Described below is a thermoelectric transducer having p-doped and n-doped thermoelectric elements which are arranged alternately and connected electrically to one another, and to a heat exchange pipe having at least one such thermoelectric transducer.
The efficient conversion of thermal energy into electrical energy is a central problem within energy conversion technology. Aside from improving thermal engines used on a large-scale, such as gas and steam turbines, other conversion methods are also increasingly employed in order to develop previously unused thermal sources and/or thermal flows, such as for instance the waste heat of steam-generating power plants. Of particular interest here are methods which can be integrated into the thermal flow of existing installations with a low installation and maintenance outlay. Suited to this in particular are thermoelectric transducers and/or thermoelectric generators of the type cited in the introduction, which are abbreviated below to TEGs. With the aid of such TEGs, heat can be converted directly into electrical current by using the so-called Seebeck effect. Alternatively, a thermoelectric transducer can also effect a change in the heat transport by using the thus named Peltier effect by an external current flow.
A requirement for the efficient use of TEGs is that a good thermal coupling of the TEG to the heat source and/or heat sink and thus the generation of a suitable thermal flow across the TEG heat exchange pipe into steam generators offer a good condition for the use of TEGs, since the thermal flow across the wall of the heat exchange pipe is produced during operation without any additional effort. No practical solution currently exists however for the combination of a TEG and a heat exchange pipe. Previously almost exclusively planar thermoelectric modules were used for the assembly of TEGs, since these are also only commercially available. In order to be able to couple the planar thermoelectric modules in a thermally sufficient manner, the heat exchanger must in most instances be modified with significant effort, which also involves complex assembly and high costs. This is nevertheless not an option for the large-scale use of TEGs in steam-generating power plants.