Identification and Inquisition of Thermoelectric Generator Unit for Efficient Waste Heat Recovery

Abstract

A Peltier device or thermoelectric generator is a solid-state semiconductor device which works on the principle of thermoelectric effect or Seebeck effect and has an inherent capability to convert heat flux directly into an EMF. Thermoelectric effect which is a result of having a physical contact between two dissimilar conductors with the presence of temperature difference across its ends is further enhanced by effective use of semiconductor materials for its fabrication. Its potential to harness low-grade waste has attracted a lot of attention of various researchers worldwide. Thermoelectric effect is difficult to maintain for longer period of time because of its continuous and consistent dependence on temperature difference across its surfaces. Early experiments indicated possibility of heat leakages within the module itself, which could have been causing drop in temperature difference along with working efficiency. The objective of this experimentation is to identify possibility of heat leakages and its possible effects (if any) on its efficiency. Two different positions were used, for the first one heat input surface was upside (hot side up) and second with heat input from below (Hot side down). This change in position will affect the convective motion of trapped air molecules and effect (if any) could be noticed. Results showed that heat transfer rate was more for hot side down with 0.22% more voltage output, 0.44% more power output, and 0.521% increment in Seebeck coefficient.