Switch cabinet cooling device with air baffle and corresponding switch cabinet arrangement

Abstract

The invention relates to a cooling device (1) for an air conditioner of a switchgear cabinet, comprising an evaporator (3) in the form of an air-liquid heat exchanger in an inner air circuit (2) and a condenser (6) in the form of an air-liquid heat exchanger in an outer air circuit (5) separated from the inner air circuit (2) by an air partition (4), the evaporator (3) has a fin group (8) through which the duct system (7) passes, characterized in that at least one of the two end faces (9) of the fin group (8) extends through the air bulkhead (4) into the external air circuit (5), and in that the duct system (7) has at least one duct elbow (10) thereon such that the at least one duct elbow (10) is arranged in the external air circuit (5).

Description

[0001] The invention is based on a cooling device for a switch cabinet air conditioner, which has an evaporator in the form of an air-liquid heat exchanger in an internal air circuit and a condenser in the form of an air-liquid heat exchanger in an external air circuit separated from the internal air circuit by an air baffle. In this case, the evaporator has a fin pack through which the pipe system passes. A cooling device of this type is described in DE 10 2012 108 110 B4. Further cooling devices are described in DE 10 2010 009 776 A1 and DE 199 47 970 A1.

[0002] Directive 2006 / 42 / EC (Machinery Directive) requires that gases used in machines do not present a risk of explosion or fire, and that failure of individual components can be assumed. Therefore, if a refrigerant-carrying part of a switchgear cooling unit leaks, it can be assumed that flammable gases (refrigerants) could enter the switchgear and ignite the internal fittings, thus causing an electric arc during operation. Without a safety function that reliably prevents this from happening, switchgear cooling units using flammable refrigerants do not meet the Machinery Directive or provide the necessary safety guarantees for the end user.

[0003] DE 10 2018 109 604 A1 describes a cooling device in which, if a leak occurs in the pipe system, the internal air circuit of the cooling device is closed at its connection point, via which the cooling device is fluidically connected to the interior of the 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 members are required and must be actuated in the event of a leak being detected and flammable refrigerant entering the interior of the switch cabinet.

[0004] It is therefore the object of the present invention to develop the cooling device described at the outset in such a way that it can be implemented using simple technical means and is therefore provided cost-effectively.

[0005] This object is achieved by a cooling device having the features of claim 1. Advantageous embodiments are in each case the subject matter of the dependent claims.

[0006] Therefore, in a cooling device of the type described at the beginning, the fin group protrudes into the external air circuit through an air baffle, wherein at least one of the two end sides is preferably an opposite end side, and the pipe system has at least one pipe elbow on it, so that the at least one pipe elbow is arranged in the external air circuit.

[0007] The invention is based on the recognition that leak-sensitive components of an air-liquid heat exchanger are pipe elbows or their connection points to the rest of the pipe system, in particular straight, non-failure-prone pipe sections. The connection points of the pipe elbows can be formed, for example, as joints, such as welded connection points, which have a higher leak sensitivity than the rest of the pipe system. If the pipe elbows are arranged in the external air circuit of the cooling device, the refrigerant that evaporates in the event of a leak, in particular a flammable refrigerant, such as propane, can be discharged via the external air circuit to the surroundings of the cooling device, in particular away from arc-generating components inside the switch cabinet housing, to which the cooling device and the internal air circuit can be connected. Air-liquid heat exchangers for switch cabinet cooling devices usually have a plurality of 180° pipe elbows at their opposite end sides, at which straight, parallel pipe sections are connected to each other in pairs via pipe elbows.

[0008] The pipe system of the fin group can have at least one connection point, preferably a joining point, particularly preferably a welding point, at a pipe elbow arranged in the external air circuit, which connection point is arranged in the external air circuit.

[0009] The pipe elbow can be a 180° pipe elbow, with a connection point for a preferably straight pipe of the pipe system at each of its opposite ends. The pipe elbow can be connected to a pipe in the external air circuit at the connection point, preferably joined, particularly preferably welded.

[0010] The duct system, insofar as it is arranged in an internal air circuit, can be free of connection points, preferably joining points, particularly preferably welding points. Particularly preferably, the duct system, insofar as it is arranged in an internal air circuit, has only straight and preferably mutually parallel duct sections. At the end side, the straight duct section can pass through the air baffle. At the passage point, the straight duct section can be sealed relative to the air baffle. The air baffle can be provided on the end side by the fins of the fin group, for example by the end fins of the fin group. At the passage point, where the straight pipe section passes through the fin, in particular the end fin, the straight pipe section can be connected to the fin, in particular the end fin, in a fluid-tight manner, for example by welding. The fin or the end fin can be a component of the air baffle, in particular in the passage area on the end side of the fin group, through which the fin group passes through the air baffle.

[0011] The fin group can have a plurality of fins which are preferably parallel or substantially parallel to one another. Of the fins, the fins facing the internal air circuit, for example the end or outer fins, in particular the end fins of the fin group, can protrude beyond the fin group and at least one pipe elbow with a sealing flange. By means of the sealing flange, the fin group can rest sealingly against the (remaining) air baffle. The fins facing the internal air circuit, for example the end or outer fins, in particular the end fins of the fin group and / or at least the sealing flange can be components of the air baffle.

[0012] In this case, the fin which faces furthest towards the external air circuit can be the end fin of the fin group, by means of which the evaporator is mounted in a fluid-tight manner in the cooling device, preferably on an air baffle. To this end, the fin, in particular the end fin, can have a sealing flange, preferably a circumferential sealing flange, in particular a sealing flange which extends around the entire circumference of the fin, in particular the entire circumference of the end fin.

[0013] The end fins may be external fins of the fin group. The fin group may have one end fin each on two opposite end sides of the evaporator. The end sides may be formed by the end fins. The duct system of the evaporator may pass through the end fins. The duct system may extend with duct elbows to the end sides or outside the end fins. The duct system may be arranged with duct elbows and preferably only with duct elbows outside the fin group.

[0014] The end fin of the fin group, such as the end fin, can be an air baffle or at least a component of an air baffle. The end fin of the fin group, such as the end fin, can have a sealing flange, such as an offset flange, which rests against the air baffle in a fluid-tight manner.

[0015] The evaporator can be accommodated in a housing of the air baffle, which housing is open in the direction of the air passage of the evaporator, wherein the evaporator bears sealingly against the housing via a sealing flange, preferably on the inner circumference of a hole in the housing.

[0016] The sealing flange can be a circumferentially closed sealing flange of the end fin of the fin group, preferably a rectangular sealing frame. In order to improve stability and sealing action, the end fin can have a higher strength than the remaining fins of the fin group, such as a greater material thickness, in particular a greater sheet thickness.

[0017] The sealing flange can bear sealingly against the edge of the hole in the hole of the air baffle, so that the hole is preferably completely closed by the end fin.

[0018] The evaporator, condenser and pipe system can be components of a refrigerator. The refrigerator can also have a compressor and an expansion member. All components of the refrigerator can be arranged completely in the external air circuit, except for the central area of ​​the fin group of the evaporator, which is arranged in the internal air circuit and through which the air flows.

[0019] The fin group can have a condensate discharge opening in the external air circuit at its end side, via which end side the fin group projects through the air baffle into the external air circuit, so that condensation collects on the at least one line elbow.

[0020] The switch cabinet arrangement has, in addition to at least one cooling device of the type described above, a switch cabinet housing on which the cooling device is mounted. In this case, air is conveyed from the interior of the switch cabinet housing via an internal air circuit of the cooling device, wherein ambient air of the switch cabinet arrangement is conveyed via an external air circuit.

[0021] The details of the present invention will be further explained below with reference to the accompanying drawings. In the accompanying drawings:

[0022] FIG1 shows a schematic diagram of a switch cabinet arrangement according to the prior art;

[0023] Figure 2 A comparative schematic diagram showing the arrangement of an evaporator in a cooling device according to the prior art and the method according to the present invention; and

[0024] Figure 3 An exploded view of an exemplary embodiment of an evaporator is shown, wherein opposite end sides of the evaporator have end fins.

[0025] FIG. 1 shows a switch cabinet arrangement with a cooling device 1 and a switch cabinet housing 100, on which the cooling device 1 is mounted. The cooling device 1 has an internal air circuit 2 and an external air circuit 5. The air contained in the interior 101 of the switch cabinet housing 100 is introduced into the internal air circuit 2 in the upper region of the cooling device, conducted through the evaporator 3 and conducted back to the interior 101 as cooling air in the lower region of the switch cabinet 100. In the interior 101 of the switch cabinet housing 100, switch cabinet components (not shown) which can generate arcs during operation, such as electrical switching devices, can be arranged. Therefore, if the pipe system 7, in the event of a leak, introduces flammable refrigerant into the atmosphere in the interior 101 of the switch cabinet housing 100, the air-gas mixture can ignite on the arc. Therefore, the switch cabinet arrangement shown in FIG. 1 can only be operated with non-flammable refrigerants in accordance with the Machinery Directive.

[0026] The pipe system 7 is a component of a refrigeration machine 15 which, in addition to the evaporator 3 in the internal circuit 2 and the condenser 6 in the external circuit 5, also has a compressor 16 and an expansion element 17. In the lower region of the cooling device 1, ambient air is sucked into the internal air circuit 2, conducted through the condenser 6 and blown out of the external air circuit 5 to the surroundings of the switch cabinet arrangement 100 in the upper region of the cooling device 1. In order to convey air through the external air circuit 5 on the one hand and through the internal 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 external air circuit 5, the fan can be in the form of a filter fan.

[0027] In order to prevent the vaporized flammable refrigerant from entering the internal air circuit 2 in the event of a leak in the pipe system 7, in the solution according to the invention, Figure 2 As shown in the example, the fin group 8 extends through the air baffle 4 into the external air circuit 5 with at least one of the two opposite end sides, preferably with both end sides 9, and the pipe system 7 has at least one pipe elbow 10 thereon, so that at least one pipe elbow 10 is arranged in the external air circuit 5. The present invention is based on the recognition that leakage of the pipe system 7 occurs in particular in the region of the pipe elbow 10 or in the region of the connection point 12 of the pipe elbow 10 to the straight section 11. Therefore, if these particularly critical areas are arranged outside the internal air circuit 2, that is, arranged in the external air circuit 5, the risk of evaporating refrigerant entering the internal air circuit 2 can be effectively reduced to almost zero.

[0028] The fin group 8 has a plurality of preferably parallel fins 13, wherein the end fins 13 of the fin group 8 facing the internal air circuit 2 protrude beyond the fin group 8 and the pipe elbow 10 on the relevant end side. In particular, the evaporator 3 is mounted in the cooling device 1, i.e., on the air baffle 4, via the end fins 13 in a fluid-tight manner. Thus, with the exception of the central region of the evaporator 3, the entire refrigerant circuit is arranged in the external air circuit 5, wherein only straight pipe sections 11 extend parallel to one another, which are not prone to leakage, so that in the event of leakage, escaping refrigerant can be discharged in a sealed manner from the internal circuit 2 to the surroundings of the cooling device 1. Condensate accumulated on the pipe elbow 10 in the external air circuit 5 is discharged from the external air circuit via the condensate discharge 18.

[0029] Figure 3 An exemplary embodiment of an evaporator 3 is shown, wherein the end fins 13 are shown in an exploded view for greater clarity. The evaporator 3 is in the form of an air-liquid heat exchanger having a fin group 8 with a plurality of parallel fins 8.1. A pipe system 7 consisting of a plurality of parallel pipe sections passes perpendicularly through the fins 8.1 of the fin group 8 to the opposite end side 9 of the evaporator 3. A pipe elbow 10 on the opposite end side 9 of the pipe system 7 protrudes from the fin group 8. On the opposite end side 9, in particular outside the fin group 8, the pipe elbow 10 is connected to the parallel pipe section via a connection point 12, for example a welding point. The connection point is prone to leakage and should therefore be arranged outside the internal air circuit, in particular in the external air circuit, where the fin group 8 is located, so that in the event of a leakage, the escaping flammable refrigerant cannot enter the interior of the switch cabinet through the internal air circuit of the cooling device, where it can ignite the electrical internal fittings of the switch cabinet, thereby generating an electric arc.

[0030] The end fin 13 shown should therefore be arranged directly on the end side 9 of the evaporator 3 and penetrated by the pipe system 7. For this purpose, the end fin 13 has a channel 22. In particular, the pipe system 7 can therefore be separated from other components of the evaporator 3, in particular the fins 8.1 of the fin group 8, at least on the circumference of the pipe elbow 10 (including the connection point 12) by the end fin. Thus, for example, the end fin 13 can be arranged together with the circumferential sealing flange 14 in the hole of an air baffle of a switch cabinet cooling device, wherein the air baffle separates the internal air circuit of the cooling device from the external air circuit. If at least the fin group 8 is arranged in the internal air circuit, the connection point 12, which is prone to leakage, can be arranged in the external air circuit through the hole of the air baffle, while maintaining the fluid separation of the internal air circuit and the external air circuit by the sealing flange 14. The end fin 13 then forms a component of the air baffle.

[0031] The end fin 13 can be formed, for example, as a sheet metal component. However, the end fin 13 can also be formed as a plastic component. The end fin can have sufficient strength, for example a sheet metal thickness, to ensure a sufficient sealing effect of the sealing flange 14. For example, the fins 8.1 of the fin group 8 can be formed from a thin sheet metal. In contrast, the end fin 13 can have a greater sheet metal thickness. The sealing flange 14 can have at least one fastening tab 21 in order to arrange the evaporator 3 in the hole of the air partition between the internal air circuit and the external air circuit (for example in a fluid-tight manner).

[0032] The features of the invention disclosed in the above description, the drawings and the claims can be used for the realization of the invention both individually and in any desired combination.

[0033] Reference Numbers List

[0034] 1Cooling device

[0035] 2 Internal air circuit

[0036] 3. Evaporator

[0037] 4 Air baffles

[0038] 5 External air circuit

[0039] 6 Condenser

[0040] 7. Pipeline System

[0041] 8 fin group

[0042] 8.1 Fin

[0043] 9. End side

[0044] 10Pipe elbow

[0045] 11 Pipeline

[0046] 12 Connection Points

[0047] 13 End fins

[0048] 14 Sealing flange

[0049] 15Refrigerator

[0050] 16 Compressor

[0051] 17 Expansion member

[0052] 18 Condensate drain port

[0053] 19 offset piece

[0054] 20 Shell

[0055] 21 Fastening piece

[0056] 22 channels

[0057] 100 switch cabinet housing

[0058] Inside 101

Claims

1. A switch cabinet cooling device (1) comprising an evaporator (3) in the form of an air-liquid heat exchanger in an internal air circuit (2) and a condenser (6) in the form of an air-liquid heat exchanger in an external air circuit (5) separated from the internal air circuit (2) by an air baffle (4), wherein: The evaporator (3) has a fin group (8), and the pipe system (7) passes through the fin group (8), characterized in that at least one of the two end sides (9) of the fin group (8) passes through the air baffle (4) and extends into the external air circuit (5), and the pipe system (7) has at least one pipe elbow (10) on at least one of the two end sides (9), so that the at least one pipe elbow (10) is arranged in the external air circuit (5).

2. The switch cabinet cooling device (1) according to claim 1, wherein: The pipe system (7) of the fin group (8) has at least one connection point (12), preferably a joining point, particularly preferably a welding point, arranged on the pipe elbow (10) in the external air circuit (5), arranged in the external air circuit (5).

3. The switch cabinet cooling device (1) according to claim 1 or 2, wherein: The pipe elbow (10) is a 180° pipe elbow (10) which has at its opposite ends a connection point (12) for a preferably straight pipe (11) of the pipe system (7), wherein the pipe elbow (10) is connected, preferably joined, particularly preferably welded to the pipe (11) in the external air circuit (5) at the connection point (12).

4. The switch cabinet cooling device (1) according to one of the preceding claims, wherein: The pipe system (7) has no connection points (12), preferably joint points, particularly preferably welding points, when arranged in the internal air circuit (2).

5. The switch cabinet cooling device (1) according to one of the preceding claims, wherein: The pipe system (7) has completely straight and preferably mutually parallel pipe sections when arranged in the internal air circuit (2).

6. Switch cabinet cooling device (1) according to one of the preceding claims, wherein: The fin group (8) has a plurality of fins (8.1) which are preferably parallel or substantially parallel to each other, wherein one of the fins (8.1) faces the external air circuit (5), preferably is an end fin (13) of the fin group (8), protruding beyond the fin group (8) and the at least one pipe elbow (10) having a sealing flange (14), and the fin group (8) rests sealingly against the air baffle (4) via the sealing flange.

7. The switch cabinet cooling device (1) according to claim 6, wherein: The fin (8.1) facing the internal air circuit (2) is the end fin (13) of the fin group (8), and the evaporator (3) is installed in the switch cabinet cooling device (1) in a fluid-tight manner via the end fin (13), preferably on the air baffle (4).

8. Switch cabinet cooling device (1) according to one of the preceding claims, wherein: The end fin (8.1), preferably the end fin (13), of the fin group (8) is the air baffle (4) or at least one component of the air baffle (4).

9. The switch cabinet cooling device (1) according to one of the preceding claims, wherein: The end fins (13) of the fin set (8) have a sealing flange (14), such as an offset piece (19), which bears sealingly against the air baffle (4).

10. The switch cabinet cooling device (1) according to claim 9, wherein: The evaporator (3) is accommodated in a shell (20) of the air baffle (4), the shell being open in the air passage direction of the evaporator (3), wherein the evaporator (3) is sealed against the shell (20) via the sealing flange (14).

11. The switch cabinet cooling device (1) according to claim 9 or 10, wherein: The sealing flange (14) is a circumferentially closed sealing flange (14) of the end fin (13), preferably a rectangular sealing frame.

12. The switch cabinet cooling device according to any one of claims 9 to 11, wherein: The sealing flange (14) sealingly bears against the border of the hole (18) in the hole (18) of the air baffle (4), so that the hole (18) is closed by the end fin (13).

13. The switch cabinet cooling device (1) according to one of the preceding claims, wherein: The evaporator (3), the condenser (6) and the pipe system (7) are components of a refrigerating machine (15) having a compressor (16) and an expansion member (17), the refrigerating machine being arranged completely in the external air circuit (5), with the exception of a central area of ​​the fin group (8) of the evaporator (3), which is arranged in the internal air circuit (2) and through which the air flows.

14. The switch cabinet cooling device (1) according to one of the preceding claims, wherein: The fin group (8) has a condensate discharge port (18) on its end side (9), and the end side extends into the external air circuit through the air baffle (4). The condensate discharge port is located in the external air circuit (5) and is used for condensate to accumulate on the at least one pipe elbow (10).

15. A switch cabinet arrangement having a switch cabinet cooling device (1) according to one of the preceding claims and a switch cabinet housing (100), the switch cabinet cooling device (1) being mounted on the switch cabinet housing, wherein: Air is conveyed from the interior (101) of the switch cabinet housing (100) via the internal air circuit (2), and ambient air of the switch cabinet arrangement is conveyed via the external air circuit (5).

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