Switchgear Cabinet Cooling Device with Air Partition and Corresponding Switchgear Cabinet Arrangement

Abstract

The present invention relates to a cooling device (1) for air conditioning a switchgear cabinet, which has an evaporator (3) in the form of a gas-liquid heat exchanger in an internal air circuit (2) and a condenser (6) in the form of a gas-liquid heat exchanger in an external air circuit (5) separated from the internal air circuit (2) via an air partition (4), the evaporator (3) having a fin pack (8) through which a pipeline system (7) passes, the cooling device (1) being characterized in that at least one of two end sides (9) of the pipeline system (7) having at least one pipe bending part (10) projects through the air partition (4) into the external air circuit (5) such that at least one pipe bending part (10) is arranged in the external air circuit (5).

Description

Technical Field

[0001] The present invention is based on a cooling device for a switchgear cabinet air conditioner, which has an evaporator in the form of a gas-liquid heat exchanger in an internal air circuit and a condenser in the form of a gas-liquid heat exchanger in an external air circuit separated from the internal air circuit via an air partition. In this case, the evaporator has a fin pack through which a pipeline system passes. This type of cooling device is described in DE 10 2012 108 110 B4. Another cooling device is described in DE 10 2010 009 776 A1 and DE 199 47 970 A1.

Background Art

[0002] Directive 2006 / 42 / EC (Machinery Directive) requires that there is no risk of explosion or fire due to gases used in the machine and that individual components may fail. Therefore, in the case of a switchgear cabinet cooling device, if a leak is assumed in a component carrying the refrigerant, it is assumed that a combustible gas (refrigerant) may enter the switchgear cabinet and ignite internal components that generate arcs during operation. Without a safety function to reliably prevent this, a switchgear cabinet cooling device using a combustible refrigerant cannot meet the Machinery Directive or operate with the necessary safety for the end-user.

[0003] DE 10 2018 109 604 A1 describes a cooling device in which, when a leak occurs in the pipeline system, the internal air circuit of the cooling device is closed at a connection point where the cooling device is fluidly connected inside the switchgear cabinet housing. Known cooling devices in the prior art, for example, require various actively driven closing members and need to be operated when a leak is detected or when a combustible refrigerant enters the distribution board, which has the drawback of complicated implementation.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, an object of the present invention is to develop a cooling device described at the beginning to be implemented using simple technical means and thus provided at low cost.

Means for Solving the Problems

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

[0006] Therefore, in a cooling device of the type described at the beginning, in the fin pack, at least one of the two end sides, preferably the opposite end sides, where the pipeline system has at least one pipe bending part, protrudes into the external air circuit through an air partition, and as a result, at least one pipe bending part is arranged within the external air circuit.

[0007] The present invention is based on the knowledge that components sensitive to leakage of the gas-liquid heat exchanger are the pipe bending parts or the connection points with the rest of their pipeline system, in particular the connection points with a pipeline section that is straight and less affected by failures. The connection points of the pipe bending parts may be formed, for example, as joining points, for example, soldered connections, and are more sensitive to leakage compared to the rest of the pipeline system. When the pipe bending parts are arranged within the external air circuit of the cooling device, refrigerant that evaporates in case of leakage, especially flammable refrigerant such as propane, may be discharged around the cooling device through the external air circuit, and in particular, it is kept away from components that generate arcs inside a switchgear cabinet housing where a cooling device with an internal air circuit may be connected. The gas-liquid heat exchanger for a switchgear cabinet cooling device usually has a number of 180° pipe bending parts on the opposite end sides, and linear parallel pipeline sections are connected to each other in pairs via the bending parts.

[0008] The pipeline system of the fin pack may have at least one connection point, preferably a joint point, particularly preferably a soldering point, arranged in the external air circuit on the pipe bend arranged in the external air circuit.

[0009] The pipe bend may be a 180° pipe bend having, at opposite ends, one connection point each, preferably for the straight pipeline of the pipeline system. The pipe bend may be connected, preferably joined, particularly preferably soldered, to the pipeline in the external air circuit at the connection point.

[0010] As long as it is arranged in the internal air circuit, the pipeline system may have no connection points, preferably no joint points, particularly preferably no soldering points. Particularly preferably, as long as it is arranged in the internal air circuit, the pipeline system has only straight, preferably parallel to each other, pipeline sections. At the end side, the straight pipeline section may pass through an air partition. At the passing point, the straight pipeline section may be sealed against the air partition. The air partition may be provided by the fins of the fin pack at the end side, for example, by the end fins of the fin pack. At the passing point of the straight pipeline section passing through the fins, particularly the end fins, the straight pipeline section may be joined liquid-tightly, for example, soldered, to the fins, particularly the end fins. The fins or end fins may be a component of the air partition, particularly in the passing region at the end side of the fin pack where the fin pack passes through the air partition.

[0011] The fin pack may preferably have a number of fins that are parallel or substantially parallel to each other. Among the fins, the fins facing the internal air circuit, for example, the end or outer fins, especially the end fins of the fin pack, may project beyond the fin pack and beyond at least one pipe bend with a sealing flange. Through the sealing flange, the fin pack may be in sealing contact with the (remaining) air partition. The fins facing the internal air circuit, for example, the end or outer fins, especially the end fins of the fin pack and / or at least the sealing flange, may be a component of the air partition.

[0012] In this case, the fins facing the external air circuit most may be the end fins of the fin pack, through which the evaporator is attached in a fluid-tight state within the cooling device, preferably on the air partition. For this purpose, the fins, especially the end fins, may have a sealing flange, preferably an outer peripheral sealing flange, especially a sealing flange extending over the entire circumference of the fins, especially the end fins.

[0013] The end fins may be the outer fins of the fin pack. The fin pack may have one end fin on each of the two opposite end sides of the evaporator. The end side may be formed by the end fins. The pipeline system of the evaporator may pass through the end fins. The pipeline system may extend beyond the end side or the end fins together with the pipe bend. The pipeline system may be arranged together with the pipe bend, preferably only with the pipe bend outside the fin pack.

[0014] The end fins of the fin pack, for example, the end fins, may be the air partition or at least one component of the air partition. The end fins of the fin pack, for example, the end fins, may have a sealing flange, for example, with an offset, that is in fluid-tight contact with the air partition.

[0015] The evaporator may be housed within an air partition housing, which is open in the air passage direction of the evaporator. The evaporator preferably abuts sealingly against the housing via a sealing flange on the inner circumference of the opening of the housing.

[0016] The sealing flange may be a sealing flange closed in the outer circumferential direction of the end fins of the fin pack, preferably a rectangular sealing frame. To enhance stability and the sealing effect, the end fins are of higher strength compared to the remaining fins of the fin pack. For example, the material may be thicker, especially the plate material.

[0017] The sealing flange may abut sealingly against the boundary of the opening at the opening of the air partition. Preferably, the opening is completely closed by the end fins.

[0018] The evaporator, condenser, and pipeline system may be components of a refrigerator. The refrigerator may further have a compressor and an expansion member. All components of the refrigerator may be arranged entirely within the external air circuit, except for the central region of the fin pack of the evaporator, which is arranged within the internal air circuit through which air flows.

[0019] The fin pack may have a condensate drain outlet on the end side protruding through the air partition into the external air circuit to drain the condensate accumulated in at least one pipe bend into the external air circuit.

[0020] The switchgear cabinet arrangement has a switchgear cabinet housing to which a cooling device of the above type is attached, in addition to at least one cooling device of this type. In this case, air is transported from the inside of the switchgear cabinet housing through the internal air circuit of the cooling device, and the air around the switchgear cabinet arrangement is transported through the external air circuit.

Brief Description of the Drawings

[0021] Further details of the present invention will be described with reference to the following figures.

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0022] FIG. 1 shows a switchgear cabinet arrangement including a cooling device 1 and a switchgear cabinet housing 100 to which the cooling device 1 is attached. The cooling device 1 has an internal air circuit 2 and an external air circuit 5. The air accommodated in the interior 101 of the switchgear cabinet housing 100 is introduced into the internal air circuit 2 in the upper region of the cooling device, passes through the evaporator 3, and returns to the interior 101 as cooled air in the lower region of the switchgear cabinet housing 100. In the interior 101 of the switchgear cabinet housing 100, there may be arranged switchgear cabinet components (not shown), such as an electrical switching device, that may generate an arc during operation. Therefore, if the pipeline system 7 leaks and releases the flammable refrigerant into the atmosphere inside the switchgear cabinet housing 100, the mixture of air and gas may be ignited by the arc. Therefore, the switchgear cabinet arrangement shown in FIG. 1 can only be operated with a non-flammable refrigerant in accordance with the mechanical instructions.

[0023] The pipeline system 7 is a component of the refrigerator 15 that has, in addition to the evaporator 3 of the internal circuit 2 and the condenser 6 of the external circuit 5, a compressor 16 and an expansion member 17. The ambient air is drawn into the internal air circuit 2 in the lower region of the cooling device 1 and blown out from the external air circuit 5 around the switchgear cabinet 100 in the upper region of the cooling device 1 through the condenser 6. In order to transport air, one fan (not shown) is arranged in each of the air circuits 2 and 5, through the external air circuit 5 on the one hand and through the internal air circuit 2 on the other hand. In the case of the external air circuit 5, the fan may be in the form of a filter fan.

[0024] In the solution of the present invention, in order to prevent the evaporating flammable refrigerant from entering the internal air circuit 2 when a leak occurs in the pipeline system 7, as illustrated in FIG. 2, the fin pack 8 projects through the air partition 4 into the external air circuit 5 at at least one, preferably both, of the two opposite end sides 9 where the pipeline system 7 has at least one pipe bending portion 10, and at least one pipe bending portion 10 is arranged within the external air circuit 5. The present invention is based on the finding that a leak in the pipeline system 7 occurs particularly in the region of the pipe bending portion 10 or at the connection point 12 with the straight section 11 of the pipe bending portion 10. Therefore, arranging these particularly important regions outside the internal air circuit 2, that is, in the external air circuit 5, can effectively reduce the risk of the evaporated refrigerant entering the internal air circuit 2 to substantially zero.

[0025] The fin pack 8 preferably has a large number of parallel fins 13, and the end fins 13 facing the internal air circuit 2 of the fin pack 8 project beyond the fin pack 8 and the associated end-side pipe bend 10. In particular, the evaporator 3 is attached in a fluid-tight manner via the end fins 13 within the cooling device 1, i.e., on the air partition 4. As a result, except for the central region of the evaporator 3 where only the straight pipe sections 11 that are not easily affected by leakage extend parallel to each other, the entire refrigerant circuit is arranged within the external air circuit 5. Thereby, in the event of a leak, the leaked refrigerant can be discharged in a sealed state from the internal circuit 2 to the surroundings of the cooling device 1. The condensed water accumulating in the pipe bend 10 within the external air circuit 5 is discharged from the external air circuit via the condensate drain outlet 18.

[0026] Figure 3 shows an exemplary embodiment of the evaporator 3, and the end fins 13 are shown in an exploded view for clarity. The evaporator 3 is in the form of a gas-liquid heat exchanger having a fin pack 8 with a large number of parallel fins 8.1. A pipeline system 7 consisting of a large number of parallel pipeline sections passes perpendicularly through the fins 8.1 of the fin pack 8 on the opposite end side 9 of the evaporator 3. The pipeline system 7 projects from the fin pack 8 at the pipe bend 10 on the opposite end side 9. On the opposite end side 9, particularly outside the fin pack 8, the pipe bend 10 is connected to parallel pipeline sections via connection points 12, such as soldering points. Since the connection points are prone to leakage, the fin pack 8 should be arranged outside the internal air circuit where it is located, particularly in the external air circuit. Thereby, in the event of a leak, the leaked combustible refrigerant will not enter the internal air circuit of the cooling device and then into the switchgear cabinet interior, and will not ignite the electrical internal components of the switchgear cabinet that may generate an arc.

[0027] Therefore, the illustrated end fins 13 are to be arranged directly on the end side 9 of the evaporator 3 and are to be passed through by the pipeline system 7. For this purpose, the end fins 13 have a passage 22. In particular, the pipeline system 7 may 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 in the vicinity of the pipe bend 10 including the joint 12. Thus, for example, the end fins 13 together with the outer peripheral sealing flange 14 can be arranged in the opening of the air partition of the switchgear cabinet cooling device, and the air partition separates the internal air circuit of the cooling device from the external air circuit. If at least the fin pack 8 is arranged within the internal air circuit, the leak-prone connection point 12 may be arranged within the external air circuit through the opening of the air partition, and the fluid separation between the internal air circuit and the external air circuit is maintained via the sealing flange 14. In this case, the end fins 13 form a component of the air partition.

[0028] The end fins 13 may be formed, for example, as sheet metal parts. However, the end fins 13 may also be formed as plastic parts. The end fins may have sufficient strength, for example, a plate thickness, to ensure a sufficient sealing action of the sealing flange 14. For example, the fins 8.1 of the fin pack 8 may be formed from thin sheet metal. In contrast, the end fins 13 may have a thicker plate thickness. The sealing flange 14 may have at least one fixing tab 21 for arranging the evaporator 3, for example, fluid-tightly, in the opening of the air partition between the internal air circuit and the external air circuit.

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

Explanation of Reference Numerals

[0030] 1 Cooling device 2 Internal air circuit 3 Evaporator 4 Air partition 5 External air circuit 6 Condenser 7 Pipeline system 8 Fin pack 8.1 Fin 9 End side 10 Pipe bending part 11 Pipeline 12 Connection point 13 End fin 14 Sealing flange 15 Refrigerator 16 Compressor 17 Expansion member 18 Condensate drain outlet 19 Offset 20 Housing 21 Fixed tab 22 Passage 100 Switchgear cabinet housing 101 Inside

Claims

1. A switchgear cabinet cooling device (1) having an evaporator (3) in the form of a gas-liquid heat exchanger in an internal air circuit (2) and a condenser (6) in the form of a gas-liquid heat exchanger in an external air circuit (5) separated from the internal air circuit (2) via an air partition (4), wherein the evaporator (3) has a fin pack (8) through which a pipeline system (7) passes, and at least one of the two end sides (9) of the fin pack (8) having at least one pipe bend (10) of the pipeline system (7) projects into the external air circuit (5) through the air partition (4), characterized in that at least one pipe bend (10) is arranged in the external air circuit (5).

2. The pipeline system (7) of the fin pack (8) has at least one connection point (12), preferably a joint point, particularly preferably a soldering point, arranged on the pipe bend (10) arranged in the external air circuit (5), of the switchgear cabinet cooling device (1) according to Claim 1.

3. The pipe bend (10) is a 180° pipe bend (10) each having one connection point (12) at opposite ends, preferably for a straight pipeline (11) of the pipeline system (7), and the pipe bend (10) is connected, preferably joined, particularly preferably soldered, to the pipeline (11) in the external air circuit (5) at the connection point (12), of the switchgear cabinet cooling device (1) according to Claim 1 or 2.

4. The pipeline system (7) has no connection point (12), preferably no joint point, particularly preferably no soldering point, as long as it is arranged in the internal air circuit (2), of the switchgear cabinet cooling device (1) according to any one of Claims 1 to 3.

5. The pipeline system (7) has only straight, preferably parallel to each other, pipeline sections as long as it is arranged in the internal air circuit (2), of the switchgear cabinet cooling device (1) according to any one of Claims 1 to 4.

6. The fin pack (8) preferably has a number of fins (8.1) that are parallel or substantially parallel to each other. Of the fins (8.1), one fin (8.1) facing the external air circuit (5), preferably the end fin (13) of the fin pack (8), protrudes beyond the fin pack (8) and beyond at least one pipe bend (10) provided with a sealing flange (14). Through the sealing flange (14), the fin pack (8) is in sealing contact with the air partition (4). The switchgear cabinet cooling device (1) according to any one of claims 1 to 5.

7. The fin (8.1) facing the internal air circuit (2) is the end fin (13) of the fin pack (8). Through the end fin (13), the evaporator (3) is mounted in the switchgear cabinet cooling device (1), preferably on the air partition (4), in a fluid-tight state. The switchgear cabinet cooling device (1) according to claim 6.

8. The end fin (8.1), preferably the end fin (13) of the fin pack (8), is the air partition (4) or at least one component of the air partition (4). The switchgear cabinet cooling device (1) according to any one of claims 1 to 7.

9. The end fin (13) of the fin pack (8) has a sealing flange (14), such as an offset (19), that is in sealing contact with the air partition (4). The switchgear cabinet cooling device (1) according to any one of claims 1 to 8.

10. The evaporator (3) is housed within the housing (20) of the air partition (4). This housing is open in the air passage direction of the evaporator (3). The evaporator (3) is in sealing contact with the housing (20) via the sealing flange (14). The switchgear cabinet cooling device (1) according to claim 9.

11. The sealing flange (14) is a sealing flange (14) closed in the circumferential direction of the end fin (13), preferably a rectangular sealing frame. The switchgear cabinet cooling device (1) according to claim 9 or 10.

12. The sealing flange (14) is in sealing contact with the boundary of the opening (18) at the opening (18) of the air partition (4) such that the opening (18) is closed by the end fins (13), the switchgear cabinet cooling device according to any one of claims 9 to 11.

13. The evaporator (3), the condenser (6), and the pipeline system (7) are components of a refrigerator (15) having a compressor (16) and an expansion member (17), and this refrigerator is disposed entirely within the external air circuit (5) except for the central region of the fin pack (8) of the evaporator (3), and this central region is disposed within the internal air circuit (2) through which air flows, the switchgear cabinet cooling device (1) according to any one of claims 1 to 12.

14. The fin pack (8) has a condensate discharge port (18) that discharges condensate accumulated in at least one pipe bending portion (10) to the external air circuit (5) on the end side (9) protruding into the external air circuit through the air partition (4), the switchgear cabinet cooling device (1) according to any one of claims 1 to 13.

15. A switchgear cabinet arrangement comprising the switchgear cabinet cooling device (1) according to any one of claims 1 to 14 and a switchgear cabinet housing (100) to which the switchgear cabinet cooling device (1) is attached, wherein air is transported from the interior (101) of the switchgear cabinet housing (100) through the internal air circuit (2), and the air surrounding the switchgear cabinet arrangement is transported through the external air circuit (5), the switchgear cabinet arrangement.

Images