EP1592028B1 - Fluid cooling device for iron core and windings - Google Patents

Abstract

Heat exchangers (14) with metallic or copper deflector plate (12), are connected in series or parallel to an iron core (11). A fluid conduit (13) with tube walls (13a-13d) extended from the plate in U-shaped fashion, is operationally connected to the iron core, to remove heat emitted from the iron core.

Description

The invention relates to the cooling of chokes and transformers according to claim 1.

In the prior art air and water cooling are known. A e.g. Forced air cooling, however, involves large construction volumes and additionally increased noise levels. Another consequence is a shorter life due to unfavorable cooling effect and a high environmental impact. The increased heating of the immediately adjacent periphery and possibly the control cabinet are further consequences. Higher degrees of protection such as IP 54 are difficult to realize.

The DE 197 01 269 A1 shows a transformer with liquid cooling for the galvanic isolation and voltage adjustment of AC and three-phase systems. The coolant flows through several temperature zones within the windings and dissipates the heat by means of a sewage system. Such constructions are expensive to produce and in case of leakage they are unusable. A retrofittability of existing transformers is not given by this solution, since the cooling is integrated as a constructive feature in the arrangement. Modularity is not given and not intended.

The WO 01/37292 A1 deals with a device for cooling a transformer. To cool the transformer, the transformer core and the transformer windings are immersed in a bath of cooling oil.

It is the object of the invention to provide a device, in particular for cooling winding packages of a mains choke or a transformer. The device should absorb and dissipate the heat from the surface as effectively as possible and at the same time be simple and inexpensive to produce, possibly even be retrofitted.

The invention achieves this object by a cooling device comprising a heat exchanger with guide plate and a cooling fluid guide communicating with the guide plate via a contact surface, and wherein a surface of the iron core communicates with a surface of the guide plate so that the heat emitted from the iron core is dissipated.

The inexpensive and easy manufacturability can be realized in that the heat exchanger comprises only a heat absorber and a standing with the heat absorber in operative connection cooling fluid guide, so the overall arrangement consists of more or less only two main components. This two-component arrangement can also be subsequently attached or placed on the surface of heat-absorbing components. The cooling can therefore be considered as a modular system, which is not bound to a particular component or would be essential to consider in the construction of a component.

Suitably, the heat absorber is a guide plate, preferably a metallic plate, in particular made of copper. As a result, a large-area heat transfer is ensured, provided that the entire surface is in operative connection with the heat-radiating surface of the component component.

It is also advantageous if the cooling fluid guide is preferably realized by means of a channel, wherein the channel is formed as a columnar hollow body and at least in the region of the operative connection with the absorber has a polygonal or rounded cross-section. The fluid can then be transported selectively and independently of the spatial position of the heat exchanger by means of a suitably sized pressure to the heat sources. An angular cross section increases the contact area between the fluid guide and the absorber. A round cross-section is cheaper to obtain.

If the cooling fluid guide runs meandering, spiraling or U-shaped on a heat absorber surface at least in the region of the active connection, the effective heat transfer increases with the number of turns since the effective area automatically increases. When mounting the guide, in particular by means of soldering or welding connections on the absorber surface, a stable and position-independent construction can be achieved. Of course, also releasable connections by means of clips or the like. possible. This would considerably reduce the service or maintenance scope in the event of a line break.

With a rounded or round cross-section, the contact area between the guide and the absorber could be increased with soldering or welding tracks. It would also be conceivable to partially or completely introduce the guide into the absorber in order to achieve a further increase in the heat transfer behavior. Pouring any gaps between the guide and Absorberausnehmungen would compensate for inaccurate fits.

If several heat exchangers are connected in series or in parallel to cool several components of a component, the result for the parallel connection is a virtually larger cross-sectional area of the coolant line and thus a reduced pressure in the tube system. The series circuit, however, would cause a better utilization of the cooling liquid, since the heat of several components would be absorbed.

Optimally, the invention is suitable for use on at least one iron core and / or a line reactor, in particular the line reactor of a regenerative converter (eg converter series SFT from Indramat Refu GmbH with sinusoidal feedback). Mains chokes have very high currents (around 600 amperes) to process and have relatively high inductances (by 180 uH). Due to the ohmic resistance of the windings, which can consist of either individual wires or copper plate or copper bars, these chokes develop a high heat loss. This heat loss can, if it is not dissipated, lead to damage to the insulation and breakdowns and incur following costs. By means of the device according to the invention, which may also be attached or produced depending on a particular application, these dangers are avoided and unnecessary costs are avoided. Of course, the same benefits would also apply to transformers or other electrical components, if the same concept were used for cooling purposes.

Fig. 1 shows a first embodiment of the invention and in detail a heat exchanger 14 with copper plate 12, a meandering formed cooling coil 13 with 90 ° bows 13a, 180 ° bows 13b, terminal lugs 13c and straight elements 13d and an iron core 11 and winding packages 10th

The line reactor of an inverter shown here comprises as components three copper windings 10 which are penetrated by three iron core legs 11. The iron core itself serves to channel the forming during operation magnetic flux. At the two end sides of the arrangement, a cooling device 14 according to the invention is attached in each case. Clearly the copper plate 12 can be seen and the coolant guide 13, which is usefully formed from a plurality of individual components (13a, 13b, 13c, 13d). The individual components can be soldered or welded together. The coolant guide 13 is soldered or otherwise secured in a meandering manner on the copper plate and transports the heat emitted by the iron core 11 and absorbed by the heat absorber 12. Both heat exchangers 14 could be supplied in parallel or in series via a pump with liquid coolant. The coolant flows through the cooling system with a force that is dependent on the pressure and cross section and effectively dissipates the heat absorbed via the absorber or the pipe walls 13, 13a, 13b, 13c. The heat absorber also emits additional heat through its surface to the environment. By enlarging this surface, e.g. By means of ribs, an additional cooling effect could be effected.

There are also other, for the invention, however, not relevant and therefore not described in detail converter components, such as. Connection angle shown.

Fig. 2 shows with the Fig. 1 largely identical components 10, 11, 12, 13, 13a, 13b. The difference to FIG. 1 is that heat exchangers are now not attached to the front sides of the iron core 11, but on the upper and lower sides and partly within the iron core encompassed by the copper winding.

The sewer system 13 of the coolant is U-shaped, connecting pieces 13c are not shown here.

The lines 13 are shown here with a round cross-section, but the support surface on the absorber 12 is thereby less than a rectangular cross-section. Therefore, a rectangular cross section would be favored or the conduit 13 should be at least partially embedded in the absorber surface.

The total of 6 heat exchangers could now be connected in series or in parallel or interconnected in any combination. In the FIG. 2 The embodiment shown is the preferred embodiment by the Applicant. Also a combination of FIG. 1 and FIG. 2 would of course be conceivable and feasible to maximize heat dissipation.

From both figures it is easy to see that a cooling according to the invention could also be applied to existing chokes / transformers. This applies without restriction, at least for the in FIG. 1 described solution. The desire for retrofitting existing solutions is therefore also taken into account by the invention. An enclosure could easily be constructed around this arrangement, which would satisfy the desire for the highest possible degree of protection and shielding. The invention ensures a very high modularity.

LIST OF REFERENCE NUMBERS

1.0

winding package

11

iron core

12

absorber

13

cooling channel

13a

90 ° bend

13b

180 ° - bow

13c

spigot

13d

Straight line

14

heat exchangers

Claims (6)

1. Mains inductor or transformer having an iron core (11), windings (10) and a cooling apparatus (12, 13, 14), wherein the cooling apparatus (12, 13, 14) comprises a heat exchanger (14) with a conductive plate (12), and a cooling fluid guide (13) which is connected to the conductive plate (12) via a contact surface, and wherein one surface of the iron core (11) is connected to one surface of the conductive plate (12), such that the heat emitted from the iron core (11) is dissipated.
2. Apparatus according to Claim 1, wherein the conductive plate (12) is a metallic plate, in particular made of copper.
3. Apparatus according to Claim 1 or 2, wherein the cooling fluid guide (13) is preferably provided by means of a channel, wherein the channel is in the form of a hollow body, in the form of a column.
4. Apparatus according to Claim 3, wherein, at least in the area of the contact surface with the conductive plate (12), the channel has a polygonal or rounded cross section.
5. Apparatus according to one of the preceding claims, wherein the cooling fluid guide (13) runs in a meandering shape, a spiral shape or a U-shape, at least in the area of the contact surface.
6. Apparatus according to one of the preceding claims, wherein a plurality of heat exchangers (14) are connected in series and/or in parallel in order to cool at least one body (11).

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