Investigation and Determination of Efficiency of the Waste Heat Recovery System Using Peltier Modules

High efficiency technology of waste heat energy utilization would change the face of the energy market. Due to the fact that the energy system and transport are based on fossil fuels, there is a huge potential for its efficient use. Despite the fact that the technology of Peltier semiconductor modules has been known for many years, there are no solutions that might be commonly disseminated. There is also a deficit of available sources that in a transparent, coherent and synthetic way could provide guidelines for the constructors of such devices, and show how much energy they can generate and what efficiency they have. Moreover, the Peltier modules available on the market are burdened with many stereotypes. When trying to use this technology, it should be remembered that in addition to the Peltier phenomenon, the module's operation is based on four other physical phenomena: two of them have a negative impact and they determine the practically obtained parameters of the Peltier module. These are: Joule effect and heat conduction phenomenon. The other two phenomena: Seebeck and Thomson ones, play slightly smaller roles. The aim of the authors was to investigate the self-made model of a thermoelectric generator TEG, constructed using Peltier modules. The paper presents the results of measurements and the method of determining the electrical efficiency of this model. Additionally, a temperature range was determined at that such recovery has a measurable utilitarian aspect and economic sense. The limitations of semiconductor technology of Peltier cells have been given, and design guidelines at construction process of such systems to optimize their efficiency are presented.