air conditioning

Abstract

The invention relates to an air conditioning system for a vehicle (5), comprising a housing with a first shell (16) and a second shell (14), and a refrigerant circuit arranged in the housing, which includes an inner heat exchanger (4) for heat exchange with interior air of the vehicle (5), an inner fan (6) associated with the inner heat exchanger (4), an outer heat exchanger (10) for heat exchange with ambient air of the vehicle (5), an outer fan (12) associated with the outer heat exchanger (10), a compressor (14) for compressing a refrigerant, and an expansion device (2) for reducing the pressure of the refrigerant, wherein the first shell (16) and the second shell (14) each have an ambient air area (16.11, 14.11) and an interior air area (16.2, 14.2), and the ambient air area (14.11) of the second shell (14) through a partition wall (20) from the interior air area (14.2) of the second shell (14) is separated, wherein the external blower (12) is arranged in the ambient air area (16.11) of the first shell (16) opposite an intake duct (22) provided in the ambient air area (14.11) of the second shell (14), which is limited on the inside air area side by the partition wall (20) of the second shell (14), wherein a sound reduction element (30) is provided on the intake duct side of the partition wall (20) of the second shell (16).

Description

[0001] The invention relates to an air conditioning system for a vehicle. The air conditioning system is, in particular, a roof-mounted air conditioning system that can be mounted on the roof of a vehicle (so-called roof-mounted air conditioning system), which may be, for example, a van, a camper van, a caravan, a mobile home, and the like. The term "vehicle" can encompass both motorized and non-motorized vehicles.

[0002] Particularly if the vehicle is a habitable vehicle such as a motorhome, in which people stay temporarily for extended periods and which typically has an interior layout with areas for eating, sleeping, and lounging, it is desirable for comfort reasons that air conditioning systems used to condition the vehicle be as quiet as possible to ensure rest and relaxation at night. In roof-mounted air conditioning systems, vibrations from the air conditioning system can be amplified via the vehicle body and emitted as sound into the vehicle interior. Rooftop air conditioning systems for mobile homes are known, for example, from WO 2015 / 131235 A1, DE 10 2011 102 343 A1, DE 10 2020 002 860 A1, DE 10 2020 002 861 A1, DE 10 2020 002 862 A1 and DE 10 2020 002 863 A1.

[0003] For passenger cars, DE 101 12 010 B4 discloses the provision of cross-sectional discontinuities to reduce noise generation and provide broadband attenuation of sound waves in air ducts. By creating a cross-sectional discontinuity at a projection, additional interference can be exploited for noise reduction.

[0004] DE 198 39 729 A1 describes a blower for a vehicle air conditioning system. The blower has a helical housing with an intake opening and a cylindrical impeller mounted for rotation within the housing. A flow straightener is arranged in the intake opening to prevent turbulent air flows from rotating. The flow straightener has a plate-shaped web that extends along a chord or the diameter of the intake opening and reaches the edge of the intake opening at the end.

[0005] DE 197 22 866 A1 describes an air duct for a motor vehicle air conditioning system that has two bends in different directions, enclosing an angle of approximately 90°. A linear connection is only possible between a small portion of the inlet opening of the air duct and a small portion of the outlet opening of the air duct. In this way, a large portion of the sound generated by a fan of the air conditioning system is reflected at least once by a wall of the duct as it passes through the air duct, so that only a small portion of the sound passes through the air duct in a straight line and without reflections, resulting in sound absorption.

[0006] The invention is based on the object of providing an air conditioning system for a vehicle, in particular a roof-mounted air conditioning system, which has a low noise level. The vehicle should, in particular, be a vehicle that can be inhabited at least temporarily.

[0007] This object is achieved by an air conditioning system having the features of claim 1.

[0008] The air conditioning system according to the invention has a refrigerant circuit comprising, as components, an internal heat exchanger for heat exchange with the vehicle's interior air, an internal fan associated with the internal heat exchanger, an external heat exchanger for heat exchange with the vehicle's ambient air, an external fan associated with the external heat exchanger, a compressor for compressing the refrigerant, and an expansion device for reducing the pressure of the refrigerant. The internal fan can generate an air flow through the internal heat exchanger. The external fan serves to generate an air flow through the external heat exchanger. The air conditioning system has a housing with a first shell and a second shell for accommodating the components of the refrigerant circuit.

[0009] The first shell has an ambient air zone and an interior air zone, which are separated from each other by a (first) partition wall. The second shell has an ambient air zone and an interior air zone, which can also be separated from each other by a (second) partition wall. When installed, the respective ambient air zones and interior air zones face each other, and the partition walls are detachably connected to each other at their ends, for example, via corresponding recesses and projections.

[0010] The interior air compartments house the interior heat exchanger and the interior fan. The ambient air compartment of the first shell houses the exterior fan. The ambient air compartment of the second shell provides an intake duct for the exterior fan. When installed, the exterior fan is positioned opposite the intake duct.

[0011] Preferably, the first shell forms an upper shell and the second shell a lower shell of the air conditioning unit housing, so that the external fan is positioned above the intake duct when installed. This has the advantage that the air blown out by the external fan leaves the air conditioning unit vertically, spaced from the vehicle roof. It is also conceivable, of course, for the first shell with the external fan to form the lower shell, and the second shell with the intake duct to form the upper shell.

[0012] The intake duct opens into one or more air inlet openings for the ambient air provided in the outer walls of the ambient air area of ​​the second shell. The outdoor heat exchanger is preferably arranged in the intake duct near these air inlet openings, so that the ambient air sucked in by the outdoor fan flows through the outdoor heat exchanger as directly as possible. On the indoor air side, the intake duct is delimited by the partition wall of the second shell.

[0013] According to the invention, a sound reduction element is arranged on this partition wall on the intake duct side. The sound reduction element serves to direct the drawn-in ambient air to the external fan in such a way that less noise is generated than if the sound reduction element were not provided. The sound reduction element is, in particular, a passive sound reduction element, i.e., it is not electrically operated.

[0014] Without the sound reduction element, the ambient air drawn in by the exterior fan would hit the partition wall unhindered, causing it to vibrate, which would then be transmitted from the air conditioning system through the vehicle body into the vehicle interior. Furthermore, the ambient air hitting the partition wall would be reflected by the partition wall, which could cause air turbulence and thus also disruptive noise.

[0015] According to a preferred embodiment, the sound reduction element has an inclined surface pointing towards the intake duct. The angle of inclination between the inclined surface and a horizontal line is a positive angle and preferably lies in an angular range of 30 to 60 degrees. The term "horizontal" refers to the installed state. The inclination can increase towards a central region of the sound reduction element, viewed in the horizontal direction. Furthermore, the inclination or gradient preferably varies within the inclined surface in the vertical direction depending on the distance of a point on the inclined surface from the external fan, wherein the variation preferably occurs continuously. The inclination of the inclined surface preferably decreases - at least in one or more subsections - the more the closer a point on the inclined surface is to the external fan, i.e. to an intake opening on the suction side of the external fan.The inclined surface designed in this way directs the ambient air sucked in by the external fan more gently, i.e. less abruptly, to the external fan, which leads to a reduction in vibrations, turbulence and thus noise.

[0016] According to a particularly preferred embodiment, the inclined surface of the sound reduction element is concavely curved in an impact area of ​​the ambient air, which preferably corresponds at least partially to the above-mentioned central area. The radius of curvature preferably depends on the diameter of the intake opening on the suction side of the external fan. Preferably, the radius of curvature essentially corresponds to the radius of the intake opening of the external fan. According to a preferred embodiment, the radius of curvature of the inclined surface decreases towards the external fan and preferably merges into the radius of the intake opening of the external fan in the direction of the intake opening.The concave curvature and in particular the adaptation of the radius of curvature to the diameter of the intake opening results in an even more even and calmer / quieter redirection of the sucked-in ambient air to the suction side of the outdoor fan, which in turn further reduces vibrations and air turbulence and results in a further reduction in noise.

[0017] The sound reduction element preferably extends from an outer section of the partition wall to a lateral boundary wall of the intake duct arranged within the ambient air region, in particular to a central section of this boundary wall, and is connected to both. The sound reduction element preferably runs obliquely to the intake direction. In longitudinal section, the sound reduction element preferably has a substantially triangular shape, in particular a right-angled triangle. The inclined surface lies opposite the angle enclosed by the legs of the triangular shape.

[0018] The boundary wall can serve to separate the intake duct and thus the ambient air region of the second shell from a compressor region of the second shell, in which the compressor and preferably the expansion device are arranged. According to an alternative embodiment, the boundary wall forms an outer wall of the air conditioning system, for example, if the compressor region is provided at a different location in the air conditioning system.

[0019] The invention is explained in more detail below with reference to the accompanying drawings. In the drawings: - Fig. 1 a perspective view of the air conditioning system according to the invention with the upper shell removed, - Fig. 2 on top view of the Fig. 1 shown air conditioning unit with removed upper shell, - Fig. 3 a sectional view of the Fig. 1 shown air conditioning system with upper shell and lower shell with hatched cut surfaces, - Fig. 4 a perspective sectional view of the Fig. 3 shown air conditioning system with hatched cut surfaces, - Fig. 5 a perspective view of the Fig. 3 shown air conditioning system according to the invention, - Fig. 6 a perspective view of the Fig. 3 shown air conditioning with cover on the upper shell, - Fig. 7 a perspective view of a lower shell of the air conditioning system according to the invention and - Fig. 8 a perspective sectional view of the Fig. 7 shown lower shell.

[0020] The Fig. The air conditioning system 1 according to the invention shown in Figures 1 to 6 comprises a refrigerant circuit (not further designated). In the refrigerant circuit, the pressure of the liquid refrigerant is increased by means of an expansion device, which is preferably designed as a throttle valve 2 (see Fig. 2) decreases, which leads to an expansion of the refrigerant. The expansion of the refrigerant in turn leads to a decrease in the temperature of the refrigerant. The cooled refrigerant is passed through an internal heat exchanger 4 and gives off its (lowered) temperature to the interior air of the vehicle 5 that is passed through the internal heat exchanger 4 by means of an internal blower 6, on the roof of which the air conditioner 1 is installed (see Fig. 3). The air cooled by the refrigerant in the interior heat exchanger 4 is recirculated into the vehicle interior by means of the interior fan 6, which leads to a temperature control of the vehicle interior. The interior fan 6 can be designed as a radial fan, with the rotation axis of the interior fan 6 preferably running transversely to the direction of travel when installed. The refrigerant is heated and evaporated in the interior heat exchanger 4 by the warm air from the vehicle interior. The interior heat exchanger 4 is therefore also referred to as an evaporator in the air conditioning mode of the air conditioning system 1.

[0021] The gaseous refrigerant now flows through a compressor 8 and is compressed therein, whereby the temperature of the refrigerant increases. The compressor 8 is also referred to as a compressor. The compressed refrigerant is passed through an external heat exchanger 10, which is flowed through by ambient air (also called outside air). The ambient air is supplied to the external heat exchanger 10 by an external blower 12. The external blower 12 is preferably designed as a radial blower, the axis of rotation of which runs in the vertical direction in the installed state. In the external heat exchanger 10, the refrigerant is cooled by the ambient air and changes back to the liquid state. The external heat exchanger 10 is therefore also referred to as a liquefier or condenser. Thereafter, the cooling cycle starts anew, and the liquid refrigerant is expanded via the throttle valve 2 and supplied to the internal heat exchanger 4.

[0022] The air conditioning system 1 according to the invention is preferably operable reversibly. This means that the air conditioning system 1 according to the invention can also be operated as a heat pump to supply heat to the vehicle interior. In this heating mode, the exterior heat exchanger 10 functions as an evaporator, and the interior heat exchanger 4 functions as a condenser. The flow direction of the refrigerant is reversed to its flow direction in the air conditioning mode.

[0023] The air conditioning system 1 according to the invention has a housing which comprises a first shell 16 and a second shell 14 (see in particular Fig. 3 to 8), which, in the assembled state, are arranged one above the other and serve to accommodate the above-described components: throttle valve 2, interior heat exchanger 4, interior blower 6, compressor 8, exterior heat exchanger 10, and exterior blower 12. Preferably, the first shell 16 forms an upper shell, and the second shell 14 forms a lower shell, as shown in the figures. The terms "upper" and "lower" refer to the state of the air conditioning system 1 when mounted on a vehicle roof.

[0024] The lower shell 14 and / or the upper shell 16 are preferably made of a foamed plastic material, preferably expanded polypropylene (EPP). Other foamed plastic materials are also possible, provided they ensure the required strength, tightness (for water and air), and fit.

[0025] The lower shell 14 has a partition wall 20 (also called the first or lower partition wall), which divides the lower shell 14 into an ambient air compressor area 14.1 and an internal air area 14.2 (see Fig. 7). The internal air area 14.2 of the lower shell 14 is used to accommodate the internal blower 6 and the internal heat exchanger 4. Correspondingly, the upper shell 16 may have a (second or upper) partition wall 21, which divides the upper shell 16 into an ambient air area 16.1 and an internal air area 16.2 (see Fig. 3 and Fig. 4). In the assembled state of the upper shell 16 and the lower shell 14, the respective internal air areas 16.2 and 14.2 are stacked on top of each other. Correspondingly, the ambient air area 16.1 of the upper shell 16 and the ambient air compressor area 14.1 of the lower shell 14 are stacked on top of each other. The partition walls 20, 21 are detachably connected to each other at the ends.

[0026] The ambient air compressor area 14.1 of the lower shell 14 is further divided by a boundary wall 18 into an ambient air area 14.11 and a compressor area 14.12. The compressor area 14.12 accommodates the compressor 8 and preferably the throttle valve 2. The ambient air area 14.11 comprises an intake duct 22, in which the external heat exchanger 10 is arranged. The intake duct 22 opens into one or more air inlet openings 24 for the ambient air provided in the outer walls of the lower shell 14 (see Fig. 5 and Fig. 6). On the inside air side, the intake duct 22 is limited by the partition wall 20. As in Fig. 2, the external heat exchanger 10 arranged in the intake duct 22 preferably runs along the unspecified outer walls of the lower shell 14 from the intermediate wall 20 to the boundary wall 18 and - seen in plan view - around the external fan 12, wherein the air inlet openings 24 are provided in the outer walls behind the external heat exchanger 10.

[0027] The ambient air area 16.1 of the upper shell 16 accommodates the external fan 12. The external fan 12 is arranged in the upper shell 16 such that its axis of rotation runs vertically when installed. The external fan 12 is arranged above the intake duct 22. The suction side (also called the inlet side) of the external fan 12 is proximal to the lower shell 14. To the side of the external fan 12 and preferably above the compressor area 14.12 of the lower shell 14, an outlet duct 28 is provided in the upper shell 16, which opens into one or more air outlet openings 29 on the outer wall of the housing opposite the direction of travel, through which the ambient air is blown back into the vehicle environment by the external fan 12 (see Fig. 5 and Fig. 6).

[0028] The external fan 12 is attached, preferably detachably, to the upper shell 16. For this purpose, the external fan 12 can, for example, be provided on its suction side with a preferably plate-shaped holder, which is clamped or hooked into corresponding receptacles of the upper shell 16, as described, for example, in the applicant's German patent application 10 2022 003 192.2.

[0029] The upper shell 16 may have an opening 23 for easy installation and replacement of the external fan 12, for example, for cleaning and repair purposes. For protection against the weather, a cover 26, made of a hard plastic, for example, may be arranged on the upper shell 16. The cover 26 does not cover the one or more air outlet openings 29 for the ambient air (see Fig. 6).

[0030] In principle, it is also conceivable to arrange the compressor area 14.12 and the components 2, 8 contained therein at a different location in the air conditioning system 1, so that the boundary wall 18 forms an outer wall or a section of an outer wall of the lower shell 14. In this case, the external heat exchanger 10 can surround the external fan 12 in a plan view, for example, in a U-shape (see, for example, DE 10 2020 002 862 A1).

[0031] The partition wall 20 extends in the transverse direction preferably over the entire width of the air conditioning system 1. The boundary wall 18 extends in the longitudinal direction of the air conditioning system 1 and preferably meets the partition wall 20 at a right angle, as in Fig. 7. Different angles are possible. A straight line between the partition wall 20 and the boundary wall 18 is not absolutely necessary. Viewed in the direction of travel, the ambient air areas 16.1, 14.11 are preferably arranged opposite to the direction of travel, while the interior air areas 14.2, 16.2 are arranged at the opposite end of the air conditioning system 1, pointing in the direction of travel. This ensures that ambient air directed by the exterior blower 12 through the exterior heat exchanger 10 and heated there is blown away from the vehicle 5 via the outlet duct 28 opposite to the direction of travel.

[0032] During operation, the external fan 12 draws in ambient air via the intake duct 22 and the external heat exchanger 10 and releases the ambient air back into the vehicle's environment on its outlet side via the outlet duct 28. If the ambient air were to strike the partition wall 20 directly and / or vertically during intake, this could lead to strong vibrations that propagate through the lower shell 14 of the housing and the vehicle body into the interior of the vehicle, where they could cause unpleasant noise for those inside. Noise can also be generated due to air turbulence due to the reflection of the drawn-in ambient air.

[0033] According to the invention, a noise reduction element 30 is therefore provided in the intake duct 22. The noise reduction element 30 is arranged below the external fan 12 on the intake duct side of the partition wall 20. The noise reduction element 30 is thus provided in the intake duct 22 in the air flow path downstream of the external heat exchanger 10.

[0034] The sound reduction element 30 preferably has an inclined surface 34 with a specific angle of inclination. The angle of inclination between the inclined surface 34 and a horizontal (in the assembled state of the air conditioning system 1) is a positive angle and is preferably between 30 degrees and 60 degrees. The angle of inclination can vary in the vertical direction depending on the distance to an intake opening 25 of the external fan 12, in particular decrease (see Fig. 3 and Fig. 4). The sound reduction element 30 preferably extends from an outer wall-side end of the partition wall 20 to the boundary wall 18, in particular to a central region of the boundary wall 18 (see Fig. 7 and Fig. 8). The sound reduction element 30 has a triangular shape in longitudinal section, in particular a rectangular triangular shape, wherein the inclined surface 34 facing the intake duct 22 and the external fan 12 is opposite the two legs enclosing the right angle (see Fig. 8).

[0035] By providing the sound reduction element 30 with the inclined surface 34, the sucked-in air is specifically redirected toward the suction side of the external fan 12, resulting in a smoother change in direction, less air turbulence, and thus lower noise. The angle of inclination of the inclined surface 34 can increase from its outer sides (seen in the horizontal direction) to an inner area (see Fig. 7).

[0036] It is particularly advantageous for noise prevention if the inclined surface is also concavely curved in an impact area of ​​the ambient air. The curvature or radius of curvature can increase in the direction toward the external fan 12, resulting in an even more targeted deflection of the drawn-in ambient air. Preferably, the radius of curvature in the direction of the intake opening 25 of the external fan 12 essentially merges dimensionally into the radius of the intake opening 25, which has a particularly positive effect on reducing air turbulence and thus noise.

[0037] On the rear side, i.e., on its side facing away from the intake duct 22, the sound reduction element 30 is preferably convexly curved. The gap 36 between the rear side of the sound reduction element 30 and the intermediate wall 20 and the boundary wall 18 can be hollow. Alternatively, the gap 36 can be filled with an insulating material that additionally dampens the sound. For simplified manufacturing, the sound reduction element 30 is preferably formed integrally with the lower shell 14. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2015 / 131235 A1

[0002] DE 10 2011 102 343 A1

[0002] DE 10 2020 002 860 A1

[0002] DE 10 2020 002 861 A1

[0002] DE 10 2020 002 862 A1 [0002, 0030] DE 10 2020 002 863 A1

[0002] DE 101 12 010 B4

[0003] DE 198 39 729 A1

[0004] DE 197 22 866 A1

[0005] DE 10 2022 003 192.2

[0028]

Claims

[1] Air conditioning system, in particular roof-mounted air conditioning system, for a vehicle (5), comprising a housing with a first shell (16) and a second shell (14), and a refrigerant circuit arranged in the housing, which - an interior heat exchanger (4) for heat exchange with the interior air of the vehicle (5), - an internal fan (6) associated with the internal heat exchanger (4), - an external heat exchanger (10) for heat exchange with ambient air of the vehicle (5), - an external fan (12) associated with the external heat exchanger (10), - a compressor (14) for compressing a refrigerant and - an expansion device (2) for reducing a pressure of the refrigerant, wherein the first shell (16) and the second shell (14) each have an ambient air region (16.11, 14.11) and an internal air region (16.2, 14.2), and the ambient air region (14.11) of the second shell (14) is separated from the internal air region (14.2) of the second shell (14) by an intermediate wall (20), wherein the external fan (12) is arranged in the ambient air area (16.11) of the first shell (16) opposite an intake duct (22) provided in the ambient air area (14.11) of the second shell (14), which intake duct is delimited on the inside air area side by the intermediate wall (20) of the second shell (14), wherein a sound reduction element (30) is provided on the intake channel side on the intermediate wall (20) of the second shell (16). [2] Air conditioning system according to claim 1, wherein the sound reduction element (30) has an inclined surface (34) on the intake duct side, wherein the angle of inclination between the inclined surface (34) and a horizontal is a positive angle. [3] Air conditioning system according to claim 2, wherein the angle of inclination of the inclined surface (34) varies depending on the distance to the external fan (12). [4] An air conditioning system according to claim 2 or 3, wherein the angle of inclination is between 30 degrees and 60 degrees. [5] An air conditioning system according to any one of claims 2 to 4, wherein the inclined surface (34) is concavely curved in an impact area of the ambient air. [6] An air conditioning system according to claim 5, wherein the curvature of the inclined surface (34) increases in the direction of the outdoor fan (12). [7] The air conditioning system according to claim 5 or 6, wherein a radius of curvature of the inclined surface corresponds to a radius of an intake opening (25) of the outdoor fan (12). [8] Air conditioning system according to one of claims 2 to 7, wherein the sound reduction element (30) extends from an outer portion of the intermediate wall (20) to a boundary wall (18) of the intake duct (22), in particular to a central portion of the boundary wall (18). [9] Air conditioning system according to one of claims 2 to 8, wherein the sound reduction element (30) has a triangular sectional surface in the longitudinal direction. [10] Air conditioning system according to one of the preceding claims, wherein the sound reduction element (30) is formed integrally with the second shell (14).

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