Device for exchanging thermal energy with ambient air and heat pump with a device of this type

Abstract

The invention relates to a device for exchanging thermal energy with ambient air, comprising a heat exchanger (14; 206; 254) through which an air flow can flow, at least one fan (20; 268) arranged downstream of the heat exchanger for conveying the air flow through the heat exchanger, and an air supply unit (24) with at least one air inlet opening (38) for supplying the air flow from the environment to the heat exchanger and an air discharge unit (26) with at least one air outlet opening (62) for discharging the air flow out of the at least one fan into the environment, wherein the at least one air inlet opening (38) and the at least one air outlet opening (62) are arranged on the same side of the device According to the invention, in order to deliver improved efficiency, the air supply unit (24) has at least one supply channel (32; 126, 128; 208; 260) feeding into the heat exchanger, which extends along an inlet surface of the heat exchanger and continuously tapers along the inlet surface, and the outflow cross-section of the at least one air outlet opening (62), defining the outflow speed of the air flow, is smaller than the inflow cross-section of the at least one air inlet opening (38) defining the inflow speed of the air flow. The invention also relates to a heat pump comprising a device of this type.

Description

[0001] Device for exchanging heat energy with ambient air and heat pump with such a device

[0002] The invention relates to a device for exchanging thermal energy with the ambient air, comprising a heat exchanger through which an air flow can flow, at least one fan arranged downstream of the heat exchanger, which fan has an impeller rotatable about an axis of rotation with blades for conveying the air flow through the heat exchanger, and an air supply device with at least one air inlet opening for supplying the air flow from the environment to the heat exchanger and an air discharge device with at least one air outlet opening for discharging the air flow from the at least one fan to the environment, wherein the at least one air inlet opening and the at least one air outlet opening are arranged on the same side of the device.

[0003] Furthermore, the invention relates to a heat pump with such a device.

[0004] Devices of the type mentioned above are used, for example, in air conditioning systems and heat pumps, where the heat exchanger can function as an evaporator to absorb heat energy from the ambient air or as a condenser to release heat energy to the ambient air. Heat pumps are often positioned outside buildings or in basements. However, installation outside buildings requires a corresponding amount of space, and installation in basements requires long supply and exhaust air ducts, which are associated with corresponding airflow losses, which impair the energy efficiency of the heat pumps. To counteract these disadvantages, heat pumps are often buried in the ground outside buildings or installed on an external wall inside buildings.However, this requires a compact design of the heat pumps and necessitates the positioning of the at least one air inlet opening and the at least one air outlet opening on the same side of the heat pump, whereby there is a risk of backflow of the air flowing out of the at least one air outlet opening to the at least one air inlet opening, so that a thermal short circuit is formed and consequently the energy efficiency is also impaired.

[0005] The object of the present invention is therefore to further develop a device and a heat pump of the type mentioned at the outset in such a way that they have improved energy efficiency.

[0006] This object is achieved according to the invention in a device of the generic type in that the air supply device has at least one supply air duct opening into the heat exchanger, which extends along an inlet surface of the heat exchanger and tapers continuously along the inlet surface, and in that the flow outlet cross section of the at least one air outlet opening defining the outlet speed of the air flow is smaller than the flow inlet cross section of the at least one air inlet opening defining the inlet speed of the air flow.

[0007] In the device according to the invention, the air flow is supplied to the heat exchanger via at least one supply air duct that opens into the heat exchanger, extending along an inlet surface of the heat exchanger that can be exposed to the air flow and continuously tapering along the inlet surface. As the air flow gradually enters the heat exchanger, the volume flow of the air flow within the supply air duct decreases in the flow direction along the inlet surface. To compensate for the constantly decreasing volume flow, the at least one supply air duct continuously tapers in the flow direction along the inlet surface. This results in the air flow being guided across the entire inlet surface at a virtually constant flow velocity, avoiding dead spots, so that flow losses that impair energy efficiency can be kept to a minimum.

[0008] The air flow is discharged to the environment via at least one air outlet opening, which is arranged on the same side of the device as the at least one air inlet opening. To prevent backflow of the air flow from the at least one air outlet opening to the at least one air inlet opening, the flow outlet cross-section of the at least one air outlet opening, which defines the outlet velocity of the air flow, is smaller than the flow inlet cross-section of the at least one air inlet opening, which defines the inlet velocity of the air flow. The smaller flow outlet cross-section results in an outlet velocity of the air flow that is greater than the inlet velocity of the air flow. This counteracts backflow of the air flow and thus a thermal short circuit that impairs energy efficiency.The device according to the invention is therefore characterized by high energy efficiency, whereby flow losses can be kept low and there is practically no mixing of the outgoing air flow with the incoming air flow.

[0009] It is advantageous if the flow outlet cross-section of the at least one air outlet opening, which defines the exit velocity of the air flow, is a maximum of 0.8 times, in particular a maximum of 0.7 times, the flow inlet cross-section of the at least one air inlet opening, which defines the inlet velocity of the air flow. The smaller the flow outlet cross-section defining the exit velocity, the greater the exit velocity of the air flow. The air flow is thus virtually ejected from the device, so that practically no mixing with the incoming air flow occurs. In an advantageous embodiment of the invention, the heat exchanger is plate-shaped. In this case, it can be provided that the inlet surface of the heat exchanger is rectangular, for example.

[0010] Alternatively, the heat exchanger can be L-shaped and have a first leg and a second leg. The two legs are aligned at an angle to each other, for example, at an angle of approximately 90°. The inlet surface of the heat exchanger extends over both legs, whereby the L-shaped design gives the heat exchanger a very compact design.

[0011] The device can be provided with an air supply duct extending across both legs of the heat exchanger. The air flow can thus be supplied to the inlet surfaces of both legs via the air supply duct, with the air supply duct continuously tapering along the inlet surfaces of both legs, thereby supplying the air flow across the inlet surfaces at a virtually constant velocity.

[0012] Alternatively, the device can be provided with two supply air ducts, each extending along one of the two legs. The supply air ducts, each extending along one of the inlet surfaces of the legs, taper continuously along the inlet surfaces and thus feed the air flow to the heat exchanger at a virtually constant velocity across the inlet surface.

[0013] With an L-shaped heat exchanger design, it is advantageous if the device has a fan whose axis of rotation is inclined relative to the surface normal of one of the two legs of the heat exchanger in the direction of the other leg. This supports uniform and low-loss flow through the heat exchanger via both legs. In particular, it can be provided that the axis of rotation is oriented towards the transition area between the two legs. In a preferred embodiment of the invention, the two legs of the heat exchanger are of different lengths and the axis of rotation is inclined relative to the surface normal of the longer leg in the direction of the shorter leg. Such an inclination of the axis of rotation achieves particularly low-loss flow through the heat exchanger.

[0014] It is advantageous if the rotation axis of at least one fan is inclined relative to a surface normal of the heat exchanger toward an end area of ​​a supply air duct. Such an inclination of the rotation axis supports uniform and low-loss airflow through the heat exchanger.

[0015] In an advantageous embodiment of the invention, the at least one supply air duct tapers in a wedge shape along the inlet surface of the heat exchanger. For example, it can be provided that the at least one supply air duct has wall sections inclined at an angle to the vertical when the device is in a horizontal position of use.

[0016] In a preferred embodiment of the invention, at least one fan is designed as an axial fan, with an associated exhaust housing that receives the airflow conveyed by the axial fan on the downstream side and has a housing outlet opening through which the airflow can flow in a tangential direction relative to a swirl movement imposed on the airflow by the rotating blades of the impeller of the axial fan. Axial fans enable a particularly uniform flow through the heat exchanger. However, axial fans have the disadvantage that the conveyed volume flow decreases even with a moderate increase in backpressure. For this reason, axial fans often have a free outflow without obstructions.In order to be able to position the at least one air outlet opening on the same side of the device as the at least one air inlet opening, it is advantageous to deflect the air flow upstream and downstream of the axial fan by 90° each. In order to minimize the pressure losses caused by the deflection, in a preferred embodiment of the device according to the invention, when using an axial fan, the swirl of the air flow caused by the rotating blades of the impeller of the axial fan is utilized for low-loss deflection. For this purpose, the air flow conveyed by the axial fan is received on the downstream side by an outflow housing, the housing outlet opening of which is positioned such that the air flow can flow through it in a tangential direction with respect to the swirl movement.Due to the swirl imparted by the axial fan, the airflow within the exhaust housing moves around the fan's rotation axis and is directed tangentially to the housing outlet. This creates a parallel flow in the area of ​​the housing outlet opening, uniformly filling the entire cross-section of the housing outlet opening, with the airflow exhibiting virtually no residual swirl. The airflow is thus deflected downstream of the axial fan with minimal flow losses.

[0017] It is advantageous if the exhaust housing forms an air intake chamber axially offset from the impeller and a motor of the axial fan that rotates the impeller around the axis of rotation. This chamber absorbs the conveyed airflow across the entire cross-section of the impeller and motor and is penetrated by the axis of rotation. When viewed from behind, the exhaust housing covers the impeller and motor like a hood. The airflow conveyed by the axial fan can thus be absorbed by the exhaust housing over a large area and thus with minimal loss across the entire cross-section of the impeller and motor.

[0018] Preferably, the housing outlet opening of the outflow housing is arranged downstream of the axial fan in a region of the outflow housing that is laterally offset from a center plane of the axial fan, wherein the center plane is aligned coaxially with the axis of rotation of the axial fan, and wherein the blading of the impeller rotates in this laterally offset region towards the housing outlet opening in a rear view of the outflow housing. In a rear view of the outflow housing looking along the axis of rotation, the center plane of the axial fan, aligned coaxially with the axis of rotation, divides the impeller into two halves. The housing outlet opening is arranged downstream of the axial fan on the side of the center plane on which the blading of the impeller rotates towards the housing outlet opening when rotating about the axis of rotation in the rear view of the outflow housing.As a result, the air flowing on this side of the center plane moves essentially tangentially toward the housing outlet, while the air flowing on the opposite side of the center plane moves in a loop-like motion toward the housing outlet. This creates a parallel flow in the housing outlet, which fills virtually the entire cross-section of the housing outlet evenly and exhibits virtually no swirl.

[0019] When using a large-area heat exchanger, it is advantageous if the device has several fans arranged next to each other.

[0020] In particular, it can be provided that the device has two axial fans, each of which is assigned an outflow housing which receives the air flow conveyed by the respective axial fan, wherein the housing outlet openings of the outflow housings open into a common air outlet duct of the air discharge device.

[0021] It is advantageous if the two axial fans and the respective associated exhaust housings are designed identically, whereby the exhaust housings have a different rotational position with respect to the respective fan rotation axis, so that their housing outlet openings are inclined towards each other in order to supply the respective conveyed air flows to the common air outlet duct with low losses.

[0022] It can be provided that at least one fan is designed as a radial fan surrounded by a spiral housing that receives the air flow conveyed by the radial fan on the downstream side and that has a housing outlet opening through which the air flow can flow in a tangential direction relative to the rotational movement of the impeller of the radial fan. Radial fans have the advantage that the conveyed volume flow hardly decreases even with a moderate increase in backpressure. In order to achieve a low-loss deflection of the air flow, in an advantageous embodiment of the invention the air flow conveyed by the radial fan is guided in a tangential direction through the housing outlet opening of the spiral housing surrounding the radial fan in the circumferential direction.

[0023] It can be provided that an air inlet duct is arranged upstream of the at least one supply air duct. The air inlet duct can have several duct sections that are connected to one another in a flow-tight manner to prevent leakage. The air inlet duct can, for example, have an air inlet nozzle and / or a bend.

[0024] In an advantageous embodiment of the invention, an air outlet duct is arranged downstream of the at least one fan. The air outlet duct can have several duct sections that are connected to one another in a flow-tight manner to prevent leakage. The air outlet duct can, for example, comprise a pipe bend and / or an air outlet nozzle.

[0025] It is advantageous if at least one end region of the air outlet duct tapers continuously in the direction of flow in order to increase the flow velocity of the air flow.

[0026] In order to reduce the noise emissions of the device, in a preferred embodiment of the invention the air discharge device comprises a silencer. In this case, it can be provided that the silencer defines the flow outlet cross-section. The silencer is preferably designed as a baffle silencer having a housing, wherein between two opposite side walls of the housing at a distance from the side walls a plurality of spaced-apart baffles are arranged, wherein the outflow cross-sections between the baffles and between the baffles and the side walls as a whole form the flow outlet cross-section defining the exit velocity of the air flow. In such a configuration, the air flow is guided between the baffles to reduce noise emissions.The flow outlet cross-section, which defines the outlet velocity of the air flow, is formed by the totality of the outflow cross-sections arranged between adjacent baffles and between the baffles and the side walls.

[0027] To expand the air flow, in a preferred embodiment of the invention, the air discharge device has a first diffuser with a maximum opening angle of 8°, wherein the outlet cross-section of the diffuser forms the flow outlet cross-section that defines the exit velocity of the air flow. To prevent the air flow from detaching from the wall of the first diffuser, the opening angle of the first diffuser is a maximum of 8°.

[0028] In an advantageous embodiment of the invention, a second diffuser is arranged downstream of the first diffuser, which is designed to form a free jet. In particular, it can be provided that the opening angle of the second diffuser is at least 90°, for example 140°. The second diffuser can be directly connected to the first diffuser. With such a configuration, an edge forms between the two diffusers, at which edge the air flow separates to form a free jet. The outlet cross-section of the first diffuser forms the flow outlet cross-section, which defines the outlet velocity of the air flow, whereas the second diffuser and in particular its outlet cross-section has no noticeable influence on the outlet velocity of the air flow due to the formation of the free jet at the edge between the two diffusers.

[0029] As already mentioned at the beginning, the invention also relates to a heat pump. In order to design the heat pump in such a way that it has improved energy efficiency, the heat pump comprises a device of the type described above.

[0030] The heat pump can, for example, be designed as an underfloor heat pump that is embedded in a floor slab or sunk into the ground.

[0031] It can also be provided that the heat pump can be positioned on an outer wall of a building room, wherein the at least one air inlet opening and the at least one air outlet opening are arranged on the outer wall.

[0032] The following description of advantageous embodiments of the invention serves to explain it in more detail in conjunction with the drawings. They show:

[0033] Figure 1: an exploded view of a first advantageous embodiment of a heat pump according to the invention with a first advantageous embodiment of a device according to the invention for exchanging thermal energy with the ambient air;

[0034] Figure 2: a perspective view of the heat pump from Figure 1;

[0035] Figure 3: a perspective view of a second advantageous embodiment of a heat pump with a second advantageous embodiment of a device for exchanging thermal energy with the ambient air; Figure 4: a third advantageous embodiment of a heat pump with a third advantageous embodiment of a device for exchanging thermal energy with the ambient air;

[0036] Figure 5: a perspective view of a silencer of the device of Figure 4;

[0037] Figure 6: a perspective view of an air outlet duct forming a first diffuser and a second diffuser directly adjoining the first diffuser;

[0038] Figure 7: a perspective view of a fourth embodiment of a heat pump with a fourth embodiment of a device for exchanging heat energy with the ambient air;

[0039] Figure 8: an exploded view of a fifth embodiment of a

[0040] Heat pump with a fifth embodiment of a device for exchanging heat energy with the ambient air;

[0041] Figure 9: a perspective partial view of the device from Figure 8;

[0042] Figure 10: a perspective view of the heat pump from Figure 8.

[0043] Figures 1 and 2 schematically illustrate a first advantageous embodiment of a heat pump 10 according to the invention, which comprises a first advantageous embodiment of a device according to the invention for exchanging thermal energy with the ambient air. The device is designated overall by reference numeral 12.

[0044] The device 12 has a flat heat exchanger 14, which is L-shaped in plan view, with a flat first leg 16 and a flat second leg 18 adjoining the first leg 16. To convey an air flow through the heat exchanger 14, the device 12 has a fan 20 arranged downstream of the heat exchanger 14 at a distance therefrom, which fan 20 is designed as an axial fan 22 in the illustrated embodiment. Upstream of the heat exchanger 14, the device 12 has an air supply device 24 for supplying the air flow from the environment to the heat exchanger 14, and downstream of the axial fan 22, the device 12 has an air discharge device 26 for discharging the air flow to the environment.

[0045] The air supply device 24 has an air inlet duct 28 forming an air inlet nozzle 30, which is directly connected in the direction of air flow to a supply air duct 32, which tapers in a wedge shape in the direction of flow and extends along an inlet surface 34 of the heat exchanger 14, which can be acted upon by the air flow. The inlet surface 34 extends over the first leg 16 and the second leg 18, so that the air flow can be supplied to both legs via the air inlet nozzle 30 and the supply air duct 32. The air inlet nozzle 30 has a circumferential inlet edge 36 facing away from the supply air duct 32, which circumferentially surrounds an air inlet opening 38 of the air supply device 24.

[0046] The axial fan 22 is mounted on a bulkhead 39 having an opening 40. The axial fan 22 has a motor 41 that rotates an impeller 42 about a rotational axis 44. The impeller 42 has blades 46. Under the action of the rotating blades 46, the air flow downstream of the axial fan 22 is imparted a swirling motion about the rotational axis 44. The bulkhead 39 separates the inflow side of the axial fan 22 from its outflow side to prevent internal backflow.

[0047] The rotation axis 44 is inclined relative to a surface normal 48 of the first leg 16 toward the second leg 18 and toward an end region 50 of the supply air duct 32 facing away from the air inlet nozzle 30. This supports the uniform flow through the heat exchanger 14 across its entire inlet surface 34.

[0048] The air discharge device 26 has, downstream of the axial fan 22, an outflow housing 52 which is designed like a hood and forms an air intake chamber 45 axially offset from the impeller 42 and the motor 41, through which the rotational axis 44 passes. In a rear view looking along the rotational axis 44, the outflow housing 52 covers the impeller 42 and the motor 41, the motor axis of which (not shown in the drawing) is aligned coaxially with the rotational axis 44. The outflow housing 52 absorbs the air flow conveyed by the axial fan 22 over a large area across the entire cross-section of the impeller 42 and the motor 41. The outflow housing 52 has a housing outlet opening 54, to which an air outlet duct 56 in the form of an air outlet nozzle 58 is connected in the flow direction of the air flow.The air outlet nozzle 58 has an air outlet edge 60 facing away from the housing outlet opening 54, which circumferentially surrounds an air outlet opening 62. The air flow can be discharged to the environment via the air outlet opening 62.

[0049] In a rear view of the outflow housing 52, the housing outlet opening 54 is arranged above one half of the blading 46, with the blading 46 rotating on this half toward the housing outlet opening 54, so that the air flow can be supplied to the housing opening 54 in a tangential direction, utilizing the swirling movement of the air flow caused by the rotating blading 46. This will be explained in more detail below with reference to the third advantageous embodiment schematically illustrated in Figure 4.

[0050] The heat pump 10 can be sunk into the ground and, for this purpose, has a trough-shaped housing 64 that is closed by a cover 66 that can be placed onto the housing 64. The cover 66 sits in a flow-tight manner on the top side of the heat exchanger 14 and the bulkhead 39 with the interposition of sealing elements 67. The housing 64 has a central housing section 68 that accommodates the heat exchanger 14, the bulkhead 39, and the axial fan 22. In addition, the central housing section 68 accommodates a hydraulic housing 72 that is arranged laterally next to the first leg 16 of the heat exchanger 14 and laterally next to the bulkhead 39 and the axial fan 22 and accommodates the hydraulic components of the heat pump 10, in particular a compressor, a condenser, and an expansion valve. The hydraulic components are known per se to those skilled in the art and are not shown in the drawing to provide a better overview.

[0051] Upstream of the central housing section 68, the trough-shaped housing 64 has a front housing section 74 which forms the supply air duct 32, and downstream of the central housing section 68, the trough-shaped housing 64 has a rear housing section 76 which forms the outflow housing 52.

[0052] The cover 66 has a cover plate 78 covering the central housing section 68 and forms the air inlet nozzle 30 and the air outlet nozzle 58, which are integrally connected to the cover plate 78.

[0053] The supply air duct 32 extends along the inlet surface 34 and opens into the heat exchanger, with the flow cross-section of the supply air duct 32 continuously decreasing along the inlet surface, thus compensating for the steadily decreasing volume flow caused by the successive entry of the air into the heat exchanger. This results in the air flow being fed to the heat exchanger 14 at a virtually constant velocity across the entire inlet surface 34, avoiding dead zones. The virtually constant velocity across the entire inlet surface 34 reduces any flow losses of the air flow. The flow conditions within the supply air duct 32 are schematically illustrated in Figure 2 using exemplary flow lines a, b, c, d, e, and f.The inlet velocity of the air flow into the air supply device 24 is defined by the flow inlet cross-section of the inlet surface 80 of the air inlet opening 38, which is circumferentially surrounded by the inlet edge 36 of the air inlet nozzle 30. The outlet velocity of the air flow from the air discharge device 26 is defined by the flow outlet cross-section of the outlet surface 82 of the air outlet opening 62, which is circumferentially surrounded by the air outlet edge 60 of the air outlet nozzle 58. The flow outlet cross-section is significantly smaller than the flow inlet cross-section. In the illustrated embodiment, the flow outlet cross-section is approximately half the size of the flow inlet cross-section. This results in the outlet velocity of the air flow being significantly greater than the inlet velocity of the air flow.The higher exit velocity ensures that the exiting air flow practically does not mix with the incoming air flow and thus a thermal short circuit is avoided, even though the air outlet opening 62 is arranged on the same side of the device 10, namely its top side, as the air inlet opening 38.

[0054] The heat pump 10 and the device 12 are thus characterized by high energy efficiency, whereby flow losses of the air flow can be kept low despite the deflection of the air flow by a total of 180°.

[0055] Figure 3 schematically illustrates a second advantageous embodiment of a heat pump 100 according to the invention, which comprises a second advantageous embodiment of a device according to the invention for exchanging thermal energy with the ambient air, which is designated by the reference numeral 102. Figure 3 shows an installation situation in which the heat pump 100 is sunk into an earth volume 104. The heat pump 100 and the device 102 are largely identical in design to the heat pump 10 and the device 12 illustrated above with reference to Figures 1 and 2. For identical components, the same reference numerals are therefore used in Figure 3 as in Figures 1 and 2, and with regard to these components, reference is made to the above explanations to avoid repetition.

[0056] The heat pump 100 and the device 102 differ from the heat pump 10 and the device 12 only in that the air inlet nozzle 30 and the air outlet nozzle 58 are omitted, so that the air flow from the environment can enter directly into the supply air duct 32 and exit directly into the environment via the housing outlet opening 54 of the outflow housing 52. The air supply device 24 is thus formed by the supply air duct 32, and the air discharge device 26 is formed by the outflow housing 52. The inlet cross-section of the supply air duct 32 forms the flow inlet cross-section, which defines the inlet velocity of the air flow, and the outlet cross-section of the housing outlet opening 54 forms the flow outlet cross-section, which defines the outlet velocity of the air flow.The incoming air flow is illustrated in Figure 3 by arrow 106, and the outgoing air flow is illustrated by arrow 108, wherein the respective lengths of arrows 106, 108 represent the average flow velocity of the incoming air flow 106 and the outgoing air flow 108, respectively. It is clear that the exit velocity is significantly greater than the inlet velocity, so that despite the arrangement of the air inlet opening and the air outlet opening on the top side of the heat pump 100 and the device 102, mixing of the two air flows and thus a thermal short circuit is avoided.

[0057] Figure 4 schematically illustrates a third advantageous embodiment of a heat pump 120 according to the invention, which comprises a third advantageous embodiment of a device according to the invention for exchanging thermal energy with the ambient air, the device being designated overall by reference numeral 122. In Figure 4, the same reference numerals as in Figures 1 and 2 are used for identical components, and with regard to these components, reference is made to the above explanations to avoid repetition.

[0058] Figure 4 shows an installation situation of the heat pump 120, in which the heat pump 120 is sunk into the ground laterally next to a wall corner 121 of a building, shown in dashed lines. The device 122 has an air supply device 124 with a first supply air duct 126 and a second supply air duct 128, wherein the first supply air duct 126 extends along the inlet surface 130 of the first leg 16 of the heat exchanger 14, and wherein the second supply air duct 128 extends along the inlet surface 132 of the second leg 18 of the heat exchanger 14. The two supply air ducts 126, 128 taper in a wedge shape along the respective inlet surface 130, 132, thereby ensuring a practically constant speed while avoiding dead spots across the inlet surfaces 130, 132.

[0059] A first air inlet duct 134 in the form of a first air inlet nozzle 136 is arranged directly upstream of the first supply air duct 126, and a second air inlet duct 138 in the form of a second air inlet nozzle 140 is arranged directly upstream of the second supply air duct 128. The two air inlet nozzles 136, 140 each have a rounded portion 142 at their inlet edge facing away from the respective supply air duct 126 or 128, which ensures a separation-free inflow of the air flow. The air inlet nozzles 136, 140, in combination with the supply air ducts 126, 128, form the air supply device 124. The inlet edges of the air inlet nozzles 136, 140 each form an air inlet opening. The flow inlet cross-sections of the air inlet openings define the inlet velocity of the air flow.

[0060] In the embodiment shown in Figure 4, a manifold 144 with a baffle 146 is connected to the air outlet nozzle 58, with the aid of which the escaping air flow is directed in the direction away from the wall corner 121. A silencer 148, shown in simplified form in Figure 5, is inserted into the air outlet nozzle 58 of the device 122. The silencer 148 is designed in the form of a baffle silencer 150 having a housing 152. The housing 152 has two opposing side walls 154, 156, which are connected to one another via an end wall 158 and a rear wall 160. Between the two side walls 154, 156, several baffles 162 of the baffle silencer 150 extend from the end wall 158 to the rear wall 160.The baffles 162 are spaced apart from each other and from the side walls 154, 156, and form outflow cross-sections 164 between them and the side walls 154, 156, through which the air flow can flow. The sum of the outflow cross-sections 164 forms the flow outlet cross-section, which defines the exit velocity of the air flow. The exiting air flow is illustrated in Figure 5 by the arrows 166.

[0061] Figure 4 schematically shows, by way of example, two streamlines a, b of the air flow entering from the environment via the first air inlet nozzle 136 and the second air inlet nozzle 140 into the first supply air duct 126 and the second supply air duct 128, respectively. Furthermore, Figure 4 schematically shows, by way of example, a streamline c of the exiting air flow. Streamline c shows the tangential deflection of the air flow within the outflow housing 52, utilizing the swirling movement about the axis of rotation 44 caused by the axial fan 22. For this purpose, the housing outlet opening 54 of the outflow housing 52 and the air outlet nozzle 58 adjoining the housing outlet opening 54 are arranged, in a rear view looking along the axis of rotation 44, above that half of the impeller 42 whose blades rotate towards the housing outlet opening 54.As a result, the air flowing from this half of the impeller is conveyed to the housing outlet opening 54 with virtually no deflection. The air flowing from the other half of the impeller 42, in contrast, performs a loop-like movement. This creates a parallel flow in the area of ​​the housing outlet opening 54 and the air outlet nozzle 58, with hardly any residual swirl. This allows for a low-loss deflection of the air flow downstream of the axial fan 22 by 90°.

[0062] Figure 6 schematically shows an air outlet duct 170 formed by a first diffuser 172 and a second diffuser 174 directly adjacent to it in the direction of flow. The opening angle of the first diffuser is a maximum of 8°. According to general knowledge in fluid mechanics, this represents the maximum opening angle for expanding a subsonic flow without separation, while slowing it down and recovering static pressure. The second diffuser 174, which adjoins the first diffuser 172 via an edge 176, has an opening angle that results in the formation of a free jet of the air flow. In the illustrated embodiment, the opening angle of the second diffuser 174 is at least 90°, for example 140°. The free jet is illustrated by the wavy line 178, and the flow direction and flow velocity of the air flow are illustrated by the arrows 180.The flow outlet cross-section, which defines the outlet velocity of the air flow, is predetermined by the outlet cross-section of the first diffuser 172, whereas the design of the second diffuser 174 and in particular its outlet cross-section has no influence on the outlet velocity due to the formation of the free jet 178.

[0063] Figure 7 schematically shows a fourth advantageous embodiment of a heat pump 200 according to the invention, which comprises a fourth advantageous embodiment of a device according to the invention for exchanging thermal energy with the ambient air, the device being designated by the reference numeral 202. The heat pump 200 is embedded in a floor plate 204 as an underfloor heat pump and, for a high transfer of thermal energy, has a very wide heat exchanger 206 to which an air flow from the environment can be fed via a wedge-shaped supply air duct 208. This air flow is generated by two identically designed axial fans arranged side by side, each of which is followed by an outflow housing 210 or 212.The outflow housings 210, 212 are configured identically to the outflow housing 52 already explained above. However, they have a different rotational position with respect to their respective rotational axes, so that their respective housing outlet openings 214, 216 face each other and open into a common air outlet duct 218, through which the air flow is discharged to the environment. The direction and speed of the incoming air flow are illustrated in Figure 7 by arrow 220, and the direction and speed of the outgoing air flow are illustrated by arrow 222. The two air flows 220, 222 are aligned antiparallel to each other, whereby the significantly higher speed of the outgoing air flow 222 ensures that it does not mix with the incoming air flow 220 and form a thermal short circuit.

[0064] Figures 8, 9 and 10 schematically illustrate a fifth advantageous embodiment of a heat pump 250, which comprises a fifth embodiment of an advantageous device for exchanging thermal energy with the ambient air, the device being designated by the reference numeral 252. The device 252 comprises a plate-shaped heat exchanger 254, to which an air flow can be supplied via an air inlet duct 256 in the form of an air inlet nozzle 258 and a supply air duct 260 tapering in a wedge shape in the flow direction, the supply air duct 260 extending and tapering along the entire inlet surface 262 of the heat exchanger 254.

[0065] On the downstream side, the heat exchanger 254 is adjoined by a hood 264 which forms an arcuately curved bulkhead 266 on which a fan 268 in the form of a radial fan 270 is held.

[0066] The radial fan 270 is circumferentially surrounded by a spiral housing 272, which receives the air flow conveyed by the radial fan 270 on the downstream side and has a housing outlet opening 274 through which the air flow flows in a tangential direction relative to the rotational movement of the impeller of the radial fan 270, illustrated by arrow 276 in Figures 8 and 10. This is particularly evident in Figure 8.

[0067] An air outlet duct 280 is connected to the spiral casing 272 in the flow direction of the air flow, which air outlet duct has a first duct section 282 in the form of a bend 284 and a second duct section 286 in the form of an air outlet nozzle 288.

[0068] The uniform air supply to the inlet surface 262 of the heat exchanger 254 is achieved by the wedge-shaped design of the supply air duct 260. The rotational axis 290 of the radial fan 270 is aligned obliquely to the flat inlet surface 262 of the heat exchanger 254 and is inclined toward an end region 292 of the supply air duct 260 facing away from the air inlet nozzle 258. This supports the uniform air supply to the heat exchanger 254 and counteracts airflow losses.

[0069] The inlet of the air inlet nozzle 258 forms the air inlet opening, and the inlet flow cross-section of the inlet defines the inlet velocity of the air flow. The outlet of the air outlet nozzle 288 forms the air outlet surface, and the outlet flow cross-section of the outlet defines the outlet velocity of the air flow. The air inlet surface and the air outlet surface are arranged on the same side of the device 252. The outlet flow cross-section defining the outlet velocity is significantly smaller than the inlet flow cross-section defining the inlet velocity of the air flow, so that the outgoing air flow, illustrated by arrow 294, has a significantly higher velocity than the incoming air flow, illustrated by arrow 296.Despite the arrangement of the air inlet surface and the air outlet surface on the same side of the device 252, the significantly higher velocity of the outgoing air flow prevents backflow of the outgoing air flow to the air inlet opening and thus a thermal short circuit. Figure 10 shows an installation situation of the heat pump 250, wherein it is arranged in a technical room 298 of a building on a floor 300, and the air inlet nozzle 258 and the air outlet nozzle 288 arranged above the air inlet nozzle 258 extend through an outer wall of the technical room 298.

Claims

PATENT CLAIMS Device for exchanging thermal energy with the ambient air, comprising a heat exchanger (14; 206; 254) through which an air flow can flow, at least one fan (20; 268) arranged downstream of the heat exchanger, which fan has an impeller (42) rotatable about an axis of rotation (44; 290) with a blade arrangement (46) for conveying the air flow through the heat exchanger (14; 206; 254), as well as an air supply device (24; 124) with at least one air inlet opening (38) for supplying the air flow from the environment to the heat exchanger (14; 206; 254) and an air discharge device (26) with at least one air outlet opening (62) for discharging the air flow from the at least one fan (20; 268) to the environment, wherein the at least one air inlet opening (38) and the at least one air outlet opening (62) on the same side of the device (12; 102; 122; 202;252) are arranged, characterized in that the air supply device (24; 124) has at least one supply air duct (32; 126, 128; 208; 260) opening into the heat exchanger (14; 206; 254), which extends along an inlet surface (34; 130, 132; 262) of the heat exchanger (14; 206; 254) and tapers continuously along the inlet surface (34; 130, 132; 262), and in that the flow outlet cross-section of the at least one air outlet opening (62) defining the outlet velocity of the air flow is smaller than the flow inlet cross-section of the at least one air inlet opening (38) defining the inlet velocity of the air flow. Device according to claim 1, characterized in that the flow outlet defining the exit velocity of the air flow The inlet cross-section of the at least one air outlet opening (62) is a maximum of 0.8 times the flow inlet cross-section of the at least one air inlet opening (38), which defines the inlet velocity of the air flow. Device according to claim 1 or 2, characterized in that the heat exchanger (206; 254) is plate-shaped. Device according to claim 1 or 2, characterized in that the heat exchanger (14) is L-shaped and has a first leg (16) and a second leg (18). Device according to claim 4, characterized in that the device (12; 102) has an air supply duct (32) which extends over both legs (16, 18) of the heat exchanger (14). Device according to claim 4, characterized in that the device (122) has two supply air ducts (126, 128), each extending over one of the two legs (16, 18).Device according to claim 4, 5 or 6, characterized in that the device (12; 102; 122; 202) has a fan (20) whose axis of rotation (44) is inclined to the surface normal (48) of one of the two legs (16, 18) in the direction of the other leg (16, 18). Device according to claim 7, characterized in that the two legs (16, 18) of the heat exchanger (14) are of different lengths and the axis of rotation (44) is inclined to the surface normal (48) of the longer leg (16) in the direction of the shorter leg (18). Device according to one of the preceding claims, characterized in that the axis of rotation (44; 290) of the at least one Fan (20; 268) is inclined relative to a surface normal of the heat exchanger (14; 254) in the direction of an end region of an air supply duct (32; 126, 128; 260). Device according to one of the preceding claims, characterized in that the at least one air supply duct (32; 126, 128; 208; 260) tapers in a wedge shape along the inlet surface (34; 130, 132; 262) of the heat exchanger (14; 206; 254). Device according to one of the preceding claims, characterized in that at least one fan (20) is designed as an axial fan (22) to which an outflow housing (52) is assigned, which receives the air flow conveyed by the axial fan (22) on the outflow side and which has a housing outlet opening (54) through which the air flow can flow in a tangential direction with respect to a swirling movement imposed on the air flow under the effect of the rotating blades (46) of the impeller (42) of the axial fan (22).Device according to claim 11, characterized in that the outflow housing (52) forms an air intake chamber (45) axially offset from the impeller (42) and from a motor (41) of the axial fan (22) which drives the impeller (42) to rotate about the rotational axis (44), said chamber receiving the conveyed air flow over the complete cross section of the impeller (42) and the motor (41) and is penetrated by the rotational axis (44), wherein the outflow housing (52) covers the impeller (42) and the motor (41) like a hood in a rear view. Device according to claim 11 or 12, characterized in that the device (122) has two axial fans, each of which is assigned an outflow housing (210, 212) which receives the air flow conveyed by the respective axial fan, wherein the housing outlet openings (214, 216) of the outflow housings (210, 212) in. a common air outlet duct (218) of the air discharge device (26). Device according to one of claims 1 to 10, characterized in that at least one fan (268) is designed as a radial fan (270) surrounded by a spiral housing (272) which receives the air flow conveyed by the radial fan (270) on the downstream side and which has a housing outlet opening (274) through which the air flow can flow in a tangential direction relative to the rotational movement (276) of the impeller (42) of the radial fan (270). Device according to one of the preceding claims, characterized in that an air inlet duct (28; 134, 138; 256) is arranged upstream of the at least one supply air duct (32; 126, 128; 260). Device according to one of the preceding claims, characterized in that an air outlet duct (56; 170; 218; 280) is arranged downstream of the at least one fan (20; 268).Device according to one of the preceding claims, characterized in that the air discharge device (24) has a silencer (148). Device according to claim 17, characterized in that the silencer (148) is designed as a baffle silencer (150) which has a housing (152), wherein between two opposite side walls (154, 156) of the housing (152) at a distance from the side walls (154, 156) a plurality of spaced-apart baffles (162) are arranged, wherein the outflow cross-sections between the baffles (162) and between the baffles (162). and the side walls (154, 156) in their entirety form the flow outlet cross-section defining the exit velocity of the air flow. Device according to one of the preceding claims, characterized in that the air discharge device (26) for expanding the air flow has a first diffuser (172) with an opening angle of a maximum of 8°, wherein the exit cross-section of the first diffuser (172) forms the flow outlet cross-section defining the exit velocity of the air flow. Device according to claim 19, characterized in that a second diffuser (174) is arranged downstream of the first diffuser (172), which is configured to form a free jet. Heat pump with a device (12; 102; 122; 202; 252) according to one of the preceding claims.

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