Modeling of a Heat Pipe for Using in Thermoelectric Energy Harvesting Systems

Abstract

Thermoelectric energy harvesting systems (EHS) consist of thermoelectric generators (TEG), which generate electrical power due to a temperature difference. Consequently, a main challenge to build up such an EHS is a good heat transfer to and from the TEG. On the one hand heat has to be send to the hot TEG side and on the other hand the waste heat from the cold TEG side has to be dissipated. For this heat transfer heat pipes are very reasonable. They have a 1000-fold better thermal conductivity than copper and so the existing heat quantity can be used more effectively. To model a heat pipe in a most general way, the modeling language Modelica^® is used. Thereby, the model can be build based on its physics as well as its material properties. The dimensions of the pipe as well as the used working fluid or the used heat pipe material are parameters adjustable for specific cases. In this contribution, the theoretical aspects of a heat pipe will be described and the modeling with Modelica^® for different modeling approaches in the simulation environment Dymola^® will be shown. Finally, the model of the heat pipe will be validated with laboratory measurements.