Switch cabinet cooling device with air partition and a corresponding switch cabinet arrangement

Abstract

The invention relates to a cooling device (1) for switch cabinet air conditioning, which has, in an internal air circuit (2), an evaporator (3) designed as an air-liquid heat exchanger and an external air circuit (5) which is separated from the internal air circuit (2) by an air partition (4) and has a condenser (6) designed as an air-liquid heat exchanger, wherein the evaporator (3) has a fin arrangement (8) which is penetrated by a pipeline system (7), characterised in that at least one of two end faces (9) of the fin arrangement (8), on which end faces the pipeline system (7) has a pipe bend (10), projects through the air partition (4) and into the external air circuit (5) such that the at least one pipe bend (10) is arranged in the external air circuit (5).

Description

[0001] Control cabinet cooling unit with air partition and a corresponding control cabinet arrangement

[0002] The invention is based on a cooling device for control cabinet air conditioning, which has an evaporator designed as an air-liquid heat exchanger in an inner air circuit and an outer air circuit separated from the inner air circuit by an air barrier and having a condenser designed as an air-liquid heat exchanger. The evaporator has a finned package through which a piping system passes. Such a cooling device is described in DE 10 2012 108 110 B4. Further cooling devices are described in DE 10 2010 009776 Ai and DE 19947970 Ai.

[0003] Directive 2006 / 42 / EC (Machinery Directive) requires that the gas used in machinery does not pose a risk of explosion or fire, although it is assumed that individual components will fail. Therefore, if a component containing a refrigerant in an enclosure cooling unit has a suspected leak, it can be assumed that flammable gas (refrigerant) will enter the enclosure and ignite on components that ignite arcs during operation. Without a safety function that reliably prevents this, enclosure cooling units that use flammable refrigerants cannot comply with the Machinery Directive or operate with the necessary safety for the end user.

[0004] DE 10 2018 109 604 Ai describes a cooling device in which, in the event of a leak in the piping system, the internal air circuit of the cooling device is closed at its connection points, via which the cooling device is fluidly connected to the interior of a switch cabinet housing. The cooling devices known from the prior art have the disadvantage of being complex to implement, since, for example, various actively driven closing elements are required, and they must be activated in the event of a detected leak or the entry of a flammable refrigerant into the interior of the switch cabinet. Therefore, the object of the invention is to further develop the cooling device described above in such a way that it can be implemented using simple technical means and is therefore inexpensive to provide.

[0005] This object is achieved by a cooling device having the features of claim i. Advantageous embodiments are the subject of the dependent claims.

[0006] Accordingly, in a cooling device of the type described above, it is provided that the plate pack projects with at least one of two, preferably opposite, end faces, on which the piping system has at least one pipe bend, through the air partition into the external air circuit, so that the at least one pipe bend is arranged in the external air circuit.

[0007] The invention is based on the finding that the leak-sensitive components of an air-liquid heat exchanger are the pipe bends or their connection points to the rest of the piping system, in particular straight, fault-resistant pipe sections. The connection points of the pipe bends can be designed, for example, as joints, such as soldered connections, which have an increased sensitivity to leaks compared to the rest of the piping system. If the pipe bends are arranged in the external air circuit of the cooling device, in the event of a leak, evaporating refrigerant, in particular flammable refrigerant, for example propane, can be diverted via the external air circuit into the environment of the cooling device and, in particular, kept away from arc-generating components in the interior of a switch cabinet housing to which the cooling device could be connected via the internal air circuit.Typically, air-to-liquid heat exchangers for control cabinet cooling units have a large number of 180° pipe bends on their opposite end faces, where straight, parallel pipe sections are connected in pairs via the bends.

[0008] The piping system of the plate pack can have at least one connection point, preferably a joint, particularly preferably a soldered joint, at the pipe bend arranged in the external air circuit. The pipe bend can be an 180° pipe bend, each of which has a connection point for a preferably straight pipe of the piping system at its opposite ends. The pipe bend can be connected to the pipe in the external air circuit at the connection point, preferably joined, particularly preferably soldered.

[0009] The piping system, insofar as it is arranged in the internal air circuit, can be free of connection points, preferably joints, particularly preferably soldered points. Particularly preferably, the piping system, insofar as it is arranged in the internal air circuit, only has straight and preferably parallel piping sections. At the end faces, the straight piping sections can pass through the air barrier. At the passage points, the straight piping sections can be sealed off from the air barrier. The air barrier can be provided at the end faces by a lamella of the lamella pack, for example by an end lamella of the lamella pack. At the passage points of the straight piping sections through the lamella, in particular the end lamella, the straight piping sections can be joined, for example soldered, to the lamella, in particular to the end lamella, in a fluid-tight manner. The lamella orThe end lamella can be part of the air barrier, in particular in a passage area on the front side of the lamella pack, with which the lamella pack passes through the air barrier.

[0010] The plate pack can have a plurality of plates, preferably parallel or substantially parallel to one another. Of the plates, a plate facing the inner air circuit, for example a terminal or outer plate, in particular an end plate of the plate pack, can protrude beyond the plate pack and the at least one pipe bend with a sealing flange. The plate pack can be in sealing contact with the (remaining) air barrier via the sealing flange. The plate facing the inner air circuit, for example a terminal or outer plate, in particular an end plate of the plate pack, and / or at least the sealing flange can be part of the air barrier.

[0011] The fin facing furthest toward the outer air circuit can be an end fin of the fin stack, via which the evaporator is mounted in a fluid-tight manner in the cooling device, preferably on the air barrier. For this purpose, the fin, in particular the end fin, can have a sealing flange, preferably a circumferential sealing flange, in particular a sealing flange that extends around the entire circumference of the fin, in particular the end fin.

[0012] The end fin can be an external fin of the fin pack. The fin pack can have an end fin on each of the two opposite end faces of the evaporator. The end faces can be formed by the end fins. The end fins can be penetrated by the evaporator's piping system. The piping system can extend beyond the end faces or the end fins with the pipe bends. The piping system can be arranged with the pipe bends, and preferably exclusively with the pipe bends, outside the fin pack.

[0013] An end lamella, for example an end lamella, of the lamella pack can be the air barrier or at least a component of the air barrier. The end lamella of the lamella pack, for example an end lamella, can have a sealing flange, such as a flange, that forms a fluid-tight seal against the air barrier.

[0014] The evaporator can be accommodated in a housing of the air barrier which is open in the air passage direction of the evaporator, wherein the evaporator is in sealing contact with the housing via the sealing flange, preferably on the inner circumference of a cutout of the housing.

[0015] The sealing flange can be a circumferentially closed sealing flange of an end plate of the plate pack, preferably a rectangular sealing frame. To increase stability and sealing effectiveness, the end plate can have increased strength compared to the other plates of the plate pack, for example, a greater material thickness, in particular a higher sheet thickness.

[0016] The sealing flange can form a sealing connection with the edge of a cutout in the air barrier, so that the cutout is preferably completely closed by the end fin. The evaporator, the condenser, and the piping system can be part of a refrigeration machine. The refrigeration machine can also have a compressor and an expansion device. All components of the refrigeration machine can be located entirely in the outer air circuit, except for a central area of ​​the evaporator's fin pack, which is located in the inner air circuit and through which air flows.

[0017] The plate pack can have a condensate drain in the external air circuit on its front side, with which it projects through the air barrier into the external air circuit, for condensate accumulating on at least one pipe bend.

[0018] A switch cabinet assembly comprises, in addition to at least one cooling device of the type described above, a switch cabinet housing to which the cooling device is mounted. Air from an interior of the switch cabinet housing is transported through the cooling device's inner air circuit, while ambient air of the switch cabinet assembly is transported through the outer air circuit.

[0019] Further details of the invention are explained with reference to the following figures.

[0020] Figure i shows a schematic representation of a switch cabinet arrangement according to the prior art;

[0021] Figure 2 shows a schematic representation of a comparison of the arrangement of an evaporator in a refrigerator according to the prior art and in the manner according to the invention; and

[0022] Figure 3 shows an exploded view of an exemplary embodiment of an evaporator with end fins on the opposite end faces.

[0023] Figure 1 shows a switch cabinet arrangement with a cooling device 1 and a switch cabinet housing too, to which the cooling device i is mounted. The cooling device i has an internal air circuit 2 and an external air circuit 5. The air taken in in the interior 101 of the switch cabinet housing too is introduced into the internal air circuit 2 in an upper region of the cooling device, passed through the evaporator 3, and returned to the interior 101 in a lower region of the switch cabinet 100 as cooled air. Switch cabinet components (not shown) that can generate arcs during operation, for example electrical switching devices, can be arranged in the interior 101 of the switch cabinet housing 100. Accordingly, if a flammable refrigerant were to leak through the piping system 7 into the atmosphere in the interior 101 of the switch cabinet housing 100 in the event of a leak, the air-gas mixture could ignite due to the arc.According to the Machinery Directive, the control cabinet arrangement shown in Figure 1 may therefore only be operated with non-flammable refrigerant.

[0024] The piping system 7 is a component of a refrigeration machine 15, which, in addition to the evaporator 3 in the inner circuit 2 and the condenser 6 in the outer circuit 5, also has a compressor 16 and an expansion element 17. In a lower region of the cooling device 1, ambient air is drawn into the inner air circuit 2, passed through the condenser 6, and blown out of the outer air circuit 5 into the surroundings of the switch cabinet arrangement 100 in an upper region of the cooling device 1. To transport the air through the outer air circuit 5 on the one hand and the inner air circuit 2 on the other hand, a fan (not shown) is arranged in each of the respective air circuits 2, 5. In the case of the outer air circuit 5, the fan can be designed as a filter fan.

[0025] In order to prevent evaporating flammable refrigerant from entering the inner air circuit 2 in the event of a leak in the piping system 7, the solution according to the invention, as shown by way of example in Figure 2, provides that the plate pack 8 projects through the air barrier 4 into the outer air circuit 5 with at least one of two opposite end faces, preferably with both end faces 9, on which the piping system 7 has at least one pipe bend 10, so that the at least one pipe bend 10 is arranged in the outer air circuit 5. The invention is based on the finding that leaks in the piping system 7 occur in particular in the region of the pipe bends 10 or the connection points 12 of the pipe bends 10 with the straight line sections 11.Consequently, if these particularly critical areas are located outside the inner air circuit 2, i.e. in the outer air circuit 5, the risk of evaporating refrigerant entering the inner air circuit 2 can be effectively reduced to almost zero.

[0026] The fin pack 8 has a plurality of preferably parallel fins 13, of which the end fin 13 of the fin pack 8 facing the inner air circuit 2 projects beyond the fin pack 8 and the pipe bends 10 on the relevant end face. In particular, the evaporator 3 is mounted in a fluid-tight manner via the end fin 13 in the cooling device 1, namely on the air partition 4. Thus, with the exception of a central area of ​​the evaporator 3, in which only straight pipe sections 11 extend parallel to one another and are less susceptible to leakage, the entire refrigerant circuit is arranged in the outer air circuit 5, so that in the event of a leak, escaping refrigerant from the inner circuit 2 can be separated and discharged into the environment of the cooling device 1. Condensate accumulating at the pipe bends 10 in the outer air circuit 5 is discharged from the outer air circuit via a condensate discharge 18.

[0027] Figure 3 shows an exemplary embodiment of an evaporator 3, wherein the end fins 13 are shown in an exploded view for better clarity. The evaporator 3 is designed as an air-liquid heat exchanger having a fin pack 8 with a plurality of parallel fins 8.1. The fins 8.1 of the fin pack 8 are penetrated perpendicular to the opposite end faces 9 of the evaporator 3 by a piping system 7 consisting of a plurality of parallel pipe sections. The piping system 7 protrudes from the fin pack 8 with pipe bends 10 on the opposite end faces 9. At the opposite end faces 9, in particular outside the fin pack 8, the pipe bends 10 are connected to the parallel pipe sections via connection points 12, for example soldered joints.The connection points are susceptible to leakage and should therefore be arranged outside the inner air circuit in which the fin pack 8 is located, in particular in the outer air circuit, so that in the event of a leak, escaping flammable refrigerant cannot enter the switch cabinet interior through the inner air circuit of the cooling device, where it can ignite on the electrical components of the switch cabinet, which can generate arcs. The end fins 13 shown should therefore be arranged directly on the end faces 9 of the evaporator 3 and penetrated by the piping system 7. For this purpose, the end fins 13 have passages 22. In particular, the piping system 7 can thus be separated from the other components of the evaporator 3, in particular from the fins 8.1 of the fin pack 8, by the end fins, at least around the circumference of the pipe bends 10, including the joints 12.For example, it is possible for the end fins 13 with the circumferential sealing flange 14 to be arranged in a cutout of an air barrier of the enclosure cooling unit, whereby the air barrier separates the inner air circuit from the outer air circuit of the cooling unit. If at least the fin pack 8 is arranged in the inner air circuit, the leak-prone connection points 12 can be arranged through the cutout of the air barrier in the outer air circuit, while the fluidic separation of the inner and outer air circuits is maintained via the sealing flange 14. The end fin 13 then forms a component of the air barrier.

[0028] The end fins 13 can, for example, be formed as sheet metal parts. However, the end fins 13 can also be formed as plastic parts. The end fins can have a strength, for example a sheet thickness, that is sufficient to ensure an adequate sealing effect of the sealing flanges 14. For example, the fins 8.1 of the fin pack 8 can be formed from thin sheet metal. In contrast, the end fin 13 can have a greater sheet thickness. The sealing flange 14 can have at least one fastening tab 21 in order to arrange the evaporator 3, for example, in a fluidically sealed manner in a breakout of an air barrier between the inner air circuit and the outer air circuit.

[0029] The features of the invention disclosed in the above description, in the drawings, and in the claims may be essential for the realization of the invention, both individually and in any combination. List of reference symbols

[0030] Cooling device Internal air circuit Evaporator Air partition External air circuit Condenser Piping system Fin pack Fin Front end Pipe bend Pipe Connection point End fin Sealing flange Refrigeration machine Compressor Expansion device Condensate drain Crank Housing

[0031] Mounting bracket passage

[0032] Control cabinet housing interior

Claims

Claims: Switch cabinet cooling device (i) which has, in an inner air circuit (2), an evaporator (3) designed as an air-liquid heat exchanger and an outer air circuit (5) separated from the inner air circuit (2) by an air partition (4) and having a condenser (6) designed as an air-liquid heat exchanger, wherein the evaporator (3) has a plate pack (8) through which a pipe system (7) passes, characterized in that the plate pack (8) projects with at least one of two end faces (9), on which the pipe system (7) has at least one pipe bend (10), through the air partition (4) into the outer air circuit (5), so that the at least one pipe bend (10) is arranged in the outer air circuit (5).Switch cabinet cooling device (1) according to claim 1, in which the pipe system (7) of the plate pack (8) has at least one connection point (12) arranged in the external air circuit (5) at the pipe bend (10) arranged in the external air circuit (5), preferably a joint, particularly preferably a soldered joint. Switch cabinet cooling device (1) according to claim 1 or 2, in which the pipe bend (10) is an 180° pipe bend (10) which has at each of its opposite ends a connection point (12) for a preferably straight pipe (11) of the pipe system (7), wherein the pipe bend (10) in the external air circuit (5) is connected, preferably joined, particularly preferably soldered, to the pipe (11) at the connection point (12). Switch cabinet cooling device (1) according to one of the preceding claims, in which the piping system (7), insofar as it is arranged in the internal air circuit (2), is free of connection points (12), preferably joints, particularly preferably soldering points.Switch cabinet cooling device (1) according to one of the preceding claims, in which the piping system (7), insofar as it is in the internal air circuit (2). is arranged, has exclusively straight and preferably mutually parallel pipe sections. Switch cabinet cooling device (1) according to one of the preceding claims, in which the plate pack (8) has a plurality of preferably parallel or substantially parallel plates (8.1), of which a plate (8.1) facing the outer air circuit (5), preferably an end plate (13) of the plate pack (8), projects beyond the plate pack (8) and the at least one pipe bend (10) with a sealing flange (14), via which the plate pack (8) bears sealingly against the air partition (4). Switch cabinet cooling device (1) according to claim 6, in which the lamella (8.1) facing the inner air circuit (2) is an end lamella (13) of the lamella pack (8), via which the evaporator (3) is mounted in a fluid-tight manner in the switch cabinet cooling device (1), preferably on the air partition (4).Switch cabinet cooling device (1) according to one of the preceding claims, in which an end lamella (8.1), preferably an end lamella (13), of the lamella pack (8) is the air barrier (4) or is at least a component of the air barrier (4). Switch cabinet cooling device (1) according to one of the preceding claims, in which an end lamella (13) of the lamella pack (8) has a sealing flange (14), such as a crank (19), which bears sealingly against the air barrier (4). Switch cabinet cooling device (1) according to claim 9, in which the evaporator (3) is accommodated in a housing (20) of the air barrier (4), which housing is open in the air passage direction of the evaporator (3), wherein the evaporator (3) bears sealingly against the housing (20) via the sealing flange (14). Switch cabinet cooling device (i) according to claim 9 or 10, wherein the sealing flange (14) is a circumferentially closed sealing flange (14) of the end louver (13), preferably a rectangular sealing frame. Switch cabinet cooling device according to one of claims 9 to 11, wherein the sealing flange (14) in a cutout (18) of the air barrier (4) sealingly abuts against an edge of the cutout (18), so that the cutout (18) is closed by the end louver (13). Switch cabinet cooling device (1) according to one of the preceding claims, in which the evaporator (3), the condenser (6) and the piping system (7) are components of a refrigeration machine (15) with a compressor (16) and an expansion device (17), which is arranged entirely in the outer air circuit (5), except for a central region of the fin pack (8) of the evaporator (3) arranged in the inner air circuit (2) and through which air flows.Switch cabinet cooling device (1) according to one of the preceding claims, in which the plate pack (8) has, on its end face (9), with which it projects through the air barrier (4) into the external air circuit, a condensate discharge (18) in the external air circuit (5) for condensate accumulating on the at least one pipe bend (10). A switch cabinet arrangement comprising a switch cabinet cooling device (1) according to one of the preceding claims and a switch cabinet housing (100) on which the switch cabinet cooling device (1) is mounted, wherein air from an interior space (101) of the switch cabinet housing (100) is transported through the internal air circuit (2), and wherein ambient air of the switch cabinet arrangement is transported through the external air circuit (5).

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