Analysis and optimization of a thermoelectric cooling air system

Abstract

A thermoelectric cooling system is based on an effect discovered by Jean Charles Athanase Peltier, in 1834, according to when an electric current runs through a junction between two semiconductors materials with different properties, heat is dissipated and absorbed. Thermoelectric modules are made of semiconductors materials sealed between two plates and according to the way of the current flow one board is cold and the other is heated. The most important parameters to evaluate the efficiency of thermoelectric cooling process are the performance coefficient, the transferred heat rate and the maximum temperature difference possible to obtain between the cold and hot sides of the thermoelectric module. This paper presents the mathematial model of the system, the available modules characteristics, the parameters that can be optimized and also the results of tests realized in an experimental thermoelectric air conditioning system. In this evaluation there were used thermoelectric modules and heat sink available in the market, temperature sensor and a software to obtain, store and compare the data. The prototype allows assisting the superficial temperatures of the thermoelectric modules' cold and hot sides, the air inlet and outlet temperatures in the heat sink, the hot and cold side's airflow, the voltage and the electric current applied in the modules. It is made a simulation using two air flows with controlated speed to the hot and the cold sides of the module and several set of tests for one, two, three and four modules coupled in paralel way. Using this data the system performance is analyzed making possible to verify the power, the voltage and the electric current that maximize the performance coefficient of the system. © 2009 by ABCM.