Thermodynamic modelling and analysis of thermoelectric cooling system

Abstract

Exergy analysis has gained significance in analysing the thermal energy systems since it locates and quantifies the irreversibilities in the system. This paper investigates the thermoelectric cooler through exergy analysis. Four thermodynamic models of the thermoelectric cooler considering the internal and external irreversibilities are developed with temperature dependent material properties and then analysed in MATLAB Simulink environment for various operating temperatures. Moreover, analytical expressions for exergy efficiency and irreversibilities for the thermoelectric cooler are developed. The results show that the exergy efficiency of the thermoelectric cooler is lower than the energy efficiency for all thermodynamic models. For a typical operating condition in the irreversible thermoelectric cooler with 31 thermocouples and with TH and TC of 303K and 293K respectively, the maximum energy and exergy efficiency obtained are 2.61 and 8.91% at optimum current of 5.88A. The results also shows that the effect of internal irreversibilities is more pronounced than the external irreversibilities in the performance of thermoelectric cooling system. The effects of irreversible heat transfer and the contact resistance in the exergy efficiency are also studied. This study will be helpful in designing the actual thermoelectric cooling systems.