Thermal Analysis of Heat Exchangers in a Thermoelectric System with Peltier Effect by Using CFD

The work belongs to the thermoelectric (TE) field of application and, within this field, it deals with thermoelectric cooling, which represents one of the most well established technology in the science of alternative refrigerators. The paper is focused on the modelling of the thermal performances of the hot and cold side heat exchangers used in a thermoelectric system based on Peltier effect. The main goal is illustrating the approach to the analysis which allowed the authors to implement a CFD model to be used in a further optimisation phase. A numerical model has been set up for one specific configuration of a TE system, a user defined subroutine has been implemented in order to take into account condensation effects. A CFD commercial software (FLUENT6) has been used to solve the thermo-fluid-dynamic fields and the results were compared with experimental data, provided by the Peltech's Research Centre based in Trieste, in order to validate the model. The hot and cold heat exchangers included in the system have been studied separately, using two different numerical domains, and assuming proper boundary conditions for the Peltier modules. The numerical approach to represent the TE system was completed by using a first approach set of equations describing TE effects, which were implemented and solved off line.