AIR CONDITIONING ARRANGEMENT

The invention relates to an air conditioning system, in particular, a cooling system, which includes at least a switch cabinet having a support assembly, on the front side of which, facing the switch cabinet doors, electrical and electronic devices to be air conditioned are arranged in rows on top of and next to one another.

A generic cooling system for electrical devices arranged in a switch cabinet is known from DE 10 2009 054 011 B4, including a switch cabinet having a support assembly, on the front side of which the electrical devices are arranged in rows on top of and next to one another, and an air conveying device, with which an air flow may be forced from top to bottom on the rear side of the support assembly, in which a partial air flow separated off from the air flow on the rear side of the support assembly may be fed in a targeted manner through multiple passage openings spaced apart from each other in a vertical direction and/or horizontal direction to the electrical devices to be cooled, which are arranged on the front side of the support assembly.

In this known solution, it is provided that in the installed switch cabinet, the support assembly includes horizontally arranged mounting strips, to which at least a portion of the devices is fastened, wherein a strip gap exists between two mounting strips adjacent to one another in the vertical direction, in the area of which the passage openings are arranged, and wherein said strip gap serves as a feed-through for the electrical connecting wires of the devices.

Electrical and/or electronic devices are frequently arranged in switch cabinets or switch boxes, in particular, in industrial control technology. During operation, the individual devices develop in part a significant heat loss, which results in a temperature increase inside the switch cabinet. To ensure the functionality of the devices, the temperature cannot exceed a maximum value. Thus, semiconductor components installed in the devices can only be operated in a functionally safe manner up to a component temperature of, for example, 85° C. or 125° C.

In developing the known solution according to DE 10 2009 054 011 B4, it was recognized that air flowing on the rear side of the switch cabinet and on the inner side thereof is comparatively cool, for example, because a cooling of the switch cabinet interior takes place via the rear wall of the switch cabinet, or because cool air is fed into this area, for example, via the inflow of cooler ambient air or via the inflow of air cooled by a heat exchanger. In addition, a passive cooling may take place as a result of heat emitted from the switch cabinet or as a result of cooling of the outer side of the switch cabinet by the ambient air.

The targeted guidance of cool air through the passage openings of the support assembly can disperse hotspots formed on the front side thereof, which is true, especially in the case in which the passage openings are arranged in the area of any forming hotspots, which can regularly occur between devices that are adjacent to one another as seen in a vertical direction. In addition, such hotspots may also form on the lee side of the devices disposed on the front side of the support frame, i.e., on the side of an electrical device facing away the air flowing on the front side of the support frame, which is in particular the case if the device is designed with a high volume or with a large surface area. Thus, in the known solution, the passage openings may therefore preferably be arranged on the lee side of the devices, so that the cool air flowing through blows directly into the respective hotspot and thereby disperses the latter. Nevertheless, the known solution leaves room for improvement, in particular, as it concerns air conditioning efficiency, in particular, cooling efficiency.

Thus, based on this prior art, the object of the invention is a further improvement to the effect that an air conditioning system, in particular, a cooling system, is created, which not only operates very efficiently, but also allows for a compact design and is easy to maintain. Such an object is achieved by an air conditioning system having the features of claim 1 in its entirety.

Because, according to the characterizing portion of claim 1, the devices situated inside the switch cabinet may be at least partially air conditioned and preferably cooled by means of a heat sink as an autonomous component in each case, an essentially homogenous temperature field may be achieved inside the switch cabinet despite varying thermal load emanating from the electrical and/or electronic devices, so that a uniform and yet efficient air conditioning of the devices is achieved. The heat sink designed as an autonomous component can be implemented in the simplest embodiment as a so-called “cold plate” in a cost-effective manner, which, depending on its thermal state, enables a homogenization of the temperature field inside the switch cabinet, in particular, in a cooling manner. The aforementioned “cold plate”, if it is made of a metal plate, is thermally conductive in an efficient manner and, starting from a cool baseline, for example, by storing a low ambient temperature outside the switch cabinet, it is able to transfer the said low temperature into the interior of the switch cabinet for cooling the devices. A plate (“cold plate”) cooled in this way allows, in particular, the switch cabinet air situated on the rear side of the support assembly to be guided in a falling manner from top to bottom along the rear side of the support assembly when the switch cabinet is installed, in order to then rise again on the front side of the support assembly under the influence of a convective heat flow caused by the heat dissipated from the devices, wherein the devices are then correspondingly cooled.

The aforementioned heat sink is therefore preferably a spatially limited autonomous body, which transfers the thermal energy stored inside it or fed to it to an adjacent medium, here in the form of air, and that the heat sink is preferably a cooling device, which dissipates waste heat in order to prevent the devices in the switch cabinet from overheating. It is understood of course that, in terms of air conditioning, such a heat sink can also be used to warm the electrical and/or electronic devices if necessary, in particular, if the said devices are switched on in an extremely cold environment and in that respect only then put into operation.

The heat sink, which includes a plate-shaped extension to form a so-called “cold plate”, may form a wall section of the switch cabinet, preferably its rear wall; however, there is also the option of integrating such a plate-shaped heat sink inside the switch cabinet, wherein care should be taken, however, that the plate-shaped heat sink does not inhibit access to the tools when the switch cabinet doors of the switch cabinet are opened, which may be prevented, for example, by designing the plate-shaped heat sink as a component of each switch cabinet door.

Another option is to mount the heat sink on a building, in particular, on the wall sections of a hall or the like, in which the respective switch cabinet is installed, and then to install the switch cabinet in front of the said building-engineered installed heat sink, in order in this way to effect air conditioning of the interior of the switch cabinet.

In another particularly preferred embodiment of the arrangement according to the invention, it is provided that a predefinable distance between the support assembly with the devices and heat sink to which they may be allocated, is adjustable by means of an adjusting device. The thermal input load inside the switch cabinet may differ depending on how many and what type of devices are affixed to the support assembly, and by adjusting the distance between the heat sink and the support assembly, it is possible to adjust the degree of the cooling capacity to be provided inside the switch cabinet.

For an optimized air flow of cool air inside the switch cabinet, it is provided that the volume of the rear flow chamber is sized many times smaller than the volume of the front flow chamber, for which purpose—in order also to achieve an improved circulation inside the switch cabinet—it may be provided that the circulation of the flowing cool air or warm air is effected by an air conveying device, preferably in the form of at least one cylindrical fan.

More energy consuming, but better in terms of the cooling capacity to be produced, it is to be provided that a gaseous coolant is introduced into circulation through cooling tubes inside the plate-shaped heat sink, in order in that way to be able to dissipate heat from the interior of the switch cabinet into the environment. Any condensate forming on the heat sink can be collected by means of a collector device inside the switch cabinet and discharged from the switch cabinet into the environment by means of an outlet device or discharge device.

FIG. 1 shows a perspective view of a switch cabinet 1 according to the invention as it is used for mounting electrical and/or electronic devices 2 such as, for example, control devices, power supply units, switching devices, fuses, sensors, etc., preferably in industrial manufacturing technology. It is noted at this point that the technical specification switch cabinet is also intended to encompass devices, such as switch boxes as well as other receptacles for the aforementioned conventional type of devices 2.

Depicted only schematically in the switch cabinet 1 is a support assembly 4, which in the exemplary embodiment is composed of two or more vertically arranged support rails 8 and, in the present case, of a total of three essentially horizontally arranged mounting strips 12, 14, 16. The mounting strips 12, 14, 16 and the support rails 8 may be connected by connecting elements, for example, in the form of crossbars or the like, not depicted in FIG. 1, wherein the mounting strips 12, 14, 16 are arranged in the direction of the front side 17 as seen in FIG. 1 in front of the support rails 8. The support rails 8 and the mounting strips 12, 14, 16 form a frame 10, which may also be preassembled accordingly and subsequently inserted into the switch cabinet 1 as support assembly 4 for the devices 2.

The devices 2 are arranged on the front side 17 of the mounting strips 12, 14, 16 and, therefore, on the front side 17 of the frame-like support assembly 4 in rows one on top of the other, preferably detachably fastened, in particular, on respective associated mounting strips 12, 14, 16. Said front side 17 of the switch cabinet 1 may be closed by a switch cabinet door, not depicted in greater detail for reasons of simpler representation, wherein said opening of the switch cabinet 1 may also be closed by a double door or other multiple doors. An air flow 34 directed essentially from top to bottom in the direction of the line arrows, may be forced on the rear side 19 of the support assembly 4, in particular, in the area of the support rails 8, by means of an air conveying device 20 (FIG. 2).

The strip gaps between the mounting strips 12, 14, 16 may be at least partially closed by means of closure elements 22, 24, 26, wherein in the area of these strip gaps, electrical connecting wires of the devices 2 are passed from the front side 17 of the frame 10 to the rear side 19 and, in this respect, the wiring and cabling may extend accordingly on the rear side 19 of the frame-like support assembly 4. For this purpose, each of the closure elements 22, 24, 26 may be designed in multiple parts, and include, in particular, for example, a wiring strip 28 (FIG. 2) and a cover element 32. Said closure elements as well as the wiring strip, in addition to the cover element, are reproduced merely by way of example, and only in a basic manner for purposes of simpler representation.

A passage opening 30 is arranged in the cover element 32, through which cooling air is able to enter from the rear side 19 to the front side 17 of the support assembly 4 and in this way may be fed to each heat-generating device 2 in a targeted manner. In the view according to FIG. 1, only the passage opening 30 for the uppermost depicted left device is visible; nonetheless one passage opening each for the second and third device 2 is also arranged in the second closure element 24 and in the third closure element 26. Instead of the solution demonstrated herein, however, the air may also be passed through every other opening from the rear side 19 to the front side 17 of the switch cabinet 1; it would be conceivable, in particular, to allow the cooling air to simply flow through between the horizontally arranged mounting strips 12, 14, 16.

FIGS. 2 through 4 each show a highly simplified side view of exemplary embodiments of the switch cabinet 1 according to the invention. The air conveying device 20 in each of the exemplary embodiments is designed as a crossflow fan or cylindrical fan and draws the air into the upper interior area of the switch cabinet 1 and conveys it to the rear side 19 of the frame 10, respectively, the support assembly 4. During its operation, the air conveying device 20 forces inasmuch an air flow 34 directed from top to bottom on the rear side 19 of the frame 10, from which partial air flows 42, 44, 46 are separated off, which enter, for example, via the passage opening 30 from the rear side 19 of the frame 10 to the front side 17, on which the electrical devices 2 are arranged. On the front side 17, the partial air flows may then combine to form a complete air flow. Said air routing is again displayed with arrows. The partial airflow 42 entering, for example, through the passage opening 30 brushes over the device 2 depicted to the upper left in FIG. 1, to which the passage opening 30 is accordingly allocated, even before the partial airflow 42 is able to combine with the additional air flows 44, 46 on the front side 17 of the frame 10. However, because of the heat to be dissipated from the devices 2 alone, a convective current in general forms on the front side 17 in the switch cabinet 1, which passes from top to bottom. Thus, the entire air flow on the front side is in turn drawn in above the devices 2 by the air conveying device 20 and transported via its outlet opening downward along the rear side 19 of the support assembly 4, so that a permanent circulation of the air in the closed switch cabinet 1 takes place.

A fastening element 48 is disposed in principle arrangement above the first mounting strip 12, to which the air conveying device 20 is connected, in particular, mounted. A first strip gap between the fastening element 48 and the first mounting strip 12 is sealed by means of a cover element 36, which essentially hermetically seals the frame 10 at this point. In contrast, a first cover element 32, which includes the passage opening 30, is arranged in the strip gap between the first mounting strip 12 and the second mounting strip 14. The first cover element 32 in this case may be insertable into the side margins of the strip gap bordered by the wiring strips 28. The passage openings 30 in this case may be predefined in the first cover element 32 or the first cover element 32 may include predetermined breaking points as a result of local material thinning, perforation or the like, by means of which the passage opening 30 may be easily produced if needed and preferably without tools. In a simplified construction, the passages between the individual mounting strips 12, 14, 16 may also be utilized to transport the air from the rear side 19 in the direction of the front side 17 for the purpose of air conditioning the devices 2.

Since the center device 2 depicted by way of example in FIG. 1 is comparatively tall overall, a second cover element 30 is inserted into the strip gap between the second mounting strip 14 and the third mounting strip 16, in the passage opening of which an air control element 50 is inserted, preferably detachably inserted, by means of which the passing cool air may be fed in a targeted manner to the front end of the second device 2. The air control element 50 may alternatively or in addition also distribute the cooled air in the horizontal direction in a corresponding manner.

Arranged below the third mounting strip 16 is a passage opening extending over the entire width of the third mounting strip 16, through which the remaining air flow 34 is able to pass from the rear side 19 to the front side 17 of the frame 10, and initially able to brush over the second device 2 (depicted at the bottom on the left hand side of FIG. 1) in a cooling manner and is subsequently suctioned off in the direction of the air conveying device 20. The structure of the support assembly 4 or the frame 10 is merely exemplary, and in practice, said components are fitted with significantly more mounting strips in horizontal and vertical alignment than are shown here by way of example for purposes of explaining the invention.

The air conditioning system according to the invention will now be described in greater detail, based on the previously described basic structures of a switch cabinet. As shown in FIG. 1, a heat sink, which air conditions, preferably appropriately cools the devices 2 located inside the switch cabinet 1, is arranged as an autonomous component 50 on the rear side of the switch cabinet 1. The heat sink 50 shown in FIG. 1 is a spatially limited, autonomous body, which transfers the thermal energy stored in it or fed to it to an adjacent medium, such as preferably air, wherein the heat sink 50 is preferably a cooling device, which dissipates heat waste in order to prevent the devices 2 in switch cabinet 1 from overheating.

In the exemplary embodiment according to FIG. 1, the heat sink 50 has a plate-shaped extension and preferably forms a wall section on the rear side of the switch cabinet 1. In this respect, therefore, the switch cabinet 1 is covered on its rear side by the heat sink 50 in such a way that the side walls of the heat sink 50 merge flush with the side walls of the switch cabinet 1. In its simplest embodiment, the heat sink 50 is designed as a so-called “cold plate”, which is accordingly able to store a low ambient temperature outside the switch cabinet 1 and then deliver it to the interior of the switch cabinet 1. As a result of said cooling of the heat sink 50 designed as a “cold plate”, the previously described heat drop gradient on the rear side 19 of the switch cabinet 1 is increased.

As shown in the exemplary embodiment according to FIG. 2, the heat or temperature sink 50 may be designed as a cool plate of a cooling device, which cooperates, in particular, with an evaporator or a cold compression machine 52, which according to the depiction according to FIG. 2 is arranged, together with its compressor and condenser, above the switch cabinet 1 on the outside thereof. The temperature of the cool air is preferably regulated in such a way that, if possible, no condensate forms on the evaporator even under unfavorable climate conditions. Any condensate appearing in the switch cabinet 1 is collected by means of a hollow rail-type collector device 54 and discharged from the switch cabinet 1 via an outlet device not further depicted.

For said layout, the concept of the heat sink 50 formed as a cooling plate is preferably designed in the form of a sandwich structure, made up of a plate-shaped carrier medium, in which preferably cooling coils or cooling lines, laid down in a meandering pattern, are imbedded. The flow line and return line of the cooling lines or cooling tubes 56 are each connected to the cooling compressor 52, which, together with the associated condenser, is fixedly mounted outside the switch cabinet 1 on the top thereof, in order not to occupy any installation space inside the switch cabinet. The cooling tubes 56 are connected to the cold compressor 12[sic-52] installed on top of the switch cabinet 1 by separable couplings not further depicted, as a result of which a simple maintenance of the cold compressor 12[sic-52] is possible or individual components of the entire cooling system may be easily replaced once the compressor 52 is separated via the separable couplings from the remaining heat sink 50.

The following exemplary embodiments will be explained only to the extent that they differ significantly from the preceding exemplary embodiments. The statements made with regard to the former apply accordingly also to the exemplary embodiments according to FIGS. 3 and 4 presented below.

In the embodiment according to FIG. 3, the frame 10, i.e., the support assembly 4, is fastened in the switch cabinet 1 by means of a permanently installed so-called servo axis 58, on which the actual frame 10 is vertically held; however, particularly preferably at an adjustable distance X to the cooled heat sink 50 arranged on the rear side. Furthermore, in the present exemplary embodiment, the heat sink 50 with the bottom connection is placed in front of a building wall 60, which may be part of an installation hallway for the switch box 1, wherein the compressor 52 in such case is also attached to the building wall 60. Said arrangement on the side of the wall may also extend along a larger hallway wall, so that multiple switch cabinets 1 with their hollow box design then remaining open on the rear side may be placed in front of the respective heat sink arrangement 50. When viewed in the direction of FIG. 3, a nano-varnish coating 62 is applied on the front side of the heat sink 50, which by itself allows the heat sink 50 to be cleaned of pollutants or accordingly facilitates cleaning in this area. In this case, the heat sink 50 could again join flush with the rear side of the switch cabinet 1 or overlap accordingly as an extension, in order in this way to enable installation options of multiple switch cabinets 1 (not depicted) for just one heat sink plate.

In the embodiment according to FIG. 4, multiple plate-shaped heat sinks 50 are each allocated to a device area 2 of the support assembly 4 and are otherwise protected to the rear against cold losses into the environment by an insulation 64. To the extent the preceding exemplary embodiments emphasize essentially the cool aspect, the respective heat sink 50 may also be provided for heat temperature control for the devices 2 of the switch cabinet 1, in order for example, to air condition in the sense of heating the devices 2 at installation locations of the switch cabinet 1 with very low temperatures, in order in this way to be able to rapidly ensure their functionality. Depending on the configuration, correspondingly designed heating lines carrying a heating medium also or alternatively appear in addition to the cooling tubes 56, wherein an electrical heating of the heat sink 50 may also be contemplated.

Based on the modular design of each heat sink 50, a large number of applications for switch cabinets 1 can be implemented. Thus, it would also be conceivable to integrate the respective heat sink 50 on the front of the door systems for the switch cabinet 1 not further depicted or to include the other wall sections thereof such as, for example support base parts, side walls and topside walls.