impeller 24 and the motor 26, through which the axis of rotation 28 passes. In a rear view along the axis of rotation 28, the exhaust housing 40 covers the impeller 24 and the motor 26, whose motor axis (not shown in the drawing) is aligned coaxially with the axis of rotation 28. The exhaust housing receives the airflow delivered by the axial fan 16 over a large area across the entire cross-section of the impeller 24 and the motor 26.

[0044] The exhaust housing 40 is in Figure 2The exhaust housing 40 is shown enlarged together with the impeller 24 and the motor 26. The exhaust housing 40 has a cuboid housing body 42 which abuts the bulkhead 32 and surrounds the exhaust channel 22 as well as the impeller 24 and the motor 26.

[0045] An air outlet nozzle 44 is attached to the top of the housing body 42, defining an air outlet opening 46 of the exhaust housing 40. The airflow conveyed by the axial fan 16 can be discharged to the environment via the air outlet opening 46.

[0046] The air outlet nozzle 44 and the air outlet opening 46 are arranged in a region laterally offset from a central plane 48 of the exhaust housing 40 (shown with dashed lines), the central plane being coaxial with the axis of rotation 28 and vertically oriented in the illustrated operating position of the device 10, and the blade 30 of the impeller 24 rotating in this laterally offset region in a rear view of the exhaust housing 40 towards the air outlet opening 46. The viewing direction in the rear view is Figure 1 Illustrated by arrow 50.

[0047] Under the action of the axial fan 16, the conveyed airflow is subjected to a swirling motion around the axis of rotation 28. The laterally offset arrangement of the air outlet nozzle 44 and the air outlet opening 46 relative to the central plane 48, and the rotating blades 30 of the impeller 24 in this laterally offset area (as seen from the rear of the exhaust housing 40), resulting in the airflow conveyed by the axial fan 16 being directed towards the air outlet opening 46 in this laterally offset area essentially tangentially with respect to the swirling motion. On the side of the central plane 48 facing away from the air outlet nozzle 44 and the air outlet opening 46, the airflow performs a loop-like motion before flowing towards the air outlet opening 46 in an essentially tangential direction.This results in a parallel flow in the air outlet nozzle 44, which uniformly fills the entire cross-section of the air outlet nozzle 44 and exhibits hardly any residual swirl. Figures illustrate the airflow in the area of ​​the exhaust housing 40. Figure 2 Some streamlines a, b, c, d and e are shown as examples with dashed lines.

[0048] The device 10 thus enables an airflow to be guided axially through the heat exchanger 12 with respect to the axis of rotation 28 and to be deflected by 90° in the exhaust housing 40 by utilizing the swirl motion generated by the axial fan 16. This deflection is associated with very low flow losses, and the airflow essentially forms a parallel flow in the region of the air outlet opening 46. The low-loss deflection of the airflow within the exhaust housing 40 is achieved even though the axial dimension of the exhaust housing 40, i.e., its depth, is smaller than its transverse dimension to the axis of rotation 28. The device 10 thus enables a low-loss deflection of the airflow by 90° while maintaining a compact design.The installation depth of the outflow housing 40 can be adjusted to the existing ratio of swirl to axial velocity of the airflow for particularly low-loss deflection of the airflow, which depends on the blading 30 of the impeller 24 used and the selected operating point of the axial fan 16.

[0049] In the Figures 3 and 4 A second advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air is shown schematically, the device as a whole being designated by reference numeral 60. For identical components, the following are designated in the Figures 3 and 4 as well as in the following sections explained in more detail Figures 5 to 13 the same reference symbols are used as in the Figure 1 and 2 To avoid repetition, reference is made to the preceding explanations regarding these components.

[0050] The in the Figures 3 and4 The device 60 shown differs from the one shown in the Figure 1 and 2 The device 10 shown is enclosed by a hood-like exhaust housing 62, which has a cylindrical side wall 64 circumferentially surrounding the exhaust channel 22, the impeller 24, and the motor 26 of the axial fan 16. This side wall extends axially from the bulkhead 32 of the axial fan 16 to a rear wall 66 opposite the axial fan 16. The rear wall 66 has a first flat rear wall section 68 inclined towards the axis of rotation 28 and a second flat rear wall section 70 also inclined towards the axis of rotation 28. The distance between the rear wall 66 and the axial fan 16 increases in each of these sections. The two rear wall sections 68 and 70 connect to an air outlet nozzle 72 of the exhaust housing 62.

[0051] The air outlet nozzle 72 defines an air outlet opening 74 and is designed in the same manner as the preceding one with reference to the Figure 1 and 2 The air outlet nozzle 44 is arranged laterally offset from a central plane 75 which is aligned coaxially with the axis of rotation 28. The central plane 75 is in Figure 4 The first rear wall section 68 and the second rear wall section 70 are positioned on the side of the central plane 75 opposite the air outlet nozzle 72. The air outlet nozzle 72 extends with a nozzle rear wall 76 to the lower end of the exhaust housing 62, the nozzle rear wall 76 being inclined backwards on the side facing away from the axial fan 16, so that the flow cross-section of the air outlet nozzle 72 widens continuously in the direction of flow.

[0052] The inclined rear wall sections 68, 70 expand the internal volume of the exhaust housing 62 on the side of the central plane 75, where the flowing air performs a loop-like motion. In this area, the volume flow rate increases continuously in the circumferential direction due to the air continuously conveyed by the impeller 24. To achieve a substantially constant flow velocity despite the increase in volume flow rate, the inclined rear wall sections 68, 70 are used, which cause an expansion of the internal volume of the exhaust housing 62 in this area.On the side of the central plane 75 opposite the rear wall sections 68, 70, the blading 30 of the impeller 24 rotates in a rear view of the exhaust housing 62 towards the air outlet opening 74, so that the airflow to the air outlet opening 74 is supplied essentially in a tangential direction with respect to the swirl motion of the airflow, as already described above with reference to the . Figure 1 and 2 This was explained. The continuously increasing flow cross-section of the air outlet nozzle 72 in the direction of flow acts as a diffuser, which slows down the flow.

[0053] The device 60 thus enables a low-loss deflection of the airflow by 90° in a very compact design.

[0054] In the Figures 5 to 8A third advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air is shown schematically, the device as a whole being designated by reference numeral 90. The device 90 has a hood-like exhaust housing 92, which, unlike the exhaust housings 62 and 40 described above, does not connect directly to the bulkhead 32 of the axial fan 16, but rather the exhaust housing 92 connects to the outlet duct 22 of the axial fan 16, having a side wall 94 abutting the outlet duct 22, which widens continuously with increasing distance from the axial fan 16 and transitions via a rounded section 96 into a rear wall 98 that widens spirally in the circumferential direction.

[0055] In device 90, the axial fan 16 is inclined relative to the heat exchanger 12, that is, the axis of rotation 28 of the axial fan 16 is inclined at an angle α of a maximum of 30°, in particular at an angle α of 5 to 10°, to the surface normal 100 of the heat exchanger 12. The inclination of the axial fan 16 supports the low-loss deflection of the airflow into the air outlet nozzle 102 of the exhaust housing 92, which defines an air outlet opening 104 and is arranged laterally offset from a central plane 106 that is coaxial with the axis of rotation 28. This is particularly evident from Figure 7clearly. The intake of the circumferentially increasing volume flow of the conveyed air from the axial fan 16 is achieved by the expansion of the internal volume of the exhaust housing 92 via the side wall 94, which continuously expands with increasing distance to the axial fan 16, and the rear wall 96, which continuously expands in the circumferential direction, so that despite the circumferentially increasing volume flow of the conveyed air, an essentially constant flow velocity can be achieved.

[0056] In device 90, the blade 30 of the impeller 24 also rotates in a rear view of the outflow housing 92 on the side of a Figure 7The airflow directed towards the air outlet nozzle 102 and the air outlet opening 104 is shown in the central plane 106, depicted with a dashed line, so that the airflow conveyed by the axial fan 16 can be supplied to the air outlet opening 104 essentially tangentially with respect to the swirl motion of the airflow. On the opposite side of the central plane 106, the air moves in a loop-like pattern before also being supplied essentially tangentially to the air outlet nozzle 102 and the air outlet opening 104.

[0057] The air outlet nozzle 102 has a wall flattening 112 between a nozzle rear wall 108 facing away from the axial fan 16 and a nozzle side wall 110 facing the central plane 106, which prevents an area of ​​lower flow velocity from forming in this area of ​​the air outlet nozzle 102.

[0058] In the transition area between the rounded section 96 and the air outlet nozzle 102, the exhaust housing 92 has a tongue-shaped, inwardly directed flow guide element 114, which ensures a precise separation of the discharged and circulating volume flow. The discharged volume flow can reach the air outlet opening 104 via the air outlet nozzle 102, while the circulating volume flow performs a loop-shaped movement around the axis of rotation 28. The separation of the discharged and circulating volume flow improves the parallel flow in the air outlet nozzle 102.

[0059] In Figure 9 A fourth advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air is shown schematically, wherein the device as a whole is designated by reference numeral 120.

[0060] The device 120 has a hood-like exhaust housing 122, which extends with a front housing section 124 to the heat exchanger 12. The front housing section 124 surrounds the fan housing 18, but only a small amount of vibration is transmitted from the axial fan 16 to the exhaust housing 122; instead, vibrations of the axial fan 16 are primarily absorbed by the heat exchanger 12.

[0061] With the exception of the front housing section 124, the outflow housing 122 is designed in the same way as the outflow housing 92 described above, so that reference can be made to the preceding explanations in this regard.

[0062] In the Figures 10 and 11A fifth advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air is shown schematically, wherein the device as a whole is designated by reference numeral 140. The device 140 has a hood-like exhaust housing 142, which is designed largely identically to the one described above with reference to the Figures 5 to 8 The exhaust housing 92 was explained. In contrast to the exhaust housing 92, the exhaust housing 142 has an air outlet nozzle 144 with a nozzle side wall 146 which is inclined to a central plane 148 which is aligned coaxially to the axis of rotation 28, so that the flow cross-section of the air outlet nozzle 144 decreases in the direction of flow and the flow velocity of the airflow in the air outlet nozzle 144 is thereby increased.

[0063] The air outlet nozzle 144 defines an air outlet opening 150, which, like the air outlet nozzle 144, is arranged laterally offset to the central plane 148, as has already been explained above.

[0064] The extent of the air outlet opening 150 transverse to the axis of rotation 28 is less than the outer radius of the impeller 24, so that a nozzle effect is created and the airflow conveyed by the axial fan 16 is flung out of the air outlet opening 150 at a considerable flow velocity.

[0065] In Figure 12 Figure 1 shows a sixth advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air. The device is designated by reference numeral 160.

[0066] The device 160 comprises a first heat exchanger 162 and a second heat exchanger 164, which are arranged one above the other and to which an axial fan 166 or 168 and a hood-like exhaust housing 170 or 172 are assigned. The two heat exchangers 162, 164 are identical in design, as are the two axial fans 166, 168 and the two exhaust housings 170, 172. The two exhaust housings 170, 172 each have an air outlet nozzle 174 or 176, respectively, which open into a common air outlet duct 178, through which the airflows conveyed by the two axial fans 166, 168 are discharged to the environment. The identically designed axial fans 166, 168 each have a Figure 12 The central plane 180 or 182, shown with a dash, is to which the air outlet nozzles 174 and 176 are offset, as already explained in detail above. With reference to the in Figure 12 In the rear view of the device 160 shown, the axial fans 166, 168 differ only in their rotational position relative to the respective fan axis of rotation, so that the airflows can be fed to the common air outlet channel with low flow losses.

[0067] In Figure 13 A seventh advantageous embodiment of a device according to the invention for exchanging heat energy with the ambient air is shown schematically, wherein the device is designated with reference numeral 200.

[0068] The device 200 differs from the embodiments described above essentially in that it has a heat exchanger 202 in the form of a heat sink 204. The heat sink 204 has fins 206 and serves to cool electronic components. The heat sink 18 can be permeated by an airflow, which is conveyed by an axial fan 208 of the device 200 and fed to a hood-like exhaust housing 210 of the device 200. In the exhaust housing 210, the airflow is deflected by 90°, as already explained in detail above, and can be discharged to the environment or to an air duct 216 connected to the air outlet 212 via an air outlet nozzle 212 and an air outlet opening 214. The air duct 216 is in Figure 13 Shown as dashed lines.

[0069] The axial fan 208 is connected on the outflow side to a base plate 218, which enables the outflow housing 210 to be rotatable about the axis of rotation of the axial fan 208, so that the outflow housing 210 can assume a predetermined rotational position in which the air outlet nozzle 212 assumes a desired orientation.

[0070] In the exhaust housing 210, the air outlet nozzle 212 and the air outlet opening 214 are also offset from a central plane that is coaxial with the fan's axis of rotation, as explained in detail above. The device 200 also enables an energy-efficient exchange of heat energy with the ambient air, whereby the airflow conveyed by the axial fan 208 can be deflected by 90° with minimal flow losses.

Claims

1. A device for exchanging thermal energy with the environmental air, comprising at least one heat exchanger (12; 162, 164), through which an air flow can flow, to which an axial fan (16; 166, 168; 208) for conveying the air flow through the heat exchanger (12; 162, 164) and an outflow housing (40; 62; 92; 122; 142; 170, 172; 210) accepting the air flow conveyed by the axial fan (16; 166, 168; 208) on the outflow side are assigned, wherein the axial fan (16; 166, 168; 208) has a motor (26) and an impeller (24) with a blading (30) which is rotatably drivable by the motor (26) about an axis of rotation (28), and wherein the outflow housing (40; 62; 92; 122; 142; 170, 172; 210) has an air outlet opening (46; 74; 104; 150; 174, 176; 214) for outputting the air flow to the environment, wherein the outflow housing (40; 62; 92; 122; 142; 170, 172; 210), axially offset from the impeller (24) and from the motor (26) of the axial fan (16; 166, 168; 208), forms an air acceptance space (41) which accepts the conveyed air flow over the complete cross-section of the impeller (24) and the motor (26) and is penetrated by the axis of rotation (28), wherein the outflow housing (40; 62; 92; 122; 142; 170, 172; 210), in a rear view, covers the impeller (24) and the motor (26) in a hood-like manner and is adapted and designed to supply the conveyed air flow to the air outlet opening (46; 74; 104; 150; 174, 176; 214) with a tangential direction component with regard to a swirl motion imposed to the air flow by the axial fan (16; 166, 168; 208), wherein the outflow housing (40; 62; 92; 122; 142; 170, 172; 210) has a rear wall (66, 98) opposite to the axial fan (16; 166, 168; 208), which has at least one rear wall section (68, 70) inclined towards the axis of rotation (28), over which the distance of the rear wall (66, 98) to the axial fan (16) increases, wherein the flow cross-section of the air flow increases over the at least one rear wall section (68, 70), characterised in that the rear wall (98) spirally extends in the circumferential direction.

2. The device according to claim 1, characterised in that the air outlet opening (46; 74; 104; 150; 174, 176; 214) downstream of the axial fan (16; 166, 168; 208) is arranged in a region of the outflow housing (40; 62; 92; 122; 142; 170, 172; 210) which is laterally offset from a central plane (48; 106; 148, 180, 182) of the axial fan (16; 166, 168; 208), wherein the central plane (48; 106; 148, 180, 182) is oriented coaxially towards the axis of rotation (28) and wherein the blading (30) of the impeller (24) rotates towards the air outlet opening (46; 74; 104; 150; 174, 176; 214) in this laterally offset region in a rear view of the outflow housing (40; 62; 92; 122; 142; 170, 172; 210).

3. The device according to claim 1 or 2, characterised in that the expansion of the air outlet opening (46; 74; 104; 150; 174, 176; 214) transversely to the axis of rotation (28) is at least 0.5 times and at most 1.9 times the outer radius of the impeller (24).

4. The device according to any one of the preceding claims, characterised in that the outflow housing (40; 62; 92; 122; 142; 170, 172; 210) has an air outlet stub (44; 72; 102; 174, 176; 212) which defines the air outlet opening (46; 74; 104; 150; 174, 176; 214), wherein the air outlet stub (44; 72; 102; 174, 176; 212) extends or tapers in the flow direction.

5. The device according to any one of the preceding claims, characterised in that the outflow housing (62; 92) has a side wall (64; 94) running in the circumferential direction.

6. The device according to claim 5, characterised in that the side wall (94) extends as the distance to the axial fan (16) increases.

7. The device according to claim 5 or 6, characterised in that the side wall (94) continuously transitions into the rear wall (98) of the outflow housing (92) via a rounding (96).

8. The device according to any one of the preceding claims, characterised in that the axial fan (16) has a fan housing (18) which defines an inflow channel (20) and an outflow channel (22), wherein the inflow channel (20) is arranged upstream of the impeller (24) and the outflow channel (22) surrounds the impeller (24) in the circumferential direction.

9. The device according to claim 8, characterised in that the inflow channel (20) runs up to a bulkhead (32) which has a breakthrough (33) adjoined by the outflow channel (22).

10. The device according to claim 9, characterised in that the outflow channel (22) forms a constriction (34) adjoining the breakthrough (33) of the bulkhead (32) which is adjoined by an annular wall (36).

11. The device according to claim 9 or 10, characterised in that the outflow housing (40) adjoins the bulkhead (32) and surrounds the outflow channel (22) in the circumferential direction.

12. The device according to any one of the preceding claims, characterised in that the heat exchanger (12) is designed to be planar and the axis of rotation (28) is oriented obliquely to the heat exchanger (12), wherein the axis of rotation (28) is oriented at an angle of at most 30° to the surface normal (100) of the heat exchanger (12).

13. The device according to any one of the preceding claims, characterised in that the outflow housing (92) has a flow guiding element (114) directed inwards with regard to the axis of rotation (28), which is arranged in the transition region between an air outlet stub (102) and a rounding (96) of the outflow housing (92).

14. The device according to any one of the preceding claims, characterised in that the outflow housing (210) is rotatably mounted about the axis of rotation (28) on a base plate (218) of the axial fan (208).

15. The device according to any one of the preceding claims, characterised in that the device (160) has several heat exchangers (162, 164), each of which is assigned an axial fan (166, 168) and an outflow housing (170, 172), wherein the air flows conveyed by the axial fans (166, 168) can be supplied to a common air outlet channel (168) via the air outlet openings (174, 176) of the outflow housings (170, 172) and the air outlet openings (174, 176) are oriented obliquely to one another.