Heat exchanger

Abstract

A heat exchanger for exchanging heat between two media in a vehicle is provided. The heat exchanger includes at least one tube, especially a double-walled tube for carrying a first medium of a first temperature, a thermoelectric material being disposed on an inner wall of the tube, and at least one guide sheet, connected to the at least one tube, for carrying a second medium of a second temperature. The at least one guide sheet is designed to carry the second medium to the outer wall of the at least one tube to allow the exchange of heat between the first and the second medium.

Description

[0001]This nonprovisional application is a continuation of International Application No. PCT / EP2010 / 069107, which was filed on Dec. 7, 2010, and which claims priority to German Patent Application No. DE 10 2009 058 676.8, which was filed in Germany on Dec. 16, 2009, and which are both herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a heat exchanger for exchanging heat between two media, as used, for example in a vehicle.[0004]2. Description of the Background Art[0005]The energy which is stored, for example, in the exhaust gas of a vehicle in the form of heat, is currently unused and discharged into the surroundings. To increase the efficiency of a system, e.g., a motor vehicle, and consequently reduce CO2 emissions during operation, a thermoelectric generator (TEG) may be implemented whose thermoelectric module (TEM) converts part of the heat to electrical energy and returns it to the system. The TEG i...

AI Technical Summary

Benefits of technology

[0012]According to an embodiment, the guide sheet may have at least one recess. The tube may be accommodated by the recess. According to such a design of the guide sheet and tube, a flow direction of the first medium may deviate from a flow direction of the second medium. For example, the first medium may flow largely orthogonally to the second medium. A flow relationship of this type permits better heat transfer between the first medium and the second medium than would be the case, for example, using a unidirectional flow (i.e., a flow in the same direction) of the two media. The guide sheet may also have a plurality of recesses for accommodating multiple tubes, in this case each tube being able to be accommodated in a separate recess.

[0020]According to another embodiment, the at least one guide sheet may be uneven in the area of the passages in the tube or uneven in the area of the at least one recess. For example, the guide sheet may be corrugated in the area of the recesses. This specific embodiment of the guide sheet offers the advantage, on the one hand, that an improved hold for the at least one tube may be achieved without additional components, since a larger area of the tube is contacted and held by the guide sheet, due to the uneven form. On the other hand, an improved heat transfer may be made possible between the guide sheet and the tube, since a greater contact line exists between the uneven guide sheet and the tube.

Problems solved by technology

Conventional TEGs are not very efficient, due to the elevated heat transfer resistance between thermoelectrically active materials and a heat source / heat sink.

Integrating the TEM into a heat exchanger has also proven to be not very practical.

Up to now, available connecting techniques have been, in part, unstable at high temperatures.

In addition, only minimal heat transfer frequently exists on the contacting of the TEM in the heat exchanger on the gas side.

According to the prior art, conventional TEMs are therefore not optimally suited for use in a TEG, due to their design and connecting techniques, and are also not very effective.

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