Theoretical study of thermoelectric cooling system performance

Abstract

This work provides a theoretical investigation to study the effect of different operational parameters on the performance of TE cooling system including the system COP and the rate of heat transfer. The parameters investigated are, the applied input power, inlet working fluid velocity, the arrangement of utilized TECs modules and fluid type. The geometry is created with ANSYS multi-physics software as a two-dimensional base case, it is consisted from two attached horizontal ducts of length (520 mm) and (560 mm), the interface surface between the two ducts contains three thermoelectric modules (4 mm height by 40 mm wide and 40 mm length). The distance between two consecutive thermoelectric modules (150 mm), the inlet and outlet duct diameter (15 mm) and the height of each duct (10 cm), the inlet voltage to thermoelectric modules ranges from 8.0 V to 12 V and the water inlet velocity to the two ducts from 0.001 to 0.01 m/s. Theoretical results showed that the overall COP of TE cooling system is increased with the applied input power up to 8.0 W then it decreases with input power up to 18 W after that it takes nearly a constant value, a noticeable enhancement in the COP is found when the three TECs are in use (Case 10) and the COP of TE cooling system using pure water and nanofluid with 0.05% of nanoparticles as coolants takes the maximum value. Nomenclature Cp Specific heat, J/kg· ° C Greek symbols COP Coefficient of performance Φ Particle volume fraction, % I Electric current, A Subscripts ṁ Mass flow rate, kg/s C Cooling N Number of thermocouples in each stage C Cold-side Q Rate of heat, W E Electric T Temperature, ° C H Heating TE Thermoelectric H Hot-side TEC Thermoelectric cooler J Junction t Transient time, s M Module V Voltage, V N N-type semiconductor í µí±‰ ̇ Volume flow rate, m 3 /s P P-type semiconductor í µí±Š ̇ Power, W