Technologie und anwendung des peltier-effektes

Abstract

The practical application of the Peltier effect has been made possible by the development of suitable thermoelectric semiconductors. The use of bismuth antimonium and bismuth selenium tellurides permits a thermoelectric figure of merit of 0·0030–0·0035 per degree Kelvin. The maximum temperature difference obtaining between the hot and cold junction of industrial thermoelements ranges between 60 and 70°C. These semiconductors are produced by powder metallurgical methods or by melting methods. The powder metallurgical method offers the advantage of freedom in shaping, but the thermoelectric figure of merit obtained is not so high as with the melting method. The latter method is generally restricted to cylindrical shapes, prismatic legs being obtained only by cutting cylindrical bodies. In the construction of heat sinks preference is currently being given to the plate type of construction since it provides mechanical stability and permits locally concentrated heat absorption. The practical use of Peltier cooling units is recommended in cases where low heat absorption capacities are required, i.e. in a range in which compressors with their high cooling capacity and high space requirements cannot be used.