Effect of temperature mismatch on the life cycle of thermoelectric generator efficiency for waste heat recovery
The electrical connected thermoelectric modules are operated under temperature mismatch conditions. The impact of thermal imbalance on the output electrical power at the module and system level has been analyzed under mismatched temperature conditions and limited working temperature.
Several thermoelectric modules can be connected in series and parallel that forming an array to provide the required voltage and current. In most thermoelectric systems, individual thermoelectric modules are subject to temperature mismatch due to different operating conditions. In this study, electro-thermal effects occurring in arrays of thermoelectric generators connected in series and in parallel, when the individual devices are exposed to non-uniform temperature gradients. This study provided both a mathematical formulation and electrical circuit equations that used to predict the output electrical power in any temperature mismatch situation. The presented results convey the idea that connecting thermoelectric generators in series produces better electrical system efficiency, provided that the temperature differences remain constant. A series of electrical connections enables more of the available power to be captured and that Joule heating losses in wirings are minimized. In the practical case where thermal-mechanical imbalances may be expected and the expected power loss due to mismatched conditions.